Studies on Nepalese Crude Drugs. XXIX. Chemical Constituents of Dronapuspi, the Whole Herb of Leucas cephalotes SPRENG.

Abstract

From the whole herb of Leucas cephalotes SPRENG., new labdane-, norlabdane- and abietane-type diterpenes named leucasdins A (1), B (2) and C (3), respectively, and two protostane-type triterpenes named leucastrins A (4) and B (5) were isolated, together with a known triterpene, oleanolic acid, five sterols, 7-oxositosterol, 7-oxostigmasterol, 7α-hydroxysitosterol, 7α-hydroxystigmasterol and stigmasterol, and eight flavones, 5-hydroxy-7,4′-dimethoxyflavone, pillion, gonzalitosin I, tricin, cosmosin, apigenin 7-O-β-D-(6-O-p-coumaroyl)glucopyranoside, anisofolin A and luteolin 4′-O-β-D-glucuronopyranoside. The structures of 1—5 were determined as (3S,6R,8R,9R,13S,16S)-9,13,15,16-bisepoxy-3,16-diacetoxy-6-formyloxylabdane, (3S,6R)-3-acetoxy-6-formyloxy-iso-ambreinolide, (4R,9S,12R,13R)-12,13-dihydroxyabiet-7-en-18-oic acid, (3S,17S,20S,24S)-3,20-dihydroxy-24-methylprotost-25-en, and (3S,17S,20S,24S)-3,20,24-trihydroxyprotost-25-en respectively, based on spectral and chemical data.