Erythroxylum coca var. ipadu Plowman (E. c. var. ipadu) was harvested from cultivated fields in the Amazonian region of Colombia, South America, to determine: (a) their leaf flavonoid profile; (b) their similarity or difference to those present in our living collection of the taxon and (c) the usefulness of the flavonoids as chemotaxonomic markers for the taxon. High performance liquid chromatography was used to separate the flavonoids while spectra analyses were used for their identification. A new flavonol was found and isolated from leaf tissue of Amazonian field-grown coca (Erythroxylum coca var. ipadu Plowman) that has not been reported. The structure of the flavonol was determined to be kaempferol 4'-O-rhamnoglucoside. The array of flavonoids present in E. c. var. ipadu is indicative and consistent with ancestralship to E. c. var. coca. The new flavonol is useful as a chemotaxonomic marker for the taxon.

Key words: Amazonian coca, Erythroxylum coca, flavonol, kaempferol rhamnoglucoside