银杏酸单体的抗肿瘤活性研究

目前银杏叶和白果的开发利用已很多,但银杏外种皮的利用率低。研究发现外种皮中含有较多的银杏酸(ginkgolic acids,GAs),为6-烷基或6-烯基水杨酸,6位上的侧链碳原子数可从13至19、侧链双健数可从0至3个,是一系列同系物的混合物。银杏酸是银杏中除了黄酮和内酯外的另一具有重要生理活性的组分,具有致敏性、细胞毒性和免疫毒性等作用,在传统意义上是银杏产品中的有毒成分[1]。而现在对于银杏酸有了新的认识,银杏酸具有多种生理药     

银杏酸凝胶制剂的研制及制剂中银杏酸的含量测定

银杏酸(Ginkgolic acid,GA)主要存在于银杏(Ginkgo biloba L.)外种皮和叶中,为6-烷基或6-烯基水杨酸的衍生物,6位上的侧链碳原子数可从13至19,侧链双键数可为0至3.常见银杏酸的结构见图1[1].研究表明[2～6],银杏酸具有抗菌、抗炎、抗肿胀等作用,对痤疮丙酸杆菌和金黄色葡萄球菌等有较好的抑制作用,可用于治疗多种皮肤病如痤疮、疥疮、皮炎等.本文以银杏酸为主药、卡波普940为基质,制备凝胶外用制剂,用于治疗寻常性痤疮,并采用HPLC法测定制剂中GA含量.     

银杏酸单体化合物的制备

 目的研究银杏酸单体化合物的制备方法，为银杏酸的应用研究提供参考，为银杏提取物中银杏酸的定量分析提供单体对照品。方法银杏外种皮用石油醚回流提取，提取物通过硅胶柱色谱分离，得银杏酸混合物，再经制备柱反复分离，得银杏酸单体。结果石油醚回流提取法所得银杏酸得率为4.06%，纯度84.59%,提取率达62.9%。银杏酸混合物经制备色谱多次分离后，得到6种银杏酸单体，其中一种为新发现的化合物，纯度均达95%以上。结论单体制备方法较为简便，可用于高纯度银杏酸单体的制备。     

烷基酚酸的生物活性研究进展

在银杏叶及外种皮中存在一类酚酸类物质 ,其含量约占银杏叶干重的 1%～ 2 % ,外种皮干重的 3%～ 4 %。主要由银杏酸、白果酚和白果二酚组成。银杏酸 (ginkgolicacids)是水杨酸分子C6位上有较长侧链的系列化合物 ,有烷基链和烯基链两大类 ,侧链长度为 13～ 17个碳、双键数为 0～ 2。银杏酸去掉羧基为白果酚 (ginkgol) ,属 3 烷基酚系列物。白果二酚 (bilobol)是 5 烷基间二苯酚系列物 ,其烷基长度为 15个碳 ,双键数 0～ 1,又称为氢化白果二酚 (hydrobilobol) [1] 。该类酚酸还存在于木贾木如树果实及其外壳中。银杏酚酸仅限于源自银杏Ginkg…     

大蒜油联合益生菌的抗菌活性研究

目的:联合应用大蒜油与益生菌,研究其共同抗菌活性。方法:采用最小抑菌浓度(MIC)、最低杀菌浓度(MBC)、抑菌圈直径测量法,测定联合抗菌指标。结果:大蒜油单体的抗菌活性明显,联合应用大蒜油与益生菌的抗菌活性无明显变化。结论:大蒜油与益生菌的抗菌作用机理存在差异,抗菌效果不同于单体抗菌效果的简单加和,联合使用未能达到明显的辅助增强效应。     

银杏酸凝胶剂的制备及抑菌试验研究

目的制备银杏酸凝胶剂,并对该制剂的体外抑菌活性进行初步研究.方法以银杏酸为主药,卡波普为基质制备凝胶剂,采用HPLC法测定制剂中银杏酸含量,并采用液体两倍稀释法测定银杏酸凝胶剂对金黄色葡萄球菌和丙酸杆菌的体外最小抑菌浓度(MIC).结果银杏酸凝胶剂对金黄色葡萄球菌和丙酸杆菌均显示不同程度的抑菌活性,其MIC分别为31.756mg·mL-1和0.992mg·mL-1.结论该制剂制备工艺可行,性质稳定,对金黄色葡萄球菌和丙酸杆菌有较好的抑制作用.     

银杏外种皮中银杏酸的体外抗肿瘤活性研究

目的:探讨银杏酸对肿瘤细胞和正常细胞生长的影响.方法:从银杏外种皮中制备纯度90%的银杏酸同系混合物.采用MTT法,检测银杏酸对各细胞株生长的抑制作用.结果:银杏酸浓度为5.0μg/ml时,对肿瘤细胞生长都有明显的抑制作用,其中对肺癌LTEP-a-2细胞抑制率达到59.1%,而对正常细胞无影响;高浓度银杏酸对正常细胞和肿瘤细胞生长的抑制作用趋于一致.结论:银杏酸对体外培养的肿瘤细胞有较强抑制作用,浓度低于5.0μg/ml时对正常细胞生长无影响.     

草龙提取物及化学成分的抗菌活性研究

目的 研究草龙提取物及化学成分的抗菌活性.方法 采用琼脂稀释法测定草龙各个部位提取物及单体成分对金黄色葡萄球菌,表皮葡萄球菌,大肠埃希菌及绿脓杆菌的抑菌效果.结果 醋酸乙酯提取物和正丁醇提取物有明显的抑菌的活性,水提取部位在高质量浓度下仅有一定的生物活性,石油醚提取物没有抑菌活性;从醋酸乙酯部位分得的没食子酸也有抑菌作用.结论 草龙醋酸乙酯部位和正丁醇部位有明显的体外抑菌作用,抑菌作用最强的是醋酸乙酯部位;没食子酸单体具有体外抑菌作用.     

银杏酸抑菌效果的初步研究

对银杏外种皮石油醚提取物和银杏酸的抑菌活性进行了初步研究,发现银杏酸和外种皮粗提物对金葡菌、蜡样芽孢杆菌、枯草杆菌均有抑制作用,对耐青霉素金葡菌也有一定的抑制作用,银杏酸与青霉素联用,具有加强作用。     

以水杨酸为假模板制备印迹聚合物对银杏酸的吸附性能研究

目的研究银杏酸吸附分离的新方法。方法采用分子印迹技术,以水杨酸为假模板分子,4-乙烯基吡啶为功能单体,通过分子自组装印迹技术合成对银杏酸具有高吸附性的印迹聚合物,运用核磁共振氢谱、红外光谱分析研究聚合物的印迹机制,扫描电镜考察聚合物的结构表征,HPLC和紫外检测法监测聚合物对总银杏酸的吸附结合特性。结果加入模板分子合成分子印迹聚合物(MIP)具备更好的三维空间结构和吸附性能,其中模板分子与功能单体以非共价键结合。在银杏外种皮提取液中MIP对银杏酸的吸附率达到95.9%;根据Scatchard分析聚合物,存在2种不同的结合位点,其中高亲和力结合位点饱和结合位点数(Q_(max1))=30 mg/g;低亲和力结合位点饱和结合位点数(Q_(max2))=80 mg/g。聚合物的吸附动力学为准二级动力学吸附。结论以水杨酸为模板制备MIP对银杏酸有很强的吸附性能,在银杏酸的分离精制中具有很好的推广应用前景。     

Kurstakins: a new class of lipopeptides isolated from Bacillus thuringiensis

A novel class of lipopeptides was isolated from Bacillus thuringiensis kurstaki HD-1. Four compounds (1-4) were separated by high-performance liquid chromatography and their primary structures determined using a combination of chemical reactions and mass spectrometry. The four lipopeptides were found to have the same amino acid sequence, Thr-Gly-Ala-Ser-His-Gln-Gln, but different fatty acids. The fatty acyl chain is linked to the N-terminal amino acid residue via an amide bond. Each lipopeptide has a lactone linkage between the carboxyl terminal amino acid and the hydroxyl group in the side chain of the serine residue. Antifungal activity was demonstrated against Stachybotrys charatum.     

银杏外种皮中银杏酚酸的超临界CO2萃取

本文对超临界CO2萃取法从银杏外种皮中萃取银杏酚酸的工艺可行性进行了研究。主要探讨了萃取压力、温度、时间等条件对银杏酚酸收率的影响，确定了超临界CO2萃取银杏酚酸的最佳条件，用HPLC法对银杏酚酸进行分析。结果表明萃取压力为30MPa，温度45℃，萃取时间6h，CO2流量为2L／min为最佳条件。超临界CO2萃取法萃取银杏外种皮中的银杏酚酸比传统方法优越，表现在得率、纯度高，无溶剂残留，操作简便。     

Anti-Toxoplasma gondii activity of GAS in vitro

ETHNOPHARMACOLOGICAL RELEVANCE: The sarcotesta of Ginkgo biloba is a Chinese herbal medicine used for treating toxoplasmosis, a serious disease requiring treatment with antibiotics that can have serious side effects. AIM OF THE STUDY: To investigate the anti-Toxoplasmagondii activity of ginkgolic acids (GAs) isolated from the Ginkgo biloba sarcotesta in Toxoplasmagondii-infected human foreskin fibroblast (HFF) cells in vitro. MATERIALS AND METHODS: The safe concentration of GAs for HFF cells was determined by methyl thiazolyl tetrazolium (MTT) cell proliferation assay. The presence of Toxoplasmagondii was measured by [3H]-thymine deoxyriboside ([3H]-TdR) and [3H]-leucine ([3H]-Leu) incorporation, as well as Giemsa staining. The positive control was the commonly used and highly effective antibiotic azithromycin. RESULTS: Light microscopy revealed that most HFF cells were infected after 4h of exposure to Toxoplasmagondii. After 48 h of exposure to either GAs or azithromycin, Toxoplasmagondii DNA and protein synthesis were minimal, there were no visible parasites in HFF cells, and the HFF cells had no significant morphological changes. CONCLUSIONS: These results demonstrate that GAs have significant anti-Toxoplasma activity with low toxicity to HFF cells, suggesting that GAs could be an alternative treatment for toxoplasmosis.     

紫金砂体外抗菌活性的研究

目的紫金砂提取物及其提取部位抗菌活性的研究。方法95%乙醇提取,系统溶剂萃取分离得到5个部位,采用纸片扩散法对提取物及提取部位进行体外抗菌活性研究。结果紫金砂提取物对金黄色葡萄球菌、大肠杆菌具有抑制作用,氯仿提取部位对大肠杆菌、枯草芽胞杆菌具有抑制作用,正丁醇提取部位对大肠杆菌、绿脓杆菌具有抑制作用。结论紫金砂提取物及提取部位具有抗菌活性。     

金银花中有机酸类成分抗血栓作用研究

目的:研究金银花中绿原酸、异绿原酸类化合物的体外抗血小板聚集作用及对人脐静脉内皮细胞过氧化损伤的影响。方法:从金银花水提醇沉液中提取制备绿原酸及其同分异构体、咖啡酸、异绿原酸等单体,研究其体外抗ADP诱导的血小板聚集作用和对H2O2损伤的人脐静脉内皮细胞的保护作用。结果:金银花中有机酸类化合物有抗ADP诱导的血小板聚集作用,绿原酸的2个同分异构体(2个)、咖啡酸、异绿原酸类(3个)IC50分别为0.0286、1.707、2.411、0.026、0.328、0.539mg/ml;对H2O2损伤咖啡酸和异绿原酸类成分均具有明显抗损伤作用,且有剂量依赖性,绿原酸虽然未观察到直接对抗作用,但具有预防性保护作用。结论:细胞膜固相色谱法研究体系中的保留成分和其药理作用有显著的相关性;金银花有机酸类成分在血栓性血管病治疗中具有潜在价值。     

Anti-inflammatory acylphloroglucinol derivatives from Hops (Humulus lupulus)

The polyphenol-enriched fraction of an ethanolic hops extract (Humulus lupulus) was separated to provide four acylphloroglucinol-glucopyranosides (1-4). 1-(2-Methylpropanoyl)phloroglucinol-glucopyranoside 1 has been isolated from hops before, whereas 1-(2-methylbutyryl)phloroglucinol-glucopyranoside 2, known as multifidol glucoside, and 1-(3-methylbutyryl)phloroglucinol-glucopyranoside 3 were found in hops for the first time. 5-(2-Methylpropanoyl)phloroglucinol-glucopyranoside 4 was identified as a new natural product. The compounds were tested for inhibition of COX-1 activity. The aglycon 5, obtained by acid hydrolysis of 1, was equally effective as phloroglucinol, with an IC(50) of 3.8 microM. The inhibitory potential of the glucosides was 1>2>3 and decreased with increasing length of the acyl side chain. Compound 4 was about 2.5-fold less active than 1 (IC(50): 23.7 and 58.7 microM, respectively).     

New decalin derivatives, eujavanoic acids A and B, from Eupenicillium javanicum

Two new decalin derivatives, eujavanoic acids A (1) and B (2), were isolated from Eupenicillium javanicum, along with several compactin derivatives. The structures of 1 and 2 were determined by spectroscopic methods and modified Mosher's method. The side chain (2-methylbutanoyloxy) and acid functionalities of compactin derivatives were necessary to show the antifungal activity.     

Production of monoclonal antibody against ginkgolic acids in Ginkgo biloba Linn

A competitive enzyme-linked immunosorbent assay (ELISA) for ginkgolic acids (GAs) was developed using monoclonal antibody (MAb) 9F raised against 6-(13-formylheptyl) salicylic acid covalently coupled to bovine serum albumin (BSA). ELISA, at an effective measuring range of 300 ng/ml-1 microgram/ml of GA15:1, was successful in detecting GAs content in ginkgo leaves and standardized extracts due to the lack of cross-reactivity against various related compounds. The sensitive and simple immunoassay developed in this study was validated to be specific for the quantitative determination of total GAs content in ginkgo crude drugs with no interference from the sample matrix. The analytical recovery of spiked GA15:1 was 103% in a concentration range between 10 and 40 mg/g dry weight of ginkgo leaves.