阅读说明：本技术 一类含水溶性取代基罗丹明荧光染料其制备方法和应用 (Water-soluble substituent-containing rhodamine fluorescent dye and preparation method and application thereof ) 是由 陈知行 张钧维 彭晓红 吴云翔 孙京府 陈朋 于 2021-07-20 设计创作，主要内容包括：本发明公开了一类含水溶性取代基的罗丹明染料及其功能化衍生物(锌离子探针和抗体标记染料),其具有通式I的结构。在染料母核的N-位连接不同水溶性取代基后其生物相容性大幅提高,具体表现在细胞内非特异性染色显著降低、细胞凋亡信号不再出现、光毒性显著降低(锌离子探针)和标记效率提升、观测时间延长(抗体标记染料)等方面。本发明所述的荧光染料可以应用于观测离体活胰岛的胰岛素释放和免疫荧光标记等领域。(The invention discloses a rhodamine dye containing water-soluble substituent groups and functional derivatives (zinc ion probes and antibody labeled dyes) thereof, which have a structure shown in a general formula I. After different water-soluble substituents are connected to the N-position of the dye mother nucleus, the biocompatibility of the dye mother nucleus is greatly improved, and the dye mother nucleus is particularly characterized in that nonspecific staining in cells is obviously reduced, apoptosis signals do not appear any more, phototoxicity is obviously reduced (a zinc ion probe) and marking efficiency is improved, and observation time is prolonged(antibody-labeled dye) and the like. The fluorescent dye can be applied to the fields of observing the insulin release of isolated living pancreatic islets, immunofluorescent labeling and the like.)

1. A rhodamine fluorescent dye containing water-soluble substituent is characterized in that the dye has the following structural general formula:

wherein R is₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈Are independent of each other;

R₁is O, C (CH)₃)₂, Si(CH₃)₂, P(O)CH₃, PO₂ ^-, PO₂CH₂CH₃Or SO₂;

R₂Is O, C, P, S, NH, N⁺HCH₃, N⁺(CH₃)₂, P(O)CH₃Or SO₂;

R₃Is CH₂, CHCH₃, C(CH₃)₂, CHF, CF₂ , CHCl, CCl₂And the various connections possible between them;

R₄and R₈Is H, CH₃, CH₂CH₃, OCH₃, OCH₂CH₃, COO^-, COOMe, CN, SO₂CH₃, SO₂NH₂Or SO₂N(CH₃)₂；

R₅And R₇Is H, OH, OCH₃, OCH₂CH₃, OCH₂CH₂OCH₃, OCH₂COOH, OCH₂C₆H₅N, COOH or the following structure;

wherein R is₉Is H, F, Cl, Br, CH₃, OCH₃Or NO₂；

R₆Is H, COOH, N (CH)₂COOH)₂Or N (CH)₂COOCH₂OCOCH₃);

X^-Being a halogen ion, ClO₄ ^-, PF₆ ^-, BF₄ ^-, CH₃COO^-And CF₃COO^-。

2. Preferably, the fluorescent dye of claim 1, wherein R is₁Is O or Si (CH)₃)₂。

3. Preferably, the fluorescent dye of claim 1, wherein R is₂Is O.

4. Preferably, the fluorescent dye of claim 1, wherein R is₃Is CH₂。

5. Preferably, the fluorescent dye of claim 1, wherein R is₄ , R₇And R₈Each independently selected from H or CH₃。

6. Preferably, the fluorescent dye of claim 1, wherein R is₅Is H, OCH₃, OCH₂CH₃, OCH₂CH₂OCH₃, OCH₂COOH or OCH₂C₆H₅N。

7. Preferably, the fluorescent dye of claim 1, wherein R is₆Is COOH, N (CH)₂COOH)₂Or N (CH)₂COOCH₂OCOCH₃)。

Technical Field

The invention relates to a rhodamine fluorescent dye containing water-soluble substituent groups, in particular to the field of fluorescent dyes in biological fluorescence analysis, and especially relates to application of the rhodamine fluorescent dye in a biological system.

Background

The rhodamine fluorescent dye has longer absorption and emission spectrum, higher brightness and better light stability, is widely applied to the fields of biological markers (protein and nucleic acid), single-molecule tracing, ion detection and the like in recent years, and gradually becomes an irreplaceable important tool for life science research. However, previous work often focuses on modification of photophysical properties of rhodamine dyes, and modification for improving biocompatibility of the rhodamine dyes is rarely reported. In recent years, the development of advanced imaging technologies such as super-resolution fluorescence microscope, rotary table confocal microscope, total internal reflection microscope, light sheet microscope and the like has brought new requirements for the development and the modification of fluorescent dyes: on the basis of adjusting the photophysical properties of the fluorescent dye, the improvement of the biocompatibility of the dye is more important to meet the requirement of long-term in-vivo fluorescence imaging.

Zinc ion (Zn)²⁺) Plays an important role in physiological and pathological processes in the living body. Most intracellular zinc ions are tightly bound with proteins, and a small part of intracellular zinc ions are dissociated in cell sap to form a free zinc pool. The concentration of zinc ions in different tissues in the organism differs by up to 8 orders of magnitude, and the concentration of free zinc in the cell sap is about 10^-10M is present in islet vesicles at a concentration of up to 10^-2M, which is because insulin and zinc ions are stored in islet vesicles in a 4:2 hexamer form, and islets in a physiological state release insulin and zinc ions together into the blood by secreting the exocytic form of vesicles after stimulation with glucose. Many fluorescent probes have been used for monitoring zinc ions, but they generally have too high affinity(in nM range)K _d) The method cannot be applied to monitoring the dynamic change process of high-concentration zinc ions in organisms; in addition, the synthesis steps of functional dyes (zinc, calcium ion dyes and the like) which have far-red emission and take silicorhodamine as a matrix are complicated, the yield is low, the development of the far-red and near-infrared functional dyes is greatly limited, and the functional dyes cannot be used together with probes with other emission wavelengths (such as a green calcium ion fluorescent probe GCaMP6 f) to indicate a complex signal transmission process in tissues; the only low-affinity red-emitting zinc ion probe RhodZin-1 reported in the literature also shows obvious phenomenon of nonspecific binding in cells in the process of monitoring the co-release of insulin/zinc ions and finally leads to apoptosis. This is sufficient to show that the zinc ion fluorescent probe kit still needs to be further developed.

Immunofluorescence technology plays an important role in the detection and identification of various bioactive substances such as proteins, cytokines, cell surface antigens, tumor markers and the like. According to the principle of antigen-antibody reaction, the immunofluorescence is to covalently couple a fluorescent dye with an antigen or an antibody, combine with the corresponding antigen or antibody, and observe the fluorescent signal through a microscope to determine the location and the property of the antigen or the antibody. It is generally believed that fluorescent dyes with better water solubility have higher antibody labeling efficiency. At present, the antibody labeling dye with far-red emission mainly comprises sulfonic acid Cy5, but the dye has low labeling efficiency, poor light stability and obvious nonspecific dyeing, and is difficult to adapt to the requirement of long-time immunofluorescence imaging. Although silicon-substituted rhodamine also has a far-red emission wavelength and a higher molar extinction coefficient, the water solubility and the chemical stability are poor, so that the silicon-substituted rhodamine is not widely applied to immunofluorescence labeling.

In conclusion, the application of the rhodamine dye and the functional derivative thereof in biological imaging is severely limited by the problem of poor biocompatibility (high phototoxicity, non-specific labeling and poor water solubility) existing in the prior rhodamine dye and the functional derivative thereof, but a universal solution for the problem is still lacked at present. Therefore, it is of great significance to propose a universal scheme for improving the biocompatibility of rhodamine and construct functional dyes with good biocompatibility based on the rhodamine parent.

Disclosure of Invention

The invention aims to solve the problem that the existing rhodamine dye and functional derivatives thereof have poor biocompatibility (high phototoxicity, nonspecific labeling and poor water solubility), provides a general solution for connecting different water-soluble substituents at the N-position of a rhodamine dye parent nucleus, applies the general solution to the construction of low-affinity impermeable membrane zinc ion probes with red and far-red emission spectra and antibody labeling dyes, and is applied to the fields of long-time monitoring of co-release of insulin and zinc ions in living insulin tissues, immunofluorescence labeling and the like.

The invention firstly provides an N-water-soluble group substituted rhodamine functional dye, which has a general formula as follows:

(I)

wherein R is₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈Independent of each other.

R₁Is O, C (CH)₃)₂, Si(CH₃)₂, P(O)CH₃, PO₂ ^-, PO₂CH₂CH₃Or SO₂。

R₂Is O, C, P, S, NH, N⁺HCH₃, N⁺(CH₃)₂, P(O)CH₃Or SO₂。

R₃Is CH₂, CHCH₃, C(CH₃)₂, CHF, CF₂ , CHCl, CCl₂And the various connections possible between them.

R₄And R₈Is H, CH₃, CH₂CH₃, OCH₃, OCH₂CH₃, COO^-, COOMe, CN, SO₂CH₃, SO₂NH₂Or SO2N (CH3) 2.

R₅And R₇Is H, OH, OCH₃, OCH₂CH₃, OCH₂CH₂OCH₃, OCH₂COOH, OCH₂C₆H₅N, COOH or the following structure.

Wherein R is₉Is H, F, Cl, Br, CH₃, OCH₃Or NO₂。

R₆Is H, COOH, N (CH)₂COOH)₂Or N (CH)₂COOCH₂OCOCH₃)。

X^-Being a halogen ion, ClO₄ ^-, PF₆ ^-, BF₄ ^-, CH₃COO^-And CF₃COO^-。

Preferably, the invention provides a series of impermeable membrane fluorescent dyes PK Zinc Red 1-5 with Red emission on the basis of a general formula I, and the structure of the impermeable membrane fluorescent dyes PK Zinc Red 1-5 is shown in a general formula II; they have a low affinity (K _dFrom 190 nanomolar to 74 micromolar) and good biocompatibility. The invention also provides a synthesis method of the series of dyes and describes the application of the dyes in detection and quantification of zinc ion concentration in vitro samples, long-term monitoring of co-release of insulin and zinc ions on living islet tissues and the like.

(II)

The invention provides a preparation method of the dye PK Zinc Red 1-5, which comprises the following steps.

Preferably, the invention provides a series on the basis of the general formula IThe column has an impermeable membrane fluorescent dye PK Zinc Red 1-3 with far-Red emission, and the structure of the impermeable membrane fluorescent dye is shown as a general formula III; they also have a lower affinity (K _d30 micromoles) and good biocompatibility, is not only suitable for long-time monitoring of co-release of insulin and zinc ions in living islet tissues, but also can be used for multicolor imaging by combining with a blue nuclear dye Hochest, a green calcium ion probe GCaMP6f and a Red mitochondrial dye PK Mito Red to explain a complex signal transmission relationship among the blue nuclear dye Hochest, the green calcium ion probe GCaMP6f and the Red mitochondrial dye PK Mito Red.

(III)

Compared with the synthetic route reported by the prior (J. Am. chem. Soc. 133, 36: 14157-14159), the preparation method reported herein has milder reaction conditions and higher yield, is more suitable for gram-scale preparation of the dye, and specifically comprises the following steps:

the selection of the method for detecting the zinc ions is changed along with the properties of the fluorescent probe and the properties of a system, cells and tissues, and the preferable detection technical scheme is realized on equipment such as a microplate reader, a fluorescence spectrophotometer, a rotary table confocal microscope and the like.

Preferably, the invention also provides a far-red-emitting fluorescent dye PK SiR Morpho based on the general formula I, the structure of the far-red-emitting fluorescent dye is shown as IV, the dye has high antibody labeling efficiency (4 dyes are labeled on average by each antibody) and shows higher light stability in immunofluorescence imaging compared with commercial dyes such as Alexa 647, Cy5 and the like.

(IV)

The invention provides a preparation method of the PK SiR Morpho dye, which comprises the following steps:

when the PK SiR Morpho dye is used for immunofluorescence imaging, the preferable detection technical scheme is realized on a confocal microscope, a high content living cell imaging system and other equipment.

Drawings

FIG. 1 is a graph of fluorescence and absorption spectra of compound PK Zinc Red-1 prepared by the invention under various Zinc ion concentrations.

FIG. 2 is a graph showing data of a Zinc ion concentration titration experiment of a compound PK zincRed-1 prepared by the present invention.

FIG. 3 is a graph of fluorescence and absorption spectra of compound PK Zinc Red-2 prepared by the invention at various Zinc ion concentrations.

FIG. 4 is a graph of data from a Zinc ion concentration titration assay of compound PK Zinc Red-2 prepared in accordance with the present invention.

FIG. 5 is a graph of fluorescence and absorption spectra of compound PK Zinc Red-3 prepared by the invention at various Zinc ion concentrations.

FIG. 6 is a graph of data from a Zinc ion concentration titration assay of compound PK zincRed-3 prepared in accordance with the present invention.

FIG. 7 is a graph of fluorescence and absorption spectra of compound PK Zinc Red-4 prepared by the invention at various Zinc ion concentrations.

FIG. 8 is a graph of data from a Zinc ion concentration titration assay for compound PK Zinc Red-4 prepared in accordance with the present invention.

FIG. 9 is a graph of fluorescence and absorption spectra of compound PK Zinc Red-5 prepared by the present invention at various Zinc ion concentrations.

FIG. 10 is a graph of data from a Zinc ion concentration titration assay of compound PK Zinc Red-5 prepared in accordance with the present invention.

FIG. 11 is a graph showing fluorescence and absorption spectra of the compound PK Zinc FarRed-1 prepared by the present invention at various Zinc ion concentrations.

FIG. 12 is a graph of data from a Zinc ion concentration titration assay for compound PK Zinc FarRed-1 prepared in accordance with the present invention.

FIG. 13 is a graph showing fluorescence and absorption spectra of the compound PK Zinc FarRed-2 prepared by the present invention at various Zinc ion concentrations.

FIG. 14 is a graph of data from a Zinc ion concentration titration assay for compound PK Zinc FarRed-2 prepared in accordance with the present invention.

FIG. 15 is a graph showing fluorescence and absorption spectra of the compound PK Zinc FarRed-3 prepared by the present invention at various Zinc ion concentrations.

FIG. 16 is a graph of data from a Zinc ion concentration titration assay for compound PK Zinc FarRed-3 prepared in accordance with the present invention.

FIG. 17 is a graph comparing the results of experiments in which the compound PK Zinc Red-1 prepared in accordance with the present invention and the reported compound RhodZin-1 were tested for co-release of insulin/Zinc ions from intact ex vivo live islets of Langerhans of mice; wherein, the signal in ROI 1 in panel a is an apoptosis signal, the signal in ROI 2 is an intracellular non-specific marker signal, and ROI 3 in panel B is an intracellular background: the fluorescent spot in ROI 4 is the insulin/zinc ion co-release signal.

FIG. 18 is a graph showing the experimental results of the co-release assay of insulin/Zinc ions on islet cell mass of mice by the compound PK zincRed-5 prepared in the present invention; the dotted line shows the outline of the cell mass, and the fluorescence point in the figure is the signal of the insulin/Zinc ion co-release detected by PK Zinc Red-5;

FIG. 19 is a graph showing the experimental results of the co-release assay of insulin/Zinc ion on intact ex vivo live islets of mice with the compound PK zincine-1 prepared in accordance with the present invention under stimulation with the drug forskolin; wherein the cell membrane is marked by a fluorescent dye FM 4-64, and the fluorescence point in the figure is an insulin/Zinc ion co-release signal detected by PK Zinc Red-1

FIG. 20 is a graph showing the results of multicolor imaging of the compound PK Zinc Far Red-3 prepared in accordance with the present invention in combination with the blue nuclear dye Hochest, the green calcium ion probe GCaMP6f and the Red mitochondrial dye PK Mito Red;

FIG. 21 is a graph showing the results of an experiment on the change of fluorescence signal when performing immunofluorescence imaging of the compound PK SiR Morpho prepared in the present invention with commercial dyes Alexa 647 and Cy 5.

The specific implementation mode is as follows:

the following examples are presented to enable those skilled in the art to more fully understand the present invention and are not intended to limit the invention in any way.

The synthesis method of the N-water-soluble group substituted rhodamine fluorescent probe is further described below by combining the examples.

Example 1 Synthesis of Compound PK zincRed-1:

(1) synthesis of compound 1 b:

compound 1a (1.00 g, 3.39 mmol, 1.0 e.q.) was first dissolved in 10 mL dry DMF and stirred at-20 ℃ for 30 min. Then, POCl is added₃(2.88 g, 18.8 mmol, 5.5 e.q.) was added dropwise to the above solution, and the temperature was raised to 60 ℃ for reaction for 3 hours. After the completion of the above reaction, the resulting solution was slowly dropped into 20 mL of an ice-water mixture, followed by addition of Na₂CO₃The reaction solution was neutralized and extracted three times with dichloromethane (40 mL each), the organic layers were collected and Na was added₂SO₄And (4) drying the solid. The resulting solution was concentrated under vacuum/reduced pressure and purified by flash column chromatography on silica gel (10% ethyl acetate/petroleum ether as developing solvent) to give compound 1b (920 mg, 2.84 mmol, 84% yield) as a yellow solid.

¹H NMR (400 MHz, Chloroform-d) δ 9.78 (s, 1H), 7.36 – 7.32 (m, 2H), 6.74 (d, J = 8.6 Hz, 1H), 4.23 (q, J = 7.2 Hz, 4H), 4.18 (s, 4H), 3.83 (s, 3H), 1.29 (t, J = 7.1 Hz, 6H)。

¹³C NMR (101 MHz, Chloroform-d) δ 190.79, 170.96, 150.67, 145.11, 130.10, 126.79, 116.46, 110.27, 61.18, 55.89, 54.43, 14.42。

(ESI) calculation of value C₁₆H₂₂NO₆ ⁺ [M+H]⁺324.14, actual value 324.35.

(2) Synthesis of compound 1 c:

to a solution of compound 1b (250 mg, 0.772 mmol, 1.0 e.q.) in trifluoroacetic acid (6 mL) was added 3-morpholinophenol (346 mg, 1.94 mmol, 2.5 e.q.) and p-toluenesulfonic acid (13.3 mg, 0.0772 mmol, 0.1 e.q.), respectively, at room temperature, followed by stirring at 80 ℃ for 12 h. After the reaction was complete, the resulting mixture was dissolved in 50 mL of CHCl₃Followed by three washes with 3M NaOAc in water. The organic layer was collected and concentrated under vacuum/reduced pressure. The crude product was then dissolved in a 1:1 mixture of DCM/MeOH (4 mL/4 mL), DDQ (176 mg total, 0.775 mmol, 1.0 e.q.) was added in three portions and the reaction continued at room temperature for 4 h. After the reaction was completed, the reaction mixture was concentrated under vacuum/reduced pressure and purified by HPLC (eluent, 20 min linear gradient, solvent B fraction rising from 50% to 95%, flow rate 5.0 mL/min, detection wavelength 545 nm, eluent A: ddH containing 0.1% (v/v) TFA₂O; eluent B: CH (CH)₃CN) gave a violet black solid compound 1c as the trifluoroacetate salt (80 mg, 0.12 mmol, 16% yield).

¹H NMR(400 MHz, Methanol-d ₄) δ 7.67 (d, J = 9.6 Hz, 2H), 7.30 (dd, J = 9.6, 2.6 Hz, 2H), 7.18 (d, J = 2.5 Hz, 2H), 7.09 (d, J = 1.9 Hz, 1H), 7.03 (dd, J = 8.2, 1.9 Hz, 1H), 6.96 (d, J = 8.2 Hz, 1H), 4.29 – 4.21 (m, 8H), 3.88 – 3.83 (m, 8H), 3.81 (s, 3H), 3.78 – 3.73 (m, 8H), 1.32 (t, J = 7.1 Hz, 6H)。

¹³C NMR(101 MHz, Methanol-d ₄) δ 173.04, 160.37, 159.96, 158.73, 151.77, 142.88, 133.64, 130.85, 125.16, 124.85, 118.27, 115.81, 115.58, 98.55, 67.45, 62.10, 56.62, 55.42, 48.36, 14.61.

HRMS (ESI) calculated value C₃₆H₄₂N₃O₈ ⁺ [M]⁺644.2966 actual value 644.2986。

(3) Synthesis of Compound PK zincRed-1:

MeOH/H in Compound 1c (50 mg, 77. mu. mol, 1.0 e.q.)₂To the O (4 mL/1 mL) mixed solution was added a 2M aqueous solution of LiOH (388. mu.L, 10.0 e.q.), and the resulting mixture was stirred at room temperature for 2 hours. After the reaction was completed, the reaction solution was acidified with a 2M hydrochloric acid solution, followed by concentration under vacuum/reduced pressure. The crude product was purified by HPLC (eluent, 20 min linear gradient, solvent B fraction rising from 35% to 95%, flow rate 5.0 mL/min, detection wavelength 545 nm; eluent A: ddH containing 0.1% (v/v) TFA)₂O; eluent B: CH (CH)₃CN) gave a purple black solid compound PK Zinc Red-1 as the trifluoroacetate salt (15 mg, 26. mu. mol, 34% yield).

¹H NMR (400 MHz, Methanol-d ₄) δ 7.68 (d, J = 9.6 Hz, 2H), 7.29 (dd, J= 9.6, 2.3 Hz, 2H), 7.18 (d, J = 2.5 Hz, 2H), 7.09 (d, J = 1.9 Hz, 1H), 7.04 – 6.97 (m, 2H), 4.24 (s, 4H), 3.87 – 3.85 (m, 8H), 3.82 (s, 3H), 3.76 – 3.73 (m, 8H)。

¹³C NMR (101 MHz, Methanol-d ₄) δ 175.04, 160.41, 159.96, 158.72, 151.71, 142.95, 133.69, 130.85, 125.03, 124.92, 118.03, 115.79, 115.57, 98.55, 67.45, 56.54, 55.45, 48.36。

HRMS (ESI) calculated value C₃₂H₃₆N₃O₈ ⁺ [M]⁺588.2340, actual value 588.2362.

Example 2 Synthesis of Compound PK zincRed-2:

(1) synthesis of compound 2 b:

compound 2a (730 mg, 2)36 mmol, 1.0 e.q.) was dissolved in 10 mL dry DMF and stirred at-20 ℃ for 30 min. Then, POCl is added₃(3.00 g, 19.6 mmol, 8.3 e.q.) was added dropwise to the above solution, and the resulting mixture was heated to 60 ℃ for reaction for 3 hours. After the completion of the above reaction, the resulting solution was slowly dropped into 20 mL of an ice-water mixture, and then the mixture was mixed with Na₂CO₃The solution was neutralized and extracted three times with dichloromethane (40 mL each), the organic layers were collected and Na was added₂SO₄And (4) drying the solid. The resulting solution was concentrated under vacuum/reduced pressure and purified by flash column chromatography on silica gel (10% ethyl acetate/petroleum ether as developing solvent) to give compound 2b (680 mg, 2.02 mmol, 86% yield) as a yellow solid.

¹H NMR (400 MHz, Chloroform-d) δ 9.77 (s, 1H), 7.35 – 7.31 (m, 2H), 6.71 (d, J = 8.5 Hz, 1H), 4.28 – 4.17 (m, 8H), 4.07 (q, J = 6.9 Hz, 2H), 1.38 (t, J = 6.9 Hz, 3H), 1.30 (t, J = 7.1 Hz, 6H)。

¹³C NMR (101 MHz, Chloroform-d) δ 190.79, 171.02, 149.89, 145.20, 129.99, 126.57, 116.23, 110.76, 64.42, 61.16, 54.07, 14.50, 14.34。

MS (ESI) calculation of C₁₇H₂₄NO₆ ⁺ [M+H]⁺338.16, actual value 338.21.

(2) Synthesis of compound 2 c:

to a solution of compound 2b (50 mg, 0.148 mmol, 1.0 e.q.) in trifluoroacetic acid (3 mL) was added 3-morpholinophenol (66.0 mg, 0.371 mmol, 2.5 e.q.) and p-toluenesulfonic acid (2.6 mg, 14.8 μmol, 0.1 e.q.), respectively, at room temperature, followed by stirring at 80 ℃ for 12 h. After the reaction was complete, the resulting mixture was dissolved in 25 mL of CHCl₃Followed by washing with 3M NaOAc in water. The organic layer was collected and concentrated under vacuum/reduced pressure. The crude product was then dissolved in a 1:1 mixture of DCM/MeOH (2 mL/2 mL) and added in three portionsDDQ (total amount 34.0 mg, 0.148 mmol, 1.0 e.q.), was reacted further at room temperature for 4 h. After the reaction was completed, the reaction mixture was concentrated under vacuum/reduced pressure and purified by HPLC (eluent, 20 min linear gradient, solvent B fraction rising from 50% to 95%, flow rate 5.0 mL/min, detection wavelength 545 nm, eluent A: ddH containing 0.1% (v/v) TFA₂O; eluent B: CH (CH)₃CN) gave a violet black solid compound 2c as the trifluoroacetate salt (11 mg, 17 μmol, 11% yield).

¹H NMR(400 MHz, Methanol-d ₄) δ 7.66 (dd, J = 9.5, 2.3 Hz, 2H), 7.29 (d, J = 9.4 Hz, 2H), 7.17 (d, J = 2.1 Hz, 2H), 7.05 (d, J = 1.6 Hz, 1H), 7.02 – 6.92 (m, 2H), 4.30 – 4.20 (m, 8H), 4.04 (q, J = 6.9 Hz, 2H), 3.89 – 3.81 (m, 8H), 3.77 – 3.71 (m, 8H), 1.40 – 1.29 (m, 9H).

¹³C NMR(101 MHz, Methanol-d ₄) δ 173.04, 160.35, 159.91, 158.69, 150.97, 142.97, 133.63, 125.12, 124.72, 118.26, 116.25, 115.81, 115.53, 98.59, 67.45, 65.91, 62.13, 55.12, 48.39, 14.97, 14.55。

HRMS (ESI) calculated value C₃₇H₄₄N₃O₈ ⁺ [M]⁺658.3123, actual value 658.3134.

(3) Synthesis of Compound PK zincRed-2:

MeOH/H in Compound 2c (10.0 mg, 15.2. mu. mol, 1.0 e.q.)₂To the O (2 mL/0.5 mL) mixed solution was added a 2M aqueous solution of LiOH (78. mu.L, 10.0 e.q.), and the resulting mixture was stirred at room temperature for 2 hours. After the reaction was completed, the reaction solution was acidified with a 2M hydrochloric acid solution, followed by concentration under vacuum/reduced pressure. The crude product was purified by HPLC (eluent, 20 min linear gradient, solvent B fraction rising from 30% to 95%, flow rate 5.0 mL/min, detection wavelength 545 nm; eluent A: ddH containing 0.1% (v/v) TFA)₂O; eluent B: CH (CH)₃CN) gave the trifluoroacetate salt of the purple black solid compound PK zincRed-2 (2.1 mg, 3.3. mu. mol, 22% yield).

¹H NMR (400 MHz, Methanol-d ₄) δ 7.66 (d, J = 9.5 Hz, 2H), 7.28 (dd, J= 9.6, 2.1 Hz, 2H), 7.17 (d, J = 2.2 Hz, 2H), 7.05 (d, J = 1.6 Hz, 1H), 7.02 – 6.93 (m, 2H), 4.24 (s, 4H), 4.05 (q, J = 6.9 Hz, 2H), 3.88 – 3.84 (m, 8H), 3.76 – 3.73 (m, 8H), 1.42 (t, J = 6.9 Hz, 3H)。

¹³C NMR (101 MHz, Methanol-d ₄) δ 175.10, 160.36, 159.90, 158.67, 150.95, 143.07, 133.66, 124.95, 124.77, 117.95, 116.24, 115.78, 115.50, 98.58, 67.45, 66.07, 55.25, 48.38, 14.86。

HRMS (ESI) theoretical value C₃₃H₃₆N₃O₈ ⁺ [M]⁺602.2497, actual value 602.2488.

Example 3 Synthesis of Compound PK zincRed-3:

(1) synthesis of compound 3 b:

compound 3a (700 mg, 2.06 mmol, 1.0 e.q.) was first dissolved in 10 mL dry DMF and stirred at-20 ℃ for 30 min. Then, POCl is added₃(2.52 g, 16.5 mmol, 8.0 e.q.) was added dropwise to the above solution, and the resulting mixture was heated to 60 ℃ for reaction for 3 hours. After the completion of the above reaction, the resulting solution was slowly dropped into 20 mL of an ice-water mixture, and then the mixture was mixed with Na₂CO₃The solution was neutralized and extracted three times with dichloromethane (40 mL each), the organic layers were collected and Na was added₂SO₄And (4) drying the solid. The resulting solution was concentrated under vacuum/reduced pressure and purified by flash column chromatography on silica gel (10% EtOAc/hexane as developing solvent) to provide compound 3b as a yellow oil (500 mg, 1.36 mmol, 66% yield).

¹H NMR (400 MHz, Chloroform-d) δ 9.76 (s, 1H), 7.36 – 7.34 (m, 2H), 6.73 (d, J = 8.6 Hz, 1H), 4.27 – 4.19 (m, 8H), 4.17 – 4.14 (m, 2H), 3.71 – 3.67 (m, 2H), 3.39 (s, 3H), 1.29 (t, J = 7.2 Hz, 6H)。

¹³C NMR (101 MHz, Chloroform-d) δ 190.70, 170.86, 149.77, 145.23, 129.95, 126.79, 116.67, 111.64, 70.61, 68.07, 61.15, 58.94, 54.00, 14.34。

MS (ESI) theoretical value C₁₈H₂₆NO₇ ⁺ [M+H]⁺368.17, actual value 368.58.

(2) Synthesis of compound 3 c:

to a solution of compound 3b (50 mg, 0.136 mmol, 1.0 e.q.) in trifluoroacetic acid (3 mL) was added 3-morpholinophenol (61.0 mg, 0.340 mmol, 2.5 e.q.) and p-toluenesulfonic acid (2.3 mg, 13.6 μmol, 0.1 e.q.), respectively, at room temperature, followed by stirring at 80 ℃ for 12 h. After the reaction was complete, the resulting mixture was dissolved in 20 mL of CHCl₃Followed by washing with 3M NaOAc in water. The organic layer was collected and concentrated under vacuum/reduced pressure. The crude product was then dissolved in a 1:1 mixture of DCM/MeOH (2 mL/2 mL), DDQ (total 31.0 mg, 0.136 mmol, 1.0 e.q.) was added in three portions and the reaction continued at room temperature for 4 h. After the reaction was completed, the reaction mixture was concentrated under vacuum/reduced pressure and purified by HPLC (eluent, 20 min linear gradient, solvent B fraction rising from 50% to 95%, flow rate 5.0 mL/min, detection wavelength 545 nm, eluent A: ddH containing 0.1% (v/v) TFA₂O; eluent B: CH (CH)₃CN) gave a violet black solid compound 3c as the trifluoroacetate salt (5.0 mg, 7.2 μmol, 5% yield).

¹H NMR (400 MHz, Methanol-d ₄) δ 7.65 (d, J = 9.4 Hz, 2H), 7.28 (dd, J= 9.7, 2.2 Hz, 2H), 7.15 (d, J = 2.2 Hz, 2H), 7.12 (d, J = 1.7 Hz, 1H), 7.06 – 6.93 (m, 2H), 4.31 (s, 4H), 4.25 (q, J = 7.1 Hz, 4H), 4.16 – 4.12 (m, 2H), 3.87 – 3.84 (m, 8H), 3.76 – 3.72 (m, 8H), 3.70 – 3.68 (m, 2H), 3.39 (s, 3H), 1.32 (t, J = 7.1 Hz, 6H)。

¹³C NMR (101 MHz, Methanol-d ₄) δ 172.85, 160.17, 159.86, 158.67, 151.01, 142.97, 133.64, 125.13, 125.11, 118.70, 117.08, 115.82, 115.49, 98.58, 72.00, 69.77, 67.45, 62.13, 59.19, 55.00, 48.39, 14.57。

HRMS (ESI) theoretical value C₃₈H₄₆N₃O₉ ⁺ [M]⁺688.3229, actual value 688.3262.

(3) Synthesis of Compound PK zincRed-3:

MeOH/H in Compound 3c (5.0 mg, 7.25. mu. mol, 1.0 e.q.)₂To the O (1.2 mL/0.3 mL) mixed solution was added a 2M aqueous solution of LiOH (40. mu.L, 10.0 e.q.), and the resulting mixture was stirred at room temperature for 2 hours. After the reaction was completed, the reaction solution was acidified with a 2M hydrochloric acid solution, followed by concentration under vacuum/reduced pressure. The crude product was purified by HPLC (eluent, 20 min linear gradient, solvent B fraction rising from 30% to 95%, flow rate 5.0 mL/min, detection wavelength 545 nm; eluent A: ddH containing 0.1% (v/v) TFA)₂O; eluent B: CH (CH)₃CN) gave a purple black solid compound PK zincRed-3 as the trifluoroacetate salt (2.0 mg, 3.1. mu. mol, 44% yield).

¹H NMR (400 MHz, Methanol-d ₄) δ 7.64 (d, J = 9.5 Hz, 2H), 7.26 (dd, J= 9.5, 2.2 Hz, 2H), 7.13 (d, J = 2.2 Hz, 2H), 7.09 (d, J = 1.7 Hz, 1H), 7.03 – 6.96 (m, 2H), 4.27 (s, 4H), 4.16 – 4.11 (m, 2H), 3.92 – 3.82 (m, 10H), 3.74 – 3.71 (m, 8H), 3.40 (s, 3H)。

¹³C NMR (101 MHz, Methanol-d ₄) δ 174.88, 160.19, 159.86, 158.65, 150.92, 143.04, 133.65, 125.13, 124.98, 118.28, 116.5, 115.76, 115.46, 98.56, 71.96, 69.83, 67.43, 59.23, 55.01, 48.36。

HRMS (ESI) theoretical value C₃₄H₃₈N₃O₉ ⁺ [M]⁺632.2603, calculated 632.2616.

Example 4 Synthesis of Compound PK zincRed-4:

(1) synthesis of compound 4 b:

compound 4a (800 mg, 2.18 mmol, 1.0 e.q.) was first dissolved in 10 mL dry DMF and stirred at-20 ℃ for 30 min. Then, POCl is added₃(2.66 g, 17.4 mmol, 8.0 e.q.) was added dropwise to the above solution, and the resulting mixture was heated to 60 ℃ for reaction for 3 hours. After the completion of the above reaction, the resulting solution was slowly dropped into 20 mL of an ice-water mixture, and then the mixture was mixed with Na₂CO₃The solution was neutralized and extracted three times with dichloromethane (40 mL each), the organic layers were collected and Na was added₂SO₄And (4) drying the solid. The resulting solution was concentrated under vacuum/reduced pressure and purified by flash column chromatography on silica gel (10% ethyl acetate/petroleum ether as developing solvent) to give compound 4b (518 mg, 1.31 mmol, 60% yield) as a yellow solid.

¹H NMR (400 MHz, Chloroform-d) δ 9.76 (s, 1H), 7.40 (dd, J = 8.2, 1.8 Hz, 1H), 7.26 (d, J = 1.6 Hz, 1H), 6.81 (d, J = 8.2 Hz, 1H), 4.65 (s, 2H), 4.31 – 4.17 (m, 10H), 1.33 – 1.23 (m, 9H)。

¹³C NMR (101 MHz, Chloroform-d) δ 190.33, 170.67, 168.06, 162.54, 148.66, 145.29, 129.79, 127.23, 117.17, 111.73, 65.62, 61.41, 61.04, 54.07, 36.46, 31.39, 14.21, 14.11。

MS (ESI) theoretical value C₁₉H₂₇NO₈ ⁺ [M+H]⁺396.17, calculated 396.26.

(2) Synthesis of compound 4 c:

to a solution of compound 4b (50 mg, 0.127 mmol, 1.0 e.q.) in trifluoroacetic acid (3 mL) was added 3-morpholinophenol (57.0 mg, 0.316 mmol, 2.5 e.q.) and p-toluenesulfonic acid (2.2 mg, 12.7 μmol, 0.1 e.q.), respectively, at room temperature, followed by stirring at 80 ℃ for 12 h. After the reaction was complete, the resulting mixture was dissolved in 20 mL of CHCl₃Followed by washing with 3M NaOAc in water. The organic layer was collected and concentrated under vacuum/reduced pressure. The crude product was then dissolved in a 1:1 mixture of DCM/MeOH (2 mL/2 mL), DDQ (total 29.0 mg, 0.127 mmol, 1.0 e.q.) was added in three portions and the reaction continued at room temperature for 4 h. After the reaction was completed, the reaction mixture was concentrated under vacuum/reduced pressure and purified by HPLC (eluent, 20 min linear gradient, solvent B fraction rising from 50% to 95%, flow rate 5.0 mL/min, detection wavelength 545 nm, eluent A: ddH containing 0.1% (v/v) TFA₂O; eluent B: CH (CH)₃CN) gave a violet black solid compound 4c as the trifluoroacetate salt (5.2 mg, 7.3 μmol, 6% yield).

¹H NMR (400 MHz, Methanol-d ₄) δ 7.60 (d,J = 9.6 Hz, 2H), 7.26 (dd,J = 9.6, 2.3 Hz, 2H), 7.14 (d,J = 2.4 Hz, 2H), 7.11 – 7.03 (m, 3H), 4.75 (s, 2H), 4.33 (s, 4H), 4.28 – 4.17 (m, 6H), 3.89 – 3.82 (m, 8H), 3.76 – 3.70 (m, 8H), 1.29 (t,J = 7.1 Hz, 6H), 1.23 (t,J = 7.1 Hz, 3H)。

¹³C NMR (101 MHz, Methanol-d ₄) δ 172.77, 170.19, 159.66, 159.49, 158.54, 149.85, 143.20, 133.58, 130.80, 126.12, 124.95, 119.28, 115.92, 115.30, 98.79, 67.52, 62.54, 62.16, 55.13, 53.31, 48.57, 14.63, 14.43。

HRMS (ESI) theoretical value C₃₉H₄₆N₃O₁₀ ⁺ [M]⁺716.3178, calculated 716.3196.

(3) Synthesis of Compound PK zincRed-4:

MeOH/H in Compound 4c (5.2 mg, 7.3. mu. mol, 1.0 e.q.)₂To the O (1.2 mL/0.3 mL) mixed solution was added a 2M aqueous solution of LiOH (40. mu.L, 10.0 e.q.), and the resulting mixture was stirred at room temperature for 2 hours. After the reaction was completed, the reaction solution was acidified with a 2M hydrochloric acid solution, followed by concentration under vacuum/reduced pressure. The crude product was purified by HPLC (eluent, 20 min linear gradient, solvent B fraction rising from 30% to 95%, flow rate 5.0 mL/min, detection wavelength 545 nm; eluent A: ddH containing 0.1% (v/v) TFA)₂O; eluent B: CH (CH)₃CN) gave a purple black solid compound PK zincRed-4 as the trifluoroacetate salt (2.5 mg, 4.0. mu. mol, 55% yield).

¹H NMR (400 MHz, Methanol-d ₄) δ 7.64 (d, J = 9.6 Hz, 2H), 7.25 (dd, J= 9.6, 2.5 Hz, 2H), 7.13 (d, J = 2.4 Hz, 2H), 7.09 – 7.02 (m, 3H), 4.75 (s, 2H), 4.32 (s, 4H), 3.87 – 3.83 (m, 8H), 3.76 – 3.71 (m, 8H)。

¹³C NMR (101 MHz, Methanol-d ₄) δ 174.90, 172.07, 159.87, 159.78, 158.63, 150.01, 143.29, 133.62, 130.85, 125.85, 124.98, 119.02, 115.76, 115.37, 98.57, 67.43, 66.43, 55.11, 48.36。

HRMS (ESI) theoretical value C₃₃H₃₄N₃O₁₀ ⁺ [M]⁺632.2239, calculated 632.2235.

Example 5 Synthesis of Compound PK zincRed-5:

(1) synthesis of compound 5 c:

compound 5b was synthesized according to the reported procedure (org. Lett., 2011, 13(17): 4558-4561). In a solution of compound 5b (100 mg, 0.249 mmol, 1.0 e.q.) in trifluoroacetic acid (6 mL) at room temperature3-morpholinophenol (99.0 mg, 0.55 mmol, 2.2 e.q.) and p-toluenesulfonic acid (4.3 mg, 25. mu. mol, 0.1 e.q.) were added, followed by stirring at 80 ℃ for 12 h. After the reaction was complete, the resulting mixture was dissolved in 20 mL of CHCl₃Followed by washing with 3M NaOAc in water. The organic layer was collected and concentrated under vacuum/reduced pressure. The crude product was then dissolved in a 1:1 mixture of DCM/MeOH (2 mL/2 mL), DDQ (total 57.0 mg, 0.25 mmol, 1.0 e.q.) was added in three portions and the reaction continued at room temperature for 4 h. After the reaction was completed, the reaction mixture was concentrated under vacuum/reduced pressure and purified by HPLC (eluent, 20 min linear gradient, solvent B fraction rising from 50% to 95%, flow rate 5.0 mL/min, detection wavelength 545 nm, eluent A: ddH containing 0.1% (v/v) TFA₂O; eluent B: CH (CH)₃CN) gave a violet black solid compound 5c as the trifluoroacetate salt (24.0 mg, 33 μmol, 13% yield).

¹H NMR (400 MHz, Methanol-d ₄) δ 8.81 – 8.77 (m, 1H), 8.39 (td,J = 7.8, 1.6 Hz, 1H), 7.99 (d,J = 8.0 Hz, 1H), 7.87 – 7.81 (m, 1H), 7.52 (d,J = 9.6 Hz, 2H), 7.27 – 7.21 (m, 3H), 7.18 – 7.12 (m, 4H), 5.48 (s, 2H), 4.31 (s, 4H), 4.13 (q,J = 7.1 Hz, 4H), 3.89 – 3.83 (m, 8H), 3.77 – 3.71 (m, 8H), 1.25 (t,J = 7.1 Hz, 6H)。

¹³C NMR (101 MHz, Methanol-d ₄) δ 172.74, 159.88, 159.43, 158.71, 154.59, 150.46, 145.92, 144.85, 143.66, 133.36, 130.84, 126.72, 126.34, 126.17, 120.18, 118.91, 115.88, 115.47, 98.59, 70.44, 67.43, 62.20, 55.19, 48.40, 14.50。

HRMS (ESI) theoretical value C₄₁H₄₅N₄O₈ ⁺ [M]⁺721.3232, actual value 721.3212.

(2) Synthesis of Compound PK zincRed-5:

after purification of compound 5c (24.0 mg, 33. mu. mol,1.0 e.q.) MeOH/H₂To the O (4 mL/1 mL) mixed solution was added 2M aqueous LiOH (168. mu.L, 10.0 e.q.), and the resulting mixture was stirred at room temperature for 2 h. After the reaction was completed, the reaction solution was acidified with a 2M hydrochloric acid solution, followed by concentration under vacuum/reduced pressure. The crude product was purified by HPLC (eluent, 20 min linear gradient, solvent B fraction rising from 30% to 95%, flow rate 5.0 mL/min, detection wavelength 545 nm; eluent A: ddH containing 0.1% (v/v) TFA)₂O; eluent B: CH (CH)₃CN) gave a purple black solid compound PK zincRed-5 as the trifluoroacetate salt (10.4 mg, 15.6. mu. mol, 48% yield).

¹H NMR (400 MHz, Methanol-d ₄) δ 8.77 – 8.70 (m, 1H), 8.33 (td,J = 7.8, 1.5 Hz, 1H), 7.96 (d,J = 7.9 Hz, 1H), 7.79 (dd,J = 7.6, 5.4 Hz, 1H), 7.54 (d,J = 9.4 Hz, 2H), 7.27 – 7.20 (m, 3H), 7.19 – 7.10 (m, 4H), 5.45 (s, 2H), 4.28 (s, 4H), 3.88 – 3.84 (m, 8H), 3.78 – 3.73 (m, 8H)。

¹³C NMR (101 MHz, Methanol-d ₄) δ 174.64, 159.92, 159.58, 158.71, 154.65, 150.27, 146.24, 144.36, 143.73, 133.44, 130.85, 126.55, 126.30, 126.08, 119.64, 118.66, 115.84, 115.48, 98.59, 70.63, 67.44, 55.17, 48.40。

HRMS (ESI) theoretical value C₃₇H₃₇N₄O₈ ⁺ [M]⁺665.2606, calculated 665.2606.

Example 6 Synthesis of Compound PK Zinc FarRed-1:

(1) synthesis of the compound bis (2-bromo-4-morpholinophenyl) methane:

to a solution of 4- (3-bromophenyl) morpholine (3.08 g, 12.7 mmol, 2.0 e.q.) in AcOH (30 mL) was added 37% formalin (0.475 mL, 6.34 mmol, 1.0 e.q.), and the reaction was warmed to 90 ℃ and stirred for 3 h. After the reaction is finished and the reaction liquid is cooled to room temperatureWith saturated NaHCO₃Neutralizing the reaction solution with an aqueous solution and using CH₂Cl₂The organic layer was extracted. The organic layer was washed with brine, then Na₂SO₄Drying and evaporating the solvent. The resulting product was purified by column chromatography (5% EtOAc/hexane) to yield bis (2-bromo-4-morpholinophenyl) methane (1.36 g, 2.74 mmol, 43% yield) as a white solid.

¹H NMR (400 MHz, Chloroform-d) δ 7.12 (d,J = 2.6 Hz, 2H), 6.88 (d,J = 8.6 Hz, 2H), 6.76 (dd,J = 8.5, 2.6 Hz, 2H), 4.03 (s, 2H), 3.86 – 3.80 (m, 8H), 3.16 – 3.08 (m, 8H)。

¹³C NMR (101 MHz, Chloroform-d) δ 150.84, 130.97, 130.42, 125.67, 119.59, 114.90, 66.88, 49.15, 40.31。

HRMS (ESI) theoretical value C₂₁H₂₅Br₂N₂O₂ ⁺ [M+H]⁺497.0264, actual value 497.0234.

(2) Synthesis of Compound morpholinyl Sithracenone:

in a flask which was thermally dried and purged with argon, bis (2-bromo-4-morpholinophenyl) methane (600 mg, 1.22 mmol, 1.0 e.q.) and anhydrous THF (9 mL) were added. Cooling the solution to-78 deg.C, and rapidly injecting with syringenBuLi (1.6M in n-hexane, 1.70 mL, 2.72 mmol, 2.2 e.q.), reaction stirred at-78 deg.C for 10 min. At the same temperature, the SiMe solution was slowly dropped into the solution by means of a syringe₂Cl₂(0.165 mL, 9.35 mmol, 1.2 e.q.) the reaction was then allowed to warm to room temperature and stirred for 30 min. After the reaction was complete, the reaction was quenched by addition of 2M hydrochloric acid and saturated NaHCO₃After the reaction solution was neutralized with an aqueous solution, CH was added₂Cl₂The organic layer was extracted. The organic layer was washed with brine, then Na₂SO₄Drying and evaporating the solvent. The crude product (silico-pyronine) was used directly in the next reaction without work-up. Dissolving the product in15 mL CH₃COCH₃And the solution was cooled to 0 ℃. Mixing KMnO₄(578 mg, 3.66 mmol, 3.0 e.q.) was ground to a fine powder and added to the reaction mixture a few times with stirring over 1 h. After further reaction for 1h at room temperature, 20 mL of CH was added₂Cl₂Diluting the reaction solution, filtering with filter paper, evaporating to remove solvent (silica gel powder can be added to adsorb fine MnO during the process₂Powder, facilitating filtration). The resulting product was purified by column chromatography (10% ethyl acetate/petroleum ether) to give morpholinyl silanthrone as a pale yellow solid (114 mg, 0.278 mmol, 23% yield).

¹H NMR (400 MHz, Chloroform-d) δ 8.39 (d,J = 8.7 Hz, 2H), 7.06 – 6.99 (m, 4H), 3.92 – 3.85 (m, 8H), 3.38 – 3.32 (m, 8H), 0.47 (s, 6H)。

¹³C NMR (101 MHz, Chloroform-d) δ 185.47, 152.62, 140.65, 132.42, 131.76, 117.21, 115.92, 66.82, 47.79, -0.99。

HRMS (ESI) theoretical value C₂₃H₂₉N₂O₃Si⁺ [M+H]⁺409.1947, actual value 409.1916.

(3) Synthesis of compound 1 e:

compound 1d (1.00 g, 4.95 mmol, 1.0 e.q.), triethylamine (1.45 mL, 10.4 mmol, 10.0 e.q.) and 4- (dimethylamino) pyridine (60.0 mg, 0.50 mmol, 0.1 e.q.) were dissolved in 20 mL of CH at room temperature₂Cl₂Then 5 mL of 1, 2-bis (chlorodimethylsilyl) ethane (1.17 g, 5.45 mmol, 1.1 e.q.) in CH₂Cl₂The solution was slowly dropped into the above mixture and stirred for 3 hours. After the reaction was completed, 30 mL of n-hexane was added to precipitate triethylamine chloride salt, which was then removed by filtration. The resulting goose-yellow oil was purified by column chromatography (alumina base, 5% ethyl acetate/petroleum ether) to give compound 1e (1.58 g, 4.60 mmol, 93% yield) as a colorless oil.

¹H NMR (400 MHz, Chloroform-d) δ 6.95 – 6.90 (m, 2H), 6.75 (d, J = 8.8 Hz, 1H), 3.73 (s, 3H), 0.84 (s, 4H), 0.05 (s, 12H)。

¹³C NMR (101 MHz, Chloroform-d) δ 156.31, 134.83, 129.33, 123.44, 115.08, 114.44, 55.00, 8.84, 0.10。

(4) Synthesis of compound 1 f:

compound 1e (100 mg, 0.292 mmol, 5.0 e.q.) and anhydrous THF (3 mL) were added to a flask that was thermally dried and purged with argon. Cooling the solution to-20 deg.C, and rapidly injecting with syringenBuLi (1.6M in n-hexane 0.20 mL, 0.32 mmol, 5.5 e.q.), reaction stirred at-20 ℃ for 15 min. At the same temperature, 1 mL of a solution of silanthrone (25.0 mg, 57.8. mu. mol, 1.0 e.q.) in anhydrous THF was slowly added dropwise with a syringe and stirring was continued for 20 min. After the reaction was complete, the reaction was quenched by addition of 2M hydrochloric acid and warmed to room temperature, and saturated NaHCO was used₃After the reaction solution was neutralized with an aqueous solution, the organic layer was extracted with EtOAc. The organic layer was washed with brine, then Na₂SO₄Drying and subsequent concentration of the reaction mixture under vacuum/reduced pressure purification by HPLC (eluent, 20 min linear gradient, solvent B fraction rising from 30% to 95%; flow rate 5.0 mL/min; detection wavelength 650 nm; eluent A: ddH containing 0.1% (v/v) TFA)₂O; eluent B: CH (CH)₃CN) gave the trifluoroacetate salt of compound 1f as a dark blue solid (16.3 mg, 31.7 μmol, 55% yield).

¹H NMR (400 MHz, Methanol-d ₄) δ 7.53 (d, J = 2.9 Hz, 2H), 7.32 (d, J = 7.9 Hz, 1H), 7.29 (d, J = 9.7 Hz, 2H), 7.06 (d, J = 1.7 Hz, 1H), 6.96 (dd, J= 9.7, 2.9 Hz, 2H), 6.89 (dd, J = 7.9, 1.7 Hz, 1H), 3.92 (s, 3H), 3.85 – 3.82 (m, 16H), 0.60 (s, 6H)。

¹³C NMR (101 MHz, Methanol-d ₄) δ 170.39, 155.28, 151.78, 150.22, 143.81, 137.61, 131.76, 129.90, 123.90, 122.44, 121.14, 115.32, 114.42, 67.59, 56.86, 48.36, -1.33。

HRMS (ESI) theoretical value C₃₀H₃₆N₃O₃Si⁺ [M]⁺514.2520, calculated 514.2495.

(5) Synthesis of Compound 1 g:

to 1 mL of a solution of Compound 1f (15.0 mg, 29. mu. mol, 1.0 e.q.) in DMF at room temperature was added K₂CO₃(40.0 mg, 0.29 mmol, 10.0 e.q.), KI (2.4 mg, 14. mu. mol, 0.5 e.q.) and ethyl bromoacetate (48 mg, 0.29 mmol, 10.0 e.q.) the reaction was stirred at 95 ℃ for 12 h. After the reaction was completed, the reaction mixture was concentrated under vacuum/reduced pressure and purified by HPLC (eluent, 20 min linear gradient, solvent B fraction rising from 50% to 95%, flow rate 5.0 mL/min, detection wavelength 650 nm; eluent A: ddH containing 0.1% (v/v) TFA₂O; eluent B: CH (CH)₃CN) gave 1g of the trifluoroacetate salt as a dark blue solid (14.3 mg, 20.8. mu. mol, 72% yield).

¹H NMR (400 MHz, Methanol-d ₄) δ 7.51 (d, J = 2.8 Hz, 2H), 7.36 (d, J = 9.7 Hz, 2H), 6.94 (dd, J = 9.7, 2.9 Hz, 2H), 6.89 – 6.84 (m, 2H), 6.75 (dd, J= 8.2, 1.9 Hz, 1H), 4.28 – 4.15 (m, 8H), 3.87 – 3.76 (m, 16H), 3.75 (s, 3H), 1.30 (t, J = 7.1 Hz, 6H), 0.59 (s, 6H)。

¹³C NMR (101 MHz, Methanol-d ₄) δ 173.10, 171.82, 155.22, 151.41, 150.15, 144.15, 141.11, 132.81, 130.20, 123.97, 122.25, 117.99, 115.44, 115.18, 67.55, 61.98, 56.52, 55.31, 48.29, 14.62, -1.30。

HRMS (ESI) theoretical value C₃₈H₄₈N₃O₇Si⁺ [M]⁺686.3256, calculated 686.3239.

(5) Synthesis of Compound PK Zinc FarRed-1:

in compound 1g (14 mg, 20. mu. mol, 1.0 e.q.) of MeOH/H₂To the O (2 mL/0.5 mL) mixed solution was added a 2M aqueous solution of LiOH (100. mu.L, 10.0 e.q.), and the resulting mixture was stirred at room temperature for 2 hours. After the reaction was completed, the reaction solution was acidified with a 2M hydrochloric acid solution, followed by concentration under vacuum/reduced pressure. The crude product was purified by HPLC (eluent, 20 min linear gradient, solvent B fraction rising from 30% to 95%, flow rate 5.0 mL/min, detection wavelength 650 nm; eluent A: ddH containing 0.1% (v/v) TFA₂O; eluent B: CH (CH)₃CN) gave the trifluoroacetate salt of PK zincFarRed-1 as a dark blue solid (8.2 mg, 13. mu. mol, 63% yield).

¹H NMR (400 MHz, Methanol-d ₄) δ 7.51 (d, J = 2.9 Hz, 2H), 7.37 (d, J = 9.6 Hz, 2H), 6.95 (dd, J = 9.7, 2.9 Hz, 2H), 6.90 (d, J = 8.2 Hz, 1H), 6.86 (d, J = 1.9 Hz, 1H), 6.76 (dd, J = 8.2, 1.9 Hz, 1H), 4.19 (s, 4H), 3.85 – 3.80 (m, 16H), 3.77 (s, 3H), 0.58 (s, 6H)。

¹³C NMR (101 MHz, Methanol-d ₄) δ 175.28, 171.99, 155.26, 151.39, 150.15, 144.26, 141.16, 132.76, 130.24, 124.00, 122.24, 117.74, 115.45, 115.20, 67.59, 56.40, 55.41, 48.30, -1.31。

HRMS (ESI) theoretical value C₃₄H₄₀N₃O₇Si⁺ [M]⁺630.2630, actual value 630.2615.

Example 7 Synthesis of Compound PK Zinc FarRed-2:

(1) synthesis of compound 2 e:

compound 2d (1.06 g, 4.95 mmol, 1.0 e.q.), triethylamine (1.45 mL, 10.4 mmol, 10.0 e.q.) and 4- (dimethylamino) pyridine (60.0 mg, 0.50 mmol, 0.1 e.q.) were dissolved in 20 mL of CH at room temperature₂Cl₂Then 5 mL of 1, 2-bis (chlorodimethylsilyl) ethane (1.17 g, 5.45 mmol, 1.1 e.q.) in CH₂Cl₂The solution was slowly dropped into the above mixture and stirred for 3 hours. After the reaction was completed, 30 mL of n-hexane was added to precipitate triethylamine chloride salt, which was then removed by filtration. The resulting goose-yellow oil was purified by column chromatography (alumina base, 5% ethyl acetate/petroleum ether) to give compound 2e (1.27 g, 3.57 mmol, 72% yield) as a colorless oil.

¹H NMR (400 MHz, Chloroform-d) δ 6.95 (s, 1H), 6.75 (s, 1H), 3.70 (s, 3H), 2.27 (s, 3H), 0.84 (s, 4H), 0.06 (s, 12H)。

¹³C NMR (101 MHz, Chloroform-d) δ 154.24, 134.76, 130.10, 129.24, 117.05, 114.88, 55.11, 22.11, 8.87, 0.14。

(2) Synthesis of compound 2 f:

compound 2e (100 mg, 0.280 mmol, 4.8 e.q.) and anhydrous THF (3 mL) were added to a flask that was thermally dried and purged with argon. Cooling the solution to-20 deg.C, and rapidly injecting with syringenBuLi (1.6M in n-hexane 0.19 mL, 0.31 mmol, 5.3 e.q.), reaction stirred at-20 ℃ for 15 min. At the same temperature, 1 mL of a solution of silanthrone (25.0 mg, 57.8. mu. mol, 1.0 e.q.) in anhydrous THF was slowly added dropwise with a syringe and stirring was continued for 20 min. After the reaction was complete, the reaction was quenched by addition of 2M hydrochloric acid and warmed to room temperature, and saturated NaHCO was used₃After the reaction solution was neutralized with an aqueous solution, the organic layer was extracted with EtOAc. The organic layer was washed with brine, then Na₂SO₄Drying and subsequent concentration of the reaction under vacuum/reduced pressure, purification by HPLC (eluent,a linear gradient of 20 min, solvent B component increased from 30% to 95%; the flow rate is 5.0 mL/min; the detection wavelength is 650 nm; eluent A: ddH with 0.1% (v/v) TFA₂O; eluent B: CH (CH)₃CN) gave the trifluoroacetate salt of compound 2f as a dark blue solid (19.0 mg, 36.0 μmol, 62% yield).

¹H NMR (400 MHz, Methanol-d ₄) δ 7.56 (d, J = 2.9 Hz, 2H), 7.37 (s, 1H), 7.15 (d, J = 9.6 Hz, 2H), 7.02 (s, 1H), 6.96 (dd, J = 9.7, 2.8 Hz, 2H), 3.91 (s, 3H), 3.89 – 3.80 (m, 16H), 2.00 (s, 3H), 0.62 (s, 3H), 0.61 (s, 3H)。

¹³C NMR (101 MHz, Methanol-d ₄) δ 168.80, 155.38, 151.58, 150.19, 142.65, 140.19, 129.95, 129.14, 125.71, 123.14, 122.63, 115.79, 114.15, 67.58, 57.05, 48.46, 18.52, -1.34, -1.49。

HRMS (ESI) theoretical value C₃₁H₃₈N₃O₃Si⁺ [M]⁺528.2677, actual value 528.2645.

(3) Synthesis of Compound 2 g:

to 1 mL of a solution of Compound 2f (15.0 mg, 28. mu. mol, 1.0 e.q.) in DMF at room temperature was added K₂CO₃(38.0 mg, 0.28 mmol, 10.0 e.q.), KI (2.4 mg, 14. mu. mol, 0.5 e.q.) and ethyl bromoacetate (46 mg, 0.28 mmol, 10.0 e.q.) the reaction was stirred at 95 ℃ for 12 h. After the reaction was completed, the reaction mixture was concentrated under vacuum/reduced pressure and purified by HPLC (eluent, 20 min linear gradient, solvent B fraction rising from 50% to 95%, flow rate 5.0 mL/min, detection wavelength 650 nm; eluent A: ddH containing 0.1% (v/v) TFA₂O; eluent B: CH (CH)₃CN) gave 2g of trifluoroacetate salt as a dark blue solid (13.3 mg, 18.9. mu. mol, 68% yield).

¹H NMR (400 MHz, Methanol-d ₄) δ 7.52 (d,J = 2.8 Hz, 2H), 7.26 (d,J = 9.7 Hz, 2H), 6.95 (dd,J = 9.7, 2.9 Hz, 2H), 6.71 (s, 1H), 6.69 (s, 1H), 4.24 (q,J = 7.1 Hz, 4H), 4.19 (s, 4H), 3.88 – 3.79 (m, 16H), 3.70 (s, 3H), 1.89 (s, 3H), 1.31 (t,J = 7.2 Hz, 6H), 0.60 (s, 3H), 0.59 (s, 3H)。

¹³C NMR (101 MHz, Methanol-d ₄) δ 173.25, 171.76, 155.38, 150.12, 149.88, 143.37, 140.82, 132.06, 129.96, 129.31, 122.28, 120.31, 115.58, 114.78, 67.59, 61.96, 56.59, 55.29, 48.36, 19.01, 14.64, -1.30, -1.52。

HRMS (ESI) theoretical value C₃₉H₅₀N₃O₇Si⁺ [M]⁺700.3413, calculated 700.3396.

(4) Synthesis of Compound PK Zinc FarRed-2:

2g of the compound (13.3 mg, 18.9. mu. mol) was dissolved in 1 mL of 12M hydrochloric acid solution and reacted under reflux for 30 min. After the reaction was complete, the reaction was concentrated under vacuum/reduced pressure and the crude product was purified by HPLC (eluent, 20 min linear gradient, solvent B fraction rising from 30% to 95%, flow rate 5.0 mL/min, detection wavelength 650 nm; eluent A: ddH containing 0.1% (v/v) TFA₂O; eluent B: CH (CH)₃CN) gave the trifluoroacetate salt of PK zincFarRed-2 as a dark blue solid (8.3 mg, 13. mu. mol, 68% yield).

¹H NMR (400 MHz, Methanol-d ₄) δ 7.51 (d, J = 2.9 Hz, 2H), 7.27 (d, J = 9.6 Hz, 2H), 6.95 (dd, J = 9.7, 2.9 Hz, 2H), 6.75 (s, 1H), 6.69 (s, 1H), 4.17 (s, 4H), 3.87 – 3.79 (m, 16H), 3.72 (s, 3H), 1.90 (s, 3H), 0.60 (s, 3H), 0.58 (s, 3H)。

¹³C NMR (101 MHz, Methanol-d ₄) δ 175.41, 171.84, 155.39, 150.12, 149.87, 143.42, 140.80, 132.06, 129.98, 129.34, 122.27, 120.11, 115.59, 114.81, 67.59, 56.49, 55.41, 48.36, 19.03, -1.30, -1.53。

HRMS (ESI) theoretical value C₃₅H₄₂N₃O₇Si⁺ [M]⁺644.2787, actual value 644.2761.

Example 8 Synthesis of Compound PK Zinc FarRed-3:

(1) synthesis of compound 3 d:

in 10 mL of 2-methoxy-3, 5-dimethylaniline (1.80 g, 11.9 mmol, 1.0 e.q.)₂Cl₂Slowly dropping 10 mL CH in the solution for 30 min₂Cl₂Diluted tetrabutylammonium bromide (5.74 g, 11.9 mmol, 1.0 e.q.), and the resulting mixture was stirred at room temperature for a further 15 min. After the reaction is finished, saturated NaHCO is used₃Neutralizing the reaction solution with an aqueous solution, and then using CH₂Cl₂The organic layer was extracted. The collected organic layer was washed with brine and then with Na₂SO₄Dried and then the solvent is evaporated. By column chromatography (elution solvent 5% CHCl)₃/Et₂O) purification of the crude product gave compound 3d as a pure colorless oil (1.75 g, 7.81 mmol, 66% yield).

¹H NMR (400 MHz, DMSO-d ₆) δ 6.55 (s, 1H), 4.92 (s, 2H), 3.57 (s, 3H), 2.21 (s, 3H), 2.17 (s, 3H)。

¹³C NMR (101 MHz, DMSO-d ₆) δ 143.10, 140.23, 132.60, 129.97, 114.49, 111.97, 58.85, 23.12, 16.39。

(2) Synthesis of compound 3 e:

compound 3d (1.13 g, 4.95 mmol, 1.0 e.q.), triethylamine (1.45 mL, 10.4 mmol, 10.0 e.q.) and 4- (dimethylamino) pyridine (60.0 mg, 0.50 mmol, 0.1 e.q.) were added at room temperatureDissolved in 20 mL CH₂Cl₂Then 5 mL of 1, 2-bis (chlorodimethylsilyl) ethane (1.17 g, 5.45 mmol, 1.1 e.q.) in CH₂Cl₂The solution was slowly dropped into the above mixture and stirred for 3 hours. After the reaction was completed, 30 mL of n-hexane was added to precipitate triethylamine chloride salt, which was then removed by filtration. The resulting goose-yellow oil was purified by column chromatography (alumina base, 5% ethyl acetate/petroleum ether) to give compound 3e (1.03 g, 2.77 mmol, 56% yield) as a colorless oil.

¹H NMR (400 MHz, Chloroform-d) δ 6.74 (s, 1H), 3.56 (s, 3H), 2.35 (s, 3H), 2.30 (s, 3H), 0.83 (s, 4H), 0.15 (s, 12H)。

¹³C NMR (101 MHz, Chloroform-d) δ 152.60, 139.36, 133.34, 132.01, 126.52, 120.55, 59.84, 23.78, 17.40, 9.19, 0.50。

(3) Synthesis of compound 3 f:

compound 3e (100 mg, 0.270 mmol, 4.7 e.q.) and anhydrous THF (3 mL) were added to a flask that was thermally dried and purged with argon. Cooling the solution to-20 deg.C, and rapidly injecting with syringenBuLi (1.6M in n-hexane 0.18 mL, 0.30 mmol, 5.2 e.q.), reaction stirred at-20 ℃ for 15 min. At the same temperature, 1 mL of a solution of silanthrone (25.0 mg, 57.8. mu. mol, 1.0 e.q.) in anhydrous THF was slowly added dropwise with a syringe and stirring was continued for 20 min. After the reaction was complete, the reaction was quenched by addition of 2M hydrochloric acid and warmed to room temperature, and saturated NaHCO was used₃After the reaction solution was neutralized with an aqueous solution, the organic layer was extracted with EtOAc. The organic layer was washed with brine, then Na₂SO₄Drying and subsequent concentration of the reaction mixture under vacuum/reduced pressure purification by HPLC (eluent, 20 min linear gradient, solvent B fraction rising from 30% to 95%; flow rate 5.0 mL/min; detection wavelength 650 nm; eluent A: ddH containing 0.1% (v/v) TFA)₂O; eluent B: CH (CH)₃CN) to give a dark blue solid compound 3fAcetate (20.4 mg, 37.6. mu. mol, 66% yield).

¹H NMR (400 MHz, Methanol-d ₄) δ 7.53 (d, J = 2.8 Hz, 2H), 7.20 (d, J = 9.7 Hz, 2H), 6.96 (dd, J = 9.7, 2.9 Hz, 2H), 6.93 (s, 1H), 3.86 – 3.82 (m, 16H), 3.80 (s, 3H), 1.91 (s, 3H), 1.89 (s, 3H), 0.61 (s, 3H), 0.60 (s, 3H)。

¹³C NMR (101 MHz, Methanol-d ₄) δ 170.52, 155.48, 150.06, 147.55, 141.97, 136.04, 133.93, 133.11, 130.72, 129.45, 122.41, 119.23, 116.00, 67.58, 60.81, 48.42, 19.48, 13.38, -1.52, -1.56。

HRMS (ESI) theoretical value C₃₂H₄₀N₃O₃Si⁺ [M]⁺542.2833, actual value 542.2814.

(4) Synthesis of Compound 3 g:

to 2 mL of a solution of Compound 3f (20.0 mg, 37. mu. mol, 1.0 e.q.) in DMF at room temperature was added K₂CO₃(50.0 mg, 0.37 mmol, 10.0 e.q.), KI (3.2. mg, 19. mu. mol, 0.5 e.q.) and ethyl bromoacetate (61 mg, 0.37 mmol, 10.0 e.q.) the reaction was stirred at 95 ℃ for 12 h. After the reaction was completed, the reaction mixture was concentrated under vacuum/reduced pressure and purified by HPLC (eluent, 20 min linear gradient, solvent B fraction rising from 50% to 95%, flow rate 5.0 mL/min, detection wavelength 650 nm; eluent A: ddH containing 0.1% (v/v) TFA₂O; eluent B: CH (CH)₃CN) gave 3g of trifluoroacetate salt as a dark blue solid compound (15.6 mg, 21.8 μmol, 59% yield).

¹H NMR (400 MHz, Methanol-d ₄) δ 7.52 (d, J = 2.9 Hz, 2H), 7.18 (d, J = 9.6 Hz, 2H), 6.95 (dd, J = 9.7, 2.9 Hz, 2H), 6.80 (s, 1H), 4.27 (s, 4H), 4.21 (q, J = 7.1 Hz, 4H), 3.86 – 3.80 (m, 16H), 3.76 (s, 3H), 1.88 (s, 3H), 1.88 (s, 3H), 1.28 (t, J = 7.1 Hz, 6H), 0.60 (s, 3H), 0.59 (s, 3H)。

¹³C NMR (101 MHz, Methanol-d ₄) δ 172.64, 171.16, 155.51, 150.05, 149.34, 143.70, 142.13, 133.46, 131.99, 131.21, 129.51, 122.35, 119.88, 115.96, 67.60, 61.88, 60.15, 54.55, 48.40, 19.69, 14.60, 13.46, -1.51, -1.57。

HRMS (ESI) theoretical value C₄₀H₅₂N₃O₇Si⁺ [M]⁺714.3569, actual value 715.3566.

(5) Synthesis of Compound PK Zinc FarRed-3:

3g of the compound (15.6 mg, 21.8. mu. mol) was dissolved in 2 mL of 12M hydrochloric acid solution and reacted under reflux for 30 min. After the reaction was complete, the reaction was concentrated under vacuum/reduced pressure and the crude product was purified by HPLC (eluent, 20 min linear gradient, solvent B fraction rising from 30% to 95%, flow rate 5.0 mL/min, detection wavelength 650 nm; eluent A: ddH containing 0.1% (v/v) TFA₂O; eluent B: CH (CH)₃CN) gave the trifluoroacetate salt of PK zincFarRed-3 as a dark blue solid (10.1 mg, 15.3. mu. mol, 68% yield).

¹H NMR (400 MHz, Methanol-d ₄) δ 7.51 (d,J = 2.9 Hz, 2H), 7.21 (d,J = 9.6 Hz, 2H), 6.96 (dd,J = 9.7, 2.8 Hz, 2H), 6.80 (s, 1H), 4.18 (s, 4H), 3.87 – 3.78 (m, 16H), 3.67 (s, 3H), 1.86 (s, 6H), 0.60 (s, 3H), 0.59 (s, 3H)。

¹³C NMR (101 MHz, Methanol-d ₄) δ 178.65, 171.59, 155.51, 150.00, 148.63, 143.05, 142.31, 132.53, 132.18, 131.33, 129.68, 122.25, 118.91, 116.01, 67.59, 60.74, 58.95, 48.39, 19.74, 13.62, -1.52, -1.54。

HRMS (ESI) theoretical value C₃₆H₄₄N₃O₇Si⁺ [M]⁺658.2943, trueThe desired value of 658.2947.

Example 9 synthesis of compound PK SiR Morpho:

in a flask that was thermally dried and purged with argon, compound 1h (76 mg, 0.270 mmol, 4.7 e.q.) and anhydrous THF (3 mL) were added. Cooling the solution to-20 deg.C, and rapidly injecting with syringenBuLi (1.6M in n-hexane 0.18 mL, 0.30 mmol, 5.2 e.q.), reaction stirred at-100 ℃ for 15 min. At the same temperature, 1 mL of a solution of silanthrone (25.0 mg, 57.8. mu. mol, 1.0 e.q.) in anhydrous THF was slowly added dropwise with a syringe and stirring was continued for 20 min. After the reaction was complete, the reaction was quenched by addition of 2M hydrochloric acid and warmed to room temperature, and saturated NaHCO was used₃After the reaction solution was neutralized with an aqueous solution, the organic layer was extracted with EtOAc. The organic layer was washed with brine, then Na₂SO₄Drying and subsequent concentration of the reaction mixture under vacuum/reduced pressure purification by HPLC (eluent, 20 min linear gradient, solvent B fraction rising from 30% to 95%; flow rate 5.0 mL/min; detection wavelength 650 nm; eluent A: ddH containing 0.1% (v/v) TFA)₂O; eluent B: CH (CH)₃CN) gave a dark blue solid compound PK SiR morphho as the trifluoroacetate salt (23.0 mg, 39.9 μmol, 70% yield).

¹H NMR (400 MHz, Methanol-d ₄) δ 7.88 (s, 2H), 7.57 (d, J = 2.8 Hz, 2H), 7.13 (d, J = 9.6 Hz, 2H), 6.97 (dd, J = 9.6, 2.7 Hz, 2H), 3.89 – 3.83 (m, 16H), 2.06 (s, 6H)。

EXAMPLE 10 Zinc ion probes PK Zinc Red 1-5 and PK Zinc FarRed 1-3 Zinc ion titration and dissociation constants ((K _d) And (4) a test method.

(1) Preparation of test solutions: various test solutions containing 1 μ M PK Zinc dye were prepared by dilution of "zero Zinc ion buffer" and "high concentration Zinc ion buffer" with each other. First, a zero-zinc ion solution containing 100 mM HEPES pH 7.4, 100 mM NaNO was prepared₃(ii) a HighConcentration Zinc ion buffer "contains 100 mM HEPES pH 7.4, 100 mM NaNO₃And 10 mM ZnSO₄. For buffer systems with free zinc ion concentrations greater than 100 nM, the two buffers were used directly in dilution with each other. For buffer systems with free zinc ion concentrations of less than 100 nM, 10 mM NTA was added to the solution to sequester high concentrations of zinc ions and the actual concentration of free zinc ions in the buffer system was calculated by the formula described in the literature (org. Lett., 2011, 13(17): 4558-4561).

(2) And (3) spectrum testing: the fluorescence spectra were measured at room temperature on Shimadzu RF-5301PC and the absorption spectra were measured at room temperature on UV-1780. The fluorescence spectra and absorption spectra of all zinc ion dyes described in the present invention were repeated 3 times at each zinc ion concentration using separately prepared solutions.

The fluorescence spectrum test results of different dyes at different zinc ion concentrations are shown in figures 1, 3,5, 7, 9, 11, 13 and 15 (the upper right inset shows the absorption spectrum), and the concentration titration test results are shown in figures 2, 4, 6, 8, 10, 12, 14 and 16.K _dIs according to the equationIs calculated. Wherein F is a given zinc ion concentrationFluorescence intensity of (1) F_minIs thatFluorescence intensity at = 0; f_maxIs the fluorescence intensity when the dye is saturated with zinc ions. The important photophysical properties of the compounds PK Zinc Red 1-5 and PK Zinc FarRed 1-3 of the invention are listed below in Table 1:

TABLE 1

Example 11 test method for observing insulin/zinc ion co-release on islet beta cells or ex vivo islet tissue using a zinc ion probe.

Islets were cultured on 35 mM glass-bottom confocal dishes (Cellvis, D35-14-1-N) for 24 hours, then washed twice and incubated in a medium containing 125 mM NaCl, 5.9 mM KCl, 2.4 mM CaCl₂、1.2 mM MgCl₂1 mM L-glutamine, 25 mM HEPES, 3 mM glucose, 0.1% bovine serum albumin, 10% glucose and 1. mu.M zinc ion dye in KRBB solution for about 15 minutes. Next, islets were stimulated with KRBB solution containing the indicated glucose concentration or/and drug and imaged. The fluorescence images 17, 18, 19, 20 were obtained by an inverted orinbus IX-81 laser confocal microscope equipped with a CSU-X1 rotating disk. The images are collected by a 60X (NA 1.35, Olympus) or 100X (NA 1.30, Olympus) oil mirror, the monochrome sampling rate is 2Hz, the double-channel sampling rate is 1Hz, and the four-color imaging sampling rate is 0.3 Hz.

Example 12 an assay for immunofluorescence imaging was performed using PK SiR Morpho and the commercial dyes Alexa 647 and Cy 5.

The dye and secondary antibody were co-incubated at a concentration ratio of 20:1 in PBS 7.4 buffer, the dye-labeled secondary antibody and free dye were separated using Sephadex G-25 column or desalting column and passed through A using nanodrop 2000₂₆₀/A₆₅₀And determining the average labeled number of the dyes of the secondary antibody. Then, immunofluorescent staining is carried out on the fixed Hela cells, and imaging is carried out on a high content living cell imaging system. The fluorescent signal is recorded by adopting a short-time shooting +1 s 650 nm laser irradiation mode, the calculation is carried out once every cycle, and the specific shooting time and the laser light intensity are as follows: PK SiR Morpho 100 ms, 50%; alexa 64750 ms, 50%; cy 520 ms, 50%. The recorded fluorescence signal is plotted against time in FIG. 21.