Sesquiterpenoids from the fruits of Alpinia oxyphylla and inhibition of nitric oxide production in lipopolysaccaride-activated macrophages

Three new norsesquiterpenoids, oxyphenol A (1), mandassion A (2) and mandassion B (3), along with three known compounds (4-6) were isolated from the fruits of Alpinia oxyphylla. Chemical structures of 1-3 were established by analysis of spectroscopic data. The absolute configuration of 2 and 3 was determined by the comparison of experimental electronic circular dichroism (ECD) spectroscopy and time-dependent density functional theory (TDDFT) calculations. Inhibitory effects of the six compounds on nitric oxide production in lipopolysaccaride-activated macrophages were evaluated, and compounds 3-5 showed significant inhibitory effect dependent on the concentration at the range of 1-50 mu M. (C) 2011 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.