Mapping the Mechanism of the Resorcinol Ring Formation Catalyzed by ArsB, a Type III Polyketide Synthase from<i>Azotobacter vinelandii</i>
作者:Sarah E. Posehn、Sun Young Kim、Andrew G. H. Wee、Dae-Yeon Suh
DOI:10.1002/cbic.201200346
日期:2012.10.15
Who's first? Aldol cyclization occurs before hydrolysis in the resorcinol ring formationcatalyzed by the type III polyketide synthase, ArsB. Synthetic C20‐TKA was not converted to alkylresorcinol by ArsB, but rather inhibited the enzyme activity, thus indicating that C20‐TKA is not an intermediate in ArsB‐catalyzed alkylresorcinol formation.
Alkylresorcinols, produced by various plants, bacteria, and fungi, are bioactive compounds possessing beneficial activities for human health, such as anti-cancer activity. In rice, they accumulate in seedlings, contributing to protection against fungi. Alkylresorcylic acids, which are carboxylated forms of alkylresorcinols, are unstable compounds and decarboxylate readily to yield alkylresorcinols. Genome mining of the rice Oryza sativa identified two type III polyketide synthases, named ARAS1 (alkylresorcylic acid synthase) and ARAS2, that catalyze the formation of alkylresorcylic acids. Both enzymes condensed fatty acyl-CoAs with three C-2 units from malonyl-CoA and cyclized the resulting tetraketide intermediates via intramolecular C-2 to C-7 aldol condensation. The alkylresorcylic acids thus produced were released from the enzyme and decarboxylated non-enzymatically to yield alkylresorcinols. This is the first report on a plant type III polyketide synthase that produces tetraketide alkylresorcylic acids as major products. (C)2010 Published by Elsevier Ltd.
Novel insights into the antibacterial activities of cannabinoid biosynthetic intermediate, olivetolic acid, and its alkyl-chain derivatives
作者:Yuan-E Lee、Takeshi Kodama、Hiroyuki Morita
DOI:10.1007/s11418-022-01672-9
日期:2023.3
revealed that the incorporation of longer alkyl chains to the C-6 position in resorcylic acid conferred antibacterial properties against Staphylococcus aureus and Bacillus subtilis. The resultant olivetolic acid (OA) derivatives with n-undecyl and n-tridecyl side-chains, even those lacking the hydrophobic geranyl moiety from their C-3 positions, exhibited strong antibacterial activities against B. subtilis