Institute of Marine Biochemistry, VAST, 18 Hoang Quoc Viet, Cau Giay, Hanoi, 10072, Vietnam.
Graduate University of Science and Technology, VAST, 18 Hoang Quoc Viet, Cau Giay, Hanoi, 10072, Vietnam.
Chem Biodivers. 2023 Nov;20(11):e202301425. doi: 10.1002/cbdv.202301425. Epub 2023 Oct 20.
From marine sponge-associated fungus Hamigera avellanea, thirteen secondary metabolites including a pair of undescribed alkaloid enantiomers (+)-hamiavemin A (4S) (+)-1 and (-)-hamiavemin A (4R) (-)-1. Compound 1 was enantiomers resolved by the Chiralpak AS-3 column, using a hexane/isopropanol mobile phase. Their structures were determined based on extensive analyses of HR-ESI-MS, 1D and 2D NMR spectra. The absolute configuration of (+)-1 and (-)-1 were assigned tentatively by ECD calculations. Among the isolates, compound 6 showed strongest antibacterial activity against Enterococcus faecalis, Staphylococcus aureus, Bacillus cereus, Escherichia coli, Salmonella enterica, and Candida albicans with the MIC values of 2, 2, 16, 32, 64, and 16 μg/mL, respectively, which were stronger than that of the positive control compound, kanamycin (MIC values ranging from 4 to 128 μg/mL). In addition, compounds 1, 2, and 9 showed moderate cytotoxic activity against three cancer cell lines, HepG2, A549, and MCF-7 with the IC50 values ranging from 55.35±1.70 to 83.02±2.85 μg/mL.
从海洋海绵共生真菌 Hamigera avellanea 中，分离得到了 13 种次生代谢产物，包括一对未描述的生物碱对映异构体 (+)-hamiavemin A (4S) (+)-1 和 (-)-hamiavemin A (4R) (-)-1。化合物 1 通过手性柱 Chiralpak AS-3，以正己烷/异丙醇为流动相进行对映异构体拆分。根据高分辨电喷雾电离质谱（HR-ESI-MS）、一维和二维核磁共振谱（1D 和 2D NMR）等的综合分析，确定了它们的结构。通过圆二色谱（ECD）计算，初步确定了 (+)-1 和 (-)-1 的绝对构型。在所分离的化合物中，化合物 6 对粪肠球菌、金黄色葡萄球菌、蜡状芽孢杆菌、大肠杆菌、肠炎沙门氏菌和白色念珠菌表现出最强的抗菌活性，MIC 值分别为 2、2、16、32、64 和 16μg/mL，均强于阳性对照化合物卡那霉素（MIC 值范围为 4 至 128μg/mL）。此外，化合物 1、2 和 9 对 HepG2、A549 和 MCF-7 三种癌细胞系表现出中等的细胞毒性，IC50 值范围为 55.35±1.70 至 83.02±2.85μg/mL。
