Majinda R R, Motswaledi M, Waigh R D, Waterman P G
Planta Med. 1997 Jun;63(3):268-70. doi: 10.1055/s-2006-957671.
The n-butanol fraction of Vahlia capensis yielded kaempferol, quercetin, afzelin, astragalin, quercitrin, isoquercitrin, rutin, gallic acid, chiro-inositol, dulcitol, and a novel biflavonoid, VC-15B (vahlia biflavone). The compounds were identified using 1D and 2D NMR techniques and FABMS. Vahlia biflavone and gallic acid were isolated, using bioassay-guided procedure and identified as the antibacterial components. Both compounds showed activity against Gram positive Staphylococcus aureus and Bacillus subtilis. Vahlia biflavone gave MIC values of 15.3 micrograms/ml and 30.6 micrograms/ml against S. aureus and B. subtilis, respectively while gallic acid gave a value of 71.3 micrograms/ml for both organisms.
海角瓦莲的正丁醇馏分产生了山奈酚、槲皮素、阿福豆苷、紫云英苷、槲皮苷、异槲皮苷、芦丁、没食子酸、手性肌醇、卫矛醇和一种新型双黄酮VC-15B（海角瓦莲双黄酮）。这些化合物通过一维和二维核磁共振技术以及快原子轰击质谱法进行鉴定。采用生物测定导向法分离出海角瓦莲双黄酮和没食子酸，并确定它们为抗菌成分。这两种化合物对革兰氏阳性菌金黄色葡萄球菌和枯草芽孢杆菌均有活性。海角瓦莲双黄酮对金黄色葡萄球菌和枯草芽孢杆菌的最低抑菌浓度分别为15.3微克/毫升和30.6微克/毫升，而没食子酸对这两种细菌的最低抑菌浓度均为71.3微克/毫升。
