title: Bleaching activity of 4-phenyl-3-(substituted benzylthio)-4H-1,2,4-triazoles.
abstract: A variety of 4-aryl- and 4-alkyl-3-(substituted benzylthio)-4H-1,2,4-triazoles were prepared and evaluated for their bleaching activity by the lettuce seedling test. Among the series of tested compounds, 4-(3-fluorophenyl)-3-(4-trifluoromethylbenzylthio)-4H-1,2,4-triazole (39) exhibited the highest bleaching activity, causing complete bleaching symptoms at 10 microM. In the dark condition, compound 39 inhibited the formation of such carotenoids as beta-carotene, violaxanthin, neoxanthin and lutein, resulting in the formation of zeta-carotene, phytoene, phytofluene and beta-zeacarotene, which were not detected in the untreated control. Treatment by compound 39 at 50 microM resulted in the amount of accumulated zeta-carotene being seven-fold higher than that of phytoene, phytofluene and beta-zeacarotene. These results suggest that compound 39 might have interfered with desaturation, especially zeta-carotene desaturation, during carotenoid biosynthesis.
mesh_terms: D002338:Carotenoids / Q000378:metabolism*; D006540:Herbicides / Q000494:pharmacology; D018545:Lactuca / Q000187:drug effects* / Q000378:metabolism; D010858:Pigmentation / Q000187:drug effects*; D010860:Pigments, Biological / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014230:Triazoles / Q000494:pharmacology*
chemical_list: D006540:Herbicides; D010860:Pigments, Biological; D014230:Triazoles; D002338:Carotenoids