Planta Med. 2003 Mar; 69(3): 247-53.

Biflavonoids with cytotoxic and antibacterial activity from Ochna macrocalyx.

Tang S, Bremner P, Kortenkamp A, Schlage C, Gray AI, Gibbons S, Heinrich M.

Centre for Pharmacognosy and Phytotherapy, The School of Pharmacy, London, UK.

Six biflavonoid and related compounds were isolated from the ethanolic extract of Ochna macrocalyx bark. One is a new compound, the isoflavanone dimer dehydroxyhexaspermone C ( 1). Previously isolated compounds obtained from the bark are biisoflavonoid hexaspermone C ( 2). tetrahydrofuran derivative ochnone ( 3). furobenzopyran derivative cordigol ( 4). and biflavonoids calodenin B ( 5). and dihydrocalodenin B ( 6). Although 3 has already been isolated, its spectral data are presented here for the first time. Isolated compounds were tested for cytotoxic activity on MCF-7 breast cancer cells using the MTT reduction assay method. Compound 5 showed cytotoxic activity (7 +/- 0.5 microM) and 6 showed moderate cytotoxicity (35 +/- 7 microM). In antibacterial assays performed using three strains of multi-drug resistant (mdr) Staphylococcus aureus (RN4220, XU212 and SA-1199-B) compounds 5 and in particular 6 showed strong antibacterial activity (MICs 5 : 64, 8, 16 microg/mL 6 : 8, 8, 8 microg/mL, respectively). The ethanolic extract of the bark also showed NF-kappaB inhibitory activity.