Diab Y, Atalla K, Elbanna K
Department of Biochemistry, Fayoum University, Fayoum, Egypt.
Drug Discov Ther. 2012 Aug;6(4):212-7.
One hundred and twenty four plant extracts were evaluated for their antimicrobial activity against four pathogenic bacteria (Staphylococcus aureus (ATCC 8095), Salmonella enteritides (ATCC 13076), Escherichia coli (ATCC 25922), and Listeria monocytogenes (ATCC 15313)) and Candida albicans yeast (ATCC 10231) using the disk diffusion and broth microdilution methods. Of the plant extracts, fourteen exhibited antimicrobial activity against two or more of the five microorganisms tested. Only the methanol extract of Lagerstroemia indica leaves exhibited antimicrobial activity against all pathogenic bacteria and C. albicans yeast that were tested. Purification of the methanol extract of L. indica leaves using antimicrobial assay-guided isolation yielded one pure active compound. The chemical structure of the isolated active compound was found to be '4-methoxy apigenin-8-C-β-D-glucopyranoside; cytisoside according to detailed spectroscopic analysis of its nuclear magnetic resonance and mass spectrometry data. The compound exhibited antimicrobial activity against C. albicans (minimum lethal concentration (MLC): 32 μg/mL), S. aureus (MLC: 16 μg/mL), S. enteritides (MLC: 16 μg/mL), E. coli (MLC: 16 μg/mL), and L. monocytogenes (MLC: 16 μg/mL). The present study found that the methanol extract of L. indica leaves holds great promise as a potential source of beneficial antimicrobial components for different applications.
使用纸片扩散法和肉汤微量稀释法，对124种植物提取物针对四种病原菌（金黄色葡萄球菌（ATCC 8095）、肠炎沙门氏菌（ATCC 13076）、大肠杆菌（ATCC 25922）和单核细胞增生李斯特菌（ATCC 15313））以及白色念珠菌酵母（ATCC 10231）的抗菌活性进行了评估。在这些植物提取物中，有14种对所测试的五种微生物中的两种或更多种表现出抗菌活性。只有紫薇叶的甲醇提取物对所有测试的病原菌和白色念珠菌酵母都表现出抗菌活性。采用抗菌测定导向分离法对紫薇叶甲醇提取物进行纯化，得到一种纯活性化合物。根据其核磁共振和质谱数据的详细光谱分析，发现分离出的活性化合物的化学结构为“4-甲氧基芹菜素-8-C-β-D-吡喃葡萄糖苷；刺槐苷”。该化合物对白色念珠菌（最低致死浓度（MLC）：32μg/mL）、金黄色葡萄球菌（MLC：16μg/mL）、肠炎沙门氏菌（MLC：16μg/mL）、大肠杆菌（MLC：16μg/mL）和单核细胞增生李斯特菌（MLC：16μg/mL）均表现出抗菌活性。本研究发现，紫薇叶甲醇提取物有望成为不同应用中有益抗菌成分的潜在来源。
