Nitric oxide (NO) production inhibitory constituents of Tabebuia avellanedae from Brazil

Abstract

From the water extract of Brazilian Tabebuia avellanedae, two new iridoids (1, 2) and a new phenylethanoid glycoside (3) have been isolated together with twelve known compounds (4-15). Their structures were determined based on the spectroscopic data. The isolated compounds inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-activated macrophage-like J774.1 cells. Compounds 1, 3, 10, 11, and 12 showed inhibitory activities more potent (IC 50, 13.8-26.1 μg/ml) than a positive control NG- monomethyl-L-arginine (L-NMMA; IC50, 27.4 μg/ml). © 2005 Pharmaceutical Society of Japan.