Diarylalkanoids as Potent Tyrosinase Inhibitors from the Stems of Semecarpus caudata

From a CHCl3-soluble extract of the stems of Semecarpus caudata (Anacardiaceae), two new diarylalkanoids, semedienone (1) and semetrienone (2), were isolated. Their structures were elucidated based on NMR spectroscopic data interpretation. These compounds possess strong tyrosinase inhibitory activity with the IC50 values of 0.033 and 0.11 mu M, respectively. Docking studies of 1 and 2 with oxy-tyrosinase were carried out to analyze their interactions. Accordingly, semedienone (1) showed good interactions with the peroxide group and amino acid residues. The biosynthesis of the isolated diarylalkanoids was proposed.

Automated summary

Two new diarylalkanoids, semedienone and semetrienone, were isolated from a CHCl3-soluble extract of Semecarpus caudata stems. They exhibited strong tyrosinase inhibitory activity, with IC50 values of 0.033 and 0.11 μM, respectively. Docking studies showed that semedienone had good interactions with peroxide group and amino acid residues. The biosynthesis pathway of these compounds was also proposed.