Institute of Medical Research and Medicinal Plant Studies, (IMPM), PO, Box 13033, Yaoundé, Cameroon.
Institute of Fisheries and Aquatic Sciences, University of Douala, PO, Box 7236, Douala, Cameroon.
BMC Complement Altern Med. 2019 Mar 11;19(1):56. doi: 10.1186/s12906-019-2459-y.
Enantia chlorantha is a plant belonging to Annonaceae Family. The Barks and leaves are used traditionally to treat infectious diseases. Earlier studies highlighted the antibacterial activity of stem barks methanol extract. This study is thus aimed at investigating the effect of fractionation on antibacterial activity of its n-butanol fraction.
The extract of E. chlorantha stem barks was obtained by maceration in methanol and then subjected to a liquid/liquid partition by successive depletion with solvents of increasing polarity. The n-butanol fraction was fractionated by adsorption chromatography on silica gel. A product was isolated from the dichloromethane/methanol (2%) fraction and the structure was determined on the basis of spectroscopic data; Proton Nuclear Magnetic Resonance (H NMR), Carbon-13 Nuclear Magnetic Resonance (C NMR), Heteronuclear Multiple Bond Correlation (HMBC), H-correlation spectroscopy (H-COSY), attached proton test (APT), heteronuclear multiple quantum coherence (HSQC). The antibacterial activity was evaluated by broth microdilution method against six reference strains and eight clinical bacterial strains.
The n-butanol fraction was found to be active with MIC values ranging from 32 to 256 μg/mL. The F sub-fraction was more efficient among the eight sub-fractions, the n-butanol fraction and comparable to Chloramphenicol used as reference antibiotic. The product obtained was elucidated as palmitin. The antibacterial activity of the latter was comparable to that of Chloramphenicol on one reference strain and 4 of the 6 clinical strains.
The F sub-fraction had better antibacterial activity than the n-butanol fraction and other sub-fractions, and possibly palmitin was the active substance responsible for the antibacterial activity of E. chlorantha.
醉鱼草属植物是番荔枝科的一种植物。其树皮和叶子传统上被用于治疗传染病。早期的研究强调了茎皮甲醇提取物的抗菌活性。因此，本研究旨在研究其正丁醇部分的分馏对其抗菌活性的影响。
醉鱼草属植物茎皮的提取物通过甲醇浸提获得，然后用溶剂进行液/液分配，溶剂的极性逐渐增加。正丁醇部分通过硅胶吸附色谱进行分离。从二氯甲烷/甲醇（2%）部分分离出一种产物，并根据光谱数据确定结构；质子核磁共振（H NMR）、碳-13 核磁共振（C NMR）、异核多键相关（HMBC）、H-相关光谱（H-COSY）、附加质子测试（APT）、异核多量子相干（HSQC）。采用肉汤微量稀释法测定六种参考菌株和八种临床分离菌的抗菌活性。
正丁醇部分表现出活性，MIC 值范围为 32 至 256 μg/mL。在八个亚馏分中，F 亚馏分比正丁醇部分和与氯霉素作为参考抗生素相当有效。从二氯甲烷/甲醇（2%）部分分离得到的产物被阐明为棕榈酸。后者的抗菌活性与氯霉素对一种参考菌株和六种临床菌株中的 4 种相当。
F 亚馏分比正丁醇部分和其他亚馏分具有更好的抗菌活性，可能棕榈酸是醉鱼草属植物抗菌活性的活性物质。
