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Die Verteilung von Coffein und Methylierten Harnsauren in den Blattern von Coffea liberica

by Oechslin, M; Baumann, T.W; Wanner, H; Association Scientifique Internationale du Café, París (Francia); 7. Colloque International sur la Chimie des Cafés Verts, Torrefies et Leurs Derives Hambourg (Alemania, R.F.) 1975.
Publisher: París (Francia) 1976Description: p. 221-223.Subject(s): COFFEA LIBERICA | COFFEA EXCELSA | CAFEINA | HOJAS | ANALISIS QUIMICO | ANALISIS DE TEJIDOS | COMPOSICION FOLIAR | COFFEA LIBERICA | COFFEA EXCELSA | CAFFEINE | LEAVES | TISSUE ANALYSIS | COFFEA LIBERICA | COFFEA EXCELSA | CAFEINE | FEUILLE | ANALYSE DE TISSUSSummary: In contrast to reports in literature we found caffeine only in trace amounts in the leaves of several-year-old Coffea liberica and C. excelsa trees. On the other hand, they do contain a substance identified as 2-methoxy-1,9-dimethyluric acid. We isolated a second uric acid derivative from the leaves of young plants which is 1,3,7,9-tetra-methyluric acid (TMUA). As a consequence of the discovery of these compounds we analysed different developmental stages of C. liberica and found that only very young plants have caffeine in appreciable concentrations (around 0,5 of d.wt.). Besides caffeine, TMUA appears in concentrations of 0.1. In the course of development (plants with three or more leaf pairs) the caffeine content drops below 0,1 and the TMUA content increases to 1,4. When the plant branches out, TMUA is replaced by 2-methoxy-1,9-dimethyluric acid. Several-year-old trees, finally, exhibit in the young leaves primarily 2-methoxy-1,9-dimethyluric acid (0,2-0,5)
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++5 ref. Sum. (De, En)

In contrast to reports in literature we found caffeine only in trace amounts in the leaves of several-year-old Coffea liberica and C. excelsa trees. On the other hand, they do contain a substance identified as 2-methoxy-1,9-dimethyluric acid. We isolated a second uric acid derivative from the leaves of young plants which is 1,3,7,9-tetra-methyluric acid (TMUA). As a consequence of the discovery of these compounds we analysed different developmental stages of C. liberica and found that only very young plants have caffeine in appreciable concentrations (around 0,5 of d.wt.). Besides caffeine, TMUA appears in concentrations of 0.1. In the course of development (plants with three or more leaf pairs) the caffeine content drops below 0,1 and the TMUA content increases to 1,4. When the plant branches out, TMUA is replaced by 2-methoxy-1,9-dimethyluric acid. Several-year-old trees, finally, exhibit in the young leaves primarily 2-methoxy-1,9-dimethyluric acid (0,2-0,5)

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