A pair of neolig nan enan tiomers with an unprecedented carb on skelet on,(+)-/(-)-angeligna nine[(+)-/(-)-1].was isolated as minor components of an aqueous extract of the Angelica sinensis root heads(guitou).Their structures were determined by spectroscopic data analysis and the absolute configurations were assigned by the circular dichroism(CD)exciton chirality method as well as electronic CD quantum calculations.The enantiomers represent the first 2,7/-cyclo-8,9z-neolignans,of which biosynthetic pathways originating from precursors ferulic acid and coniferyl alcohol is proposed.In an in vivo test,both the enantiomers showed significant hypnotic effects at a dose of 10 mg/kg(i.g.).
Youzhe ChenQinglan GuoChengbo XuChenggen ZhuJianjun ZhangJiangong Shi
Gastradefurphenol(1),a minor 9.9'-neolignan with a novel carbon skeleton substituted by two phydroxybenzyls was isolated from an aqueous extract of the Gastrodia elata rhizomes(tian ma).Its structure was determined by extensive spectroscopic data analysis.Solvent-dependent free rotational restriction of bonds and equilibrium of two molecular states are discussed by comparison of the NMR spectroscopic data of 1 in acetone-d6 with those in CD3OD.A biogenetic pathway of 1 is postulated to be associated with metabolic processes of L-tyrosine.
Xue ZhouQing-Lan GuoCheng-Gen ZhuCheng-Bo XuYa-Nan WangJian-Gong Shi
Two new 8-O-4' neolignan glycosides, named matteustruthiosides A(1) and B(2) were isolated from the aerial parts of Matteuccia struthiopteris. Their chemical structures were characterized on the basis of various spectroscopic techniques. The absolute configurations of them were determined by experimental circular dichroism(CD) spectra. Compounds 1 and 2 were inactive against influenza A(H1N1) virus in vitro.
Ling-Juan ZhuFei YanJin-Peng ChenNan ZhangXue ZhangXin-Sheng Yao