Brassinosteroids, sterols and lup-20(29)-en-2α,3β,28-triol from Rheum Rhabarbarum
摘要:
The new pentacyclic triterpene lup-20(29)-en-2 alpha,3 beta,28-triol and its 3,28-dipalmitoyl ester were identified from panicles of Rheum rhabarbarum on the basis of their spectral data (H-1 NMR,. C-13 NMR, MS, IR). Besides the brassinosteroids brassinolide, castasterone and 24-epicastasterone, the phytosterols campesterol, stigmasterol, sitosterol and isofucosterol were identified from the same plant material.