Caffeoylshikimic acid

We have synthesized aU three possible regioisomers of caffeoylshikimic acid (CSA) and investigated their tandem mass spectra [20]. As in the case of CGAs, all tandem mass spectra are dramatically different, allowing for unambiguous assignment of regiochemistry (Table 7). 

FIGURE 26 Isomeric caffeoylshikimic acids and caffeoylquinic acid lactones (CQLs). 

Dihydroxycinnamoyl) See 3-0-Caffeoylshikimic acid in The Combined Chemical Dictionary. 

Haalam, E. et al.. The Shikimate Pathway Butterworths, (London), 1974, rev) Fukuoka, M. et al, Chem. Pharm. Bull, 1982, 30, 3219 5-Caffeoylshikimic acid)... 

Maier, V. P., D. M. Metzler, and A. F. Huber 3-0-Caffeoylshikimic acid (dacty-liferic acid) and its isomers, a new class of enzymic browning substrates. Biochem. Biophysic. Res. Commun. 14, 124—128 (1964). 

Fukuoka, M. Chemical and Toxicological Studies on Bracken Fern, Pteridium aqui-linum var. latiusculum. VI. Isolation of 5-0-Caffeoylshikimic Acid as an Antithiamine Factor. Chem. Pharm. Bull. (Japan) 30, 3219 (1982). 

The above-mentioned hypothesis (see Section 4.2.1.4) that 4-coumaroylshikimate is hydroxylated to caffeoylshikimate and then the caffeoyl moiety is re-transferred to coenzyme A by the same acyltransferase is an example for caffeoylshikimate as a caffeoyl donor. As already indicated before, this is also true for the formation of caffeoylglucarate and -galactarate in tomato (Strack et al, 1987b Strack and Gross, 1990). Also dicaffeoylquinic acids can be formed by caffeoyl transfer from chlorogenic acid to another chlorogenic acid molecule in sweet potato (Kojima and Kondo, 1985 Villegas et al, 1987). 

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