Home|Journals|Articles by Year|Audio Abstracts
 

Research Article

ECB. 2017; 6(6): 22-


CAFFEINE BIOSYNTHESIS AND PURINE METABOLISM IN LEAVES OF MASCAROCOFFEA SPECIES

Wei-Wei Deng, Jean-Jacques Rakotomalala, Chifumi Nagai, Hiroshi Ashihara.




Abstract

Caffeine, a purine alkaloid, was not detected in leaves of two Mascarocoffea species, Coffea millotii and Coffea perrieri. Trigonelline, a pyridine alkaloid, occurred in these species, but the levels (3−4 μmol g-1fresh weight) were much lower than that of Robusta coffee (Coffea canephora) (36 μmol g-1 fresh weight). Feeding experiments with [8-14C]adenine indicated that purine alkaloid biosynthesis was terminated at 7-methylxanthine formation and as a consequence theobromine and caffeine were not produced in Coffea millotii and Coffea perrieri. The adenine salvage activity was lower, but its degradation activity was higher in leaves of these Mascarocoffea species than those in Coffea canephora. The metabolic fate of the purine nucleosides, [8-14C]inosine, [8-14C]guanosine and [8-14C]xanthosine was investigated in leaves of Coffea millotii. The biosynthesis of 7-methylxanthine, but not theobromine or caffeine, from these precursors was detected. Large amounts of these purine nucleosides were catabolized via allantoin. Limited amounts of [8-14C]inosine and [8-14C]guanosine were salvaged and utilized for RNA synthesis, however, no [8-14C]xanthosine salvage was observed.Little or no 14C-metabolites were observed when [8-14C]theobromine and [8-14C]caffeine were applied to leaf disks of Coffea millotii. From the results obtained in this study, possible metabolic pathways of purines in Mascarocoffea species are discussed.

Key words: Coffea canephora, Coffea millotii, Coffea perrieri, Mascarocoffea, caffeine, trigonelline, adenine, purine salvage, biosynthesis, metabolism






Full-text options


Share this Article


Online Article Submission
• ejmanager.com




ejPort - eJManager.com
Refer & Earn
JournalList
About BiblioMed
License Information
Terms & Conditions
Privacy Policy
Contact Us

The articles in Bibliomed are open access articles licensed under Creative Commons Attribution 4.0 International License (CC BY), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.