Center for Chemical and Pharmaceutical Institute, Ural Federal University, Yekaterinburg, 620002, Russia; Natural Products Division, Department of Chemistry, Sri Venkateswara University, Tirupati, India.
Department of Biochemistry, Virginia Tech, Blacksburg, VA, 24060, USA; Department of Pathophysiology, The Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, Shantou, 515031, Guangdong Province, China.
Microb Pathog. 2019 Nov;136:103667. doi: 10.1016/j.micpath.2019.103667. Epub 2019 Aug 13.
Rhynchosia beddomei Baker (R. beddomei) is a viscous hairy under shrub, belongs to the family of Fabaceae and widely distributed in Deccan and Carnatic regions of South India. In the present investigation, four flavonoids such as an isoflavone, 5,7-dihydroxy-4'-methoxyisoflavone (RB-1), a flavonol, quercetin-7-O-methylether (RB-2), two flavone C-glycosides, isovitexin (RB-3) and 5,7,3',4'-tetrahydroxy-6-C-β-d-glucopyranosyl flavone (RB-4) were isolated from the flowers of R. beddomei Baker through bioassay guided fractionation. Subsequently, antimicrobial activity of compounds against drug resistant gram positive and negative bacteria and fungi revealed RB-2 and RB-4 have shown highest minimal inhibition concentrations against Pseudomonas aeruginosa and Candida albicans. RB-2 and RB-4 enclosed OH groups at 5th position on the ring A, 3' and 4' ortho dihydroxyl groups positioned on the ring B and accomplished efficacious antibacterial activity. In addition, Docking studies perceptible that RB-4 conferred highest binding energy of -10.5 kcal/mol and exhibited eloquent polar and non-polar interactions with active site residues of N-Myristoyltransferase (Nmt) of Candida albicans while binding energy of -7.5 kcal/mol was recorded for peptidyldeformylase (PaPDF) of Pseudomonas aeruginosa. Moreover, these compounds obey Lipinski's rule of five and exerts good drug likeness properties and might be ratified as lead molecules for further investigations to prevent panicking microbial infections.
Beddomea rhynchosia Baker（R. beddomei）是一种粘性多毛的矮小灌木，属于豆科植物，广泛分布于印度南部的德干高原和卡纳塔克邦地区。在本研究中，从 R. beddomei Baker 的花中分离得到了四种类黄酮，包括一种异黄酮，5,7-二羟基-4'-甲氧基异黄酮（RB-1）、一种黄酮醇，槲皮素-7-O-甲醚（RB-2）、两种黄酮 C-糖苷，异荭草苷（RB-3）和 5,7,3',4'-四羟基-6-C-β-D-吡喃葡萄糖基黄酮（RB-4）。随后，对化合物进行了抗耐药革兰氏阳性和阴性细菌和真菌的抗菌活性测试，结果表明 RB-2 和 RB-4 对铜绿假单胞菌和白色念珠菌的最小抑菌浓度最高。RB-2 和 RB-4 在 A 环的 5 位上含有 OH 基团，B 环上有 3'和 4'邻位二羟基基团，具有有效的抗菌活性。此外，对接研究表明，RB-4 与白色念珠菌 N-豆蔻酰转移酶（Nmt）的活性位点残基具有最高的结合能-10.5 kcal/mol，并表现出强烈的极性和非极性相互作用，而铜绿假单胞菌的肽脱甲酰酶（PaPDF）的结合能为-7.5 kcal/mol。此外，这些化合物符合 Lipinski 的五规则，具有良好的药物相似性特性，可能被确认为进一步研究的先导化合物，以防止微生物感染的恐慌。
