Flavonoids as markers for Erythroxylum Taxa

Abstract

Leaf extracts of Erythroxylum coca var. ipadu Plowman ( E. c . var. ipadu ) produced five O -conjugates of taxifolin and one O -conjugate of quercetin flavonoids, while the equivalent extract from Erythroxylum novogranatense var. truxillense (Rusby) Plowman ( E. n . var. truxillense ) afforded four flavonoids: (a) the first, an O -conjugate of quercetin; (b) the second, an O -conjugate of fisetin; and (c) the third and fourth O -conjugates of kaempferol. The flavonols of E. n . var. truxillense contained 4′-OEt whereas in E. c . var. ipadu none was found. E. n . var. truxillense contained the flavonol fisetin which was not found in E. c . var. ipadu and has not been previously reported for the taxa. The major sugars in leaf extracts were acylated rhamnosides with either 7, 3 or 4′ linkage or combinations thereof. Flavonoids of the four cultivated Erythroxylum taxa, all of which contain the cocaine alkaloid, differ, and may be used as chemotaxonomic markers for the taxa.