Suppression of SOS-inducing activity of chemical mutagens by metabolites from microbial transformation of (+)-longicyclene.
In this study, biotransformation of (+)-longicyclene (1) by Aspergillus niger (NBRC 4414) and the suppressive effect on umuC gene expression by chemical mutagens 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (furylfuramide) and aflatoxin B1 (AFB1) of the SOS response in Salmonella typhimurium TA1535/pSK1002 were investigated. Initially, compound 1 was converted to three new terpenoids, (-)-(10R)-10-hydroxy-longicyclic acid (2), (+)-(10S)-10-hydroxy-longicyclic acid (3), and (+)-10-oxo-longicyclic acid (4) by A. niger , and their conversion rates were 27, 23, and 30%, respectively. The metabolites suppressed the SOS-inducing activity of furylfuramide and AFB1 in the umu test. Compounds 1-4 were hardly showing a suppressive effect on umu gene expression of the SOS responses in S. typhimurium TA1535/pSK1002 against furylfuramid. However, metabolites showed a suppressive effect against AFB1. Compound 4 had gene expression by chemical mutagen AFB1, was suppressed 53% at <1.0 mM, and was the most effective compound in this experiment.
Sakata
Kazuki
K
Department of Applied Chemistry, Faculty of Science and Engineering, Kinki University, Kowakae, Higashiosakashi, Osaka 577-8502, Japan.
Miyazawa
Mitsuo
M
D020106:Acrylamide / Q000633:toxicity; D016604:Aflatoxin B1 / Q000633:toxicity; D016587:Antimutagenic Agents / Q000378:metabolism* / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D009153:Mutagens / Q000633:toxicity*; D013014:SOS Response, Genetics / Q000187:drug effects*; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics; D012717:Sesquiterpenes / Q000378:metabolism* / Q000494:pharmacology; D021241:Spectrometry, Mass, Electrospray Ionization; D013055:Spectrophotometry, Infrared
D016587:Antimutagenic Agents; D009153:Mutagens; D012717:Sesquiterpenes; D020106:Acrylamide; D016604:Aflatoxin B1