Variation of Alkaloid Content in Erythroxylum coca Leaves from Leaf Bud to Leaf Drop

A sequential study describing the content (%) of alkaloids inleaves of Erythroxylum coca var. coca Lam. from leaf bud developmentto leaf drop has not previously been conducted. The length oftime the leaf resides on the plant and its concurrent metabolicactivity also has not been defined. In the present study, cocaine,methyl ecgonine, hygrine, tropinone, trans -cinnamoylcocaine,cis-cinnamoylcocaine, tropacocaine and cuscohygrine were monitoredto determine: (1) their content and patterns of accumulationfrom leaf bud to leaf drop; (2) the time leaves resided on theplant; and (3) whether leaves were metabolically active untilleaf drop. E. coca plants were grown in a controlled environmentfor 37 months. Leaves similar in chronological age were extractedand analysed for alkaloid content by gas chromatography (GC)and gas chromatography/mass spectrometry (GC/MS). Cocaine washighest in 7 d old rolled leaves (0·75%) and declinedto 0·39% at leaf drop. Cocaine, methyl ecgonine, hygrine,tropinone, trans -cinnamoylcocaine, cis-cinnamoylcocaine, cuscohygrineand tropacocaine content in 35 d old (mature) leaves was 0·61,0·59, 0·68, 0·08, 0·31, 0·55,0·52, and 0·05%. respectively. Cocaine, methylecgonine, hygrine, cis -cinnamoylcocaine, and cuscohygrine displayeda gradual decline from week 2 to week 36 of leaf duration. Tropinoneand tropacocaine were the least abundant of the alkaloids monitored.Cis-cinnamoylcocaine content exceeded cocaine at week 12, 16,and weeks 19 to 23 of leaf duration. Trans -cinnamoylcocainewas highest in rolled leaves (week 1) and in expanded leavesafter week 30. The monitored alkaloids appeared to be part ofthe metabolically active pool of the leaf. Leaves remained onthe E. coca plants for 36 weeks.Copyright 1994, 1999 AcademicPress Cocaine, methyl ecgonine, hygrine, tropinone, trans-cinnamoylcocaine, cis-cinnamoylcocaine, cusco-hygrine, tropacocaine, leaf bud, rolled leaves, expanded leaves, alkaloids, patterns, fluctuation, Erythroxylum coca var. coca, E, coca