Madikizela B, Aderogba M A, Finnie J F, Van Staden J
Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal, Scottsville 3209, Private Bag X01,Pietermaritzburg, South Africa.
Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal, Scottsville 3209, Private Bag X01,Pietermaritzburg, South Africa.
J Ethnopharmacol. 2014 Oct 28;156:228-34. doi: 10.1016/j.jep.2014.09.003. Epub 2014 Sep 16.
The emergence of drug resistant-tuberculosis and other pathogenic diseases over the past decades, constitutes a serious threat to human health worldwide. According to a 2012 report by the World Health Organization (WHO), South Africa, China, India and Russia are the countries with the highest prevalence of Multi-Drug Resistant tuberculosis (MDR-tuberculosis) as they represented 60% of the total. Several reports have documented antimycobacterial properties of Terminalia species but only a few species from this genus have been explored for their antimycobacterial constituents. The crude extracts of Terminalia phanerophlebia showed good antimicrobial activities in our previous study against two Mycobacterium as well as two other bacterial strains responsible for opportunistic infections related to respiratory ailments. This paper studies the isolation of compounds responsible for such activities and to isolate compounds responsible for antimicrobial activities from the crude extracts of Terminalia phanerophlebia leaves.
Terminalia phanerophlebia crude extracts obtained from 80% methanol was successively extracted with hexane, dichloromethane (DCM), ethyl acetate (EtOAc) and n-butanol. The fractions obtained and isolated compounds were tested for their antibacterial activities against Mycobacterium aurum, Mycobacterium tuberculosis, Staphylococcus aureus and Klebsiella pneumoniae. Bioguided fractionation of the EtOAc fraction afforded two bioactive compounds. Structure elucidation was carried out using NMR (1D and 2D) spectroscopic methods.
EtOAc fraction exhibited highest antimicrobial activities and its fractionation afforded methyl gallate (methyl-3,4,5-trihydroxybenzoate) (1) and a phenylpropanoid glucoside, 1,6-di-O-coumaroyl glucopyranoside (2) These compounds are reported from Terminalia phanerophlebia for the first time. Both compounds showed good antimicrobial activity against all bacterial strains tested with minimum inhibitory concentration (MIC) values ranging from 63 to 250 µg/mL. Inhibition of Mycobacterium tuberculosis by 1,6-di-O-coumaroyl glucopyranoside (2) at a MIC value of 63 µg/mL was noteworthy, as this bacterial strain is reported to be the leading cause of tuberculosis worldwide.
Good antimicrobial activities exhibited by the compounds isolated from Terminalia phanerophlebia authenticate the traditional use of this plant in treating tuberculosis and its related symptoms. Compound (2), 1,6-di-O-coumaroyl glucopyranoside could serve as a lead compound for tuberculosis drug discovery.
在过去几十年中，耐药结核病和其他致病疾病的出现对全球人类健康构成了严重威胁。根据世界卫生组织（WHO）2012年的一份报告，南非、中国、印度和俄罗斯是耐多药结核病（MDR - 结核病）患病率最高的国家，它们占总数的60%。几份报告记录了榄仁属植物的抗分枝杆菌特性，但该属中只有少数物种的抗分枝杆菌成分得到了研究。在我们之前的研究中，显脉诃子的粗提物对两种分枝杆菌以及另外两种与呼吸道疾病相关的机会性感染细菌菌株表现出良好的抗菌活性。本文研究了显脉诃子叶粗提物中负责此类活性的化合物的分离，并从中分离出具有抗菌活性的化合物。
从80%甲醇中获得的显脉诃子粗提物依次用己烷、二氯甲烷（DCM）、乙酸乙酯（EtOAc）和正丁醇萃取。对所得馏分和分离出的化合物进行了对金色分枝杆菌、结核分枝杆菌、金黄色葡萄球菌和肺炎克雷伯菌的抗菌活性测试。对EtOAc馏分进行生物导向分级分离得到了两种生物活性化合物。使用NMR（一维和二维）光谱方法进行结构解析。
EtOAc馏分表现出最高的抗菌活性，其分级分离得到了没食子酸甲酯（3,4,5 - 三羟基苯甲酸甲酯）（1）和一种苯丙素糖苷，1,6 - 二 - O - 香豆酰吡喃葡萄糖苷（2）。这些化合物首次从显脉诃子中报道。两种化合物对所有测试的细菌菌株均表现出良好的抗菌活性，最低抑菌浓度（MIC）值范围为63至250μg/mL。1,6 - 二 - O - 香豆酰吡喃葡萄糖苷（2）对结核分枝杆菌的抑制作用值得注意，其MIC值为63μg/mL，因为据报道该细菌菌株是全球结核病的主要病因。
从显脉诃子中分离出的化合物表现出良好的抗菌活性，证实了该植物在治疗结核病及其相关症状方面的传统用途。化合物（2），1,6 - 二 - O - 香豆酰吡喃葡萄糖苷可作为结核病药物发现的先导化合物。
