Isolation, Crystal Structure, and In Silico Aromatase Inhibition Activity of Ergosta-5, 22-dien-3β-ol from the Fungus Gyromitra esculenta

Abstract

Ergosterol derivatives exhibited copious promising biological activities. +e fungus Gyromitra esculenta is widely distributed in Europe and North America. In order to examine the chemical properties of Gyromitra esculenta, a phytochemical study has been preceded and resulted in the isolation of the steroid, ergosta-5, 22-dien-3β-ol (brassicasterol), from its methanol extract.+e complete identification and absolute configuration of the isolated compound have been established by X-ray structural analysis to be (22E, 24R)-24-methylcholesta-5, 22-dien-3beta-ol. +e reported cytotoxicity and the great structural similarity of the isolated compound with the cocrystallized ligand of the aromatase enzyme inspired us to run molecular docking studies against that protein. Ergosta-5, 22-dien-3β-ol occupied the target protein with a binding mode almost the same as the cocrystallized ligand and a binding affinity of −33.55 kcal/mol, which was better than that of the cocrystallized ligand (−22.61 kcal/mol). +is promising result encouraged us to conduct in silico ADMETand toxicity studies of ergosta-5, 22-dien-3β-ol against 6 models, and the results expected the likeness of the isolated compound to be a drug. In conclusion, ergosta-5, 22-dien-3β-ol has been isolated from Gyromitra esculenta, identified by X-ray structural analysis, and exhibited promising in silico activities against aromatase enzyme.