Abstract
N-Methylprolines were detected in all fourteen species of Rhamnaceae tested, representing eleven genera and it is probable that these compounds are a chemotaxonomic feature of the family. Various species in different genera of other families previously reported to contain N-methylprolines were examined for their presence, but these were found as constituents of only a limited number of the tested species, although they were a feature of particular genera, for example Annona, Berberis, Phoradendron, Laurus and Trichilia. In most of the species found to contain N-methylprolines, their content was high, the yield from the majority of species being in excess of 0.5 % of the dry weight. In the limited number of N-methylproline-containing species in which both the aerial parts and roots of the same plant were tested separately, these compounds were detected in both, with the yields from the aerial parts being higher than those from the roots. The level of hydroxylation of the compounds in the aerial parts was higher than that in the roots.