Caesalminaxins A-L, cassane diterpenoids from the seeds of Caesalpinia minax.

摘要: Fourteen new cassane diterpenoids, caesalminaxins A–L (1–14), and three known compounds were isolated from the seeds of Caesalpinia minax. Among 3 4 possess a rare spiro C/D ring system. The C-16 epimeric mixture 1/2 has an unprecedented carbon skeleton, presumably derived by cleavage C-13–C-14 bond. Compound 5 is first example diterpenoid with A/B structures elucidated on basis 1D 2D NMR analysis, absolute configurations 3, 4, 9, 11 determined single-crystal X-ray crystallography. Biosynthesis pathways for 1/2, are postulated. Compounds 8, bonducellpin D exhibited moderate activity against four tested human cancer cell lines, HepG-2, K562, HeLa, Du145.