Screening study of lead compounds for natural product-based fungicides: antifungal activity and biotransformation of 6alpha,7alpha-dihydroxy-beta-himachalene by Botrytis cinerea.
Eleven beta-himachalene derivatives were tested, using the poisoning food technique, for their potential antifungal activity against the phytopathogen Botrytis cinerea. Compounds 1-11 displayed moderate activity, whereas the 6,7-diol derivative (12) produced an inhibition of 91% after 6 days. The microbial transformation of 12 was investigated and yielded four new compounds hydroxylated at positions C-5 (13), C-2 (14), C-4 (15), and C-12 (16). The structures were established on the basis of their spectroscopic data including two-dimensional NMR analysis (HMQC, HMBC, nOesy) and nOes. The results obtained from biotransformation experiments shed further light on the detoxification mechanism of the phytopathogenic fungus against this compound and give an indication of the structural modifications that may be necessary if substrates of this type are to be further developed as selective fungal control agents for B. cinerea.
Daoubi
Mourad
M
Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Cádiz, s/n, Apartado 40, 11510 Puerto Real, Cádiz, Spain.
Hernández-Galán
Rosario
R
Benharref
Ahmed
A
Collado
Isidro G
IG
D001565:Benzoates / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D020171:Botrytis / Q000187:drug effects* / Q000378:metabolism*; D004852:Epoxy Compounds / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D005659:Fungicides, Industrial / Q000378:metabolism / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D012717:Sesquiterpenes
C504096:6alpha,7alpha-dihydroxy-beta-himachalene; D001565:Benzoates; D004852:Epoxy Compounds; D005659:Fungicides, Industrial; D012717:Sesquiterpenes; C412292:himachalene