ANTIFUNGAL POLYOXYGENATED FATTY-ACIDS FROM AELLANTHUS-PARVIFOLIUS

Two polyoxygenated fatty acids with antifungal activity have been isol ated from aerial parts of Aeollanthus parvifolius (Labiatae) using bio assay-guided isolation procedures. Spectroscopic analysis was used to identify the compounds as (Z)-4 xi,9 xi-diacetoxy-6 xi,7 xi-epoxy-5 xi -hydroxy-8-oxododeca-2-enoic acid and (Z)-4 xi,6 xi,7 xi,9 xi-tetraace toxy-5 xi-hydroxy-8-oxododeca-2-enoic acid. Both of these compounds in hibited spore germination of Cladosporium cucumerinum. Minimum inhibit ory doses were 1 mu g and 5 mu g, respectively, but only the former in hibited germination of Aspergillus niger at a dose of 5 mu g. Neither compound exhibited antibacterial activity. (Z)4 xi,9 xi-Diacetoxy-6 xi ,7 xi-epoxy-5 xi-hydroxy-8-oxododeca-2-enoic acid reduced the hyphal g rowth of Pythium ultimum. The mode of action was not resolved but did not involve either the disruption of the cell wall membrane or the inh ibition of extracellular enzymes. Application of (Z)-4 xi,6 xi,7 xi,9 xi-tetraacetoxy-5 xi-hydroxy-8-oxodo-deca-2-enoic acid to seedling pla nts did not give any protection against fungal attack, and indeed the compound appeared to be phytotoxic.