Metabolites screening

The genus Herbidospora is one of the unexplored actinomycetes genera with only a limited number of secondary metabolites reported. In this study, an unknown metabolite not found in the UV database was detected in a liquid culture of Herbidospora sp. RD 11066. Chromatographic separation and structural analysis by NMR and MS revealed that these metabolites are chromanone and chromene derivatives. The former polyketides are positional isomers of the methyl substituent on the aromatic ring and convert each other by acetal exchange by two phenolic hydroxy groups.