Secondary Metabolites with Herbicidal and Antifungal Activities from Marine-Derived Fungus Alternaria iridiaustralis

Weed and soil-borne pathogens could synergistically affect vegetable growth result in serious losses. Investigation of agricultural bioactive metabolites from marine-derived fungus Alternaria iridiaustralis yielded polyketides (1−4), benzopyrones (5−7), meroterpenoid derivatives (8), alkaloid (9). The structures absolute configurations new 1, 3, 5−6, 8 were elucidated by extensive spectroscopic analyses, as well comparisons between measured calculated ECD 13C NMR data. Compounds 1−4, 6, 9 showed herbicidal potentials against the radicle Echinochloa crusgalli seedlings. Especially exhibited inhibition rates over 90% at concentrations 20 40 μg/mL, even better than commonly used chemical herbicide acetochlor. Furthermore, also performed a wide spectrum malignant weeds Digitaria sanguinalis, Portulaca oleracea, Descurainia sophia. 5−8 antifungal activities carbendazim-resistant strains Botrytis cinerea, with minimum inhibitory concentration (MIC) values ranging 32 to 128 which those carbendazim (MIC = 256 μg/mL). 6 integrated effects both weed. Overall, A. iridiaustralis, produces 1−9, potential for use microbial pesticide control weed pathogens.