This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
Synonyms: chlorogenic acid hydrolysis, chlorogenate degradation
|Superclasses:||Degradation/Utilization/Assimilation → Aromatic Compounds Degradation|
Expected Taxonomic Range: cellular organisms
Chlorogenic acids (CGA) are involved in producing the bitter effect of coffee, as a property of their decomposition in phenolic compounds during roasting. CGA mainly include caffeoyl-quinic acids (CQA), dicaffeoyl-quinic acids (diCQA) [Campa03] and feruloyl-quinic acids (FQA). Chlorogenic acid (5-CQA) is one of the major soluble phenolic compounds that are accumulated in the green beans of coffee. Other hydroxycinnamoyl quinic acids (HQAs), is accumulated in particular in green beans of the cultivated species Coffea canephora [Mahesh07]. Biosynthesis of 5-CQA can be catalyzed by a cytochrome P450 enzymes, from Arabidopsis. But only one of them hydroxylates the chlorogenic acid precursor p-coumaroyl quinate. CYP98A35 appears to be the first C3¢H capable of metabolizing p-coumaroyl quinate and p-coumaroyl shikimate with the same efficiency. The results indicated that HQA biosynthesis and accumulation occurred mainly in the shoot tip and in the phloem of the vascular bundles. The biosynthetic activity of chlorogenic acids was clearly reduced in ripening and ripe seeds, especially in Coffea canephora [Koshiro]. Alternate ways of CGA biosynthesis is shown here: chlorogenic acid biosynthesis II.
About this pathway: Dietary antioxidants from plant sources are usually phenolics. Chlorogenic acid (CGA) has high bioavailability and it is hydrolyzed to caffeic acid. The degradation is done by microbial enzymes found in Aspergillus niger, Burkholderia mallei and Acinetobacter baumannii. The antioxidant capacity is enhanced by its availability to multiple mechanisms that are involved in scavenging of free-radicals, such as metal-ion chelation and inhibition of free-radical forming enzymes. CGA releasing enzymes are of immense interest in industrial applications [Benoit07a] to help the release of aromatic compounds found in agricultural by-products like apple marc and coffee pulp.
Benoit07a: Benoit I, Bourne Y, Navarro D, Canaan S, Lesage-Meessen L, Herweijer M, Coutinho PM, Asther M, Record E (2007). "Gene overexpression and biochemical characterization of the biotechnologically relevant chlorogenic acid hydrolase from Aspergillus niger." Appl Environ Microbiol 73(17);5624-32. PMID: 17630312
Campa03: Campa C, Noirot M, Bourgeois M, Pervent M, Ky CL, Chrestin H, Hamon S, de Kochko A (2003). "Genetic mapping of a caffeoyl-coenzyme A 3-O-methyltransferase gene in coffee trees. Impact on chlorogenic acid content." Theor Appl Genet 107(4);751-6. PMID: 12861362
Koshiro: Koshiro Y, Jackson MC, Katahira R, Wang ML, Nagai C, Ashihara H "Biosynthesis of chlorogenic acids in growing and ripening fruits of Coffea arabica and Coffea canephora plants." Z Naturforsch [C] 62(9-10);731-42. PMID: 18069248
Mahesh07: Mahesh V, Million-Rousseau R, Ullmann P, Chabrillange N, Bustamante J, Mondolot L, Morant M, Noirot M, Hamon S, de Kochko A, Werck-Reichhart D, Campa C (2007). "Functional characterization of two p-coumaroyl ester 3'-hydroxylase genes from coffee tree: evidence of a candidate for chlorogenic acid biosynthesis." Plant Mol Biol 64(1-2);145-59. PMID: 17333503
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