Angiotensin-converting enzyme (ACE) inhibitory activity of Solanum torvum and isolation of a novel methyl salicylate glycoside

A methanolic extract from Solanum torvum fruits exhibited inhibitory activity against the angiotensin-converting enzyme (ACE) with an IC50 value of 1.2 mg/mL. On the basis of a bioassay-guided isolation, an ACE inhibitory active compound, namely (E)-2,3-dihydroxycyclopentyl-3-(3′,4′-dihydroxyphenyl)acrylate (1) (IC50 of 778 µg/mL), was obtained, together with a novel methyl salicylate glycoside - torvumoside [methyl salicylate 2-O-(2′-O-β-apiofuranosyl, 6′-O-β-xylopyranosyl)-β-glucopyranoside] (3) and a known compound, lariciresinol-4,4′-O-β-D-diglucoside (2). This is the first report of these compounds in this plant.