Department of Chemistry, Faculty of Sciences, University of Dschang, Dschang, Cameroon.
Organic and Bioorganic Chemistry, Faculty of Chemistry, Bielefeld University, 33501 Bielefeld, Germany.
Molecules. 2021 Aug 9;26(16):4810. doi: 10.3390/molecules26164810.
A total of nine sesquiterpenoid lactones together with phenolic compounds and other terpenes were identified from the crude methanol extract of Kunth. Compounds were isolated using different chromatographic techniques and their structures were determined by NMR and IR spectroscopy as well as mass spectrometry. The structures of some detected compounds were assigned based on LC-ToF-ESI-MS screening of main fractions/subfractions from flash chromatography and comparison with isolated analogues as standards. The findings revealed not only the in-source loss of water as the base peak in hirsutinolides but also the in-source loss of corresponding alcohol when the oxygen at position 1 is alkylated. The present study also draws up a complement of data with respect to hirsutinolide-like sesquiterpene lactones whose LC-MS characteristics are not available in the literature. The chemophenetic significance is also discussed. Some of the isolated compounds were reported for the first time to be found in the species, the genus as well as the plant family. The medium-polar fractions of the crude extract, also containing the larger amount of sesquiterpenoid lactones, exhibited activity both against a cancer cell line and bacterial strains. Isolated lactones were also active against the cancer cell line, while the chlorogenic derivatives also valuable in genus showed potent radical scavenging activity. This is the first report of cytotoxic and antibacterial activities of our samples against the tested strains and cell line. The present study follows the ongoing research project dealing with the characterization of taxa with antibacterial and antiparasitic activities from Cameroonian pharmacopeia.
从昆特甲醇提取物中鉴定出了总共 9 种倍半萜内酯化合物，以及酚类化合物和其他萜类化合物。采用不同的色谱技术分离化合物，通过 NMR 和 IR 光谱以及质谱确定其结构。根据从快速色谱的主要馏分/亚馏分进行的 LC-ToF-ESI-MS 筛选以及与分离的类似物作为标准进行比较，对一些检测到的化合物的结构进行了分配。研究结果不仅揭示了水在 hirsutinolides 中作为基峰的源内损失，还揭示了位置 1 的氧被烷基化时相应醇的源内损失。本研究还补充了有关 hirsutinolide 类倍半萜内酯的 LC-MS 特征在文献中不可用的数据。还讨论了其化学分类学意义。一些分离出的化合物是首次在该物种、属和植物科中发现的。粗提取物的中等极性部分也含有大量倍半萜内酯，对癌细胞系和细菌菌株均表现出活性。分离出的内酯对癌细胞系也具有活性，而绿原酸衍生物在属中也具有很高的自由基清除活性。这是我们的样品对测试菌株和细胞系的细胞毒性和抗菌活性的首次报道。本研究遵循正在进行的研究项目，该项目涉及从喀麦隆药典中具有抗菌和抗寄生虫活性的分类群的特征描述。
