Antimicrobial and immunomodulatory properties of prenylated xanthones from twigs of Garcinia staudtii.

Phytochemical investigation of the methanol extract of the twigs of Garcinia staudtii yielded four new prenylated xanthones, staudtiixanthones A-D (1-4), along with eleven known compounds. Their structures were determined by analysis of 1D and 2D NMR spectra and by comparison of spectroscopic data with those previously reported. Some of these compounds have been evaluated for antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). The new compounds were also screened for phagocyte chemiluminescence, neutrophil chemotaxis, T-cell proliferation, cytokine production from mononuclear cells and cytotoxicity. They were found to exhibit potent immunomodulatory activities.