Beiträge zur Kenntnis des Kaffees

NMR Reinvestigation of the Caffeine–Chlorogenate Complex in Aqueous Solution and in Coffee Brews

“…The complex formed between caffeine and chlorogenate, a well-known major polyphenolic constituent of green coffee bean, was isolated one century ago by Gorter. 1 Sondheimer et al 10 determined the equilibrium constant of the complex reaction in water by spectrophotometric method. The same method has been used by Kappeler et al 11 to study caffeine as well as other purine alkaloids complexation with chlorogenate.…”

“…1 Several complexes of caffeine with polyphenols 2 and aromatic hydroxy acids such as methyl gallate, 3-nitrobenzoic acid, 3 5-chlorosalicylic acid, 4 pyrogallol, 5 catechins, 6 theaflavin, 7 gallic acid and quercitin, 8 and cyclodextrins, 2,9 have been investigated. The complex formed between caffeine and chlorogenate, a well-known major polyphenolic constituent of green coffee bean, was isolated one century ago by Gorter.…”

Determination of Chlorogenic Acid in Coffee

“…The compound was first isolated by Gorter (7), who found it widely distributed in the leaves and seeds of numerous plants. Freudenberg (6) and Fischer (5) described the structure of the compound as the quinic acid ester of caffeic acid.…”

“…2, were isolated through the potassium caffeine complex, while sample 3 was separated by solvent partition, As chlorogenic acid is not available commercially, an extraction and purification procedure is included in this paper. The isolation of chlorogenic acid from coffee through the potassium caffeine complex is a modification, by Kremers (10) of this laboratory, of previously reported methods (6,7). Extract 1 kg.…”

Enzymatic synthesis of chlorogenic acid from caffeoyl coenzyme A and quinic acid

“…1) which was identified as chlorogenic acid in the following way. The ~4Clabelled product from an experiment using [2-14C] caffeic acid was diluted with unlabelled chlorogenic acid (25 rag) and acetylated using acetic anhydride pyridine [17]. Pentaacetylchlorogenic acid (mp/ 180-183°C from benzene, MS: M ÷ 564 m/e) resulted with a specific activity of 894 dpm//lmol.…”