Detoxification Mechanism of 88-Dimethyl-3-(R-phenyl)amino-145(8H)-naphthalentrione Derivatives by Botrytis cinerea

摘要

The effect of 8,8-dimethyl-3-[(R-phenyl)amino]-1,4,5(8H)-naphthalentrione derivatives (compounds >1–>13) on the mycelial growth of Botrytis cinerea was evaluated. The fungitoxic effect depended on the substituent and its position in the aromatic ring. Compounds substituted with halogens in meta and/or para positions (compounds >3, >4, >5 and >7), methyl (compounds >8 and >9), methoxyl (compounds >10 and >11), or ethoxy-carbonyl groups (compound >12) presented higher antifungal activity than compound >1, which had an unsubstituted aromatic ring. In addition, compounds with halogens in the ortho position, such as compounds >2 and >6, and a substitution with an acetyl group in the para position (compound >13) were less active. The role of the ABC efflux pump Bctr B-type as a defense mechanism of B. cinerea against these naphthalentrione derivatives was analyzed. This pump could be involved in the detoxification of compounds >2, >6, and >13. On the contrary, this mechanism would not participate in the detoxification of compounds >1, >7, >9 and >12. Finally, the biotransformation of compound >7 by B. cinerea was studied. A mixture of two biotransformed products was obtained. One of them was compound >7A, which is reduced at C1 and C4, compared to compound >7. The other product of biotransformation, 7B, is oxidized at C7.