Three novel sesquiterpene polyol esters from the root bark of Celastrus angulatus Maxim and their nitric oxide inhibitory activity.

Three new sesquiterpene polyol ester compounds angulatin V [1β,15-diacetoxy-2β-(α-methyl)-butanoyloxy-4α,6α-dihydroxy-8α-isobutanoyloxy-9β-benzoxy-β-dihydroagarofuran], angulatin W [1β,2β-diacetoxy-4α,6α-dihydroxy-8-carbonyl-9β-benzoxy-15-isobutanoyloxy-β-dihydroagarofuran], angulatin X [1β,2β,8α-triacetoxy-4α, 6α-dihydroxy-9β-benzoxy-15-nicotinyl-β-dihydroagarofuran] (1-3), together with one known compound Putterine B (4), were isolated from the root bark of Celastrus angulatus Maxim. The structures of compounds 1-3 were elucidated by NMR, HRESIMS, IR data, and comparison with the literature data. The anti-inflammatory activity of all compounds was evaluated by measuring nitric oxide production in RAW264.7 macrophages. Compounds 1-4 showed no significant nitric oxide inhibitory activity at 2.5 and 5 μM concentrations.