Biflavonoids with Cytotoxic and Antibacterial Activity from Ochna macrocalyx

Abstract

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 μM) and 6 showed moderate cytotoxicity (35 ± 7 μM). 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 μg/mL 6 : 8, 8, 8 μg/mL, respectively). The ethanolic extract of the bark also showed NF-κB inhibitory activity.

Ochnaceae - Ochna macrocalyx - biflavonoids - antibacterial - mdr - cytotoxicity - NF-κB - ethnopharmacology

References

• 1 Schlage C, Mabula C, Mahunnah R LA, Heinrich M. Medicinal plants of the Washambaa (Tanzania): Documentation and ethnopharmacological evaluation.  Plant Biology. 2000;  2 83-92
• 2 Hansen M B, Nielsen S E, Berg K. Re-examination and further development of a precise and rapid dye method for measuring cell growth/cell kill.  J Immunol Methods. 1989;  119 203-10
• 3 Bork P M, Bacher S, Schmitz M L, Kaspers U, Heinrich M. Hypericin as a non-antioxidant inhibitor of NF-κB.  Planta Medica. 1999;  65 297-300
• 4 Gibbons S, Udo E E. The effect of reserpine, a modulator of multidrug efflux pumps, on the in vitro activity of tetracycline against clinical isolates of methicillin resistant Staphylococcus aureus (MRSA) possessing the tet (K) determinant.  Phytother Res. 2000;  14 139-40
• 5 Moreira I C, Sobrinho D C, De Carvalho M G, Braz-Filho R. Isoflavonone dimers hexaspermone A, B and C from Ouratea hexasperma .  Phytochemistry. 1994;  35 1567-72
• 6 Hostettmann K, Marston A. Countercurrent chromatography in the preparative separation of plant derived natural products.  J Liq Chromatogr RT. 2001;  24 1711-21
• 7 Marston A, Zagorski M G, Hostettmann K. Antifungal polyphenols from Cordia goetzei .  Helv Chim Acta. 1988;  71 1210-9
• 8 Drewes S E, Hudson N A, Bates R B, Linz G S. Novel dimeric chalcone based pigments from Brackenridgea zanguebarica .  Tetrahedron Lett. 1984;  25 105-8
• 9 Drewes S E, Hudson N A, Bates R B, Linz G S. Medicinal plants of Southern Africa. Part 1. Dimeric chalcone-based pigments from Brackenridgea zanguebarica .  J Chem Soc Perkin Trans. 1987;  I 2809-13
• 10 Messanga B, Tih R G, Sondengam B L, Martin M T. et al . Biflavonoids from Ochna calodendron .  Phytochemistry. 1994;  35 791-4
• 11 Ingram D, Sanders K, Kolybaba M, Lopez D. Case-control study of phytoestrogens and breast cancer.  Lancet. 1997;  350 990-4
• 12 Bremner P, Heinrich M. Natural products as modulators of the NF-κB-pathway.  Journal of Pharmacy and Pharmacology. 2002;  54 453-72
• 13 Williamson E M. Synergy and other interactions in phytomedicines.  Phytomedicine. 2001;  8 401-9