Organic Letters 2013-03-01

Structures and biomimetic synthesis of novel α-pyrone polyketides of an endophytic Penicillium sp. in Catharanthus roseus.

Teigo Asai, Dan Luo, Kouwa Yamashita, Yoshiteru Oshima

Index: Org. Lett. 15(5) , 1020-3, (2013)

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Abstract

Novel polyketides, citreoviripyrone A (1) and B (2), known citreomontanin (3), and (-)-citreoviridin (4) were isolated from the mycelium of the endophytic fungus. The endophytic fungus, which belongs to the genus Penicillium, was separated from surface-sterilized healthy leaves of Catharanthus roseus. The structures of 1 and 2 were determined on the basis of NMR data, and 1 was characterized as an α-pyrone polyketide featuring bicyclo[4.2.0]octadiene. The biomimetic synthesis of 1 and 2 from 3 elucidated a plausible biosynthetic pathway. Both Zn(II)-type and NAD(+)-dependent histone deacetylase inhibitors significantly enhanced the production of 1 and 3.