Emanuel L. Johnson

Flavonoids as markers for Erythroxylum Taxa: E. coca var. ipadu and E. novogranatense var. truxillense

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.

LEAF FLAVONOIDS AS CHEMOTAXONOMIC MARKERS FOR TWO ERYTHROXYLUM TAXA

Leaf extracts of Erythroxylum coca var. coca Lam. (E. c. var. coca) yielded six O-eonjugates of Eriodictyol flavonoids, while the equivalent extracts from Erythroxylum novogranatense var. novogranatense (Morris) Hieron (E. n. var. novogranatense) contained five flavonoids, two of which were O-conjugates of Luteolin and three were O-conjugates of Kaempferol. All six of E. c. var. coca methanolic extracted peaks (resolved by HPLC) were found to have a 2, 3 single bond, which in E. n. var. novogranatense is replaced by a 2- hydroxy allene. The other primary difference in the predominant flavonoids between these taxa is the chemical composition of the sugar and/or acyl O-conjugation and site(s) at which this conjugation occurred. The results suggest that the most abundant O-conjugated flavonoids of E. c. var. coca and E. n. var. novogranatense may be used as chemotaxonomic markers for the two taxa. Therefore, the O-conjugated peaks of Eriodictyol , are distinct chemotaxonomic markers for E. c. var. coca and the O-conjugated peaks Luteolin and Kaempferol for E. n. var. novogranatense. These taxa are two of the four cultivated Erythroxylum taxa that contain commercial quantities of the cocaine alkaloid in their leaves, this entity also sets apart the taxa from other members of Erythroxylum. We suggest that the biochemistry of flavonoids of other Erythroxylum taxa may also be species selective

Kaempferol (rhamnosyl) glucoside, a new flavonol from Erythroxylum coca. var.ipadu

Abstract A new flavonol, kaempferol rhamnosyl diglycoside, was isolated from leaf tissue of Amazonian field-grown coca Erythroxylum coca var. ipadu Plowman. The structure of the flavonol has been determined as kaempferol 4′- O -(rhamnosyl)glucoside by spectral analyses. The array of flavonoids present in E. c . var. ipadu currently under cultivation in Colombian fields is indicative of a recent cross, consistent with ancestralship to E. c. var. coca and the flavonol is useful as a chemotaxonomic marker for the taxon.

Modeling the effects of nitrogen on components of coca yield

Estimating yields (leaf dry weights) of Erythroxylum coca var. coca Lam. (coca) in regions where there is no access requires a method that can be used remotely. A simulation model that characterizes coca growth under varying weather conditions offers such a method. To develop this model, crop response to its environment must be quantified. The current experiment examined how a range in nitrogen (N) availability affected N status of various parts of the coca plant and components of yield. Minimal and maximal values for N concentration in leaves, stems, and roots were determined and N status calculated. Young leaves (a small yield component) had the highest N concentration, the greatest demand for N, and showed the greatest N stress. Old leaves had the next highest N concentration and a high demand for N, but showed the lowest N stress. Nitrogen status in old leaves was most affected by N availability. Dry weights of each leaf type increased with increased N availability, but leafcocaine concentration was not affected. Stems and taproots had the lowest N concentrations and these were not affected by N availability. Lateral roots, closer to the source ofN, had N concentrations that reflected N availability, however lateral root dry weights were not affected by N supply. Increased N availability increased (a) the number of growing points on the plant, (b) the number of leaves per growing point, and (c) the size of old leaves. Increases in these components translate into increased yields. Leaf yields correlated with the N status of leaves (r=0.58, p≤0.001), but variability in leaf yields for a given N status was too high to have strong predictive power.

Effect of soil pH on mineral element concentrations of two Erythroxylum species

Abstract Erythroxylum coca var. coca Lam. (E. coca) and Erythroxylum novogranatense var. novogranatense (Morris) Hieron (E. n. novogranatense) are two of four Erythroxylum species grown in the tropics of South America for cultural medicines and the alkaloid benzoylmethylecgonine. In a published study of biomass production over a soil pH range of 3.5 to 7.0, E. coca grew best at a pH equal to and below 5.5, and E. n. novogranatense grew best within the pH range of 4.7 to 6.0. Erythroxylum coca was tentatively classified as more tolerant to metal toxicities [aluminum (Al) and manganese (Mn)] than E. n. novogranatense, however, concentration patterns of mineral elements for E. coca and E. n. novogranatense tissue have not been reported, nor have the mechanisms of differential acid‐soil‐tolerance been elucidated. In the current study, the effects of soil pH on concentrations of Al, calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), Mn, and zinc (Zn) in leaves, stems, and roots were investiga...

Alkaloid Content in Two Erythroxylum Taxa During Juvenile Growth and Development

ABSTRACT Erythroxylum coca var. coca Lam. And Erythroxylum novogranatense var. novogranatense (Morris) Hieron (E.n. var. novogranatense) were grown in a controlled environment for 52 weeks to monitor the content of hygrine, tropinone, tropacocaine, methyl ecgonine, cocaine and cis- and trans-cinnamoylcocaine in seeds, plant parts, and organs during juvenile growth. Embryos and endosperms of var. coca contained cocaine while only embryos of var. novogranatense contained cocaine. Tropacocaine was present in hypocotyls, stems and roots of var. novogranatense, but not in var. coca. Trans-cinnamoylcocaine was the most abundant alkaloid in cotyledons (12 weeks after seeding) and leaves (24 weeks after seeding) in both var. coca and var. novogranatense. After 52 weeks of seeding growth, cocaine was the preeminent alkaloid in leaves of both taxons with a cocaine content of 0.66 percent in var. coca and 1.04 percent in var. novogranatense.