Kumbicins A-D: bis-indolyl benzenoids and benzoquinones from an Australian soil fungus, Aspergillus kumbius

Heather J. Lacey, Daniel Vuong, John I. Pitt, Ernest Lacey and Andrew M. Piggott

Aust. J. Chem. 2015, 69, 152-160.

Publication Date: November 12, 2015

https://doi.org/10.1071/CH15488

Abstract:

A soil survey conducted in southern Queensland, Australia, identified a novel isolate belonging to the genus Aspergillus subgenus Circumdati section Circumdati, Aspergillus kumbius FRR6049. Cultivation and fractionation of secondary metabolites from A. kumbius revealed a unique chemotype comprising three new bis-indolyl benzenoids, kumbicins A–C, and a new bis-indolyl benzoquinone, kumbicin D, along with the previously reported compounds asterriquinol D dimethyl ether, petromurins C and D, aspochracin, its N-demethyl analogue JBIR-15, and neohydroxyaspergillic acid. The structures of kumbicins A–D were assigned by detailed spectroscopic analysis. Kumbicin C was found to inhibit the growth of mouse myeloma cells (IC₅₀ 0.74 μg mL^–1) and the Gram-positive bacterium Bacillus subtilis (MIC 1.6 μg mL^–1).

Available at BioAustralis:

kumbicins A–C

asterriquinol D dimethyl ether

petromurins C

aspochracin

JBIR-15

neohydroxyaspergillic acid