Antifungal potential of two synthetic vanadium (IV) oxalate compounds to control blue mold of oranges and apples under storage conditions

Abstract

The antifungal potentials of two vanadium oxalate compounds (C7H11N2)2[VO(C2O4)2(H2O)]·2H2O (compound 1) and {(CH6N3)2[VO(C2O4)2]}n (compound 2) against Penicillium expansum and Penicillium italicum were investigated. The compounds inhibited both fungi in well diffusion and plate growth inhibition assays and via volatile production methods. Compound 2 was able to reduce spore germination of P. expansum and P. italicum by 40.87% and 42.00%, respectively. Neither compound exhibited cytotoxicity in human cells. In vivo assays with stored apples showed a reduction in a blue mold by 49% and 25% by compounds 1 and 2, respectively. Both compounds were able to completely prevent blue mold in stored oranges. Microscopic examination demonstrated, that compound 2 caused drastic morphological effects on morphogenesis, and limit the spore germination of P. italicum on oranges and the destruction of P. expansum hyphae on apples. Both compounds inhibited biofilm by 78.48% and 73.83% and patulin reduction by 43.31% and 40%, respectively. Novelty impact statement The present work highlights the successful use of two vanadium oxalate complexes as antifungal agents to reduce blue mold on apples and citrus. Both compounds are able to limit radial growth and spores germination as well as reduce biofilm and Patulin production and affect mycelium morphogenesis.