Chiral inosine 5 '-zinc diphosphate (II) metal coordination polymer as well as synthesis method and application thereof

Abstract

The invention discloses a chiral inosine 5 '-zinc diphosphate (II) metal coordination polymer as well as a synthesis method and anti-tumor application thereof. The polymer is prepared by taking inosine 5 '-disodium diphosphate (IDP) as a main ligand, 4, 4'-azpy as an auxiliary ligand and zinc (II) salt through a multi-component synergistic assembly strategy, regulating the pH value to be 4-6 and adopting a solution method or a solvothermal method. The molecular formula of the compound is C80H112N32O62P8Zn6, Zn (II) ions present hexa-coordinate distorted octahedron and tetracoordinate distorted tetrahedron configurations, and CD spectrum and Flack parameter (0.033 (11)) prove that the compound has a clear chiral structure. An in-vitro experiment shows that the polymer has remarkable proliferation inhibition activity on various tumor cell strains such as HepG2, SK-OV-3 / DDP (cis-platinum drug-resistant strain) and the like, ICM on HepG2 cells reaches 8.45 + / -0.36 mu M, and the polymer has extremely low toxicity (ICgt; 100 [mu] M), the drug resistance of cis-platinum can be overcome, the tumor selectivity is high, the safety is good, and an important material basis and an application prospect are provided for research and development of novel efficient anti-tumor drugs.

Description

Technical Field

[0001] This invention relates to the fields of coordination chemistry and pharmaceutical technology, specifically to a zinc(II) metal coordination polymer with chiral inosine 5'-bisphosphate disodium salt as the main ligand and 4,4'-azopyridine as the auxiliary ligand, its synthesis method, and its application. Background Technology

[0002] Nucleoside polyphosphate-metal complexes, as key molecular functional units in living systems, hold profound scientific significance for revealing the essence of biochemical processes, particularly their three-dimensional structure and dynamic structure-activity relationships. The function of biomolecules depends not only on their chemical composition but also on their three-dimensional spatial arrangement. Nucleoside polyphosphates form stable complexes through coordination with metal ions, directly influencing fundamental life activities such as enzyme catalysis, signal transduction, and genetic information transmission. However, a systematic understanding of the precise geometric parameters and conformational dynamics of these complexes remains lacking, severely hindering a deeper understanding of their mechanisms of action in metabolic networks. High-precision crystallographic studies to elucidate their structural characteristics will provide crucial theoretical support for clarifying the molecular basis of enzyme-metal-substrate interactions, holding significant scientific value for life sciences, synthetic biology, and drug design.

[0003] Chirality plays a crucial role in living systems, determining not only the recognition, interaction, and functional expression of biomolecules, but also profoundly influencing the design and development of drugs, especially metal-based drugs. In the field of metal drugs, the chiral coordination environment directly affects the selective binding to biological targets, cellular uptake efficiency, and metabolic pathways, thus determining the efficacy and toxicity of drugs. Therefore, constructing precisely structured, chiral-controllable metal coordination systems is of great significance for developing novel, highly efficient, low-toxicity, and targeted inorganic drugs. Using natural chiral nucleotide molecules as ligands and constructing chiral coordination polymers with biocompatible metal ions such as zinc not only mimics the structure and function of metal-nucleotide complexes in vivo, but also provides a new material platform for achieving chirality-dependent drug delivery, enzyme-mimicking catalysis, and intelligent drug release. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a novel metal coordination polymer of inosine 5'-zinc(II) diphosphate that can be characterized based on X-ray diffraction (XRD), as well as its synthesis method and application.

[0005] This invention provides a novel method for synthesizing crystalline nucleoside polyphosphates, namely a multi-component synergistic assembly strategy. For example, using inosine 5'-bisphosphate disodium salt as the main ligand and 4,4'-azopyridine as the auxiliary ligand, a crystalline zinc(II) inosine 5'-bisphosphate metal coordination polymer was obtained by pH control.

[0006] The molecular formula of inosine 5'-bisphosphate disodium salt is C5'-10 H 12 N4O 11 P2 2- Its molecular weight is 426.17 g / mol; its chemical structural formula is as follows:

[0007] In this molecular structure, the pH sensitivity of IDPs primarily stems from the ionization of its phosphate groups and the enol oxygen on its bases. Their dissociation constants (pKa) determine the molecule's net charge and morphology at different pH values. The ionization of the phosphate group is the most significant source of IDP pH sensitivity. The diphosphate group has three ionizable protons, and their dissociation occurs stepwise. When pKa1 ≈ 1.5–2.0, the first proton of the terminal phosphate group (β-phosphate) dissociates; when pKa2 ≈ 2.5–3.0, the first proton of the phosphate group closest to the ribose (α-phosphate) dissociates; and when pKa3 ≈ 6.5–7.5, this is the most critical pKa for the entire molecule, and it is generally considered to be the dissociation of the second phosphate group (usually the second proton of the β-phosphate). The ionization of the base (hypoxanthine) plays a secondary role in pH sensitivity; the N1-H group of hypoxanthine also exhibits weak acidity, with a pKa of 8.8–9.2. The pH sensitivity of IDPs is inseparable from their coordination activity. pH precisely regulates the charge, three-dimensional conformation, and binding ability and mode of IDPs with metal ions by controlling the ionization state of IDP phosphate groups and bases, thus profoundly affecting their functions in biochemistry and materials science.

[0008] The molecular formula of 4,4'-azopyridine is C 10 H8N4, with a molecular weight of 184.20 g / mol, has the following chemical structure: its coordination ability primarily derives from its pyridine nitrogen atom. When pKa1 ≈ 3-4, a proton is typically added to the nitrogen atom of the pyridine ring. At higher pH values, the pyridine nitrogen is not protonated, leaving lone pair electrons available, resulting in strong coordination ability. The molecule can act as a bridging ligand to construct extended structures.

[0009]

[0010] The inosine 5'-zinc(II) diphosphate metal coordination polymer of the present invention has the following chemical structural formula:

[0011] This coordination polymer uses divalent zinc ions (Zn(II)) as the central metal ion, with inosine 5′-bisphosphate disodium salt (IDP) as the main ligand. Both the nucleoside base and phosphate group can participate in coordination. The Zn(II) ion can exhibit two typical coordination configurations: a six-coordinate distorted octahedral geometry and a four-coordinate distorted tetrahedral geometry. In the coordination environment, the coordinating atoms of the central metal ion mainly originate from the oxygen atom in the bisphosphate group, the nitrogen atom in the base, the coordinated water molecule, and the nitrogen atom of the auxiliary ligand 4,4'-azopyridine (azpy). Notably, the metal anion moiety does not participate in coordination in this structure. The entire coordination structure is extended and constructed into a long-range ordered three-dimensional network framework through the bridging function of 4,4'-azopyridine.

[0012] The synthetic route for the inosine 5'-zinc(II) diphosphate metal coordination polymer described in this invention is as follows: Figure 1 As shown. The synthesis method of the above inosine 5'-zinc(II) diphosphate metal coordination polymer is as follows: equal amounts of inosine 5'-diphosphate disodium salt, 4,4'-azopyridine and zinc(II) metal salt are weighed, dissolved in a polar solvent, and a coordination reaction is carried out under certain pH conditions (heating or reflux) to obtain the target product.

[0013] Specifically, the synthesis can be carried out using either a solution method or a solvothermal method.

[0014] When using a solution-based synthesis, the specific steps include: 1) Weigh out equal amounts of inosine 5'-bisphosphate disodium salt and zinc acetate (II), dissolve them in a polar solvent to obtain a mixed solution, and stir at room temperature for 5-10 min; 2) Add an equal amount of 4,4'-azopyridine to the obtained mixed solution and place it in a reflux reflux apparatus. Adjust the pH to 4-6 and react at 55-60°C to the reflux temperature range of polar solvents until complete. 3) After the reaction, the solution is concentrated to remove most of the solvent, allowed to stand, precipitate, and the solid is separated to obtain the crystalline inosine 5'-zinc diphosphate (II) ternary coordination polymer.

[0015] In this method, the polar solvent is generally pure water, or a combination of water and one or more of the organic solvents methanol, ethanol, acetonitrile, and DMSO. The concentration of methanol or ethanol is 20-50% by volume, preferably 20-30% by volume. When the polar solvent is a mixture of water and two or more of the aforementioned organic solvents, the ratio of the organic solvents can be arbitrary. The amount of polar solvent used can be determined as needed. Typically, 1 mmol of inosine 5'-bisphosphate disodium is dissolved in 20-40 mL of water (water only); 1 mmol of 4,4'-azopyridine and 1 mmol of zinc(II) metal salt can be dissolved in 10-20 mL of water or an organic polar solvent, respectively. In the specific dissolution steps, inosine 5'-bisphosphate disodium salt and zinc acetate (II) can be dissolved separately in a polar solvent, water, while 4,4'-azopyridine can be dissolved in an organic solvent, and then the two solutions can be mixed together for reaction. Alternatively, inosine 5'-bisphosphate disodium salt and zinc acetate can be mixed and then dissolved in a polar solvent, water, while 4,4'-azopyridine can be dissolved in an organic solvent, and then the two solutions can be mixed together for reaction. In this method, if a polar solvent, water, is used to dissolve 4,4'-azopyridine, an appropriate amount of co-solvent can be added during dissolution (or before reflux of the mixed solution). The co-solvent is usually methanol or ethanol, and the amount added can be selected as needed, specifically calculated as 5-10 mL of methanol or ethanol for 1 mmol of 4,4'-azopyridine.

[0016] In steps 1) and 2) of this method, inosine 5'-bisphosphate disodium salt can react with zinc acetate (II) first, and then 4,4'-azopyridine can be added to carry out step 3); or 4,4'-azopyridine can react with zinc acetate (II) first, and then inosine 5'-bisphosphate disodium salt can be added to carry out step 3).

[0017] In step 1) of this method, the selected zinc(II) metal salt can be any other anionic zinc(II) salt, such as zinc(II) sulfate, zinc(II) chloride, zinc(II) nitrate, zinc(II) perchlorate, etc., in addition to zinc(II) acetate.

[0018] In step 2) of this method, whether the reflux reaction is complete can be detected by thin-layer chromatography. Under the above-mentioned limiting conditions, the reflux reaction takes about 0.5 to 1 hour to complete.

[0019] In step 3) of this method, concentrating to remove most of the solvent usually means concentrating to remove 80-95% of the amount of polar solvent added.

[0020] When synthesized using a solvothermal method, the specific steps include: 1) Weigh out equal amounts of 5'-bisphosphate disodium salt, zinc acetate and 4,4'-azopyridine, dissolve them in a polar solvent to obtain a mixed solution, and adjust the pH to 4-6; 2) The resulting mixed solution is placed in a container, frozen with liquid nitrogen, then evacuated to a vacuum, sealed, and then reacted at 60-80℃ until complete to obtain the crystalline inosine 5'-bisphosphate ternary polymer.

[0021] In this method, the polar solvent is generally pure water, or a combination of water and one or more of the organic solvents methanol, ethanol, acetonitrile, and DMSO. The concentration of methanol or ethanol is 20-50% by volume, preferably 20-30% by volume. When the polar solvent is a mixture of water and two or more of the aforementioned organic solvents, the ratio of the organic solvents can be arbitrary. The amount of polar solvent used can be determined as needed. Typically, 1 mmol of inosine 5'-bisphosphate disodium is dissolved in 20-40 mL of water (water only); 1 mmol of 4,4'-azopyridine and 1 mmol of zinc(II) metal salt can be dissolved in 10-20 mL of water or a polar organic solvent, respectively. In the specific dissolution steps, inosine 5'-bisphosphate disodium salt and zinc acetate (II) can be dissolved separately in a polar solvent, water, while 4,4'-azopyridine can be dissolved in an organic solvent, and then the two solutions can be mixed together for reaction. Alternatively, inosine 5'-bisphosphate disodium salt and zinc acetate can be mixed and then dissolved in a polar solvent, water, while 4,4'-azopyridine can be dissolved in an organic solvent, and then the two solutions can be mixed together for reaction. In this method, if a polar solvent, water, is used to dissolve 4,4'-azopyridine, an appropriate amount of co-solvent can be added during dissolution (or before reflux of the mixed solution). The co-solvent is usually methanol or ethanol, and the amount added can be selected as needed, specifically calculated as 10-20 mL of methanol or ethanol for 1 mmol of 4,4'-azopyridine.

[0022] In step 2) of the above solvothermal synthesis method, the container is usually a thick-walled glass tube, and the reaction takes about 12 to 24 hours to complete at 60 to 80°C.

[0023] The raw materials involved in the above two methods, inosine 5'-bisphosphate disodium salt, zinc acetate, and 4,4'-azopyridine, are all commercially available pharmaceutical products. Inosine 5'-bisphosphate disodium salt CAS number 54735-61-4, abbreviated as IDP in this application; 4,4'-azopyridine CAS number 2632-99-7, abbreviated as azpy in this application; zinc acetate CAS number 5970-45-6. All of the above raw materials were purchased from Adamas Chemical Reagents. The inosine 5'-bisphosphate zinc(II) coordination polymer synthesized from the above three raw materials is abbreviated as IDP-Zn(II)-azpy in this application.

[0024] The present invention also includes the chiral structure of the above-mentioned inosine 5'-zinc(II) diphosphate coordination polymer at the structural level.

[0025] The present invention also includes the application of the above-mentioned inosine 5'-zinc(II) diphosphate metal coordination polymer in the preparation of antitumor drugs.

[0026] The present invention also includes an antitumor drug prepared using the above-mentioned inosine 5'-zinc(II) diphosphate metal coordination polymer as the active ingredient.

[0027] Compared with existing technologies, this invention provides a novel crystalline inosine 5'-zinc(II) diphosphate coordination polymer and its synthesis method. Furthermore, by combining solid-liquid circular dichroism (CD) spectroscopy, the chiral induction, transfer, and amplification processes in this coordination polymer were studied from a crystallographic visualization perspective. Its inhibitory activity against the proliferation of human tumor cell lines such as HepG2, SK-OV-3, SK-OV-3 / DDP, BEL-7404, and T-24 was investigated. The results show that it possesses significant in vitro antitumor activity and has good potential pharmaceutical value, making it promising for the preparation of various antitumor drugs. Attached Figure Description

[0028] Figure 1 : Synthetic route diagram of metal coordination polymers of this invention; Figure 2 X-ray diffraction pattern of single crystal coordination polymer in this embodiment; Figure 3 The infrared spectrum of the coordination polymer in this embodiment; Figure 4 Thermogravimetric diagram of the coordination polymer in this embodiment; Figure 5 X-ray powder diffraction pattern of the coordination polymer in this embodiment. Detailed Implementation

[0029] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited to these embodiments.

[0030] Examples of solution synthesis of the target product: Example 1

[0031] Weigh out equal amounts of inosine 5'-bisphosphate disodium salt and zinc acetate, 0.05 mmol each, and dissolve them separately in 15 mL of pure water. Mix the two solutions and stir at room temperature for 5-10 min. Dissolve an equal amount of 4,4'-azopyridine in 10 mL of ethanol and add it to the above mixed solution. Adjust the pH to 4-6 and react at 60 °C for 0.5-1 hour. After concentrating and evaporating to remove most of the solvent (80% of the amount of solvent added), cool to room temperature, let stand, and a reddish-brown solid will precipitate. Separate the solid, dry it, and obtain a reddish-brown solid product (yield 65%).

[0032] The obtained reddish-brown solid product was analyzed by infrared spectroscopy, thermogravimetric analysis, single-crystal X-ray diffraction, and powder X-ray diffraction. The specific spectral characteristics are as follows: (1) Single-crystal X-ray diffraction pattern, the spectrum is as follows Figure 2 As shown.

[0033] (2) Infrared spectrum, its spectrum is as follows Figure 3 As shown, IR(KBr):3405, 1696, 1607, 1420, 1209, 1109, 1053, 998, 938, 847, 789,716, 647, 604, 570, 535 cm −1 .

[0034] (3) Thermogravimetric diagram, its spectrum is as follows Figure 4 As shown.

[0035] (4) X-ray powder diffraction pattern of the complex, such as Figure 5 As shown.

[0036] Therefore, it can be determined that the obtained reddish-brown solid product is a ternary coordination polymer of inosine 5'-bisphosphate-zinc(II)-4,4'-azopyridine, with the molecular formula C 80 H 112 N 32 O 62 P8Zn6 has a molecular weight of 3144.02 g / mol. In this ternary coordination polymer, the Zn(II) ion can exhibit two typical coordination configurations: a six-coordinate distorted octahedral geometry and a four-coordinate distorted tetrahedral geometry; its crystallographic parameters are detailed in Table 1-2, and its chemical structural formula is as follows:

[0037] Table 1: Crystallographic data of IDP-Zn(II)-azpy complexes

[0038] Table 2: Partial bond lengths (Å) and bond angles (°) of IDP-Zn(Ⅱ)-azpy complexes

[0039] Example 2 Weigh out equal amounts of inosine 5'-bisphosphate disodium salt and zinc acetate, 0.05 mmol each, mix them and dissolve them in 30 mL of pure water. Dissolve an equal amount of 4,4'-azopyridine in 10 mL of 100% (volume) ethanol. Mix the two solutions and adjust the pH to 4-6. React the resulting mixed solution at 60 °C for 0.5-1 hour. After concentrating and evaporating to remove most of the solvent (85% of the amount of solvent added), cool to room temperature, let stand, and a reddish-brown solid will precipitate. Separate the solid, dry it, and obtain a reddish-brown solid product with a yield of 60%.

[0040] Example 3 Weigh out equal amounts of inosine 5'-bisphosphate disodium salt and zinc acetate, 0.05 mmol each, and dissolve them separately in 15 mL of pure water. Mix the two solutions and stir at room temperature for 5-10 min. Dissolve an equal amount of 4,4'-azopyridine in 10 mL of 100% (volume) methanol and add the above mixed solution. Adjust the pH to 4-6 and react at 60 °C for 0.5-1 hour. After concentrating and evaporating to remove most of the solvent (80% of the amount of solvent added), cool to room temperature, let stand, and a reddish-brown solid will precipitate. Separate the solid, dry it, and obtain a reddish-brown solid product (yield 55%).

[0041] Example 4 Weigh out equal amounts of inosine 5'-bisphosphate disodium salt and zinc acetate, 0.05 mmol each, and dissolve them separately in 15 mL of pure water. Mix the two solutions and stir at room temperature for 5-10 min. Dissolve equal amounts of 4,4'-azopyridine in 10 mL of a mixture of 95% (volume) methanol and 95% (volume) ethanol (methanol to ethanol volume ratio of 1:1). Add the above mixed solution and adjust the pH to 4-6. React at 60 °C for 0.5-1 hour. After concentrating and evaporating to remove most of the solvent (80% of the solvent added), cool to room temperature, let stand, and a reddish-brown solid precipitates. Separate the solid, dry it, and obtain the reddish-brown solid product (yield 55%).

[0042] Example 5 Weigh out equal amounts of 4,4'-azopyridine and zinc nitrate, 0.05 mmol each, and dissolve them separately in 10 mL of ethanol and 15 mL of pure water. Mix the two solutions and stir at room temperature for 5-10 min. Dissolve an equal amount of inosine 5'-bisphosphate disodium salt in 15 mL of pure water and add the above mixed solution. Adjust the pH to 4-6 and react at 60 °C for 0.5-1 hour. After concentrating and evaporating to remove most of the solvent (80% of the amount of solvent added), cool to room temperature, let stand, and a reddish-brown solid will precipitate. Separate the solid, dry it, and obtain the reddish-brown solid product (yield 75%).

[0043] Example 6 Weigh out equal amounts of inosine 5'-bisphosphate disodium salt and zinc nitrate, 0.05 mmol each, and dissolve them separately in 15 mL of pure water. Mix the two solutions and stir at room temperature for 5-10 min. Dissolve an equal amount of 4,4'-azopyridine in 10 mL of 100% (volume) ethanol and add the above mixed solution. Adjust the pH to 4-6 and react at 60 °C for 0.5-1 hour. After concentrating and evaporating to remove most of the solvent (80% of the amount of solvent added), cool to room temperature, let stand, and a reddish-brown solid will precipitate. Separate the solid, dry it, and obtain the reddish-brown solid product (yield 65%).

[0044] Example 7 Weigh out equal amounts of inosine 5'-bisphosphate disodium salt, 4,4'-azopyridine, and zinc acetate, 0.02 mmol each, and add them to a 20 cm Pyrex thick-walled glass tube sealed at one end. Then add 10 mL of a mixture of 80% (volume) pure water and 20% (volume) ethanol (volume ratio of pure water to ethanol is 4:1), adjust the pH to 4-6, seal the open end under vacuum, mix well, and place in an oven at 60°C for 24 hours to obtain a reddish-brown product (crystals) with a yield of 85%. Infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, single-crystal X-ray diffraction, and ultraviolet spectroscopy analysis of the reddish-brown product obtained in this example confirmed that the obtained reddish-brown solid product is a ternary coordination polymer of inosine 5'-bisphosphate-zinc(II)-4,4'-azopyridine.

[0045] Example 8 Weigh out equal amounts of inosine 5'-bisphosphate disodium salt, 4,4'-azopyridine, and zinc acetate, 0.02 mmol each, and add them to a 20 cm Pyrex thick-walled glass tube sealed at one end. Then add 10 mL of a mixture of 20% (volume) pure water and 80% (volume) methanol (volume ratio of pure water to methanol is 1:4) and adjust the pH to 4-6. Seal the open end of the tube under vacuum, mix well, and place it in an oven at 60 °C for 24 hours to obtain a reddish-brown product (crystals) with a yield of 85%.

[0046] Example 9 Weigh out equal amounts of inosine 5'-bisphosphate disodium salt, 4,4'-azopyridine, and zinc nitrate, 0.02 mmol each, and add them to a 20 cm Pyrex thick-walled glass tube sealed at one end. Then add 10 mL of a mixture of 80% (volume) pure water and 20% (volume) ethanol (volume ratio of pure water to ethanol is 4:1) and adjust the pH to 4-6. Seal the open end of the tube under vacuum, mix well, and place it in an oven at 60 °C for 24 hours to obtain a reddish-brown product (crystals) with a yield of 85%.

[0047] Example 10 This patent explores the chirality (including chiral induction, transfer amplification, etc.) in the structure of coordination compounds by combining crystal structure analysis of coordination compounds with solid-state and liquid circular dichroism (CD) spectroscopy.

[0048] Solid-state circular dichroism (CD) spectroscopy: The sample and potassium bromide were thoroughly ground and compressed into a tablet at a ratio of 1:200 to ensure uniform and transparent tableting; Solution-state circular dichroism (CD) spectroscopy: A 2.5×10⁻⁶ tablet was prepared using water as the solvent. ‒5 The sample concentration was mol / L. During the test, the voltage of the photomultiplier tube (HT) was generally less than 700 V to ensure that the sample concentration was appropriate, the CD signal was accurate, the scan rate was 100 nm / min, and the response time was 1 s. During the test, a constant current of N2 was introduced to keep the test temperature stable within the range of 25-30°C.

[0049] Its solution-state circular dichroism (CD) spectrum exhibits a positive characteristic peak of +2.32±0.2 mdeg at 226 nm and a negative characteristic peak of -2.61±0.2 mdeg at 268 nm; its solid-state circular dichroism (CD) spectrum exhibits a negative characteristic peak of -0.41±0.02 mdeg at 214 nm, a broad positive characteristic peak of +0.62±0.02 mdeg in the range of 246-271 nm, and a broad positive characteristic peak of +0.40±0.02 mdeg in the range of 301-362 nm; the Flack parameter characterized by single-crystal X-ray diffraction is 0.033 (11).

[0050] To intuitively and deeply understand the transfer of chirality from the molecular to the supramolecular level, the following structural information levels need to be considered. The first level of structural information involves the coordination geometry of the metal ions in the coordination environment. In coordination polymers, this represents nodes in a multidimensional topological structure; in discrete coordination compounds (mononuclear or multinuclear), it represents the molecular structure of the complex. This level of structural information is fundamental for both coordination polymers and discrete coordination compounds, and the corresponding chirality is molecular chirality. The second level of structural information involves the assembly of molecular building blocks into one-dimensional helical structures through weak intermolecular forces in a specific spatial arrangement, and the assembly of single-stranded helical structures into two- or three-dimensional structures through non-covalent interactions. The chirality corresponding to this level is supramolecular chirality. Furthermore, conjugated planar molecules possess certain π-π stacking interaction capabilities. These molecules can also produce different chirities through different π-π stacking patterns. An ABAB arrangement will form an achiral assembly, while an ABCDEF arrangement will form a chiral assembly. In nucleotide coordination supramolecular systems, hydrogen bonding is typically the most significant interaction, followed by base pair complementarity, while π-π stacking interactions are relatively minor. In this project, the introduction of the co-ligand 4,4'-azopyridine may enhance the contribution of π-π stacking interactions to supramolecular assembly. The final level of structural information involves the macroscopic morphology of the material. Advanced nanoscale characterization techniques will be employed to study and analyze the morphology of the material, which is essential for a complete understanding of the transfer of molecular chirality to the chirality of nanoscale supramolecular assemblies.

[0051] Example 11 To fully illustrate the use of the inosine 5'-bisphosphate-zinc(II)-4,4'-azopyridine polymer (hereinafter referred to as IDP-Zn(II)-azpy) in pharmaceutical applications, the applicant conducted antitumor activity experiments on it.

[0052] I. Experiments on the inhibitory activity of IDP-Zn(II)-azpy on the proliferation of various human tumor cell lines: 1. Cell lines and cell culture This experiment used SK-OV-3 (human ovarian adenocarcinoma cell line), T24 (human bladder cancer cell line), OS-RC-2 (human renal cancer cell line), NCI-H-460 (human large cell lung cancer cell line), Hep G2 (human liver cancer cell line), MGC803 (human gastric cancer cell line), etc.

[0053] All cell lines were cultured in DMEM medium containing a mixture of 10% FBS, bovine fetal serum, and 1% penicillin and streptomycin, and incubated at 37°C in a 5% CO2 incubator. The OS-RC-2 cell line was cultured in RPMI-1640 medium containing a mixture of 10% FBS, bovine fetal serum, and 1% penicillin and streptomycin, with all other conditions being the same.

[0054] 2. Initial screening After each cell line adhered to the 96-well plates, the solution was replaced with serum-free DMEM. For OS-RC-2, RPMI-1640 was used. Drugs were added 12 to 18 hours later. The compounds used in this experiment (all with a purity ≥95%) were prepared to an intermediate concentration of 200 μmol / L. 20 μL of this intermediate concentration compound solution was added to a 96-well plate containing 180 μL of cell culture, resulting in a final compound concentration of 20 μmol / L. The final DMSO concentration was ≤1%. The inhibitory effect of the compounds on tumor cell growth at this concentration was tested. Cells with an inhibition rate greater than 50% and exhibiting morphological changes consistent with inhibited (or damaged) cells under a light microscope (e.g., cell shrinkage, fragmentation, floating, etc.) were considered effective in the initial screening, and the inhibition rate was calculated.

[0055] 3. Cell growth inhibition assay (MTT method) The test compound was dissolved in DMSO and diluted with serum-free medium to intermediate concentrations of 200 μmol / L, 100 μmol / L, 50 μmol / L, 25 μmol / L, and 12.5 μmol / L. The solution was then filtered through a microporous membrane with a diameter of d = 0.22 μm for sterilization and stored at 4°C.

[0056] A series of tumor cell lines in the logarithmic growth phase were seeded at 180 μL per well in 96-well plates, with 200 μL of PBS (phosphate-buffered saline) added to the edge wells, resulting in a cell concentration of approximately 1 × 10⁻⁶ cells / well. 4 / well, cultured for 12 hours, after cell attachment, replaced with serum-free DMEM, OS-RC-2 replaced with RPMI-1640, intermediate concentration of compound solution for 12 to 18 hours, each compound concentration was set up in 5 replicates, the final concentration of DMSO was ≤1%, and corresponding negative control group (culture medium containing only cells and an equal amount of DMSO, no drug) and blank control group (culture medium containing only an equal amount of drug, no cells) were also set up in 5 replicates for each group, and the drug treatment time was 48 h. Four hours before the end of culture, 10 µL of MTT (5 mg / mL PBS) was added to each well. After culturing for another 4 hours, the culture medium was discarded, and 100 µL of DMSO was added to each well. The plates were shaken for 7 minutes to fully dissolve the crystals. The blank control group was zeroed. The absorbance (A) after removing the background light absorption value was measured using a microplate reader at dual wavelengths of 570 nm / 630 nm. The inhibition rate of the drug on tumor cell growth was calculated. Then, the IC50 of IDP-Zn(II)-azpy against the above-mentioned tumor cell lines was calculated using the Bliss method. 50 The values ​​are shown in Table 3.

[0057]

[0058] Table 3: IC50 of Polymer 1 against different tumor cell lines 50 Value (μM)

[0059] Note: "-" in the table indicates that the compound did not show growth inhibitory activity against the cell line.

[0060] IDP-Zn(II)-azpy has shown certain drug development potential and value. It exhibits inhibitory activity in various tumor cell lines, especially showing relatively high sensitivity (IC50) against HepG2 liver cancer cells. 50 = 8.45±0.36 μM), and showed low toxicity to normal hepatocytes HL-7702 (IC50 = 8.45±0.36 μM). 50 The concentration >100 μM indicates that the compound possesses certain tumor selectivity. Notably, IDP-Zn(Ⅱ)-azpy remained active (IC50 >100 μM) in cisplatin-resistant SK-OV-3 / DDP cells. 50 =13.40±2.03 μM), which is significantly better than the effect of cisplatin in this cell line (64.57±1.63 μM), suggesting that it may have the potential to overcome cisplatin resistance, which provides an important basis for its application in the treatment of drug-resistant tumors.

[0061] In summary, the inosine 5'-zinc(II) diphosphate coordination polymer of the present invention exhibits significant in vitro antitumor activity and toxicity selectivity, and helps to overcome tumor cell drug resistance, thus possessing good potential pharmaceutical value and promising for use in the preparation of various antitumor drugs.

Claims

1. A metal-coordinated polymer of inosine 5'-zinc(II) diphosphate, the chemical structure of which is shown below: The molecular formula of this coordination polymer is C2 80 H 112 N 32 O 62 P8Zn6 has a molecular weight of 3144.02 g / mol. It has Zn(II) ions as the central metal ion and inosine 5'-bisphosphate disodium salt as the main ligand. Both the nucleoside base and the phosphate group can participate in coordination. Zn(II) ions exhibit two typical coordination configurations: six-coordinate aberrant octahedral geometry and four-coordinate aberrant tetrahedral geometry. In the coordination environment, the coordinating atoms of the central metal ion come from the oxygen atom in the bisphosphate group, the nitrogen atom in the base, the coordinated water molecule, and the nitrogen atom of the auxiliary ligand 4,4'-azopyridine.

2. The inosine 5'-zinc(II) diphosphate metal coordination polymer as described in claim 1, characterized in that: The coordination polymer has a chiral structure, and its solution-state circular dichroism (CD) spectrum shows a positive characteristic peak of +2.32±0.2 mdeg at 226 nm and a negative characteristic peak of -2.61±0.2 mdeg at 268 nm; its solid-state circular dichroism (CD) spectrum shows a negative characteristic peak of -0.41±0.02 mdeg at 214 nm, a broad positive characteristic peak of +0.62±0.02 mdeg at 246-271 nm, and a broad positive characteristic peak of +0.40±0.02 mdeg at 301-362 nm; the Flack parameter characterized by single-crystal X-ray diffraction is 0.033 (11).

3. The method for synthesizing the inosine 5'-zinc(II) diphosphate metal coordination polymer according to claim 1, characterized in that... Includes the following steps: 1) Weigh out equal amounts of inosine 5'-bisphosphate disodium salt and zinc acetate, dissolve them in a polar solvent, water, and stir at room temperature for 5-10 minutes to obtain a mixed solution; 2) Dissolve an equal amount of 4,4'-azopyridine in an organic polar solvent, combine it with the above mixture, adjust the pH to 4-6, place it in a reflux apparatus, and react it at 60°C to the reflux temperature of the polar solvent for 0.5-1 h until complete (monitored by thin-layer chromatography). 3) After the reaction, the solution is concentrated to remove 80%-95% of the solvent, allowed to stand, and the solid is separated to obtain the inosine 5'-zinc(II) diphosphate metal coordination polymer.

4. The method for synthesizing the inosine 5'-zinc(II) diphosphate metal coordination polymer according to claim 3, characterized in that: Zinc acetate (II) can be replaced by other anionic zinc (II) salts, such as zinc sulfate, zinc nitrate, zinc chloride, and zinc perchlorate.

5. The method for synthesizing the inosine 5'-zinc(II) diphosphate metal coordination polymer according to claim 3, characterized in that: Inosine 5'-bisphosphate disodium salt can be reacted with zinc(II) salt first, and then 4,4'-azopyridine can be added; alternatively, 4,4'-azopyridine can be reacted with zinc(II) salt first, and then inosine 5'-bisphosphate disodium salt can be added.

6. The method for synthesizing the inosine 5'-zinc(II) diphosphate metal coordination polymer according to claim 1, characterized in that... Includes the following steps: 1) Weigh out equal amounts of inosine 5'-bisphosphate disodium salt, zinc acetate (II) and 4,4'-azopyridine, dissolve them in a polar solvent to obtain a mixed solution, and adjust the pH to 4-6; 2) The resulting mixed solution was placed in a thick-walled glass tube, frozen with liquid nitrogen, and then evacuated to a vacuum. The tube was then sealed and reacted at 60–80 °C for 12–24 h until complete, thus obtaining the inosine 5'-zinc(II) diphosphate metal coordination polymer.

7. The method for synthesizing the inosine 5'-zinc(II) diphosphate metal coordination polymer according to claim 3 or 6, characterized in that: The polar solvent is one of water and methanol, ethanol, acetonitrile organic solvents, or any combination of two or more of them; wherein the concentration of methanol or ethanol is 20-50% by volume, preferably 20-30% by volume.

8. The use of the inosine 5'-zinc(II) diphosphate metal coordination polymer as described in claim 1 in the preparation of antitumor drugs.

9. An antitumor drug prepared using the inosine 5'-zinc(II) diphosphate metal coordination polymer as described in claim 1 as the active ingredient.

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