(+)- and (-)-Alternarilactone A: Enantiomers with a Diepoxy-Cage-like Scaffold from an Endophytic Alternaria sp.
J Nat Prod
; 82(4): 735-740, 2019 04 26.
Article
en En
| MEDLINE
| ID: mdl-30767530
ABSTRACT
The enantiomers (+)- and (-)-alternarilactone A (1), the first examples of dibenzo-α-pyrones bearing a diepoxy-cage-like moiety, were isolated from the endophytic fungus Alternaria sp. hh930. The deficiency in 1H-1H COSY and HMBC correlations caused by the highly oxidized caged system of 1 and the deceptive and ambiguous signals such as "W" couplings in NMR data increased the risk of structure misassignment of 1. By performing a quantum chemical calculation of the NMR chemical shifts together with a DP4+ probability analysis and single-crystal X-ray crystallographic experiment, their structures were unambiguously determined, and their absolute configurations were determined by ECD calculations.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Alternaria
Idioma:
En
Revista:
J Nat Prod
Año:
2019
Tipo del documento:
Article