Anti-inflammation furanoditerpenoids from Caesalpinia minax Hance

Twelve furanocassane derivatives, including six previously unreported were isolated from the seeds of Caesalpinia minax Hance. Neocaesalminin A (1) was found with an unusual A-seco-rearranged cassane skeleton. The inhibitory effect on NO production for all compounds was evaluated in vitro. Furanoditerpenes were responsible for this herb’s anti-inflammation activity. [Display omitted] •Cassane furanoditerpenes, six previously unreported were isolated from seeds of Caesalpinia minax Hance.•Neocaesalminin A, a furanoditerpene, has an unusual A-seco-rearranged cassane skeleton.•Inhibitory effects on NO production for all compounds were evaluated in vitro.•Cassane furanoditerpenes were responsible for the Caesalpinia minax Hance anti-inflammation activity. Cassane skeletons are rare in nature, but often possess valuable medicinal properties. A furanoditerpenoid with an unusual A-seco-rearranged cassane skeleton, neocaesalminin A, and five furanoditerpenoids were isolated from seeds of Caesalpinia minax Hance, along with six known cassane derivatives, 7-O-acetyl-bonducellpin C, caesalmin F, caesalmin C, ζ-caesalmin, caesalmin E1 and caesalpinin K. Compound structures were determined by spectroscopy (HR-ESI-MS, UV, IR, 1D NMR, 2D NMR), X-ray crystallography and quantum chemical computation of electronic circular dichroism). Three of the previously known compounds exhibited significant inhibition of nitric oxide production of RAW264.7 macrophages stimulated by lipopolysaccharide (LPS).