Unusual dimeric tetrahydroxanthone derivatives from Aspergillus lentulus and the determination of their axial chiralities.

ABSTRACT: The research on secondary metabolites of Aspergillus lentulus afforded eight unusual heterodimeric tetrahydroxanthone derivatives, lentulins A-H (2-9), along with the known compound neosartorin (1). Compounds 1-6 exhibited potent antimicrobial activities especially against methicillin-resistant Staphylococci. Their absolute configurations, particularly the axial chiralities, were unambiguously demonstrated by a combination of electronic circular dichroism (ECD), Rh₂(OCOCF₃)₄-induced ECD experiments, modified Mosher methods, and chemical conversions. Interestingly, compounds 1-4 were the first samples of atropisomers within the dimeric tetrahydroxanthone class. Further investigation of the relationships between their axial chiralities and ECD Cotton effects

SUBMITTER: Li TX 

PROVIDER: S-EPMC5150534 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature