Preparation method and application of betulinic acid silicon phthalocyanine

Abstract

The present invention discloses a preparation method and application of betulinic acid silicon phthalocyanine. The method uses betulinic acid as a ligand to synthesize a betulinic acid axially substituted silicon phthalocyanine complex. The method comprises the following steps: (1) reflux filtering white dichlorosilicon phthalocyanine, potassium carbonate and betulinic acid in a toluene solution; (2) purifying the crude product with an eluent on a silica gel column and drying it to obtain betulinic acid silicon phthalocyanine. The Bai‑SiPc prepared by this method has good biocompatibility and strong phototoxicity, and is a type of photosensitizer with excellent photodynamic therapy performance.

Description

Technical Field

[0001] The present invention belongs to the field of complexes, and in particular to a method for preparing a betulinic acid axially substituted silicon phthalocyanine complex. The complex is used as an anticancer photosensitizer and is applied in photodynamic therapy for tumors. Background Art

[0002] Photodynamic therapy (PDT) holds a crucial position in cancer treatment and is a novel approach for treating cancer, HIV, and diseases such as wet macular degeneration. Key to PDT is the photosensitizer. Phthalocyanine complexes are considered promising photosensitizers due to their high singlet oxygen quantum yield, stable structure, easy modification, maximum absorption wavelength around 670 nm, easy penetration into the red region of human tissue, and ease of preparation. However, due to their poor water solubility, phthalocyanines tend to aggregate in physiological environments, affecting their singlet oxygen generation rate and, consequently, their effectiveness in PDT, limiting their application in PDT. Another drawback of phthalocyanines is their limited ability to target and enrich tumor cells. This limited ability reduces their uptake by tumor cells and can lead to toxic side effects in normal tissues, significantly limiting their application in PDT.

[0003] Betulic acid is a lupane-type triterpenoid with promising pharmacological properties, including anticancer, antioxidant, anti-inflammatory, anti-atherosclerotic, antiviral, hepatoprotective, and immunomodulatory activities as a natural medicine. Betulic acid inhibits tumorigenesis through apoptosis, autophagy, and metastasis pathways in various cancer types. Incorporating betulic acid into the axial position of silicon phthalocyanine enhances its solubility and improves the efficacy of photodynamic therapy.

[0004] Therefore, this paper introduces the active structural group of the natural drug betulinic acid into silicon phthalocyanine to synthesize natural drug groups to replace silicon phthalocyanine, giving silicon phthalocyanine solubility and high biological activity. Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation method and application of betulinic acid silicon phthalocyanine.

[0006] The object of the present invention is achieved in this way. The betulic acid axially substituted silicon phthalocyanine complex of the present invention is a compound with the following structure:

[0007]

[0008] The preparation method of betulinic acid silicon phthalocyanine of the present invention is characterized by comprising the following steps: the betulinic acid silicon phthalocyanine is prepared by refluxing dichlorosilicon phthalocyanine, potassium carbonate and betulinic acid in a toluene solution.

[0009] The preparation method of betulinic acid silicon phthalocyanine is characterized in that: the betulinic acid silicon phthalocyanine is prepared by using dichlorosilicon phthalocyanine, potassium carbonate and betulinic acid in a toluene solution under stirring and reflux at 135°C for 48 hours, after the reaction is completed and cooled to room temperature, filtering and washing to obtain a crude product, and then using petroleum ether and ethanol to purify it on a silica gel column three times, and drying to obtain a solid blue-green product.

[0010] The betulinic acid silicon phthalocyanine of the present invention or the betulinic acid silicon phthalocyanine prepared by the preparation method is used as a mitochondrial targeting marker and a phthalocyanine photosensitizer for fluorescence imaging-guided photodynamic therapy.

[0011] Specifically, the present invention describes a method for preparing a mitochondrial-targeted betulinic acid-based axially substituted silicon phthalocyanine complex. This method involves introducing betulinic acid into the axial position of silicon phthalocyanine to synthesize a novel betulinic acid-substituted silicon phthalocyanine complex (Bai-SiPc). Betulinic acid is a lupane-type triterpenoid with promising pharmacological properties, including anticancer, antioxidant, anti-inflammatory, anti-atherosclerotic, antiviral, hepatoprotective, and immunomodulatory activities. Furthermore, betulinic acid inhibits tumorigenesis through apoptosis, autophagy, and metastasis pathways in various cancer types. Therefore, this method for preparing betulinic acid-based axially substituted silicon phthalocyanines has made them a potential photosensitizer for mitochondrial-targeted labeling and fluorescence imaging-guided photodynamic therapy.

[0012] The method for preparing betulinic acid silicon phthalocyanine of the present invention comprises the following steps: (1) refluxing and filtering dichlorosilane phthalocyanine, potassium carbonate and betulinic acid in a toluene solution; and (2) purifying the crude product with an eluent on a silica gel column and drying the product to obtain betulinic acid silicon phthalocyanine.

[0013] The betulinic acid silicyl phthalocyanine of the present invention is prepared by stirring and reflux in a toluene solution at 135°C for 48 hours, and after the reaction is completed and cooled to room temperature, filtering and washing to obtain a crude product, which is then purified three times on a silica gel column with petroleum ether and ethanol, and dried to obtain a solid blue-green product.

[0014] Beneficial effects of the present invention: Natural medicines refer to medicines that have certain pharmacological activities and are extracted from animals, plants, minerals, etc. They basically have anti-inflammatory, antioxidant and anti-cancer effects. Betulinic acid is usually extracted from birch and has antibacterial, antiviral, anti-diabetic, anti-parasitic, immunomodulatory and anti-cancer effects. Introducing betulinic acid axially into the axial position of silicon phthalocyanine to synthesize betulinic acid silicon phthalocyanine photosensitizer is a reasonable strategy to achieve the advantages of phthalocyanine, low cost and good biocompatibility, and can be used for cancer treatment. In this study, natural drugs were introduced into silicon phthalocyanine to synthesize a new type of betulinic acid axially substituted silicon phthalocyanine. On the one hand, the reference of natural drugs can improve the biocompatibility of silicon phthalocyanine; on the other hand, the combination of natural drugs with chemotherapy effects and phthalocyanine is expected to achieve the therapeutic effect of combining chemotherapy with photodynamic therapy. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a diagram for evaluating the dark toxicity and phototoxicity of Bai-SiPc in MCF-7 cells. DETAILED DESCRIPTION

[0016] The present invention is described in detail below in conjunction with embodiments: Specific embodiment 1

[0017] Synthesis of Betulic Acid Silicon Phthalocyanine (Bai-SiPc)

[0018] Dichlorosilylphthalocyanine SiPcCl2 (0.09 g, 0.15 mmol), potassium carbonate (0.03 g, 0.20 mmol), and betulinic acid (0.15 g, 0.33 mmol) were mixed and placed in a 100 mL three-necked round-bottom flask containing 20 mL of dry toluene. The mixture was stirred and refluxed at 135°C for 48 hours. After the reaction was complete and cooled to room temperature, the crude product was filtered and washed to obtain the crude product. The crude product was purified three times on a silica gel column using an eluent (petroleum ether / anhydrous ethanol, volume ratio = 30:1). After drying, 0.16 g of the blue-green solid product (Bai-SiPc) was obtained, with a yield of 33.3%. Synthesis characterization: 1H NMR (400 MHz, CDCl3, ppm): δ = 9.72 (m, 8H; H1), 8.41 (m, 8H; H2), 4.70 (d, J = 8.0 Hz, 4H; H24), 4.15 (d, J =7.8 Hz,4H; H25), 3.08 (m, 2H; H3), 2.03 (s, 2H; H21), 1.71 (s, 4H; H19), 1.67 (s, 4H; H9), 1.62 (s, 4H; H15), 1.60 (s, 4H; H9), 1.58 (s, 4H; H14), 1.54 (s,4H; H10), 1.50 (s, 2H; H20), 1.46 (s, 6H; H26), 1.39 (s, 4H; H18), 1.28 (s,4H; H5), 1.24 (s, 4H; H4), 1.17 (s, 4H; H16), 1.02 (s, 4H; H13), 0.99 (s, 4H;H6), 0.94 (s, 4H; H11), 0.87 (s, 4H; H7), 0.85 (s, 4H; H8), 0.78 (s, 4H;H12), 0.73 (s, 4H; H22), 0.58 (m, 6H; H17), 0.44 (d, J = 8.0 Hz, 4H; H23).MALDI-TOF-MS: m / z calc. for [M+H]+ 1451.312 found 1450.83+1. 234, found 234. Specific embodiment 2

[0019] In the above Example 1, the mass of dichlorosilylphthalocyanine was changed to 0.18 g, the mass of potassium carbonate was changed to 0.06 g, and the mass of betulinic acid was changed to 0.30 g. Other reaction conditions remained the same, and the yield was 22.1%. Specific embodiment three

[0020] In the above Example 1, the mass of dichlorosilylphthalocyanine was changed to 0.18 g, the mass of potassium carbonate was changed to 0.09 g, and the mass of betulinic acid was changed to 0.45 g. Other reaction conditions remained the same, and the yield was 27.1%. Specific embodiment 4

[0021] Evaluation of dark toxicity and phototoxicity of betulinic acid axially substituted silicon phthalocyanine Bai-SiPc in MCF-7 cells

[0022] The dark toxicity and phototoxicity of Bai-SiPc prepared in Example 1, 2 or 3 on MCF-7 breast cancer cells were evaluated, and the cell viability of MCF-7 cells was assessed using the CCK-8 method. The experimental conditions were with and without 671 nm laser irradiation. Bai-SiPc showed no cytotoxicity in the absence of light. This result indicates that Bai-SiPcc has high biocompatibility and is non-toxic. In cells treated with 2.5 μM Bai-SiPc, the use of a laser with a wavelength of 671 nm, a power density of 100 mW / cm2 and continuous irradiation for 5 minutes can significantly improve the killing effect on MCF-7 cells, with an IC50 value of 1.5 μM. Figure 1 FIG2 is a graph showing the dark toxicity and phototoxicity evaluation of Bai-SiPc of the present invention in MCF-7 cells. The graph shows that Bai-SiPc itself has photodynamic therapy properties.

Claims

1. A betulinic acid silicon phthalocyanine, characterized in that: A compound having the following chemical structure: 。 2. The method for preparing betulinic acid silicon phthalocyanine according to claim 1, characterized in that: The method comprises the following steps: the betulic acid silicon phthalocyanine is prepared by using dichlorosilicon phthalocyanine, potassium carbonate and betulic acid in a toluene solution and refluxing to obtain the betulic acid silicon phthalocyanine.

3. The preparation method of betulinic acid silicon phthalocyanine according to claim 2, characterized in that: The betulinic acid silicon phthalocyanine is prepared by stirring and refluxing dichlorosilicon phthalocyanine, potassium carbonate and betulinic acid in a toluene solution at 135° C. for 48 hours. After the reaction is completed and cooled to room temperature, the crude product is filtered and washed to obtain a crude product, which is then purified on a silica gel column three times with petroleum ether and ethanol, and dried to obtain a solid blue-green product.

4. Use of the betulinic acid silicon phthalocyanine according to claim 1 or the betulinic acid silicon phthalocyanine prepared by the preparation method according to claim 2 or 3 in the preparation of a phthalocyanine photosensitizer for photodynamic therapy.

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