产生大环聚酮类天然产物放线菌的分子筛选研究

目的 建立一套简便、快速、高效的大环聚酮类化合物产生菌基因筛选体系 ,为聚酮类药物筛选搭建一个新的技术平台 ;认识 PKS- I基因在不同环境放线菌群中的分布规律 ,为新药筛选中微生物资源的定向分离提供依据。方法 通过对大环聚酮类化合物生物合成途径所用的 I型聚酮合成酶氨基酸和核苷酸序列的同源性比较分析 ,设计了一对引物用于扩增 KS/ AT功能域约 1.6 kb目的基因片段 ,依据放线菌基因组中 I型 PKS合成酶基因的存在与否标定可能的大环聚酮类天然产物产生菌。结果 利用建立的大环聚酮类化合物产生菌基因筛选体系对 98株嗜碱放线菌、99株链霉菌、46株嗜盐放线菌和 75 7株稀有放线菌进行了筛选 ,研究表明嗜碱放线菌、链霉菌、嗜盐放线菌和稀有放线菌 I型聚酮合成酶基因的阳性率分别为 2 6 .5 %、2 0 .4%、15 .2 %和 9.35 %。结论 利用组合放线菌基因组 DNA快速提取技术和 PKS- I基因兼并引物 PCR扩增技术建立了快速、简便、高效的大环聚酮类化合物产生菌基因筛选体系 ,并对不同环境条件的放线菌菌群的PKS- I基因分布进行了研究 ,结果不仅表明了放线菌 PKS I聚酮合成酶分布的广泛性 ,而且表明极端环境放线菌 ,尤其是嗜碱放线菌是大环聚酮类化合物潜在的丰富资源 ,为新药筛选有效菌源的确定提供了?

Research Progress of Ketolide Antibiotics

Macrolide antibiotics have been widely used in clinic due to their good antibacterial effects and high safety, but the drug-resistant bacteria appear constantly. To solve the problem of drug resistance in pathogens, scholars obtain the third generation of macrolide antibiotics, ketolide antibiotics, which are developed by modifying the structure of macrolide antibiotics, thereby efficiently solving the problem. Ketolide antibiotics are a type of erythromycin derivatives with macrolide structure, and the typical drugs mainly include telithromycin, cethromycin and solithromycin, etc . This paper briefly introduced the recent progress of ketolide antibiotics, with an attempt to provide help to the research and development of new macrolide antibiotics.

Metabolism of Praziquantel in Erythromycin, Acetylspi-ramycin and Dexamethasone Induced Rat Liver Micro-somes

Our results show that in liver microsomes from erythromycin,acetylspiramycin and dexamethsone pretreated rats,the rate of praziquantel( PQT)disappearence was increased as compared with control rat When microsomes from erythromycin-treated rats were exposed to PQT in the presence of potassium ferricyanide which broke down the cytochrome P-450 Fe(Ⅱ)-metabolite complexes and restored the functional cytochrome P-450,PQT metabolism was further increased. Acetylspiramycin did not form the complexes, so potassium ferricyanide showed no effect on the PQT metabolism in microsomes from acetylspiramycin-treated rats. Triacetyloleandomycin,a specific inhibitor of cytochrome P-450ⅢAI, inhibited PQT metabolism by 53% in liver microsomes from dexamethasone-treated rats.These results indicate the cytochrome P-450ⅢA seems to be involved in metabolism of PQT in rat liver microsomes.

麝香化学成分及抗肿瘤研究进展

麝香作为一味用药历史悠久、药效确切的名贵中药材,具有较高的药用和经济价值。麝香主要含有大环酮类、吡啶生物碱类、甾体类、多肽蛋白质类、芳香族杂环类等化学成分。而对麝香及其成分的药理研究主要侧重于抗炎、强心和抗肿瘤等方面。此外,含麝香的中药复方制剂,如西黄丸、六神丸、八宝丹在临床上应用广泛,主要用于抗肿瘤的辅助治疗。本文就麝香的化学成分、抗肿瘤作用、毒理作用及其复方制剂在防治肿瘤方面的临床应用进行归纳总结,旨在为麝香及其复方制剂的进一步开发利用及麝香抗肿瘤作用的深入研究提供参考。

天然麝香的化学成分及药理研究进展

麝香作为名贵中药材,应用广泛,具有很高的药用价值和经济价值。麝香的主要活性成分包括甾体类化合物、大环酮类和多肽蛋白质等。药理学研究主要侧重于抗炎、强心和抑瘤等方面。文章就近年来麝香的化学成分和药理作用方面的文献进行归纳总结,旨在为麝香的临床应用和开发利用提供参考。