DIFFERENCES IN CHEMICAL CONSTITUENTS OF MANGIFERA-INDICA, INFECTED WITH ASPERGILLUS-NIGER AND FUSARIUM-MONILIFORMAE

The isolation and characterization of the chemical constituents of different parts of Mangifera indica, sound and infected with two pathogenic fungi, viz. Aspergillus niger and Fusarium moniliformae, are described. Natural occurrence of two polyketideshikimate-derived depsides is reported for the first time. Additionally, a number of xanthones, flavonoids, triterpenes and amino acids, not encountered before in this species, are reported. The co-occurrence of mangiferin, 1,3,6,7-tetra- and 1,3,5,6,7-pentaoxygenated xanthones and the quantitative variation of the latter two compounds with the growing of the plant and during the fungal infection are biochemically significant. The protector role of the flavonoids and other C15 metabolites to M. indica from the ingress of the fungal hyphae is indicated. The two pathogenic fungi secreted a number of mycotoxins in different parts of the host species during its vegetation and flowering periods. During the elaboration of these toxic metabolites, the host-pathogen interaction played an important role. Evidence is presented for A. niger as a mycotoxin producing fungus. © 1978.