Antifungal Activity of a New Triterpenoid Glycoside from Pithecellobium racemosum (M.)

Purpose. In a continuation of our search for novel antifungal compounds from higher plants, the standard extract of the bark of Pithecellobium racemosum was found to have good activity against important AIDS-related opportunistic yeasts. Methods. The extract was subjected to bioguided fractionation using silica gel column chromatography which led to purification of triterpene glycosides. The structures of these compounds were determined by a combination of spectroscopic (IR, NMR, HRMS) and chemical methods. Results. Compound 1 is a new glycoside, 3-O[-L-arabinopyranosyl (1 -2)][-L arabinopyranosyl (1 -6)]2-acetoamido-2-deoxy--D-gluco-pyranosyl oleanolic acid and Compound 2 was identified as the known compound 3-O-[-L-arabinopyranosyl (l-2)]-L-arabinopyranosyl (1-6)] 2-acetamido-2-deoxy--D-glucopyranosyl echinocystic acid. Conclusions. Compound 1 is a new glycoside, 3-O-[-L-arabinopyranosyl (1-2)]-L-arabinopyranosyl (l-6)]-2-acetoamido-2-deoxy--D-glucopyranosyl oleanolic acid and exhibits moderate antifungal activity against T. mentogrophytes, C. albicans and S. cerevisiae with MIC values of 6.25, 12.5 and 12.5 g/ml respectively.     

五环三萜类化合物的构效关系

五环三萜类化合物作为皂草苷的糖苷配基在自然界中广泛存在，它们中的许多化合物已被用作传统医学的抗炎药物。目前，一些三萜类化合物已被报道具有抗肿瘤细胞增殖、诱导细胞凋亡及抗AIDS作用。笔者讨论了一些五环三萜类化合物的药理活性与结构的关系。     

Microbial transformation of asiatic acid by Alternaria longipes

Asiatic acid is a major pentacyclic triterpene isolated from Centella asiatica. It shows a variety of bioactivities. In order to obtain its derivatives, potentially useful for detailed pharmacological studies, the substrate was subjected to incubations with selected micro-organisms. In this work, asiatic acid was converted into three new compounds: 2α,3β,23,30-tetrahydroxyurs-12-ene-28-oic acid (1), 2α,3β,22β,23-tetrahydroxyurs-12-ene-28-oic acid (2), and 2α,3β,22β,23,30-pentahydroxyurs-12-ene-28-oic acid (3) by the fungus Alternaria longipes AS 3.2875. The structures of the three metabolites were determined by 1D and 2D NMR spectral data.     

亚麻叶白千层化学成分研究

目的研究亚麻叶白千层Melaleucalinariifolia枝、叶中的化学成分。方法采用硅胶、SephadexLH-20、ODS、以及Pre-HPLC等现代分离方法进行系统地分离纯化,并根据化合物的理化性质和波谱数据进行结构鉴定。采用CCK8法初步评价化合物1～6对6种肿瘤细胞(人肺腺癌NCI-H441细胞、人大细胞肺癌NCI-H460细胞、人肺癌A549细胞、人卵巢腺癌SKOV3细胞、人宫颈癌HeLa细胞和人肾透明细胞癌caki-1细胞)的体外细胞增殖抑制活性。结果从亚麻叶白千层醋酸乙酯部位分离得到15个化合物,分别鉴定为3-O-乙酰熊果酸(1)、3β-acetoxy-11-ursen-13α,30-olide(2)、betulinal(3)、diospyrolide(4)、3β-O-(E)-cumaroyl-alphitolinsaeure(5)、3',4'-二羟基肉桂酸白桦脂酸酯(6)、熊果醇(7)、白桦脂醇(8)、豆甾-4-烯-3-酮(9)、5,7,4'-三羟基黄酮3-O-α-L-毗喃鼠李糖苷(10)、山柰酚-3-O-(6′′-没食子酰基)-β-D-葡萄糖苷(11)、α-生育酚(12)、methoxytocopherol(13)、α-tocopherolquinone(14)、植醇(15)。CCK8测试结果显示,化合物1、3、5、6对人类肿瘤细胞显示出中等强度的增殖抑制作用。结论所有化合物均为首次从该植物中分离得到,其中化合物2、4、5、9～11、13、14为首次从该属植物中分离得到。化合物1、3、5、6对人类肿瘤细胞表现出一定的细胞毒活性,半数抑制浓度(IC50)值在3.85～25.63μmol/L。     

Selective antileishmania activity of 13,28‐epoxy‐oleanane and related triterpene saponins from the plant families Myrsinaceae,Primulaceae, Aceraceae and Icacinaceae

Maesa saponins with the 13,28‐epoxy‐oleanane triterpene core skeleton were described recently to possess strong and selective in vitro and in vivo antileishmania activity. In the absence of direct chemical derivatization possibilities, a structure‐based literature search was carried out to explore a structure‐activity relationship. Crude alcohol extracts from several plant species of Myrsinaceae, Primulaceae, Aceraceae and Icacinaceae were evaluated for in vitro activity against Leishmania infantum intracellular amastigotes and cytotoxicity on MRC‐5_SV2 cells, while the saponin content was evaluated qualitatively by TLC. A clear correlation was found between the presence of close analogue 13,28‐epoxy‐oleanane triterpene saponins and potent and selective antileishmania activity. This was most striking in Maesa species, except for M. macrosepala. Interesting activities were also found in extracts that did not exactly match the TLC characteristics of the Maesa saponin references, as was the case for Ardisia angusta, A. amherstiana, A. caudata, A. gigantifolia, A. roseiflora, Myrsine affinis, Acer brevipes and A. laurinum var. petelotii. This study indicates that the 13,28‐epoxy‐oleanane triterpene moiety is essential for selective antileishmania potential and that several other plant species could still be explored for antileishmania drug discovery. Copyright © 2009 John Wiley & Sons, Ltd.     

丰城鸡血藤化学成分的研究

目的:分离和鉴定丰城鸡血藤的活性成分.方法:用溶剂法和色谱方法分离化合物,用波谱方法鉴定其结构.结果:从丰城崖豆藤中分离得到10个化合物,其中8个为黄酮类化合物(1～8):毛蕊异黄酮(1),染料木苷(2),gliricidin(3),8-甲雷杜辛(4),阿夫罗摩辛-7-O-β-D-吡喃葡萄糖苷(5),澳白檀苷(6),异甘草素(7)和3,5,7,4'-四羟基-3'-甲氧基黄烷-7-O-β-D-吡喃葡萄糖苷(8);2个为三萜类化合物,羽扇豆醇(9)和无羁萜-3β-醇(10).结论:10个化合物均为首次从该植物中获得.探讨毛蕊异黄酮等在NMR测定中的溶剂效应,纠正了文献[1-2]中该化合物碳谱数据的一些归属错误.     

五环三萜皂苷生物合成与调控的研究进展

五环三萜皂苷是一类重要的天然产物,具有多种生理活性,临床应用前景诱人,但自然界中,其产量较低。采用分子生物学与蛋白质组学相关知识,通过代谢工程或基因工程进行五环三萜皂苷生物合成的工厂化生产,具有广阔的市场前景。综述了五环三萜皂苷生物合成途径及其调控因子的研究进展,并简要探讨了五环三萜皂苷生物合成的研究方法。     

准噶尔大戟的化学成分研究

目的 对准噶尔大戟中的化学成分进行分离鉴定.方法 采用硅胶、Sephadex LH-20及MPLC制备色谱技术,通过理化方法和光谱分析鉴定其结构.结果 从准噶尔大戟的乙醇提取物中得到11个化合物,分别鉴定为香茅二醇(Ⅰ)、白桦脂醇(Ⅱ)、白桦脂酸(Ⅲ)、齐墩果酸(Ⅳ)、7-O-β谷甾醇(Ⅴ)、3-甲氧基-4-羟基反式苯丙烯酸正二十八醇酯(Ⅵ)、二十八酸(Ⅶ)、I-二十八烯(Ⅷ)、24-亚甲基-环阿尔廷醇(Ⅸ)、大戟醇(Ⅹ)、β-谷甾醇(Ⅺ).结论 化合物Ⅰ～Ⅷ均为首次从该植物中分离得到.     

五环三萜皂苷的药理作用研究进展

五环三萜皂苷是天然产物中重要的成分之一,大多具有广泛的药理活性,临床应用前景十分诱人。随着五环三萜皂苷研究的不断深入,对其药理学作用机制的阐明和新药研发已成为此类化合物研究的热点之一。就国内外学者对五环三萜皂苷抗肿瘤、护肝、抗炎、以及机体免疫调节等药理学作用的研究进展做一综述。     

3种五环三萜类化合物及其衍生物抗艾滋病的研究进展

五环三萜类化合物是许多中草药的主要有效成分,在自然界分布广泛,具有抗肿瘤、抗HIV、抗炎等多种生物活性。一般分为羽扁豆烷型、齐墩果烷型、熊果烷型等结构类型,桦木酸、齐墩果酸和熊果酸为五环三萜类化合物的代表性化合物,分属这3种类型。对该类化合物的结构修饰,已获得大量具有较强抗HIV活性的化合物。综述了近年来这3种天然产物及其结构修饰物抗艾滋病的研究进展。