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Delitschiapyrone A, a Pyrone–Naphthalenone Adduct Bearing a New Pentacyclic Ring System from the Leaf-Associated Fungus Delitschia sp. FL1581
journal contribution
posted on 2015-12-17, 05:57 authored by Jian-Guang Luo, Xiao-Bing Wang, Ya-Ming Xu, Jana M. U’Ren, A. Elizabeth Arnold, Ling-Yi Kong, A. A. Leslie GunatilakaDelitschiapyrone
A (1), an α-pyrone–naphthalenone
adduct with an unprecedented pentacyclic ring system, was isolated
from a solid culture of the leaf-associated fungus Delitschia sp. FL1581. The structure of 1 was elucidated by spectroscopic
analysis and X-ray crystallography, and its absolute configuration
was defined by experimental and calculated ECD. Biosynthetically,
the unique 6/6/5/7/6 pentacyclic core of 1 may be formed
by an intermolecular Diels–Alder-type addition of the precursors
derived from (1′R)-2′,3′-dihydropyrenocine
C (2) and 6-ethyl-2,7-dimethoxyjuglone (3) found to co-occur with 1 in this fungus.