Lasiojasmonates A-C, three jasmonic acid esters produced by Lasiodiplodia sp., a grapevine pathogen

In this study, a strain (BL 101) of a species of Lasiodiplodia, not yet formally described, which was isolated from declining grapevine plants showing wedge-shaped cankers, was investigated for its ability to produce in vitro bioactive secondary metabolites. From culture filtrates of this strain three jasmonic acid esters, named lasiojasmonates A–C and 16-O-acetylbotryosphaerilactones A and C were isolated together with (1R,2R)-jasmonic acid, its methyl ester, botryosphaerilactone A, (3S,4R,5R)-4-hydroxymethyl-3,5- dimethyldihydro-2-furanone and (3R,4S)-botryodiplodin. The structures of lasiojasmonates A–C were established by spectroscopic methods as (1R⁄,2R⁄,30S⁄,40R⁄,50R⁄)-4-hydroxymethyl-3,5-dimethyldihydro- 2-furanone, (1R⁄,2R⁄,30S⁄,40R⁄,50R⁄,100R⁄,120R⁄,130R⁄,140S⁄) and (1R⁄,2R⁄,30S⁄,40R⁄,50R⁄,100S⁄,120R⁄,130R⁄, 140S⁄)-4-(4-hydroxymethyl-3,5-dimethyltetrahydro-furan-2-yloxymethyl)-3,5-dimethyldihydro-2-furanones jasmonates (1, 4 and 5). The structures of 16-O-acetylbotryosphaerilactones A and C were determined by comparison of their spectral data with those of the corresponding acetyl derivatives obtained by acetylation of botryosphaerilactone A.Themetabolites isolated, except 4 and5,were tested at1 mg/mLonleavesof grapevine cv. Cannonau and cork oak using the leaf puncture assay. They were also tested on detached grapevine leaves at 0.5 mg/mL and tomato cuttings at 0.1 mg/mL. In all phytotoxic assays only jasmonic acidwas found to be active. All metabolites were inactive in the zootoxic assay at 50 lg/mL.