Erythroxylum coca

Propagation

Germination

Cultivated stands of coca var. ipadu rarely produce viable seeds due to the lack of both stylar forms. It is mostly propagated by cutting further contributing to the lack of fertile seeds. There seem to be no barriers to producing fertile seeds if both stylar forms were to be brought together.[3]

The germination rate of fresh, de-pulped coca seeds is approximately 95% but after 24 days of storage at 4°C, this decreases to 29% and stays constant for 32 days (the end of the study period). Ungerminated seeds at the end of the study were nonviable, as determined by a tetrazolium test.[1]

After pericarp removal, floating seeds have <2% germination and a high microbial load.[2]

Depulped seeds can be disinfected by immersing them in a 70:30 mixture of ethanol and sodium hypochloride solution in a slight vacuum (200 kPa) for 20 minutes followed by triple rinsing in distilled water.¹[4]

Seeds can be direct sown (after depulping and disinfection) 3 cm deep in plastic pots filled with Pro-Mix/vermiculite (1:1 w/w). Radicle protrudence through the testa occurs in 3 days to 6 weeks. Emergence from the medium occurs 6-10 weeks after sowing.[2]

Vegetative

Coca var. ipadu cuttings root easily and survive for several weeks if kept damp. As other varieties of coca are not as easily rooted, this seems to be an artificially selected trait from years of shifting agricultural production in the Amazon.[3]

Thirty-centimeter cuttings of coca var. ipadu are taken after the leaves are harvested and direct planted in soil nurseries about 15 cm deep.[3]

In-Vitro

Calli cultures can be induced in leaf sections of coca var. coca using 0.6 mg/L 2,4-D, 0.06 mg/L IBA, and 0.5 mg/L BAP. Cocaine production on Anderson rhododendron medium was an order of magnitude higher than either modified Murashige-Tucker or Gamborg B5 media.[5]

Shoot proliferation (derived from excised embryos) can be induced with 2.22 uM BA, 0.25 uM IBA, and 0.65 uM GA on modified Murashige and Tucker medium. Initial tests with other species of the Erythroxylum genus revealed that Gelrite was a more suitable gelling agent than agar.[6]

Cultivation

Coca is primarily grown at a high altitude in very favorable tropical environments.[3]

Coca var. ipadu does not grow well as a secondary plant in the understory. They often lose their vigor and become diseased after a few years of growth.[3]

The optimal temperature for coca var. coca leaf growth is 27°C compared to 19, 23, or 31°C.[7]²

Harvest

Coca var. ipadu grows to 1-1.5 m tall and produces its first harvest within 6 months after cuttings are taken. From 30 to 50% of the leaves may be harvested every two weeks in good growing conditions.[3]

Coca var. coca does not reach sexual maturity until about 14 months after germination, though this can be reduced to nine months with environmental manipulation.[2]

Greenhouse-grown coca var. coca seeds after one year are approximately 22cm tall and have a total dry leaf mass of approximately 1.9 g.[2]

Yield

Coca var. coca grown in pots have an average total (roots, shoots, leaves) dry mass of 19.6 grams after two years from seed.[8]

Soilless

Soil

Fertilization

Greenhouse-grown, 2-year-old coca var. coca plants in 1 L pots can be fertilized with 2 g/l standard 20-20-20 NPK fertilizer every three weeks. Field-grown plants received 30 kg/ha (3 g m^-2) 20-20-20 NPK per month.[9]

Osmocote 9-month slow-release fertilizer (13-13-13) added to pots of sandy loam soil at 112 g/kg is sufficient for good growth in coca var. coca.[8]

Coca var. coca grown in soil with a pH of 3.5 accumulated more than seven times the total dry mass compared to soil with a pH of 7.0 after two years. Similarly, a mineral deficiency was evident (chlorosis, leaf distortion) at pH 6.5 and 7.0. The authors recommend cultivation at ph 3.5-5.5.[8] This dramatic effect of pH might be responsible for the large discrepancies in coca growth in the literature. Uncontrolled or unstated pH cultivation studies should be treated with caution when interpreting the results.

Temperature

Lighting

The highest yield of dry leaf mass in coca var. coca is at 400 µmol m^-2s^-1 compared to either 155 or 250 µmol m^-2s^-1. Coca var. coca is more shade adapted than novogranatense but it still loses productivity at low illumination.[7][^note1]

[10]

Pests

Coca and novogranatense are relatively unbothered by herbivorous pests with proper control methods. Several species of Eloria (moths) have been recorded consuming Erythroxylum spp. in the larval stage and pupating on the plants.[11] If left unchecked, they can consume up to 80% of a coca harvest. Similarly, Psittacastis cocae moth larvea feed on the leaves and young shoots. Leaf cutter ants (Acromyrmex spp., Oecodoma spp.) can also cause considerable damage if left to flourish. Aegoidus pacificus beetles burrow through the stem allowing pathogenic fungi to penetrate and kill the plant.[12]

Damping off is a common problem, especially at the seedling stage, but mature plants are also affected. Other common diseases include a kind of rust and “witch’s broom”.[12]

In densely humid growing conditions, coca plants can be weakened by extensive lichen growth. Likewise, parasitic Loranthaceae can diminish productivity.[12]

Ecology

Morphology

Identification of the Erythroxylum genus was first published in 1756 by P. Brown (pg. 278).[13] Identification of E. coca was given in 1786 by Lamark (pg. 393).[14]

Roots

Stem

Leaves

Inflorescence

Seeds

[15]

Phytochemistry

Coca is grown primarily for its ecgonine alkaloids, notably cocaine. Erythroxylum is the only known genus to produce these alkaloids.[16] As a consequence of the illicit nature of cocaine, the phytochemistry of Erythroxylum is extensively studied.

Even after storage for 44 years, coca leaves can contain 0.03% cocaine.[17]

In the Erthryxylum genus, only coca and novogranatense contain appreciable amounts of cocaine alkaloids.[18]

Coca var. ipadu has consistently one-half to one-third the concentration of cocaine compared to coca var. coca. The concentration ranges from 0.11% to 0.41% dry weight.[3]

Infraspecific Variation

Biosynthesis

Tropane alkaloid biosynthesis likely evolved independently in Solanacea and Erythroxylaceae. This is evidenced by the difference in the enzymes responsible for the tropinone-reduction step.[19]

The concentration of cocaine in leaves of coca var. coca depends on temperature, reaching the highest levels at a lower temperature (24°C) than the ideal leaf growing temperature (26°C). Cocaine concentration is largely independent of illumination between 155-400 µmol m^-2 s^-1.[7][^note1]

Distribution

Tropane alkaloids are synthesized in the leaf.[6][5][20] Calli derived from leaf tissue are capable of synthesizing cocaine and related alkaloids, though at several orders of magnitude lower than in intact leaves (~0.008%).[5] However, in-vitro shoot cultures produce cocaine at a similar level as greenhouse-grown plants (0.51% dw).[6] Storage by complexation with hydroxycinnamoyl quinate esters in vacuoles is likely a contributor to the accumulation of high concentrations of cocaine in whole tissues.[21]

The leaves of coca contain 0.13-0.86% cocaine. The seeds of coca do not contain any cocaine.[18].

Timecourse

Young seedlings of coca var. coca contain very little cocaine. The concentration in the leaves increases steadily from about 6 weeks and levels out to adult concentration at about 24 weeks after germination. The roots, stems, and hypocotyl of juvenile seedlings of coca var. coca do not contain detectable levels of cocaine.[2]

Improvement

Artificial selection in the illicit production of coca for glyphosate resistance, dense biomass, and high cocaine content has seen a boom in the last two decades due to governmental eradication efforts. These cultivars are chemically distinct from existing varieties mainly in the minor alkaloid profiles.[22]

Identification

The entire genome of E. coca var. ipadu and E. novogranatense var. truxillense has been sequenced with 584 Mbp and 573 Mbp respectively.[23]

Varieties

• Erythroxylum coca var. ipadu (Amazonian coca)
• Erythroxylum coca var. coca

Minor Cultivars

• Tingo Peruana[22][24]
• Peruana Blanca[22][24]
• Amarga[22][24]
• Peruana Negra[22][24]
• Pomarosa[22][24]
• Chirosa[22][24]
• Pati Roja (Patiroja)[22][24]
• Gigante[22][24]
• Amazonas[22][24]
• Tingo Negra[22][24]
• Boliviana Blanca[22][24]
• Boliviana Roja[22][24]
• Boliviana Negra[22][24]
• Cuarentana[22][24]
• Tingo Maria[22][24]
• Dulce[22][24]
• Caturra[24]
• Tingo Macho[24]
• Millonaria[24]

DNA profiling has demonstrated that “coca var. ipadu” currently (2003) cultivated across Colombia is a hybrid between coca var. coca and novogranatense var. truxillense.[25] This hybridization is further supported by later (2010) morphological evidence.[26]

[27] [28] [29]

Inheritance

Methods

Boiling ethanol is the only extraction solvent to produce quantitative results without artifacts. The methods involving various acid/base techniques resulted in esterification products. Prolonged extraction with chloroform resulted in cocaine breakdown products. Heptane, in isolation, does not dissolve cocaine sufficiently.[16]

Short-styled coca var. ipadu and long-styled coca var. coca crosses are fertile and produce normal seedlings.[3]

Alkaloid spectrum and concentration cannot be used for chemotaxonomic identification since the intraspecies variations of alkaloids are more than the infraspecies variation.[16]

History & Society

Amazonian coca (var. ipadu) was historically consumed as a dried powder given in a ceremonial context or as a medicinal tea. It is still consumed as a powder today, though it is more commonly used for work.[3]

Coca var. ipadu contains a significant quantity of vitamins and minerals. Some tribes of the Amazon add these leaf powders directly to food purely for the nutritional content.[3]

Work Log

19 Nov 2023

Anderson media is pH adjusted to 3.25-4.25 and uses 400 ml/L ammonium nitrate and 480 mg/L potassium nitrate as the nitrogen sources. This is roughly 1/4 the nitrogen concentration compared to MS media.

08 May 2023

So I was reading about Camellia sinensis fertilization and noticed some similarities. Perhaps coca prefers a similarly high ammonium:nitrate ratio?

Osmocote plus has a roughly 1:1 ratio of ammonium to nitrate and is recommended for coca cultivation. Fish emulsion is also a common fertilizer suggestion. Proteinaceous nitrogen breaks down into ammonium/a before being oxidized by bacteria. Maybe the reason for the success of these fertilizers is due to the atypically high concentration of ammonia.

Similarly, fertilizers designed for acid loving plants often include nitrogen from urea or ammonium salts, e.g. Miracle Grow Miracid. Those fertilizers and soil mixes are also frequently recommended.

Maybe the success of some soil mixes is due solely/primarily to the use of fish emulsion and not on any other media type inclusion.

Every instance of a person suggesting a fertilizer is either proteinaceous or ammoniacal. 1) 2

Plants adapted to grow under waterlogged and very acid soil conditions, which may have a low potential for producing the nitrate reductase enzyme, tolerate and even prefer ammonium-nitrogen nutrition. [30]

Notes

Bibliography

1. Johnson, E. L., Seed Viability of Two Erythroxylum Species Stored at 4 °C, Planta Medica, vol. 55, no. 7, pp. 691--691, December 1989. doi: 10.1055/s-2006-962311. Abstract
   Thieme E-Books \& E-Journals
2. Johnson, Emanuel L., Alkaloid Content in Two Erythroxylum Taxa During Juvenile Growth and Development, Journal of Herbs, Spices \& Medicinal Plants, vol. 10, no. 2, pp. 47--61, 2002. doi: 10.1300/J044v10n02_06. 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.
3. Plowman, Timothy, Amazonian Coca, Journal of Ethnopharmacology, vol. 3, no. 2, pp. 195--225, March 1981. doi: 10.1016/0378-8741(81)90054-4. Abstract
   A general overview of various aspects of Amazonian coca (Erythroxylum. coca var. ipadu) is presented. This plant is considered a distinct variety of coca which has been developed as a cultivated plant in the upper Amazon basin. It differs from typical Andean coca in morphological, physiological and chemical features as well as in the method of preparation and use by Amazonian tribes. The main topics here discussed are the history, distribution, botany, chemistry, origin, methods of preparation and use, and the effects of Amazonian coca.
4. JOHNSON, EMANUEL L. and ELSOHLY, MAHMOUD A., Content and De Novo Synthesis of Cocaine in Embryos and Endosperms from Fruit of Erythroxylum Coca Lam, Annals of Botany, vol. 68, no. 5, pp. 451--453, November 1991. doi: 10.1093/oxfordjournals.aob.a088277. Abstract
   There is controversy as to whether the mature fruit of Erythroxylum coca var. coca Lam. contains the cocaine alkaloid (benzoylmethylecgonine). In the present study, cocaine was monitored to determine if it was present in embryos and endosperms of mature fruit of E. coca var. coca Lam., and if present, the time required for de novo synthesis in imbibing seed. Seeds from mature fruit of E. coca were dissected to separate the embryos from the endosperms. The separated embryos and endosperms were analysed for cocaine. Subsequently, endosperms and embryos from seed imbibed. under a light and dark treatment were separated on days 3, 6, 9, 12 and 15 and analysed for cocaine. Cocaine was present in embryos (0.005\% of d. wt) and endosperms (0–001\% of d. wt) of mature fruit of E. coca. De novo synthesis of cocaine occurred only in embryos of seed imbibed under light after day 9 of imbibition.
5. Docimo, T. and Davis, A. J. and Luck, K. and Fellenberg, C. and Reichelt, M. and Phillips, M. and Gershenzon, J. and D’Auria, J. C., Influence of Medium and Elicitors on the Production of Cocaine, Amino Acids and Phytohormones by Erythroxylum Coca Calli, Plant Cell, Tissue and Organ Culture (PCTOC), vol. 120, no. 3, pp. 1061--1075, March 2015. doi: 10.1007/s11240-014-0660-8. Abstract
   Erythroxylum coca (Erythroxylaceae) is the source of the tropane alkaloid cocaine. Several lines of evidence suggest that tropane alkaloid biosynthesis in E. coca differs from that in solanaceous species, but there are many gaps in our understanding of the pathways in both groups. The development of an E. coca cell culture that produces cocaine could provide a reproducible model system for discovering novel biosynthetic genes and study pathway regulation. Calli cultures were successfully established from young leaf explants on three different media: Anderson’s Rhododendron, Gamborg B5, and modified Murashige-Tucker, all supplemented with growth regulators: 2,4-D (0.6~mg L−1), indole butyric acid (0.06~mg L−1), and benzylaminopurine (0.5~mg L−1). All accumulated cocaine and cinnamoylcocaine at levels of 0.05–0.5~nmol per gram dry weight, as determined by LC–MS, several orders of magnitude below the concentration found in the intact plant. Anderson’s Rhododendron medium supported the highest level of tropane alkaloid production, as well as the highest level of the amino acids arginine, glutamate, proline and phenylalanine, all thought to be precursors of cocaine, but contained generally lower levels of hydroxycinnamate-quinate esters, such as chlorogenic acid. These differences may be ascribed to its relatively low content of nitrate or salts, or its high content of adenine. Addition of 100~μM salicylic acid or coronalon, an analog of the bioactive jasmonic acid-isoleucine conjugate, did not result in any increase in tropane alkaloid production. These E. coca calli could provide valuable material for studies on tropane alkaloid biosynthesis and regulation.
6. Lydon, John and Zimmerman, Richard H. and Fordham, Ingrid M. and Lusby, William R., Tissue Culture and Alkaloid Production of Erthroxylum Coca Var. Coca, Journal of Herbs, Spices \& Medicinal Plants, vol. 2, no. 1, pp. 3--14, December 1993. doi: 10.1300/J044v02n01_02. Abstract
   A tissue culture method was developed to study the biosynthesis of alkaloids in Erythroxylum coca var. coca. Shoot cultures were established from excised embryos of seed from Erythyroxylum coca var. coca and grown on a semi-solid medium. Alkaloids extracted from leaves of shoot cultures and the parent plant were identified by gas chromatography-mass spectrometric (GC/MS) analysis and quanitifed by gas chromatography. Shoot cultures that were developed from one Erythroxylum coca var. coca plant produced the major and minor alkaloids common to the species. The cocaine levels of the shoot cultures were 50 percent of that produced by the parent plant but within the range reported for the species. Maximal levels of cocaine were produced in the leaves of shoot cultures within eight days after transfer to fresh media. The production of alkaloids in the shoot cultures demonstrates that roots are not necessary for tropane alkaloid production in Erythroxylum coca var. coca.
7. Acock, MARY C. and Lydon, {\relax JOHN} and Johnson, {\relax EMANUEL} and Collins, {\relax RONALD}, Effects of Temperature and Light Levels on Leaf Yield and Cocaine Content in Two Erythroxylum Species, Annals of Botany, vol. 78, no. 1, pp. 49--53, July 1996. doi: 10.1006/anbo.1996.0094. Abstract
   Published information on the response ofErythroxylumcrops to temperature and photosynthetic photon flux density (PPFD) is more descriptive than quantitative. The objective of this study was to quantify the effects of temperature and PPFD on leaf growth and cocaine content in the major cocaine-producing species. Plants ofErythroxylum cocavar. coca (Coca) andErythroxylum novogranatensevar. novogranatense (Novo) were grown in artificially-lighted controlled environment chambers with a 12h photoperiod and at day/night temperatures of 20/16, 25/21, 30/26 or 35/31°C and at PPFDs of 155, 250 or 400μmolm−2s−1for 53d before leaves were harvested for dry weight and cocaine concentration determinations. Subsequently, chamber temperatures were altered to provide constant day/night temperatures of 19, 23 or 27°C. Plants were grown for 180d under these conditions and harvested a second time. Leaf yields in response to temperature were best expressed as quadratic functions. The optimum average daily temperature for leaf growth was near 27°C in both species. Novo was more vegetatively vigorous than Coca. Leaf mass at the first harvest was lowest in plants grown under 155μmol m−2s−1for both species. At the second harvest the only change was that there was no difference in leaf mass between 155 and 250μmol m−2s−1in Coca. Leaf cocaine concentration was not affected by PPFDs{$<$}400μmol m−2s−1but was affected by temperature. In Coca, leaf cocaine concentration was maximum at a mean daily temperature of 24°C at the first harvest and at 19°C at the second harvest. In Novo, leaf cocaine concentration was maximum at a mean daily temperature of 25°C at the first harvest but there was no effect of temperature at the second harvest. Coca leaves had higher cocaine concentration than Novo leaves at all temperatures at the first harvest but at the second harvest, there was no significant difference in leaf cocaine concentration between species except in the lowest temperature treatment when leaf cocaine concentration was higher for Coca. Cocaine production on a per plant basis was largely a function of leaf mass.
8. Johnson, Emanuel L. and Campbell, T. Austin and Foy, Charles D., Effect of Soil pH on Mineral Element Concentrations of Two Erythroxylum Species, Journal of Plant Nutrition, vol. 20, no. 11, pp. 1503--1515, November 1997. doi: 10.1080/01904169709365352. 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 investigated. At pH 3.5, roots of both species accumulated high concentrations of Al that decreased as soil pH increased, however, there was no pH × species interaction. The highest concentration of Ca was found in the leaves of both species, however, E. coca accumulated more Ca as soil pH increased than did E. n. novogranatense. Manganese and Zn levels were highest in roots of both species (E. coca and E. n. novogranatense); levels in all tissues decreased with increasing pH. Manganese concentration was highest in roots of E. coca and Zn concentration was highest in tissues of E. n. novogranatense. Copper, Fe, K, and Mg levels were erratic with increasing pH, indicating that sufficient amounts of these nutrients are acquired at low pH levels. Root concentrations of Fe and K in E. coca increased markedly between pH 3.5 and 4.7. At pH 3.5, E. coca demonstrated no symptoms of mineral deficiency and/or toxicity, however, chlorosis, leaf distortion and root atrophy were prevalent at pH 6.5 and 7.0. By contrast, E. n. novogranatense demonstrated diminished growth and root atrophy at soil pH 3.5, whereas at pH 6.5 and 7.0, although biomass production was reduced, no symptoms of mineral deficiency and/or toxicity were present. The species obviously behave differentially at pH extremes and E. coca appears to be most tolerant of extremely acid soils; the two species may also differ in mineral sensitivities between the species at higher pH levels. Erythroxylum coca may compete more effectively with Al for Ca binding sites within the root, and may have greater internal tolerance of Mn, compared with E. n. novogranatense.
9. Moore, James M. and Casale, John F. and Klein, Robert F. X. and Cooper, Donald A. and Lydon, John, Determination and In-Depth Chromatographic Analyses of Alkaloids in South American and Greenhouse-Cultivated Coca Leaves, Journal of Chromatography A, vol. 659, no. 1, pp. 163--175, January 1994. doi: 10.1016/0021-9673(94)85018-6. Abstract
   Methodology is described for the detection and/or determination of cocaine and minor alkaloids in South American coca as well as in greenhouse- and tropical-cultivated field coca of known taxonomy. Coca leaf from Bolivia, Peru, Ecuador and Colombia were subjected to the determination of cocaine, cis- and trans-cinnamoylcocaine, tropacocaine, hygrine, cuscohygrine and the isomeric truxillines. The greenhouse samples were cocaine-bearing leaves of the genus Erythroxylum and included E. coca var. coca, E. novogranatense var. novogranatense and E. novogranatense var. truxillense, and the alkaloids determined were cocaine, ecgonine methyl ester, cuscohygrine, tropacocaine and the cinnamoylcocaines. The tropical-cultivated coca were E. novogranatense var. novogranatense and E. coca var. coca. Cocaine and minor alkaloids were isolated from basified powdered leaf samples using a toluene extractant, followed by acid-Celite column chromatography. The isolated alkaloids were determined by capillary gas chromatography with flame ionization or electron-capture detection. Methodology is also presented for the isolation and mass spectral analysis of numerous trace-level coca alkaloids of unknown structure.
10. Lydon, John and Casale, John F. and Kong, Hyesuk and Sullivan, Joseph H. and Daughtry, Craig S. T. and Bailey, Bryan, The Effects of Ambient Solar UV Radiation on Alkaloid Production by Erythroxylum Novogranatense Var. Novogranatense†, Photochemistry and Photobiology, vol. 85, no. 5, pp. 1156--1161, 2009. doi: 10.1111/j.1751-1097.2009.00562.x. Abstract
    Truxillines are alkaloids produced by Erythroxylum species and are thought to be derived from the UV-driven dimerization of cinnamoylcocaines. This study was conducted to determine the effects of ambient UV radiation on the production of truxillines in Erythroxylum novogranatense var. novogranatense. Field plants were grown under shelters covered with plastic filters that were transparent to UV radiation, filtered UV-B, or both filtered UV-B and UV-A radiation. The treatments had no significant effect on plant biomass or specific leaf weight. Absorption values in the UV-C and UV-A region of acidified-methanol leaf extracts were higher for plants exposed to UV radiation compared to the no UV radiation treatment. There was a trend in decreasing levels of trans-cinnamoylcocaine and a statistically significant decrease in levels of cis-cinnamoylcocaine in the leaves of plants exposed to UV radiation compared to the no UV radiation treatment. Truxilline levels increased in leaves from plants exposed to UV radiation compared to the no UV radiation treatment. Most significantly, the ratio of truxillines to total cinnamoylcocaines in the leaves was affected by UV, increasing with increased UV exposure. The results support the hypothesis that UV radiation is involved in the formation of truxillines from cinnamoylcocaines.
11. Blum, Murray S. and Rivier, Laurent and Plowman, Timothy, Fate of Cocaine in the Lymantriid Eloria Noyesi, a Predator of Erythroxylum Coca, Phytochemistry, vol. 20, no. 11, pp. 2499--2500, January 1981. doi: 10.1016/0031-9422(81)83080-4. Abstract
    Larvae of the lymantriid moth Eloria noyesi, which are obligate feeders on Erythroxylum coca, excrete most of the ingested cocaine as unchanged base. Cocaine, analysed by mass fragmentography, is readily, detectable in the blood of larvae and is presumably sequestered during larval feeding, since it is present in the bodies of adult moths that do not feed on E. coca. Cocaine is an effective feeding deterrent for the ant Monomorium pharaonis when present at a concentration below that found in the leaves of E. coca.
12. Plowman, Timothy and Weil, Andrew T., Coca Pests and Pesticides, Journal of Ethnopharmacology, vol. 1, no. 3, pp. 263--278, October 1979. doi: 10.1016/S0378-8741(79)80015-X. Abstract
    The major pests of coca are listed and discussed along with methods used to control them in the past and present. Results of analyses for pesticide residues in samples of commercial Peruvian coca leaves are presented. Levels of pesticides found in these samples are too low to be considered a medical risk to coca chewers.
13. Browne, Patrick and Ehret, Georg Dionysius, The Civil and Natural History of Jamaica, 1756. url: http://archive.org/details/mobot31753000808003.
14. Lamarck, Jean-Baptiste and Poiret, Jean-Louis-Marie, Encyclopédie Méthodique. Botanique, vol. 2, pp. 1--776, 1786. url: https://www.biodiversitylibrary.org/item/15260.
15. Boesewinkel, F. D. and Geenen, J., Development of Ovule and Seed-Coat of Erythroxylum Coca Lamk., Acta botanica neerlandica, vol. 29, no. 4, pp. 231--241, January 1980. doi: 10.1111/j.1438-8677.1980.tb01200.x. Abstract
    The inner and outer integuments of Erythroxylum coca are both of dermal derivation. The outer integument is initially 3 cells and later 3-5 cells thick. The inner integument is at first 3 cells thick to become multiplicative and ultimately about 20 cells thick and thus forming the greater part of the mass of the seed. The inner layer is developed as an endothelium. The nucellus is oblong by mitotic activity in the part beneath the embryo sac. The testa and legmen are crushed with the exception of the fibrous exotegmen. The flattened cells of the inner layer contain tannin. The relationship between Erythroxylaceae and Linaceae is discussed.
16. Rivier, Laurent, Analysis of Alkaloids in Leaves of Cultivated Erythroxylum and Characterization of Alkaline Substances Used during Coca Chewing, Journal of Ethnopharmacology, vol. 3, no. 2, pp. 313--335, March 1981. doi: 10.1016/0378-8741(81)90061-1. Abstract
    Several solvents were tested for the extraction of the alkaloids in Erythroxylum coca. The resulting crude extracts were analyzed by gas chromatography-mass spectrometry. Ethanol extraction was found to be the only quantitative method presenting no artifacts. It was established that cocaine and cis- and trans-cinnamoylcocaine were the endogenous alkaloids in E. coca leaves. From the several breakdown compounds arising during long-term extraction with H2SO4 or CHCl3, ecgonine methyl ester was the only alkaloid fully identified; ecgonidine methyl ester was tentatively identified on the basis of its mass spectrum fragmentation pattern. Quantification by mass fragmentography of the three endogenous compounds was performed using a stable-isotope dilution technique on individual leaves of single branches of E. coca, E. novogranatense and E. novogranatense var. truxillense. The relative amounts of these alkaloids changed with leaf age as well as between species and varieties. The variation in alkaloid levels between individual leaves was too great to allow the use of the ratio between cocaine and the cinnamoylcocaine levels as a taxonomic marker. The initial pH value of 17 different alkaline substances traditionally used during coca leaf chewing was measured after dissolution in H2O; values ranged between 10.1 and 12.8. Buffer capacity was determined by titration with HCl. Three types of curve shapes were obtained which could correspond to NaOH, Na2CO3 and NaHCO3 titration curves. One sample of alkaline material had no buffer capacity at all. The recovery and breakdown of the cocaine contained in E. coca leaf powder was monitored for one hour at various pHs at 37°C. The levels of cocaine and benzoylecgonine did not change by more than 17\% at any of the pHs tested (6.0, 9.0 and 11.5). It was concluded that the alkaline substances are mainly responsible for the transformation of the alkaloids to free bases and not for a major hydrolysis of cocaine.
17. Aynilian, G. H. and Duke, J. A. and Gentner, W. A. and Farnsworth, N. R., Cocaine Content of Erythroxylum Species, Journal of Pharmaceutical Sciences, vol. 63, no. 12, pp. 1938--1939, December 1974. doi: 10.1002/jps.2600631223. Abstract
    Concentrations of cocaine ranging from 0.00008 to 0.00882\% were found in herbarium specimens of seven of eight species of the genus Erythroxylum that were examined by GLC. A sample of E. coca which was at least 44 years old contained 0.03\% cocaine.
18. Holmstedt, Bo and Jäätmaa, Eva and Leander, Kurt and Plowman, Timothy, Determination of Cocaine in Some South American Species of Erythroxylum Using Mass Fragmentography, Phytochemistry, vol. 16, no. 11, pp. 1753--1755, January 1977. doi: 10.1016/0031-9422(71)85082-3. Abstract
    Thirteen South American species of Erythroxylum have been analyzed for their cocaine content. Cocaine was found only in E. coca Lam., E. novogranatense (Morris) Hieron. and E. novogranatense var. truxillense (Rusby) Machado. The amount of cocaine was determined by mass fragmentography using deuterium labelled cocaine as internal standard
19. Jirschitzka, Jan and Schmidt, Gregor W. and Reichelt, Michael and Schneider, Bernd and Gershenzon, Jonathan and D’Auria, John Charles, Plant Tropane Alkaloid Biosynthesis Evolved Independently in the Solanaceae and Erythroxylaceae, Proceedings of the National Academy of Sciences, vol. 109, no. 26, pp. 10304--10309, June 2012. doi: 10.1073/pnas.1200473109. Abstract
    The pharmacologically important tropane alkaloids have a scattered distribution among angiosperm families, like many other groups of secondary metabolites. To determine whether tropane alkaloids have evolved repeatedly in different lineages or arise from an ancestral pathway that has been lost in most lines, we investigated the tropinone-reduction step of their biosynthesis. In species of the Solanaceae, which produce compounds such as atropine and scopolamine, this reaction is known to be catalyzed by enzymes of the short-chain dehydrogenase/reductase family. However, in Erythroxylum coca (Erythroxylaceae), which accumulates cocaine and other tropane alkaloids, no proteins of the shortchain dehydrogenase/reductase family were found that could catalyze this reaction. Instead, purification of E. coca tropinonereduction activity and cloning of the corresponding gene revealed that a protein of the aldo-keto reductase family carries out this reaction in E. coca. This protein, designated methylecgonone reductase, converts methylecgonone to methylecgonine, the penultimate step in cocaine biosynthesis. The protein has highest sequence similarity to other aldo-keto reductases, such as chalcone reductase, an enzyme of flavonoid biosynthesis, and codeinone reductase, an enzyme of morphine alkaloid biosynthesis. Methylecgonone reductase reduces methylecgonone (2-carbomethoxy-3tropinone) stereospecifically to 2-carbomethoxy-3β-tropine (methylecgonine), and has its highest activity, protein level, and gene transcript level in young, expanding leaves of E. coca. This enzyme is not found at all in root tissues, which are the site of tropane alkaloid biosynthesis in the Solanaceae. This evidence supports the theory that the ability to produce tropane alkaloids has arisen more than once during the evolution of the angiosperms.
20. Docimo, Teresa and Reichelt, Michael and Schneider, Bernd and Kai, Marco and Kunert, Grit and Gershenzon, Jonathan and D’Auria, John C., The First Step in the Biosynthesis of Cocaine in Erythroxylum Coca: The Characterization of Arginine and Ornithine Decarboxylases, Plant Molecular Biology, vol. 78, no. 6, pp. 599--615, April 2012. doi: 10.1007/s11103-012-9886-1. Abstract
    Despite the long history of cocaine use among humans and its social and economic significance today, little information is available about the biochemical and molecular aspects of cocaine biosynthesis in coca (Erythroxylum coca) in comparison to what is known about the formation of other pharmacologically-important tropane alkaloids in species of the Solanaceae. In this work, we investigated the site of cocaine biosynthesis in E. coca and the nature of the first step. The two principal tropane alkaloids of E. coca, cocaine and cinnamoyl cocaine, were present in highest concentrations in buds and rolled leaves. These are also the organs in which the rate of alkaloid biosynthesis was the highest based on the incorporation of 13CO2. In contrast, tropane alkaloids in the Solanaceae are biosynthesized in the roots and translocated to the leaves. A collection of EST sequences from a cDNA library made from young E. coca leaves was employed to search for genes encoding the first step in tropane alkaloid biosynthesis. Full-length cDNA clones were identified encoding two candidate enzymes, ornithine decarboxylase (ODC) and arginine decarboxylase (ADC), and the enzymatic activities of the corresponding proteins confirmed by heterologous expression in E. coli and complementation of a yeast mutant. The transcript levels of both ODC and ADC genes were highest in buds and rolled leaves and lower in other organs. The levels of both ornithine and arginine themselves showed a similar pattern, so it was not possible to assign a preferential role in cocaine biosynthesis to one of these proteins.
21. Pardo Torre, José Carlos and Schmidt, Gregor W. and Paetz, Christian and Reichelt, Michael and Schneider, Bernd and Gershenzon, Jonathan and D’Auria, John C., The Biosynthesis of Hydroxycinnamoyl Quinate Esters and Their Role in the Storage of Cocaine in Erythroxylum Coca, Phytochemistry, vol. 91, pp. 177--186, July 2013. doi: 10.1016/j.phytochem.2012.09.009. Abstract
    Complexation of alkaloids is an important strategy plants utilize to facilitate storage in vacuoles and avoid autotoxicity. Previous studies have implicated hydroxycinnamoyl quinate esters in the complexation of purine alkaloids in Coffea arabica. The goal of this study was to determine if Erythroxylum coca uses similar complexation agents to store abundant tropane alkaloids, such as cocaine and cinnamoyl cocaine. Metabolite analysis of various E. coca organs established a close correlation between levels of coca alkaloids and those of two hydroxycinnamoyl esters of quinic acid, chlorogenic acid and 4-coumaroyl quinate. The BAHD acyltransferase catalyzing the final step in hydroxycinnamoyl quinate biosynthesis was isolated and characterized, and its gene expression found to correlate with tropane alkaloid accumulation. A physical interaction between chlorogenic acid and cocaine was observed and quantified in vitro using UV and NMR spectroscopic methods yielding similar values to those reported for a caffeine chlorogenate complex in C. arabica. These results suggest that storage of cocaine and other coca alkaloids in large quantities in E. coca involves hydroxycinnamoyl quinate esters as complexation partners.
22. Casale, John F. and Mallette, Jennifer R. and Jones, Laura M., Chemosystematic Identification of Fifteen New Cocaine-Bearing Erythroxylum Cultigens Grown in Colombia for Illicit Cocaine Production, Forensic Science International, vol. 237, April 2014. doi: 10.1016/j.forsciint.2014.01.012. Abstract
    Colombian coca farmers have historically cultivated three varieties of coca for cocaine production (Erythroxylum novogranatense var. novogranatense, Erythroxylum novogranatense var. truxillense, and Erythroxylum coca var. ipadu). Within the past 13 years, 15 new cultigens of cocaine-bearing Erythroxylum have been propagated by Colombian coca farmers; each with differing physical characteristics, yet producing cocaine alkaloids at similar levels found in the historical and native varieties. Fifteen new cultigens were collected from throughout Colombia and propagated along with the three historical varieties within an experimental field in Colombia. Five plants/cultigen were randomly selected and examined for alkaloid content to determine their varietal characteristics when compared to the three known varieties. Ten cultigens gave classic Erythroxylum coca var. ipadu alkaloid profiles, four cultigens produced alkaloid profiles consistent with a hybridization of Erythroxylum novogranatense and Erythroxylum coca var. ipadu, while one cultigen gave heterogeneous alkaloid profiles that could not be characterized.
23. White, Dawson M. and Meinhardt, Lyndel and Bailey, Bryan and Pirro, Stacy, The Complete Genome Sequences of Erythroxylum Coca and Erythroxylum Novogranatense, no. 11:457, April 2022. doi: 10.12688/f1000research.108549.1. Abstract
    The flowering plant genus Erythroxylum contains approximately 280 species, including the economically and socially consequential crops called coca. We present the genome sequences of Erythroxylum coca and E. novogranatense , two cultigens produced for medicinal and quotidian use in the Andes and Amazon regions of South America, as well as the international cocaine industry. Sequencing was performed on an Illumina X-Ten platform, and reads were assembled by a de novo method followed by finishing via comparison with several species from the same genus. The BioProject, raw and assembled data can be accessed in GenBank for E. coca (PRJNA676123; JAJMLV000000000) and E. novogranatense (PRJNA675212; JAJKBF000000000)
24. Zapata, Rodríguez and Villafrade, Fausto, Genome Size and Descriptors of Leaf Morphology as Indicators of Hybridization in Colombian Cultigens of Coca Erythroxylum Spp, November 2015. url: https://repositorio.uniandes.edu.co/handle/1992/13477. Abstract
    Recent biochemical and morphological data suggests that coca crops in Colombia are increasingly composed of hybrids coming from traditionally cultivated varieties of Erythroxylum coca and Erythroxylum novogranatense. Previous studies can not discriminate these cultigens on the basis of linear measurements of leaf morphology. The current study aims at measuring quantifiable differences in Fourier Elliptic Descriptors of leaf morphology and genome sizes among collected Colombian cultigens. Our current hypothesis is that hybrids must show intermediate morphologies and genome sizes of the parental varieties, and that these variables could be correlated. Given this scenario genome size and leaf morphology could be used as indicators of hybridization in cultivated coca populations, and used for the identification of further collected material. However no informative differences of leaf morphology or genome size were found between studied cultigens
25. Johnson, Emanuel L and Saunders, James A and Mischke, Sue and Helling, Charles S and Emche, Stephen D, Identification of Erythroxylum Taxa by AFLP DNA Analysis, Phytochemistry, vol. 64, no. 1, pp. 187--197, September 2003. doi: 10.1016/S0031-9422(03)00206-1. Abstract
    Erythroxylum coca, indigenous to the Andean region of South America, is grown historically as a source of homeopathic medicine. However, in the last century, cultivation of E. coca and several closely-related species for the production of illicit cocaine has become a major global problem. Two subspecies, E. coca var. coca and E. coca var. ipadu, are almost indistinguishable phenotypically; a related cocaine-bearing species also has two subspecies (E. novogranatense var. novogranatense and E. novogranatense var. truxillense) that are phenotypically similar, but morphologically distinguishable. The purpose of this research was to discover unique AFLP DNA patterns (“genetic fingerprinting”) that characterize the four taxa and then, if successful, to evaluate this approach for positive identification of the various species of coca. Of seven different AFLP primer pairs tested, a combination of five proved optimal in differentiating the four taxa as well as a non-cocaine-bearing species, E. aerolatum. This method of DNA fragment separation was selective, and faster, for coca identification, compared with analyses based on flavonoid chemotaxonomy. Using the 5-primer AFLP approach, 132 known and unknown coca leaf accessions were evaluated. Of these, 38 were collected in 1997–2001 from illicit coca fields in Colombia, and all were genetically differentiated from coca originating in Peru and Bolivia. Based on the DNA profiling, we believe that the Colombian coca now represents a hybridization of E. coca var. ipadu. Geographical profiling within Colombia also seems feasible as new coca production areas are developed or new types of coca are introduced within traditional growing areas.
26. Galindo Bonilla, Aída and Fernández Alonso, José Luis, Plantas de coca en Colombia. Discusión crítica sobre la taxonomía de las especies cultivadas del género Erythroxylum P. Browne (Erythroxylaceae), 2010. url: https://digital.csic.es/handle/10261/38534. Abstract
    [EN]Forensic botany is in high demand in Colombia in connection with plant material, mainly “coca” from illicit crops. The taxonomic study of the two species and four varieties of Erythroxylum P. Browne (Erythroxylaceae) cultivated in Colombia was carried out. Hybridization between E. coca and E. novogranatense and between the two varieties of E. coca is suggested, and important changes in the geographic distribution of all taxa are described. Both, hybridization and changes in distribution patterns are due to anthropic intervention.
27. Johnson, E. L., Inter- and Intra-Specific Variation among Five Erythroxylum Taxa Assessed by AFLP, Annals of Botany, vol. 95, no. 4, pp. 601--608, January 2005. doi: 10.1093/aob/mci062.
28. Johnson, Emanuel L and Schmidt, Walter F and Cooper, Donald, Flavonoids as Chemotaxonomic Markers for Cultivated Amazonian Coca, Plant Physiology and Biochemistry, vol. 40, no. 1, pp. 89--95, January 2002. doi: 10.1016/S0981-9428(01)01348-1. Abstract
    Purported ‘Amazonian coca,’ Erythroxylum coca var. ipadu Plowman (E.~coca var. ipadu) was harvested from cultivated fields in Colombia, South America to determine: (a) its identity; (b) if its leaf flavonoids were complimentary to those present in leaf tissue of E.~c. var. ipadu in our collection derived from Colombia; and (c) if complimentary, indicative of kinship to E.~coca var. ipadu obtained from Colombia, or a related Erythroxylum taxon. Leaf extracts from Amazonian field-grown coca afforded eight O-conjugated flavonoids: two O-conjugates of taxifolin, one O-conjugate of quercetin, two O-conjugates of eriodictyol and three O-conjugates of kaempferol. Present also in leaf tissue of Amazonian field-grown coca, but lacking in leaf tissue from our collection of E.~c. var. ipadu was an O-ethyl ester typically found in E.~coca var. coca, kaempferols and a 7-O-rutinoside commonly encountered in the E.~novogranatense taxons. Flavonoids found in our collection of E.~coca var. ipadu were five O-conjugated derivatives of taxifolin and an O-conjugated quercetin. Leaf flavonoids of currently cultivated Amazonian coca are a mixture of those present in E.~coca var. coca, E.~coca var. ipadu and E.~novogranatense var. truxillense, whereas those present in our authenticated living collection are derivatives of E.~coca var. coca. Our data suggest that the Amazonian coca under cultivation in Colombia is a genetic hybrid cross between E.~coca var. coca and E.~novogranatense var. truxillense, occurring after 1972.
29. {van der Hoogte}, Arjo Roersch and Pieters, Toine, From Javanese Coca to Java Coca: An Exemplary Product of Dutch Colonial Agro-Industrialism, 1880-1920, Technology and Culture, vol. 54, no. 1, pp. 90--116, 2013. doi: 10.1353/tech.2013.0045. Abstract
    In 1875 the Botanical Garden of Buitenzorg introduced two coca plants on the island of Java, which was then part of the Netherlands East Indies. Within a thirty-year period, starting in 1892, Java succeeded in becoming the world\&\#39;s leading
30. Hagin, J. and Olsen, S.R. and Shaviv, A., Review of Interaction of Ammonium ‐ Nitrate and Potassium Nutrition of Crops, Journal of Plant Nutrition, vol. 13, no. 10, pp. 1211--1226, October 1990. doi: 10.1080/01904169009364147. Abstract
    Literature review indicates that higher crop yields may be obtained with a mixture of nitrate and ammonium than with either source alone. An adequate supply of potassium enhances ammonium utilization and thus improves yields, when a mixed ammonium‐nitrate nitrogen nutrition is applied. Nitrate reduction in plant tissues consumes either chemical energy and organic acids, or competes for products of photolysis. When ammonium is applied to the roots, high concentrations of it may accumulate having a strong toxic effect. Potassium activates plant enzymes functioning in ammonium assimilation and transport of amino acids. A summary of the experiments performed by the authors indicates that a mixed ammonium, nitrate and potassium nutrition affects especially N uptake and thus production of organic nitrogen compounds.