3-Feruloylquinic acid

The principal CGA isomers identified in green coffee include three caffeoylquinic acid isomers, 3-CQA [327-97-9], 4-CQA [905-99-7], and 5-CQA [906-33-2], three dicaffeoylquinic acid isomers, 3,4-diCQA [14534-61-3], 3,5-diCQA [2450-53-5], and 4,5-diCQA [57378-72-0], and three feruloylquinic acid isomers, 3-FQA [1899-29-2], 4-FQA, and 5-FQA [40242-06-6]. The total CGA level is somewhat higher in robustas compared to arabicas. The 5-CQA is the predominant isomer both in arabicas, ie, 4—5% dry basis (db), and in robustas, 5—6% db, and is known to form in vitro and possibly in vivo complexes with caffeine [58-08-2]. Greater compositional differences between robustas and arabicas are found in the minor CGA isomers, eg, 3,4-diCQA, 5-FQA,... 

R=H, chlorogenic acid (3 -caffeoylquinic acid) R=CH3, feruloylquinic acid... 

Several studies reflect the widespread use of the LC-MSn for the characterization of phenolic acids, predominantly chlorogenic acids (Clifford and others 2003, 2005, 2006a,b,c). For example, using LC-MS3 it is possible to discriminate between different isomers of coumaroylquinic acid, caffeoylquinic acid, and feruloylquinic acid. In addition, a hierarchical key was proposed to facilitate the process of identification when standards are not available (Clifford and others 2003). 

Cereal bran and bran-enriched products are the most important source of wall-bound cinnamates with up to 30 and 7 mg ferulate/10 g in maize and wheat bran, respectively. This would make these products the richest dietary source of ferulic acid. However, coffee brew could supply up to 10 mg ferulate (as feruloylquinic acid, FQA) per 200 ml cup [13], and it is the first for conjugated ferulic acid, followed by Citrus juices. 

An HPLC method for chlorogenic acids with lactones in six different commercial brands of roasted coffee was developed by Schrader et al. (143). Hydroxycinnamic acid derivatives, including mono- and di-caffeoylquinic acids, corresponding lactones, and feruloylquinic acids were extracted from coffee with methanol at 80°C for 1 h under reflux. An HPLC method using step-gradient elution with 2% aqueous acetic acid (eluent A) and ACN (eluent B) for a 75-min run time was developed. Determination was carried out by HPLC with UV detection at 324 nm, and further confirmation was conducted by HPLC-thermospray (TSP)-MS and HPLC-diode array detection. Elution order for mono-caffeoylquinic acid (CQA) was 3-CQA, 5-CQA, followed by 4-CQA, which was different from the usual elution order of mono-CQA (Fig. 17). These results indicate that it is currently not possible to predict the elution order of different reversed-phase packings due to the different selectivity (143). 

Carrots (Duacus carota) contain a range of chlorogenic acids including 3-0-and 5-O-caffeoylquinic acids, 3-0-p-coumaroylquinic acid, 5-O-feruloylquinic acid, and 3,5-O-dicaffeoylquinic acids (Fig. 1.30). These chlorogenic acids are found in almost all varieties of carrot with a 10-fold higher level of 5-O-caffeoylquinic acid in purple carrots [Alasalvar et al., 2001]. 

Green coffee beans (Coffea arabica) are one of the richest dietary sources of chlorogenic acids. 5-O-Caffeoylquinic acid is the dominant chlorogenic acid accounting for 50% of the total. This is followed by 3-0- and 4-O-caffeoyl-quinic acid, the three analogous feruloylquinic acids and 3,4-0-, 3,5-0- and 4,5-O-dicaffeoylquinic acids (Fig. 1.32) [Clifford, 1999]. Levels decline ca. 80% during the roasting of coffee beans, but sizable amounts with substantial antioxidant activity are still found in the typical cup of coffee. 

Chlorogenic acid has been used as a name for 5-O-caffeoylquinic acid by the authors of the reports cited except [Monteiro et al., 2007], 3-, 4-, or 5-CQA, 3-, 4-or 5-O-caffeoylquinic acid BA, benzoic acid CA, caffeic acid CLA, chlorogenic acid or 5-O-caffeoylquinic acid dHCA, dihydrocaffeic acid diCQA, dicaffeoylquinic acid FA, ferulic acid FQA, feruloylquinic acid GA, gallic acid HA, hippuric isoFA, isoferulic acid m-CA, ra-coumaric acid ra-HPPA, m-hydroxyphenylpropionic acid p-CA, p-coumaric acid p-HBA, p-hydroxybenzoic acid PPA, phenylpropionic acid. 

Cyciohexanecarboxyiic acid, 1,3,4-trihydroxy-5-[[3-(4-hydroxy-3-methoxyphenyl)-1-oxo-2-propenyljoxy]-, (1a,3a,4a,5p)- 3-0-feruloylquinic acid 3797, 3973, 3974a, 4249, 4402 ... 

In carrots, the principal phenolics are the hydroxycinnamic acid derivatives. Of these, caffeic acid derivatives are the main components (20-100 mg/kg fw. depending on the cultivar), while ferulic acid derivatives are accumulated in intermediate quantities (10-20 mg/kg) and p-coumaric derivatives, 4-hydroxybenzoic acid derivatives and vanillic acid are present in trace amounts [38]. The main compound in carrots is chlorogenic acid, which has been estimated as between 23 and 121 mg/kg f w. depending on the cultivar. However, in carrot tops, this compound can reach 375-400 mg/kg [40], while cryptochlorogenic, neochlorogenic and 5-feruloylquinic acids have also been detected. 

Dihydroxy-4-methoxy)cinnamoyl-4-O-feruloylquinic acid 3dmC FQA dmC F H... 

Eleven chlorogenic acids (e.g., p-coumaroylquinic acids, caffeoylquinlc acids, feruloylquinic acids) were extracted fiom coffee and analyzed on a Cjg column... 

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