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Updated: Jun 19, 2025

Facile Preparation of 4-Substituted Quinazoline Derivatives
Published on: February 15, 2016
Biosynthesis of Ester-Bond Containing Quinolone Alkaloids with (3R,4S) Stereoconfiguration
Yujing Zeng1, Tiantian Lu1, Shuya Ren1
1School of Marine Sciences, Sun Yat-sen University, Guangzhou 510006, China.
Abstract:
Asperalins represent a novel class of viridicatin natural products with potent inhibitory activities against fish pathogens. In this study, we elucidated the biosynthesis of asperalins in the Aspergillus oryzae NSAR1 heterologous host and identified the FAD-dependent monooxygenase AplB stereoselectively hydroxylates viridicatin to yield a unique 3R,4S configuration. The monomodular NRPS AplJ catalyzes a rare intramolecular ester bond formation reaction using dihydroquinoline as a nucleophile. Subsequent modifications by cytochrome P450 AplF, chlorinase AplN, and prenyltransferase AplE tailor the anthranilic acid portion, leading to the formation of asperalins. Additionally, we explored the potential of AplB for the hydroxylation of viridicatin analogs, demonstrating its relaxed substrate specificity. This finding suggests that AplB could be developed as a biocatalyst for the synthesis of viridicatin derivatives.
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