| Abstract: | From a MeOH extra of Psiadia trinervia, seven phenolic compounds were isolated by gel filtration and reversed-phase chromatography. Six of them are known compounds, namely 3,4-di-O-caffeoylquinic acid ( 2 ), 3,5-di-O-caffeoylquinic acid ( 3 ), caffeic acid, and three 3-methoxyflavonoids. Compound 1 is a 3,4-di-O-caffeoyl derviative of (1S,3R,4R,5R)-1,3,4, 5-tetrahydroxycyclohexanecarboxylic acid, a novel steroisomer of (?)-quinic acid. Following hydrolytic treatment of the MeOH extract, ethyl 3-O-caffeoylquinate ( 4 ), ethyl 3,4-di-O-caffeoylquinate ( 5 ), and ethyl 3,5-O-caffeoylquinate ( 6 ) were isolated. The latter three compounds are artifacts. The configuration of 1-3 was established by NMR and CD (exciton chirality method). |
