Synthesis and antifungal activity of analogues of naturally occurring botrydial precursors

Abstract

Analog compounds of the proposed intermediates of the biogenetic pathway to botrydial have been synthesized. These compounds were tested for their potential antifungal activity against the phytopathogenBotrytis cinerea. Our results showed a fungistatic effect of some compounds on mycelium growth. The most significant effect was exerted by 2-α-hydroxy-2,3-dihydro-1-epiprobotrydial, which inhibited growth ofB. cinerea. Some aspects of structure-activity relationships are discussed.

Biotransformation of the Fungistatic Sesquiterpenoid Patchoulol by Botrytis cinerea

“…The antifungal properties of patchoulol ( 1 ) were established against the growth of B. cinerea using the “poisoned food” technique − (see Experimental Section), and the commercial fungicide Euparen was used as a standard. Patchoulol ( 1) displayed inhibitory activity at 40 and 60 ppm for 1 and 3 days, respectively, and total inhibition at 80 and 100 ppm for 4 days.…”

Biotransformation of Bioactive Isocaryolanes by Botrytis cinerea

“…Chromatography of the neutral fraction (4 days, 6 flasks) gave (8R,9R)isocaryolane-8,9-diol (5) (22 mg), (3S,8R,9R)-isocaryolane-3,8,9-triol (8) (8 mg), (4R,8R,9R)-isocaryolane-8,9,15-triol (7) (4 mg), (6R,8S,9R)isocaryolane-6,8,9-triol (9) (8 mg), (6S,8S,9R)-isocaryolane-6,8,9-triol (11) (<1 mg), (2R,5S,8R,9R)-isocaryolane-5,8,9-triol (10) (2 mg), and dihydrobotrydial (32 mg). Chromatography of the neutral fraction (9 days, 6 flasks) gave (8R,9R)-isocaryolane-8,9-diol (5) (20 mg), (3S,8R,9R)-isocaryolane-3,8,9-triol (8) (4 mg), (4R,8R,9R)-isocaryolane-8,9,15-triol (7) (2 mg), (6R,8S,9R)-isocaryolane-6,8,9-triol (9) (15 mg), (6S,8S,9R)-isocaryolane-6,8,9-triol (11) (<1 mg), (2R,5S,8R,9R)-isocaryolane-5,8,9-triol (10) (10), 195 (12), 180 (11), 165 (5), 151 (7), 140 (10), 139 (100), 123 (22), 109 (22), 107 (15), 98 (17), 97 (18), 81 (16) ' ASSOCIATED CONTENT b S Supporting Information. 1 H and 13 C NMR spectra of compounds 6À11.…”

Fungal terpene metabolites: biosynthetic relationships and the control of the phytopathogenic fungus Botrytis cinerea

“…The effect on the growth of the fungus of a number of compounds related to botryane biosynthetic intermediates has been studied. Treatment of caryophyllene oxide (64) with aqueous acid leads to the formation of clovane-2b,9a-diol (69). 59 If the Brønsted acid is replaced by the p-acid catalyst tetracyanoethylene and an alcohol is used as a solvent, solvolysis of the caryophyllene (64) oxide leads to the formation of 2b-alkoxyclovan-9a-ols 70-75 (Scheme 7).…”