Chlorogenic acid, extraction from

Figure 6.9 MS and MS/MS (negative ion mode) of peaks 1 and 2 (chlorogenic acid and its isomer), peak 3 (caffeic acid) and peak 4 (chlorogenic acid isomer) from isolated HPLC chromatograms of potato extracts.

Table 11.5 Caffeine and chlorogenic acid removal from coffee beans extract...

Chlorogenic acid forms a 1 1 complex with caffeine, which can be crystallized from aqueous alcohol and yields very little free caffeine on extraction with chloroform. Other compounds with which caffeine will complex in this way include isoeugenol, coumarin, indole-acetic acid, and anthocyanidin. The basis for this selection was the requirement for a substituted aromatic ring and a conjugated double bond in forming such a complex. This kind of complex does modify the physiological effects of caffeine.14 Complex formation will also increase the apparent aqueous solubility of caffeine in the presence of alkali benzoates, cinnamates, citrates, and salicylates.9... 

Saldana MDA. 1997. Extraction of caffeine, trigonelline and chlorogenic acid from Brazilian coffee beans using supercritical CO2 MSc. Thesis, UNICAMP, Campinas, Brazil. 

Fig. 2.48. Separation of an extract by HPLC under optimized conditions in a 250 mm X 2 mm i.d., 5 pm particle, C18 column. The mobile phase was a gradient prepared from 0.03 per cent TFA in water (a) and acetonitrile (b) mobile phase composition (%) was changed from 90a 10b to 64a 36b in 35 min. The flow rate was 0.2 ml/min, the temperature 25°C, and detection was performed at 210 and 330 nm. Peak assignments 1 = pseudochlorogenic acid 2 = neochlorogenic acid 3 = chlorogenic acid 4 = cryptochlorogenic acid 5 = cynarin 6 = cynaroside 7 = scolymoside 8 = 3,4-di-O-caffe- oylquinic acid 9 = 1,3-di-O-caffeoylquinic acid 10 = 4,5-di-O-caffeoylquinic acid 11 = cynaropikrin. Reprinted with permission from M. Hausler et al. [148].

Fig. 2.49. Profile of Hypericum perforatum extract with the H LC-MS attributions of the components detected. 1 = chlorogenic acid isomer 2 = 3-0- -coumaroylquinic acid 3 = chlorogenic acid 4 = rutin 5 = hyperoside 6 = isoquercitrin 7 = 3,3, , , 7-pentahydroxyflavanone 7-0-rhamnopyranoside 8 = quercitrin 9 = quercetin 10 = 13,118 tapigenin 11 = pSeudohypericin 12 = hypericin 13 = hyperforin analogue 14 = hyperform dialogue 15 = hyperforin 16 = adhyperforin. Reprinted with permission from M. Brolis eta. [ ].

Fig. 2.56. HPLC chromatogram of (a) Golden peel and (b) Golden pulp extracts at 280 nm. Peaks 1 = procyanidin B3 2 = procyanidin Bl 3 = ( + )-catechin 4 = procyanin B2 5 = chlorogenic acid 6 = ( — )-epicatechin 7 = caffeic acid 8 = phloretin derivative 9 = phloridzin 10 = rutin 11, 12 and 13 = flavonol glucosides. Reprinted with permission from A. Escarpa et al. [160].

Figure 6.6 HPLC chromatogram of the extract from Superior potato flesh (a) and of the same extract spiked with standards (b). Identification p.1, chlorogenic acid p.2, chlorogenic acid isomer p.3, caffeic acid p.4, p-coumaric acid p.5, ferulic acid p.6, t-cinnamic acid. Column, Inertsil ODS-3 V (5 p.m, 4.0 X 250 mm) flow rate, l.OmL/min column temperatures, 20°C mobile phase, acetonitrile 0.5% formic acid (gradient mode) detector, UV at 280 nm.

Figure 6.8 UV spectra of standard chlorogenic acid (a) trans-cinnamic acid (b) cafFeic acid (c) p-coumaric acid (d) and femlic acid (e). The spectra of peaks 1 (chlorogenic acid) (f), peak 2 (chlorogenic acid isomer) (g), and peak 3 (caffeic acid) (h) were determined with HPLC fractions isolated from extracts of Superior potato peel.

The phenolics ( + )catechin and (— )epicatechin are common flavanols in several fruits (128). Apples and pears contain other phenolic compounds such as quinic, shikimic, chlorogenic, and caffeic acids (39). Durkee and Poapst (162) reported that the two major phenolic constituents of core tissues and seeds of McIntosh apples were chlorogenic acid and phloridzin. After hydrolysis of extracts from core tissues, the identified phenolics were phloretin, caffeic acid, p-coumaric acid, phloretic acid, and trace amounts of ferulic acid. Studies have shown that apple leucoanthocyanins yield catechin, epicatechin, cyanidin, and pelargonidin after hydrolysis (163, 164). Van Buren et al. (164) also reported that a purified leucoanthocyanin from apples was either a dimer or oligomer containing ( —) epicatechin, and 5,7,3, 4 -flavin-3,4-diol. 

For phenolics in fruit by-products such as apple seed, peel, cortex, and pomace, an HPLC method was also utilized. Apple waste is considered a potential source of specialty chemicals (58,62), and its quantitative polyphenol profile may be useful in apple cultivars for classification and identification. Chlorogenic acid and coumaroylquinic acids and phloridzin are known to be major phenolics in apple juice (53). However, in contrast to apple polyphenolics, HPLC with a 70% aqueous acetone extract of apple seeds showed that phloridzin alone accounts for ca. 75% of the total apple seed polyphenolics (62). Besides phloridzin, 13 other phenolics were identified by gradient HPLC/PDA on LiChrospher 100 RP-18 from apple seed (62). The HPLC technique was also able to provide polyphenol profiles in the peel and cortex of the apple to be used to characterize apple cultivars by multivariate statistical techniques (63). Phenolic compounds in the epidermis zone, parenchyma zone, core zone, and seeds of French cider apple varieties are also determined by HPLC (56). Three successive solvent extractions (hexane, methanol, aqueous acetone), binary HPLC gradient using (a) aqueous acetic acid, 2.5%, v/v, and (b) acetonitrile fol-... 

Two predominant phenolic compounds (neochlorogenic and chlorogenic acids) in prunes and prune juice can be analyzed by reversed-phase HPLC with diode array detection along with other phenolic compounds (65). Phenolic compounds were extracted from prunes with methanol and aqueous 80% methanol and analyzed by HPLC. Ternary-gradient elution (a) 50 mM NaH4H2P04, pH 2.6, (b) 80% acetonitrile/20% (a), and (c) 200 mM phosphoric acid, pH 1.5, was employed for an 80-min run time. Four wavelengths were monitored for quantitation 280 nm for catechins and benzoic acids, 316 nm for hydroxycinnamates, 365 nm for flavonols, and 520 nm for anthocyanins. Phenolic analysis of pitted prune extract is presented in an HPLC chromatogram in Fig. 9, which is based on work done by Donovan and Waterhouse (65). 

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). 

Subsequent tests with velvetleaf, Kodkia, Jerusalem artichoke, and cocklebur showed that their allelopathic action altered water balance (55,94,95). Growth reductions in sorghum and soybean seedlings in nutrient solution amended with extracts from these weeds correlated with high diffusive resistances and low leaf water potentials. Stomatal closure occurred in plants treated with the more concentrated extracts. Depressions in water potential were due to a reduction in both turgor pressure and osmotic potential. A lower relative water content was also found in velvetleaf-treated plants. These impacts on water balance were not from osmotic factors. Allelochemicals from these weeds have not been thoroughly ascertained, but the present evidence shows that some contain phenolic inhibitors. Lodhi (96) reported that Kodkia contains ferulic acid, chlorogenic acid, caffeic acid, myricetin, and quercetin. As noted earlier, an effect on plant-water relationships is one mechanism associated with the action of ferulic acid. 

The dried herbs of some Artemisia species have been used for the treatment of inflammation, blood diseases caused by the disturbance of menses, haematemesis, haematuria, hemorrhoids and diarrhea in Chinese, Korean and Japanese traditional medicine. In Japan, A. princeps and A. montana are the main species used for these purposes. Chlorogenic acid, methyl chlorogenate, 3,5-di-(9-caffeoylquinic acid, 4,5-di-CJ-cafifeoylquinic acid and 3,4-di-O-caffeoylquinic acid were isolated from the leaf of A. montana, and these compounds can be called "caffeetaimins" "Fig. (31)". We found that these caffeetannins inhibited the ADP plus NADPH-induced lipid peroxidation in rat liver microsomes. [17] Furthermore, as shown in "Table (12) and Table (13)", the acetone extracts of A. montana reduced the elevations of LPO, GOT and (JOT in the serum of rats fed peroxidized oil for 7 days. Caffeic acid and chlorogenic acid also inhibited the elevation of serum TG, LPO, TC, GOT and GPT "Table (14) and Table (15)". 

Because standards of HCTA are not commercially available, for quantitative analysis chlorogenic acid or free hydroxycinnamic acids are used as external standards. Standards of flavonols commercially available are quercetin and myricetin glucoside and other flavonols glycoside (e.g. rutin). Alternatively, the single HCTA and flavonols can be isolated from a grape skins extract by performing semipreparative HPLC. 

Each patent has somewhat different features and claims. We select one patent for more detailed discussion to highlight certain technical facets of the process. First we explain the (often misunderstood) effect of water on the extractability of caffeine by selective supercritical carbon dioxide. A number of references report that dry carbon dioxide cannot extract caffeine from dry coffee, either green or roasted, but moist carbon dioxide can. The inability of dry carbon dioxide to extract caffeine from coffee should not be misconstrued to mean that dry carbon dioxide cannot dissolve neat caffeine. This same moist-versus-dry effect is experienced if, for example, methylene chloride is used to extract caffeine from coffee. Dry methylene chloride cannot decaffein-ate dry coffee but moistened coffee can be decaffeinated. It is thought that the caffeine is chemically bound in a chlorogenic acid structure present in the coffee bean. Thus, water somehow acts as a chemical agent it frees caffeine from its bound form in the coffee matrix in both the carbon dioxide and the methylene chloride processes. 

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