A new cerebroside from the entomopathogenic fungus Ophiocordyceps longiissima: Structural-electronic and antioxidant relations. Experimental and DFT calculated studies
作者:Abdelsamed I. Elshamy、Tatsuro Yoneyama、Nguyen Van Trang、Ninh The Son、Yasuko Okamoto、Sayaka Ban、Masaaki Noji、Akemi Umeyama
DOI:10.1016/j.molstruc.2019.127061
日期:2020.1
The chemical characterization of n-butanol soluble extract of the fungus Ophiocordyceps longiissima NBRC 106965 afforded a new cerebroside, 1-O-(beta-D-glucopyranosyl)-(2S,3R,4E,8E)-2-[(20R)-2'-hydroxyheptadecanoylamino]-9-methylheptadeca-4,8-diene-1,3-diol, trivially named ophiocordylongiiside A (1), in addition to 22E,24R-24-methylcholest-5,22-diene-3-O-beta-D-O-glucopyranoside (2). The chemical structure of 1 was established based upon the by modern spectroscopic and chemical techniques. Compound 1 exhibited strong DPPH-free radical scavenging with the IC50 value of 55.72 mg/mL. The biological result can be explained by density functional theoretical (DFT) calculation, in which antioxidant activity is mostly controlled by the O-H bond dissociation enthalpy (BDE) following hydrogen atom transfer (HAT) mechanism. In all studied environments, the lowest BDE values are found in 2'-OH. (C) 2019 Elsevier B.V. All rights reserved.