Unit of Food Microbiology, Department for Farm Animals and Veterinary Public Health, Institute of Food Safety, Food Technology and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria.
Core Facility Bioactive Molecules, Screening and Analysis and Research Platform Bioactive Microbial Metabolites (BiMM), Konrad Lorenz Strasse 24, 3430, Tulln an der Donau, Austria.
Sci Rep. 2024 Oct 25;14(1):25310. doi: 10.1038/s41598-024-75510-1.
Screening for new bioactive microbial metabolites, we found a novel okaramine derivative, for which we propose the trivial name lemmokaramine, as well as two already known okaramine congeners - okaramine H and okaramine J - responsible for antimicrobial activity of the recently described microscopic filamentous fungus, Keratinophyton lemmensii BiMM-F76 (= CCF 6359). In addition, two novel substances, a new cyclohexyl denominated lemmensihexol and a new tetrahydroxypyrane denominated lemmensipyrane, were purified and characterized. The compounds were isolated from the culture extract of the fungus grown on modified yeast extract sucrose medium by means of flash chromatography followed by preparative HPLC. The chemical structures were elucidated by NMR and LC-MS. The new okaramine (lemmokaramine) exerted antimicrobial activity against Gram-positive and Gram-negative bacteria, yeasts and fungi and anticancer activity against different mammalian cell lines (Caco-2, HCT116, HT29, SW480, MCM G1, and MCM DLN). Furthermore, we found a significant antioxidant effect of lemmokaramine following HO treatment indicated by activation of the Nrf2 pathway. This is the first report describing analysis and structural elucidation of bioactive metabolites for the onygenalean genus Keratinophyton.
我们筛选新的生物活性微生物代谢产物时，发现了一种新型的奥卡胺衍生物，我们将其命名为莱莫卡胺，并分离到了两种已知的奥卡胺同系物——奥卡胺 H 和奥卡胺 J，它们负责最近描述的丝状微观真菌——角蛋白酶 Lemmensii BiMM-F76（=CCF 6359）的抗菌活性。此外，还分离并鉴定了两种新型物质，一种新型环己基命名为莱莫森西醇，一种新的四羟基吡喃命名为莱莫西吡喃。这些化合物是通过快速色谱法和制备高效液相色谱法从真菌在改良酵母提取物蔗糖培养基上的培养物提取物中分离得到的。通过 NMR 和 LC-MS 确定了化合物的化学结构。新型奥卡胺（莱莫卡胺）对革兰氏阳性和革兰氏阴性细菌、酵母和真菌具有抗菌活性，对不同的哺乳动物细胞系（Caco-2、HCT116、HT29、SW480、MCM G1 和 MCM DLN）具有抗癌活性。此外，我们发现莱莫卡胺在 HO 处理后具有显著的抗氧化作用，这表明 Nrf2 通路被激活。这是第一个描述角蛋白酶属生物活性代谢产物的分析和结构阐明的研究。
