紫菀中三萜及甾体化合物的研究

从紫菀(Aster tataricusL.f.)的根及根茎中分离得到11个化合物,经IR、NMR、MS、X-ray单晶衍射等波谱方法分别鉴定为紫菀酮(shionone)(1)、木栓酮(friedelin)(2)、表木栓醇(epi-friedelanol)(3)、蒲公英萜醇(taraxerol)(4)、α-菠甾醇(-αspinasterol)(5)、二十二碳酸(decosanoic acid)(6)、豆甾醇(stigmasterol)(7)、β-谷甾醇(-βsitosterol)(8)、α-菠甾醇--βD-葡萄糖苷(-αspinasterol--βD-glucoside)(9)、豆甾醇--βD-葡萄糖苷(stigmasterol--βD-glucoside)(10)、胡萝卜苷(daucosterol)(11)。化合物6为首次从该属植物中获得,化合物5,9,10为首次从该植物中分得。活性实验研究结果表明紫菀酮(1),表木栓醇(3)可显著抑制氨水所致小鼠咳嗽。     

蒙椴树皮化学成分的研究

为研究蒙椴（Tilia mongolica Maxim.）树皮的化学成分,通过溶剂萃取、硅胶柱色谱、重结晶分离纯化,从蒙椴树皮中分离得到7个化合物,根据其红外光谱、质谱和核磁共振谱数据鉴定为β-香树脂醇乙酸酯（1）,计曼尼醇乙酸酯（2）,羽扇豆醇（3）,二十四碳酸（4）,三棕榈酸甘油酯（5）,β-谷甾醇（6）,胡萝卜苷（7）。其中化合物1-5、7均为首次从椴树属植物中分离得到,化合物6为首次从该植物中分离得到。     

Transformations of Glycyrrhizic Acid: XV. Synthesis of Triterpene Saponins with Monosaccharide Residues Attached through Ester Bonds

Triterpene saponins, glycoside analogues of glycyrrhizic acid with a modified carbohydrate chain containing monosaccharide residues attached through ester bonds, were synthesized. To this end, peracetylated glycyrrhizic acid or its 30-methyl ester were glycosylated by 2,3,4,6-tetra-O-acetyl--D-gluco- or --D-galactopyranosyl bromide in dichloroethane in the presence of Ag₂CO₃. Glycerrhetinic acid saponin with D-Galp residues exhibited a higher antiulcer activity than glycyrrhizic acid in rats at a dose of 25 mg/kg.     

Isomotiol,a new triterpene from strychnos potatorum

Isomotiol (fern-8-en-3β-ol) was isolated from the leaves of Strychnos potatorum; it was not known previously as a natural product, but it has been obtained by acidic isomerization of compounds with a fern-7-ene or a fern-9(11)-ene skeleton. From the leaves and the bark mixtures of sitosterol, stigmasterol and campesterol were also isolated.     

Bacterial triterpenoids of the hopane series from the methanotrophic bacteria Methylocaldum spp.: phylogenetic implications and first evidence for an unsaturated aminobacteriohopanepolyol

The hopanoid content of the two methanotrophic bacteria Methylocaldum szegediense and Methylocaldum tepidum was investigated. 35-Aminobacteriohopane-30R,31R,32R,33S, 34S-pentol and its 3beta-methyl homologue were present in both strains. In M. tepidum, they were accompanied by 35-aminobacteriohopane-31R,32R,33S, 34S-tetrol and its 3beta-methyl homologue. The side chain structure was identical to those previously reported from two other obligate methanotrophs, Methylococcus capsulatus and Methylomonas methanica. The two Methylocaldum species shared with the Methylococcus species the presence of 3beta-methylhopanoid as well as of a hopanoid releasing adiantol upon H(5)IO(6)/NaBH(4) treatment. A rare feature was in addition found in M. szegediense. The saturated hopanoids were accompanied by an unsaturated aminobacteriohopanepentol with a Delta(11) double bond. Comparison of the hopanoid fingerprints was in accordance with the close phylogenetic relationship of Methylococcus and Methylocaldum. The major difference was the absence of sterols in Methylocaldum which were always detected in the Methylococcus species.     

Terpenoids of Rhododendron japonicum

From Rhododendron japonicum were isolated two diterpene glucosides, pieroside B and grayanoside B, and two new triterpenes, 2α,3α,24-trihydroxy