A New Monoterpenoid Glucoindole Alkaloid From Dipsacus asper

The monoterpenoid glucoindole alkaloids comprise a large class of structurally complex natural products that have attracted widespread attention owing to their biological activities and structural diversity. In the present study, we investigated the constituents of a methanol extract of Dipsacus asper roots and obtained a new monoterpenoid glucoindole alkaloid, (3R,5S)-5-carboxyvincosidic acid 22-loganin ester (1), together with the known alkaloid (3S,5S)-5-carboxystrictosidic acid 22-loganin ester (dipsaperine) (2). We herein report our structural elucidation of 1 by spectroscopic analysis and its anti-inflammatory activity as revealed by its inhibition of nitric oxide production in lipopolysaccharide-activated RAW264.7 cells.