Feruloyl quinic acid

The treatment and environment of green coffee beans affects the concentrations of both caffeoyl- and feruloyl quinic acids,52 and several decomposition products have been recognized. Some of these products, in this case from steam-treated green coffee beans, are given in Figure 5.53... 

Anthocyanin (cyanidin) pigmentation can be observed in some cultivars, although its nature has not been fully determined. 3 -Caffeoylquinic is the principal phenolic acid derivative, although 4 - and 5 -caffeoylquinic acids are also present. A concentration of 167 mg caffeic acid per kg has been reported in apricots [19]. The presence of the corresponding p-coumaroyl-and feruloyl quinic acid derivatives has also been reported [16], as have p-coumaroylglucose and feruloyl glucose. 

The main phenolic acid derivative is chlorogenic acid, although 3 -caffeoylquinic and 4 -cafFeoylquinic acids, and p-coumaroyl- and feruloyl-quinic acid derivatives have also been reported [16]. Up to 128mg caffeic acid per kg fresh peaches have been reported [19]. 

The main phenolic acid derivative is chlorogenic acid (575-632 mg/kg f.w.), although neochlorogenic (trace) and cryptochlorogenic acids (8-11 mg/kg), 5 -feruloyl quinic acid (15-17 mg/kg), and caffeoyl, feruloyl and sinapoylglucose have also been reported [63]. 

Cloning of a cDNA encoding HCT from tobacco N. tabacum, NtHCT) stems and expression of the recombinant protein in fully functional form in E. coli as a fusion product have also been carried out, with kinetic parameters of the purified protein determined (C. L. Cardenas etal, manuscript in preparation). " The overall catalytic propenies of recombinant NtHCT with various hydroxycinnamoyl CoAs (9-13) using either shikimic (29) or quinic (28) acid as substrate were quite informative (C. L. Cardenas et al, manuscript in preparation). With shikimic acid (29) at a saturating concentration, the observed /feat/Am of recombinant NtHCT established that the dominant HCT activity was with -coumaroyl CoA (9) (114840mor ls ) over that of caffeoyl (10), feruloyl (11), or sinapoyl (13) CoA (48 420, 6880, and 420 moF 1 s , respectively). Recombinant NtHCT was able, however, to less efficiently transfer hydroxycinnamoyl moieties from -coumaroyl CoA (9) and caffeoyl CoA (10) to quinic acid (28). Indeed, /fcat/Am values at saturating concentration of quinic acid (28) were lower by approximately 7.5- and 131-fold for/)-coumaroyl CoA... 

Bell peppers, both green and red, contain low amounts of phenolic acid derivatives p-Coumaric (< 4 mg/kg), caffeic (< 10 mg/kg), ferulic (<15 mg/kg), sinapic (<5 mg/kg) and vanillic (10 mg/kg) acids [77]. Caffeoyl glucose, feruloyl glucose and sinapoyl glucose are the main hydroxycinnamic acid derivatives found, while no quinic acid derivatives have been detected [63]. Feruloyl glucose may accumulate up to 11 mg/kg f.w. and sinapoyl glucose up to 5 mg/kg in some red cultivars. 

Phenolic compounds have sometimes been used to detect adulterations of fruit juices and jams. Most of them are flavonols, but some HCA derivatives can be used since they are typical of some fruit species such as tartaric derivatives in grape. For example, grape juice can be detected by the presence of caffeoyl-, / -coumaroyl-, and feruloyl-tartaric acids, whereas the presence of quinic esters of HCA would imply adulteration with other fruits. A method has also been developed for detection and quantitation of pulpwash, a lower-quality juice product, in orange juice [9] feruloyl and sinapoyl glucose, in addition to different other phenolic compounds, were present in much larger amounts in pulpwash. 

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