Dracaenogenins A and B, new spirostanols from the red resin of Dracaena cochinchinensis

A 12(13→14)abeospirostanol dracaenogenin A (1) and a spirostanol dracaenogenin B (2) were isolated from Chinese dragon's blood, the red resin of Dracaena cochinchinensis (Agavaceae). Their structures were established as (14S,25R)12(13→14)abeospirosta-5,13(18)-diene-1β,3β,15α-triol (1) and (25R) spirost-5-ene-1β,3β,14α,15α-tetrol (2) by means of spectroscopic analysis, especially by 2D NMR spectra, and X-ray crystallographic analysis. Dracaenogenin A (1) is the first example of a 12(13→14)abeospirostane spirostanoid found in nature. Its biogenesis from ruscogenin (3) through namogenin (4) and 2 was tentatively proposed.