Biosynthesis, accumulation and degradation of theobromine in developing Theobroma cacao fruits

We have studied the purine alkaloid content and purine metabolism in Theobroma cacao fruits at differing growth stages: Stage A (young small fruit, fresh weight, ca. 2 g); stage B (medium size fruit, fresh weight, ca. 100 g) and stage C (large size, fresh weight, ca. 500 g). The major purine alkaloi...

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Veröffentlicht in:Journal of plant physiology. - 1979. - 161(2004), 4 vom: 14. Apr., Seite 363-9
1. Verfasser: Zheng, Xin-Qiang (VerfasserIn)
Weitere Verfasser: Koyama, Yoko, Nagai, Chifumi, Ashihara, Hiroshi
Format: Aufsatz
Sprache:English
Veröffentlicht: 2004
Zugriff auf das übergeordnete Werk:Journal of plant physiology
Schlagworte:Journal Article Alkaloids Carbon Radioisotopes Purines Caffeine 3G6A5W338E Theobromine OBD445WZ5P
Beschreibung
Zusammenfassung:We have studied the purine alkaloid content and purine metabolism in Theobroma cacao fruits at differing growth stages: Stage A (young small fruit, fresh weight, ca. 2 g); stage B (medium size fruit, fresh weight, ca. 100 g) and stage C (large size, fresh weight, ca. 500 g). The major purine alkaloid in stage A fruits (mainly pericarp) was theobromine (0.7 micromol g(-1) fresh weight), followed by caffeine (0.09 micromol g(-1) fresh weight). The theobromine content of the pericarp decreased sharply with tissue age, and the caffeine content decreased gradually. A large amount of theobromine (22 micromol g(-1) fresh weight) had accumulated in seeds (mainly cotyledons) of stage C fruits. Theobromine was found also in the seed coat and placenta. Tracer experiments with [8-(14)C]adenine show that the major sites of theobromine synthesis are the young pericarp and cotyledons of T. cacao fruits. Limited amounts of purine alkaloids may be transported from the pericarp to seed tissue, but most purine alkaloids that accumulated in seeds appeared to be synthesised in cotyledons. Degradation of [8-(14)C]theobromine and [8-(14)C]caffeine to CO2 via 3-methylxanthine and ureides (allantoin and allantoic acid) was detected only in the pericarp of stage C fruits
Beschreibung:Date Completed 29.06.2004
Date Revised 30.09.2020
published: Print
Citation Status MEDLINE
ISSN:1618-1328