Lanostanoid triterpenes from the fungus Rigidoporus microporus

• Published in: Natural product research Vol. 35; no. 21; pp. 3945 - 3954
• Main Authors: Rincón, Yuliet A., Siless, Gastón E., Amado, Lucía Daniela, Dansey, María Virginia, Grassi, Emanuel, Schenone, Nahuel, Cabrera, Gabriela M.
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 02-11-2021
• Subjects: 1-methyl-19-nor-lanostane; 3-ketolanostanes; antifungal activity; liver X receptors; Rigidoporus microporus; liver X receptors; 3-ketolanostanes; Rigidoporus microporus; antifungal activity; 1-methyl-19-nor-lanostane
• ISSN: 1478-6419; 1478-6427
• DOI: 10.1080/14786419.2020.1752205

Five new lanostanoid triterpenes were isolated from the extract of R. microporus. Three of the metabolites (1-3) present a Δ
8,9
skeleton with an uncommon keto functionality at C-1. Another compound (4) has an unprecedented rearranged skeleton in which methyl-19 was transposed to C-1, with conjugated double bonds at Δ
1-10
and Δ
8-9
. All of the compounds have hydroxylated or furane-cyclized side-chains. The structures were elucidated by spectroscopic methods, and the absolute configuration of the hydroxyl-bearing carbon in the side chain of compound 5 was established in silico. The metabolites were evaluated for their antifungal activity and the bioactivity as agonist/antagonists of the liver X receptors (LXRs). Compound 4 presents antifungal activity and compounds 3 and 5 are the agonists of LXRs.