2β,3α--Dihydroxyurs-12-en-28-oic acid （6） is a naturally occurring diastereoisomer of corosolic acid with glycogen phosphorylase inhibitory activity. A new strategy for the semi-synthesis of 6 was developed. Using...2β,3α--Dihydroxyurs-12-en-28-oic acid （6） is a naturally occurring diastereoisomer of corosolic acid with glycogen phosphorylase inhibitory activity. A new strategy for the semi-synthesis of 6 was developed. Using the commercially available ursolic acid （1） as the starting materials, 6 was synthesized through five facile reactions with a high stereoselectivity and an overall yield of 47,3%, The structure of 6 was confirmed by optical rotation, ESI-MS, 1H NMR and 13C NMR data,展开更多
From the fruit of Rosa davidii Crep., eleven compounds were isolated and identified by spectral evidence, viz. 2 alpha, 3 beta, 19 beta -trihydroxyl-olean-12-en-28-oic acid (1), 2 alpha, 3 beta -dihydroxyl-urs-28 (13)...From the fruit of Rosa davidii Crep., eleven compounds were isolated and identified by spectral evidence, viz. 2 alpha, 3 beta, 19 beta -trihydroxyl-olean-12-en-28-oic acid (1), 2 alpha, 3 beta -dihydroxyl-urs-28 (13)-lactone (2), arjunic acid (3), euscaphic acid (4), 2 alpha, 3 beta -dihydroxyl-urs-12-en-28-oic acid (5), oleanolic acid (6), kaempferol (7), tiliroside (8), quercetin (9), daucosterol (10) and beta -sitosterol (11). Among them, 1 and 2 were new compounds.展开更多
Two new pentacyclic triterpene acids, 1a, 3b-dihydroxyl-olean-12-en-28-oic acid and 1a, 2a, 3b-trihydroxyl-olean-12-en-28-oic acid, were isolated from the arial parts of Sabia parviflora.
A new oleanane-type triterpene was isolated from the roots of Doellingeria scaber. Its structure was identified as 3-oxo-16a-hydroxy-olean-12-en-28-oic acid based on 1D and 2D NMR spectroscopy and X-ray analysis.
Two new triterpenes, 2α,3β-dihydroxyurs- 12-en- 18,19-epoxy-28-oic acid （1） and 18,19-seco, 2α, 2α-dihydroxyl-19-oxo-urs- 11,13（18）-dien-28-oic acid （2） were isolated from the herbaceous part of Duchesnea in...Two new triterpenes, 2α,3β-dihydroxyurs- 12-en- 18,19-epoxy-28-oic acid （1） and 18,19-seco, 2α, 2α-dihydroxyl-19-oxo-urs- 11,13（18）-dien-28-oic acid （2） were isolated from the herbaceous part of Duchesnea indica. Their structures were elucidated by spectroscopic analysis, including 2D NMR technique. The isolated compounds exhibited moderate cytotoxic activities against HeLa and L929 cell lines.展开更多
基金Financial support from the Fundamental Research Funds for the Central Universities(No.DUT12JB08)
文摘2β,3α--Dihydroxyurs-12-en-28-oic acid （6） is a naturally occurring diastereoisomer of corosolic acid with glycogen phosphorylase inhibitory activity. A new strategy for the semi-synthesis of 6 was developed. Using the commercially available ursolic acid （1） as the starting materials, 6 was synthesized through five facile reactions with a high stereoselectivity and an overall yield of 47,3%, The structure of 6 was confirmed by optical rotation, ESI-MS, 1H NMR and 13C NMR data,
文摘利用硅胶柱色谱反复层析从黄背越橘的乙酸乙酯部分分得7个化合物,根据理化性质和光谱数据鉴定,分别为β-谷甾醇(β-sitosterol,Ⅰ),熊果酸(ursolic acid,Ⅱ),蒲公英萜醇(taraxerol,Ⅲ),蒲公英萜酮(taraxerone,Ⅳ),木栓酮(friedelin,Ⅴ),木栓醇(friedelinol,Ⅵ),19,24-d ihydroxyurs-12-en-3-one-28-oic ac id(Ⅶ).
文摘Two new pentacyclic triterpene acids, 1a, 3b-dihydroxyl-olean-12-en-28-oic acid and 1a, 2a, 3b-trihydroxyl-olean-12-en-28-oic acid, were isolated from the arial parts of Sabia parviflora.
文摘A new oleanane-type triterpene was isolated from the roots of Doellingeria scaber. Its structure was identified as 3-oxo-16a-hydroxy-olean-12-en-28-oic acid based on 1D and 2D NMR spectroscopy and X-ray analysis.
基金sponsored by the Scientific Research Foundation of Tianjin Medical University,Tianjin,China.
文摘Two new triterpenes, 2α,3β-dihydroxyurs- 12-en- 18,19-epoxy-28-oic acid （1） and 18,19-seco, 2α, 2α-dihydroxyl-19-oxo-urs- 11,13（18）-dien-28-oic acid （2） were isolated from the herbaceous part of Duchesnea indica. Their structures were elucidated by spectroscopic analysis, including 2D NMR technique. The isolated compounds exhibited moderate cytotoxic activities against HeLa and L929 cell lines.
