Decumbic anhydride from the stem barks of (Anacardiaceae).

From an EtOAc-soluble fraction of the stem barks of (Anacardiaceae), decumbic anhydride () and four known compounds - were isolated. Their chemical structures were elucidated based on the spectroscopic data interpretation. The GIAO-DFT calculation of C NMR chemical shifts was carried out to clarify the structure of . The absolute configuration of was assigned based on the Cotton effects in its ECD spectrum. Compound showed potent tyrosinase inhibitory activity with an IC value of 52.2 μM.