Centro Nacional de Investigación Disciplinaria en Salud Animal e Inocuidad (CENID SAI-INIFAP), Carretera Federal Cuernavaca-Cuautla No. 8534 / Col. Progreso, C.P. 62550, Jiutepec, Morelos, A.P. 206-CIVAC, Mexico.
Universidad Politécnica de Morelos. Boulevard Cuauhnáhuac #566, Col. Lomas del Texcal, Jiutepec, Morelos, CP 62550, Mexico.
Microb Pathog. 2019 Nov;136:103660. doi: 10.1016/j.micpath.2019.103660. Epub 2019 Aug 6.
Antimicrobial resistance has been increasing in recent years and is most frequently found in pathogenic microorganisms resistant or multiresistant to drugs. The secondary metabolites of plants have been evaluated as alternatives for control and treatment of these microorganisms. The aim of this study was to isolate and identify the secondary metabolites with antibacterial activity from Caesalpinia coriaria (Jacq) Willd fruit. Hydroalcoholic extract (CCHA), was subjected to a bipartition with ethyl acetate giving two fractions an aqueous (Aq-F) and an organic (EtOAc-F). The isolation of bioactive fraction (EtOAc-F) allowed obtain two important compounds, methyl gallate (1) and gallic acid (2). These compounds were identified by high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR). The CCHA, both fractions and the isolated compounds were evaluated in vitro to determine their Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) against Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Listeria monocytogenes and Staphylococcus aureus. Gallic acid (2) showed the lowest MIC on S. typhi, (0.156 mg/mL), L. monocytogenes and S. aureus (1.25 mg/mL), while methyl gallate (1) had the best inhibitory effect against E. coli and P. aeruginosa (1.25 mg/mL). On the other hand, methyl gallate (1) showed the best MBC on P. aeruginosa (2.50 mg/mL), and gallic acid (2) had the lowest MBC on P. aeruginosa and L. monocytogenes. In conclusion, methyl gallate (1) and gallic acid (2) are the compounds responsible for the antibacterial activity of Caesalpinia coriaria fruit.
近年来，抗菌药物耐药性不断增加，在耐药或多药耐药的致病微生物中最为常见。植物的次生代谢产物已被评估为控制和治疗这些微生物的替代品。本研究的目的是从金合欢果实中分离和鉴定具有抗菌活性的次生代谢产物。水醇提取物（CCHA）经乙酸乙酯二部分萃取，得到水相（Aq-F）和有机相（EtOAc-F）。活性部分（EtOAc-F）的分离得到两种重要化合物：没食子酸甲酯（1）和没食子酸（2）。这些化合物通过高效液相色谱（HPLC）和核磁共振（NMR）进行鉴定。CCHA、两个馏分和分离得到的化合物在体外进行评估，以确定其对大肠杆菌、铜绿假单胞菌、伤寒沙门氏菌、单核细胞增生李斯特菌和金黄色葡萄球菌的最小抑菌浓度（MIC）和最小杀菌浓度（MBC）。没食子酸（2）对伤寒沙门氏菌、单核细胞增生李斯特菌和金黄色葡萄球菌的 MIC 值最低（0.156mg/mL），而没食子酸甲酯（1）对大肠杆菌和铜绿假单胞菌的抑制效果最好（1.25mg/mL）。另一方面，没食子酸甲酯（1）对铜绿假单胞菌的 MBC 最佳（2.50mg/mL），没食子酸（2）对铜绿假单胞菌和单核细胞增生李斯特菌的 MBC 最低。综上所述，没食子酸甲酯（1）和没食子酸（2）是金合欢果实具有抗菌活性的化合物。
