Biotransformation of guttiferones, Symphonia globulifera metabolites, by Bipolaris cactivora, an endophytic fungus isolated from its leaves.

The search for active microorganisms for the biotransformation of guttiferone A (1) and C (6) has been successfully undertaken from a collection of endophytic fungi of Symphonia globulifera. Of the twenty-five isolates obtained from the leaves, three are active and have been identified as Bipolaris cactivora. The products obtained are the result of xanthone cyclisation with the formation of two regioisomers among four possible and corresponding to 1,16-oxy-guttiferone and 3,16-oxy-guttiferone. The biotransformation conditions were studied. Interestingly, both oxy-guttiferones A are present in the plant, and the ratio of 3,16-oxy-guttiferone to 1,16-oxy-guttiferone is 4 : 1, very close to that observed by biotransformation (3.8 : 1). These results are consistent with the involvement of endophytes in their formation pathway from guttiferone A, in planta. Finally, biotransformation made it possible to obtain and describe for the first time oxy-guttiferones C.

Three new species of Gliocephalotrichum causing fruit rot on different hosts from Brazil.

The genus Gliocephalotrichum (Nectriaceae), originally described as a soil-borne fungus, has been associated with postharvest diseases, especially of tropical fruits. Taxonomic studies using both morphological and molecular phylogenetic analyses have contributed to recognition of novel species in several countries. However, in Brazil, only three isolates of Gliocephalotrichum have been collected from soil samples and roots since the late 1970s. Our study expands the sample range using many Gliocephalotrichum isolates obtained from rotting fruits of tropical plant species in different states of Brazil. Polyphasic taxonomy was assessed with phylogenetic analyses of DNA sequences from four nuclear loci, morphological comparisons, and pathogenicity tests. As a result, three known species (G. bulbilium, G. longibrachium, and G. simplex) were identified from new hosts and locations in Brazil. In addition, three new species are described-G. abrachium, G. brasiliense, and G. caryocaris. A key to all Gliocephalotrichum species worldwide is provided. Although species of Gliocephalotrichum have not been considered to be important plant pathogens, this study shows they may cause postharvest fruit rot in tropical fruits and therefore have an impact in communities that depend economically on the harvest and sale of these fruits.