Abstract Medicinal plants are known as sources of potential antibacterial compounds including alkaloids. The aim of the present study was to evaluate the antibacterial activities of the extract, fractions, and some secondary metabolites isolated from the leaves of Crinum glaucum A. Chev. (Amaryllidaceae). The antibacterial activities were performed with the ethanol (EtOH) extract, as well as with ethyl acetate (EtOAc) and n-butanol (n-BuOH) fractions. Repeated column chromatography of the fractions led to the isolation of several compounds and their structures were elucidated mainly by means of extensive spectroscopic analysis [(one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR), mass spectrometry)] and the comparison with published data. This includes eleven alkaloids: (3S)-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (1), lycorine (2), ungeremine (3), ambelline (4), macronine (5), 5,6-dihydrobicolorine (6), trisphaeridine (7), hippadine (8), adenosine (9), arolycoricidine (10), pratorimine (11); two steroids: β-sitosterol (12), β-sitosterol-3-O-β-D-glucopyranoside (14) and one triterpene: oleanolic acid (13). Apart from lycorine (2), all these secondary metabolites are isolated from C. glaucum for the first time. The in vitro antibacterial activity of the EtOH extract, and the n-BuOH and EtOAc fractions as well as compounds 2, 3, 6 and 9 against pathogenic bacteria was performed. All extracts and fractions showed varying levels of antibacterial properties against at least one of the bacteria strains tested. The n-BuOH fraction was the most active extract with the lowest minimal inhibitory concentration (MIC) value of 64 µg/mL against Enterococcus faecalis. For pure compounds, the best MIC (8 µg/mL) was obtained with ungeremine (3) against Enterococcus faecalis and Pseudomonas aeruginosa. Our results show the antimicrobial potential of C. glaucum and scientifically validate its uses in traditional medicine against infectious diseases including cough and sexually transmitted infections. Ungeremine seems to be the antimicrobial active ingredient of this medicinal plant.

中文翻译：

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来自药用植物 Crinum glaucum A. Chev 的抗菌次生代谢物。（石蒜科）

摘要 药用植物被认为是包括生物碱在内的潜在抗菌化合物的来源。本研究的目的是评估从 Crinum glaucum A. Chev 的叶子中分离出的提取物、馏分和一些次生代谢物的抗菌活性。（石蒜科）。使用乙醇 (EtOH) 提取物以及乙酸乙酯 (EtOAc) 和正丁醇 (n-BuOH) 馏分进行抗菌活性。馏分的重复柱层析导致了几种化合物的分离，它们的结构主要通过广泛的光谱分析[（一维（1D）和二维（2D）核磁共振（NMR），质谱）来阐明） ] 以及与已发布数据的比较。这包括十一种生物碱：(3S)-1,2,3, 4-四氢-β-咔啉-3-羧酸 (1), 石蒜碱 (2), ungeremine (3), ambelline (4), macronine (5), 5,6-dihydrobicolorine (6), trisphaeridine (7), hippadine (8), 腺苷 (9), arolycoricidine (10), pratorimine (11); 两种类固醇：β-谷甾醇 (12)、β-谷甾醇-3-O-β-D-吡喃葡萄糖苷 (14) 和一种三萜：齐墩果酸 (13)。除了石蒜碱 (2)，所有这些次生代谢物都是首次从 C. glaucum 中分离出来。进行了 EtOH 提取物、n-BuOH 和 EtOAc 级分以及化合物 2、3、6 和 9 对病原菌的体外抗菌活性。所有提取物和级分对至少一种所测试的细菌菌株显示出不同水平的抗菌特性。n-BuOH 部分是活性最强的提取物，对粪肠球菌的最低抑菌浓度 (MIC) 值为 64 µg/mL。对于纯化合物，使用 ungeremine (3) 获得了对粪肠球菌和铜绿假单胞菌的最佳 MIC (8 µg/mL)。我们的结果显示了 C. glaucum 的抗菌潜力，并科学地验证了其在传统医学中的用途，以对抗包括咳嗽和性传播感染在内的传染病。Ungeremine 似乎是这种药用植物的抗菌活性成分。并科学验证其在传统医学中的用途，以对抗包括咳嗽和性传播感染在内的传染病。Ungeremine 似乎是这种药用植物的抗菌活性成分。glaucum 并科学验证其在传统医学中的用途，以对抗包括咳嗽和性传播感染在内的传染病。Ungeremine 似乎是这种药用植物的抗菌活性成分。