School of Pharmaceutical Science and Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming 650500, China.
College of Pharmacy, Changchun University of Chinese Medicine, Changchun 130117, China.
Bioorg Chem. 2023 Nov;140:106780. doi: 10.1016/j.bioorg.2023.106780. Epub 2023 Aug 12.
Seven rarely spirooxindole alkaloids, voagafricines A-G (1-7) were isolated from the stem barks of Voacanga africana. Their structures were unambiguously elucidated by comprehensive spectroscopic data and electronic circular dichroism (ECD) analyses. 1 and 2 possess a unique indoleone system in conjugation with a 3,4'-decahydroquinoline spiral ring originating from seco-quinolhiddin core of the precursor, furthermore 1 undergo decarburization formed a novel C-3-nor monoterpenoid indole. All isolates were evaluated for their antibacterial activities against MBLs producing Escherichia coli strains. Compounds 1 and 7 were found to be potent inhibitors against E. coli 298 and 140 by targeting biofilm. Possible interaction sites of 1 and 7 with biofilm were preliminarily explored by means of molecular docking.
从 Voacanga africana 的茎皮中分离得到了 7 种罕见的螺环吲哚生物碱，即 voagafricines A-G（1-7）。通过综合光谱数据和电子圆二色性（ECD）分析，明确了它们的结构。1 和 2 具有独特的吲哚酮系统，与 3,4'-十氢喹啉螺旋环共轭，该螺旋环源自前体的 seco-quinolhiddin 核心，此外，1 经历脱碳化形成了一种新型 C-3-降单萜吲哚。所有分离物均评估了其对产 MBLs 的大肠杆菌菌株的抗菌活性。化合物 1 和 7 被发现是针对生物膜的 E. coli 298 和 140 的有效抑制剂。通过分子对接初步探讨了 1 和 7 与生物膜的可能相互作用位点。
