Allelopathy Journal

The aerial parts of Piqueria trinervia Cav. (Asteraceae) afforded a new compound, 1β-glucosyl-piquerol A and its structure was established by 1D and 2D NMR, IR, UV and Mass Spectrometry. In contrast with its aglycone, 1β-glucosyl-piquerol A did not inhibit seed germination, and radicle elongation of Amaranthus hypochondriacus and Echinochloa crus-galli. Considering P. trinervia have medicinal properties, 1β-glucosyl piquerol A was found inactive against the human pathogenic microorganisms Bacillus subtilis, Escherichia coli, Vibrio cholerae, Salmonella typhi. and Staphylococcus aureus. It is proposed that synthesis of this monoterpene glycoside could be a potential mechanism to avoid autotoxicity, while hydrolysis in the soil by a microbial glycosidase could release the allelopathic compound Piquerol A. Alternatively mechanical damage of P. trinervia leaves, may also induce hydrolysis of 1β-glucosyl-piquerol A by an endogenous glycosidase.