Lumiquinone A, an α-Aminomalonate-Derived Aminobenzoquinone from Photorhabdus luminescens.

Lumiquinone A (1), an unusual aminobenzoquinone member within the phenylpropanoid class of natural products, together with the known compound 3,5-dihydroxy-4-isopropyl-trans-stilbene (2), was isolated from the entomopathogenic bacterium Photorhabdus luminescens TT01. On the basis of the analysis of extensive 2D NMR and high-resolution ESI-QTOF-MS spectral data, the structure of 1 was determined to be a 2-amino-5-hydroxy-1,4-benzoquinone substituted with (E)-2-phenylvinyl and isopropyl functional groups. Free α-aminomalonate medium supplementation significantly enhanced production of 1 relative to 2 in a dose-dependent manner, suggesting that promiscuous polyketide synthase processing of malonate- versus α-aminomalonate-derived substrates represents a competitive route for polyketide structural diversification. Metabolites 1 and 2 were active against Bacillus subtilis and Saccharomyces cerevisiae.