海洋细菌抗胶质瘤活性物质的发现及生物活性研究

发布时间：2018-01-16 06:16

本文关键词：海洋细菌抗胶质瘤活性物质的发现及生物活性研究　出处：《浙江大学》2017年博士论文　论文类型：学位论文

【摘要】：胶质瘤是最常见和死亡率最高的脑肿瘤,多位于脑功能区,手术切除极为困难,药物对胶质瘤的防治尤显重要。传统的第一代抗胶质瘤药和目前临床上唯一可单独用于胶质瘤治疗的金标药替莫唑胺均属于细胞毒类烷化剂,具有毒副作用大和耐药性等严重不足,临床上迫切需要具有新作用机制的抗胶质瘤新药物。海洋微生物的次级代谢产物是抗胶质瘤先导化合物的重要资源。本论文从多种海洋来源的样品中分离得到了 255株海洋细菌,以抑制胶质瘤细胞增殖为导向筛选获得了 27株活性菌株;研究了其中5株放线菌(Streptomycesfradiae PTZ0025、Streptomyces sp.P11-23B、Pseudonocardiasp.HS7、Streptomycessp.Q24 和Streptomycessp.P83B)的化学成分及其抗胶质瘤活性。应用各种柱层析和HPLC,从这5株菌的培养物中分离到23个化合物,通过各种核磁共振谱、高分辨质谱、二级质谱和化学降解等相结合的方法鉴定了它们的化学结构,发现了 8 个新化合物,它们是:fradimycin A(2)、fradimycin B(3)、fradic acid A(5)、fradic acid B(6)、streptodepsipeptide P11A(8)、streptodepsipeptide P11B(9)、curvularin-7-O-α-D-glucopyranoside(12)和3-acetylamino-N-2-thienyl-propanamide(15)。抗胶质瘤活性研究发现了 18个化合物对胶质瘤细胞的增殖均有抑制作用,其中化合物7、8、12、13、21和22这6个活性化合物还可明显降低胶质瘤U87-MG细胞不同代谢途径关键酶的蛋白表达水平。非常有意义的是,这6个活性化合物分别是从可降低胶质瘤细胞葡萄糖消耗和乳酸生成的3株放线菌(Streptomyces sp.P11-23B、Psuudonocardia sp.HS7和Streptomycessp.P83B)的培养物中获得,提示,以抑制胶质瘤增殖和影响胶质瘤细胞葡萄糖消耗和乳酸生成为导向发现目标活性化合物的意义和应用前景。Streptodepsipeptide P11A(8)抗胶质瘤活性强、对正常胶质细胞毒性小,可诱导胶质瘤U87-MG细胞凋亡和阻滞胶质瘤U87-MG和U251细胞周期于Go/G1期。该化合物还可降低胶质瘤U87-MG细胞乳酸生成和选择性下调胶质瘤U87-MG细胞不同代谢途径的多个关键酶的蛋白表达水平,并促使胶质瘤细胞代谢向正常细胞主导的氧化磷酸化途径转变。因此,新化合物8作为抗肿瘤先导化合物具有进一步深入研究的价值。
[Abstract]:Glioma is the most common and the highest mortality brain tumors, mostly located in the brain functional areas, surgery is extremely difficult to remove. Traditional first-generation anti-glioma drugs and the only gold standard drug temozolamide which can be used in the treatment of glioma alone are cytotoxic alkylates. Has the toxic side effect big and the drug resistance and so on serious insufficiency. New anti-glioma drugs with new mechanism are urgently needed clinically. Secondary metabolites of marine microbes are important resources for antiglioma lead compounds. 255 strains of marine bacteria. A total of 27 active strains were obtained by targeting the inhibition of glioma cell proliferation. Five of them, Streptomyces fradiae PTZ0025, Streptomyces sp.P11-23B were studied. Pseudonocardiasp.HS7. The chemical constituents and anti-glioma activity of Streptomycessp.Q24 and Streptomyces sp. P83B were analyzed by various column chromatography and HPLC. Twenty-three compounds were isolated from the cultures of the 5 strains and their chemical structures were identified by means of nuclear magnetic resonance spectroscopy (NMR), high resolution mass spectrometry (HRMS), secondary mass spectrometry and chemical degradation. Eight new compounds were found. They are: fradimycin acid A5. Fradic acid 6, streptodepsipeptide P11A 8). Streptodepsipeptide P11BN9). Curvularin-7-O- 伪 -D-glucopyranoside 12). And 3-acetylamino-N-2-thienyl-propanamide15). 18 compounds were found to inhibit the proliferation of glioma cells. Among them, the six active compounds, 7, 8, 12, 12, 13, 13, 21 and 22, could significantly reduce the expression of key enzymes in different metabolic pathways of U87-MG cells. The six active compounds were isolated from three actinomycetes strains Streptomyces sp.P11-23B which could reduce glucose consumption and lactic acid production in glioma cells. Psuudonocardia sp.HS7 and Streptomyces sp. P83B). The significance and application prospect of target active compounds by inhibiting glioma proliferation and affecting glucose consumption and lactic acid production of glioma cells. P11A (. 8) strong anti-glioma activity. It has little toxicity to normal glial cells. It can induce apoptosis of U87-MG glioma cells and block the cell cycle of U87-MG and U251 glioma cells in Go/G1 phase. The compound can also reduce the production and selection of lactate in U87-MG glioma cells. The protein expression of several key enzymes in different metabolic pathways of U87-MG cells was down-regulated selectively. The metabolism of glioma cells was changed to the oxidative phosphorylation pathway dominated by normal cells. Therefore, the new compound 8 has the value of further research as a leading antitumor compound.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R915

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