Acautalides A-C, Neuroprotective Diels-Alder Adducts from Solid-State Cultivated Acaulium sp. H-JQSF.

The solid-state cultivation of Acaulium sp. H-JQSF isolated from Armadillidium vulgare produces acautalides A-C (1-3) as skeletally unprecedented Diels-Alder adducts of a 14-membered macrodiolide to an octadeca-9,11,13-trienoic acid. The acautalide structures, along with the intramolecular transesterifications of 1-acylglycerols, were elucidated by mass spectrometry, nuclear magnetic resonance, chemical transformation, and single-crystal X-ray diffraction. Compounds 1-3 were found to be neuroprotective with antiparkinsonic potential in the 1-methyl-4-phenylpyridinium-challenged nematode model, with the magnitude impacted by the glycerol esterification.