Studies on coumarins from the root of Angelica pubescens Maxim. IV. Structures of angelol-type prenylcoumarins.

Abstract

The root of Angelica pubescens MAXIM. (Umbelliferae) afforded seven new coumarins, angelols B-H (2-8), together with a known coumarin, angelol A (formerly simply called angelol). The structures of these coumarins were determined on the basis of spectral and chemical evidence as 6-(1-acyloxy-2, 3-dihydroxy-3-methylbutyl)-7-methoxycoumarins and 6-(2-acyloxy-1, 3-dihydroxy-3-methylbutyl)-7-methoxycoumarins and 6-(2-acyloxy-1, 3-dihydroxy-3-methylbutyl)-7-methoxycoumarins. Furthermore, in the course of this investigation we revised the reported structure of angelol A (1)