Faculty of Agriculture and Life Science, Hirosaki University, 3-Bunkyo-cho, Hirosaki 036-8561, Japan.
Institute of Natural Medicine, University of Toyama, Toyama 930-0194, Japan.
Molecules. 2021 Jul 19;26(14):4364. doi: 10.3390/molecules26144364.
A series of cyclohumulanoids, i.e., tricocerapicanols A-C (-), tricoprotoilludenes A () and B (), tricosterpurol (), and tricoilludins A-C (-) were isolated along with known violascensol () and omphadiol () from the culture broth of , an inedible but not toxic mushroom. The structures were fully elucidated on the basis of NMR spectroscopic analysis, and the suggested relative structures were confirmed via density functional theory (DFT)-based chemical shift calculations involving a DP4 probability analysis. In the present study, the H chemical shifts were more informative than the C chemical shifts to distinguish the diastereomers at C-11. The absolute configurations of - were determined by comparing the experimental and calculated electronic circular dichroism (ECD) spectra. For and , the same chirality was assigned according to their biosynthetic similarities with the other compounds. The successful assignment of some Cotton effects was achieved by utilizing DFT calculations using simple model compounds. The plausible biosynthesis of - was also discussed on the basis of the structural commonality and general cyclohumulanoid biosynthesis. Compounds and were found to simultaneously induce hyphal swelling and branching at 5.0 μg/mL against a test fungus
从不可食用但无毒的蘑菇中分离到的 culture broth 中，分离出了一系列环羊毛甾烷类化合物，即 tricocerapicanols A-C(-)、tricoprotoilludenes A()和 B()、tricosterpurol()和 tricoilludins A-C(-)，以及已知的 violascensol()和 omphadiol()。基于 NMR 光谱分析，充分阐明了这些化合物的结构，并通过基于密度泛函理论（DFT）的化学位移计算（包括 DP4 概率分析）证实了建议的相对结构。在本研究中，与 C 化学位移相比，H 化学位移更能区分 C-11 处的非对映异构体。通过比较实验和计算的电子圆二色性（ECD）光谱，确定了-的绝对构型。对于和，根据它们与其他化合物的生物合成相似性，赋予了相同的手性。通过使用简单模型化合物的 DFT 计算，可以成功分配一些 Cotton 效应。基于结构的共性和一般环羊毛甾烷类化合物的生物合成，还讨论了-的可能生物合成途径。在 5.0 μg/mL 时，化合物和同时诱导菌丝肿胀和分枝，对测试真菌有抑制作用。
