Research Unit of Applied and Environmental Chemistry, Department of Chemistry, Faculty of Science, University of Dschang, P.O. Box 67, Dschang, Cameroon.
Research Unit of Microbiology and Antimicrobial Substances, Department of Biochemistry, Faculty of Science, University of Dschang, P.O. Box 67, Dschang, Cameroon.
Biomed Res Int. 2022 Jun 15;2022:7856305. doi: 10.1155/2022/7856305. eCollection 2022.
The use of natural products for medicinal purposes is becoming more and more common nowadays, as evidenced by the presence in plants of secondary metabolites with different potentials such as antioxidant and antibacterial properties. We evaluated in this work the antimicrobial activities of the extracts and some isolated compounds from the seeds of Hiern. (Rubiaceae), a Cameroonian medicinal plant traditionally used to cure microbial infections. The ethanol extract was prepared by maceration and extracted with ethyl acetate and -butanol. The EtOAc ( = 168 g) and -BuOH ( = 20 g) extracts were further fractionated by silica gel column chromatography to isolation of compounds. Their structures were elucidated by spectroscopic analysis and by comparison with published data. The antibacterial activity of extracts and compounds was assessed by evaluating the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against pathogenic bacteria. Thirteen compounds including four alkaloids (veprisine (), naucleofficine III (), vepridimerine B (), and vepridimerine C ()), three triterpenes (barbinervic acid (), 3---L-rhamnopyranosyl quinovic acid (), and oleanolic acid ()), one steroid (-sitosterol-3---D-glucopyranoside ()), four phenolic compounds (scopoletin (), gallic acid (), quercetin-3---D-glucopyranoside (), and kaempferol 3---L-rhamnopyranoside-7---L-rhamnopyranoside ()), and one iridoid (borreriagenin ()) were isolated from the EtOAc and -BuOH extracts. These compounds were identified by 1D and 2D NMR combined analysis as well as by melting point comparison. The EtOH, EtOAc, and -BuOH extracts exhibited significant antibacterial activities (MIC = 32-128 g/mL; MBC = 64-256 g/mL) against (Gram-positive bacterium), , , and (Gram-negative bacteria). Among the isolated compounds, scopoletin () showed a moderate activity against with MIC and MBC values of 16 g/mL and 32 g/mL, respectively. It appears that, chemotaxonomically, some of the isolated compounds have already been obtained from the genus but to the best of our knowledge, this is the first report on the phytochemical investigation of . Although many other studies need to be achieved, our results support the use of in traditional medicine to cure infectious diseases particularly those caused by the tested bacteria.
如今，天然产物在药用方面的应用越来越普遍，这一点可以从植物中存在具有不同潜力的次生代谢产物得到证明，如抗氧化和抗菌特性。我们在这项工作中评估了 Hiern.（茜草科）种子的提取物和一些分离化合物的抗菌活性，Hiern. 是一种喀麦隆药用植物，传统上用于治疗微生物感染。乙醇提取物通过浸提制备，并用乙酸乙酯和正丁醇提取。EtOAc（= 168 g）和 -BuOH（= 20 g）提取物进一步通过硅胶柱色谱分离化合物。通过光谱分析和与已发表数据的比较来阐明它们的结构。通过评估最低抑菌浓度（MIC）和最低杀菌浓度（MBC）来评估提取物和化合物对致病菌的抗菌活性。从 EtOAc 和 -BuOH 提取物中分离得到 13 种化合物，包括 4 种生物碱（veprisine（）、naucleofficine III（）、vepridimerine B（）和 vepridimerine C（））、3 种三萜（barbinervic 酸（）、3---L-鼠李吡喃糖基喹诺酸（）和齐墩果酸（））、1 种甾体（-谷甾醇-3---D-吡喃葡萄糖苷（））、4 种酚类化合物（东莨菪内酯（）、没食子酸（）、槲皮素-3---D-吡喃葡萄糖苷（）和山奈酚 3---L-鼠李吡喃糖苷-7---L-鼠李吡喃糖苷（））和 1 种环烯醚萜（borreriagenin（））。这些化合物通过 1D 和 2D NMR 组合分析以及熔点比较来鉴定。EtOH、EtOAc 和 -BuOH 提取物对 （革兰氏阳性菌）、、、和 （革兰氏阴性菌）表现出显著的抗菌活性（MIC = 32-128 g/mL；MBC = 64-256 g/mL）。在所分离的化合物中，东莨菪内酯（）对 具有中等活性，MIC 和 MBC 值分别为 16 g/mL 和 32 g/mL。似乎，从化学分类学的角度来看，一些分离得到的化合物已经从 属中获得，但据我们所知，这是首次对 进行植物化学研究的报道。尽管还需要进行许多其他研究，但我们的结果支持在传统医学中使用 来治疗传染病，特别是由测试细菌引起的传染病。
