Kalbessa Abera, Dekebo Aman, Tesso Hailemichael, Abdo Teshome, Abdissa Negera, Melaku Yadessa
Chemistry Department, School of Applied Natural Sciences, Adama Science and Technology University, Adama, Ethiopia.
Chemistry Department, College of Natural Sciences, Jimma University, Jimma, Ethiopia.
J Trop Med. 2019 Aug 14;2019:8486214. doi: 10.1155/2019/8486214. eCollection 2019.
The genus , with species close to 152, is traditionally used to treat wide ranges of ailments in humans and animals. is one of the species found in Ethiopia and traditionally used as a laxative, antirheumatic agent, insecticide, antibacterial agent, and antimalarial agent. In view of its traditional use, the root bark was sequentially extracted with -hexane, EtOAc, and MeOH to afford 0.78%, 4%, and 6% crude extracts, respectively. The chromatographic separation of the EtOAc extract using silica gel column chromatography yielded three pure compounds: tetratriacontanyl caffeate (), 12--dodeca-2,4-dienoylphorbol-13-acetate (), and naringenin (). This is the first report of the isolation of and its kind from the genus and most probably from the Thymelaeaceae family. The structures of these compounds were characterized and identified by NMR and mass spectrometric analyses and comparison with literature data. The EtOAc extract and isolated compounds were assessed for their antibacterial and antioxidant activities. The EtOAc extract (1.5 mg/mL) showed significant inhibitory activity against , , , and bacterial strains with the highest inhibition zone observed against (23 mm), which is even greater than that of the reference drug ciprofloxacin (22 mm). However, the inhibition displayed on these bacterial strains for the three pure compounds was marginal with variable degrees of potency between the compounds. The better activity of the crude extract could be due to the synergistic interactions of several phytochemicals present in the extract, which cannot be the case when pure compounds are evaluated alone. The antioxidant activities of the extracts and isolated compounds were evaluated using DPPH and ferric thiocyanate methods. The EtOAc and MeOH extracts and compounds and were found to inhibit the DPPH radical by 70.7, 66.9, 85.8, and 52.8%, respectively. The EtOAc extract and compound inhibited peroxidation of lipids by 84 and 86%, respectively. The radical scavenging displayed by compound was significant compared with that displayed by ascorbic acid, indicating the strong antilipid peroxidation potential of the extract of root barks of . Therefore, the extracts of the root bark of can be used as a remedy in combating diseases caused by bacteria and free radicals provided that further comprehensive evaluation could be recommended for the conclusive decision on potential candidacy of this plant.
该属约有152个物种，传统上用于治疗人类和动物的多种疾病。[物种名称]是在埃塞俄比亚发现的物种之一，传统上用作泻药、抗风湿剂、杀虫剂、抗菌剂和抗疟剂。鉴于其传统用途，对其根皮依次用正己烷、乙酸乙酯和甲醇进行提取，分别得到0.78%、4%和6%的粗提物。采用硅胶柱色谱法对乙酸乙酯提取物进行色谱分离，得到三种纯化合物：三十四烷基咖啡酸酯（[化合物1名称]）、12-十二碳-2,4-二烯酰佛波醇-13-乙酸酯（[化合物2名称]）和柚皮素（[化合物3名称]）。这是首次从该属以及很可能从瑞香科中分离出[化合物1名称]及其同类化合物的报道。通过核磁共振和质谱分析以及与文献数据比较对这些化合物的结构进行了表征和鉴定。对乙酸乙酯提取物和分离出的化合物进行了抗菌和抗氧化活性评估。乙酸乙酯提取物（1.5毫克/毫升）对[细菌名称1]、[细菌名称2]、[细菌名称3]和[细菌名称4]菌株显示出显著的抑制活性，对[细菌名称1]观察到的抑制圈最大（23毫米），甚至大于参考药物环丙沙星（22毫米）。然而，三种纯化合物对这些细菌菌株的抑制作用较小，化合物之间的效力程度各不相同。粗提物活性更好可能是由于提取物中存在的几种植物化学物质的协同相互作用，而单独评估纯化合物时情况并非如此。采用二苯基苦味酰基自由基（DPPH）法和硫氰酸铁法评估提取物和分离出的化合物的抗氧化活性。发现乙酸乙酯提取物和甲醇提取物以及化合物[化合物1名称]和[化合物3名称]分别能抑制70.7%、66.9%、85.8%和52.8%的DPPH自由基。乙酸乙酯提取物和化合物[化合物1名称]分别能抑制84%和86%的脂质过氧化。与抗坏血酸相比，化合物[化合物3名称]表现出显著的自由基清除能力，表明[物种名称]根皮提取物具有很强的抗脂质过氧化潜力。因此，[物种名称]根皮提取物可用于对抗由细菌和自由基引起的疾病，前提是可以建议进行进一步的全面评估，以便就该植物的潜在候选资格做出最终决定。
