Phytochemical study of the heartwood of Artocarpus lakoocha Roxb. led to the isolation of two stilbenes, namely oxyresveratrol and resveratrol. From the roots of A. gomezianus Wall, ex Tre'c. nine pure compounds were isolated. These compounds are the flavonoids isocyclomorusin, cycloartocarpin, artocatpin, norartocarpetin, cudraflavone C and albanin A. The others are the stilbene resveratrol, the benzenoid resorcinol and the naphthalene phenyl- β-naphthylamine. In addition, the presence of β-sitosterol and stigmasterol was detected. The structures of all of these isolates were determined by extensive spectroscopic studies, including comparison of their UV, IR, MS and NMR properties with previously reported data. Each of these compounds was evaluated for its tyrosinase inhibitory activity. It was found that oxyresveratrol, resveratrol and norartocarpetin possessed the most potent activity. The structure-activity relationships of these compounds were also discussed.
