A New Method for the Preparative Isolation of Chlorogenic Acid Lactones from Coffee and Model Roasts of 5-Caffeoylquinic Acid

Abstract

Chlorogenic acid lactones (CQL) are known to contribute to the bitter taste of roasted coffee. CQL might also have beneficial biological activities. Until now, there is a lack of pure standard compounds for quantification and biological testing. Using high-speed countercurrent chromatography, milligram amounts of lactones could be isolated. The structures of 3-O-caffeoyl-γ-quinide, 4-O-caffeoyl-muco-γ-quinide, and 5-O-caffeoyl-epi-δ-quinide were confirmed by 1D and 2D NMR spectroscopy including (13)C NMR data, which were previously not available from the literature. An UHPLC method was developed that enabled the separation of the lactones from roasted coffee in significantly shorter time than conventional HPLC.

Polyphenol content, in vitro bioaccessibility and antioxidant capacity of widely consumed beverages

“…Likewise, peaks 9′ and 10′ also had a quasimolecular ion at m / z 335. Despite similarities to caffeoylshikimic acid in m / z value, the presence of a fragment ion at m / z 161 in both mass spectra, originated by the loss of a lactone moiety, allowed their identification as caffeoylquinic lactones formed during coffee roasting (Table ) …”

Bioactive Micronutrients in Coffee: Recent Analytical Approaches for Characterization and Quantification

“…This is exemplified in the method of Machmudah et al [120] where SCCO 2 and water were used, in countercurrent flow mode, to effect the separation of CGA from caffeine. Recently, a method based on the high-speed mode (HSCCC), which could be used for the preparative isolation of milligram amount of CGA from coffee, was explained [140]. …”

“…Using 1 H-NMR and partial least squares discriminant analysis (OPLS-DA) models, TRG and CGA were found among the main metabolites that can characterize and separate C. arabica samples according to their geographical origin [153]. Recently, structures of CGA lactones, which hitherto were not available in the literature, were established from NMR data [140]. Self-association and complexation of coffee constituents, both in coffee brews and in aqueous media, can pose serious challenge for their analytical resolutions.…”

Does roasted coffee contain chlorogenic acid lactones or/and cinnamoylshikimate esters?

“…CGAs and their derivatives are known to contribute to the acidity, astringency and bitterness of the final beverage (Scholz & Maier, 1990;Trugo & Macrae, 1984). Food Research International xxx (2013 On the other hand, chlorogenic acid lactones (CGLs) are formed from CGAs during roasting through a process that involves the loss of a water molecule from the quinic acid moiety and the formation of an intramolecular ester bond (Kaiser, Birkholz, Colomban, Navarini, & Engelhardt, 2013;Shearer et al, 2003) as shown by the group of Farah (Shearer et al, 2003) (Figs. 1 and 2).…”