Antibacterial pterocarpans from Erythrina subumbrans

作者：Rukachaisirikul Thitima^*; Innok Phongsak; Aroonrerk Nuntana; Boonamnuaylap Woraluk; Limrangsun Saranya; Boonyon Chanakan; Woonjina Umpawan; Suksamrarn Apichart

来源：Journal of Ethnopharmacology, 2007, 110(1): 171-175.

DOI：10.1016/j.jep.2006.09.022

• Erythrina subumbrans
• Leguminosae
• pterocarpans
• flavanones
• isoflavone
• antibacterial activity

Seven pterocarpans, erybraedin B (1), erybraedin A (2), phaseollin (3), erythrabyssin 11 (4), erystagallin A (5), erythrabissin-1 (6) and erycristagallin (7), two flavanones, 5-hydroxysophoranone (8) and glabrol (9), and one isoflavone, erysubin F (10), were isolated from the stems of Erythrina subumbrans (Leguminosae). Their structures were identified by means of spectroscopy. This is the first report of the isolation of the non-alkaloidal compounds from Erythrina subumbrans and the observed dehydration of 6a-hydroxypterocarpans 5 and 6 in CDCl3 to the corresponding pterocarpenes 11 and 12, respectively. Compounds 8 and 9 were isolated for the first time from the genus Erythrina. Compounds 2 and 4 exhibited the highest degree of activity against Streptococcus strains with an MIC range of 0.78-1.56 mu g/ml, whereas compound 7 exhibited the highest degree of activity against Staphylococcus strains, including drug-resistant strains (MRSA and VRSA), with an MIC range of 0.39-1.56 mu g/ml. Interestingly, compounds 2, 4, 5 and 7 were more active against several strains of Streptococcus and Staphylococcus than the standard antibiotics vancomycin and oxacillin. Compound 7 showed the highest level of activity against all VRSA strains tested, with an MIC range of 0.39-1.56 mu g/ml, which were resistant to both antibiotics. These compounds may prove to be potent phytochemical agents for antibacterial activity, especially against the MRSA and VRSA strains.

• 出版日期2007-3-1