Chlorogenic acid is an ester of caffeic acid and quinic acid, is a major phenolic compound in coffee, isolated from the leaves and fruits of dicotyledonous plants. This compound, long known as an antioxidant, also slows the release of glucose into the bloodstream after a meal.
Contents
1 Chemical properties 2 Biological importance 3 Pharmaceutical & industrial applications 4 Recent studies 5 References
Chemical properties Structurally, chlorogenic acid is the ester of caffeic acid with the 3-hydroxyl group of quinic acid.
Biological importance This acid is an important factor in plant metabolism. It is also an antioxidant and an inhibitor of the tumor promoting activity of phorbol esters; at concentrations as high as 100 g/µL, does not inhibit the 5-lipoxygenase activity of ionophore-stimulated human polymorphonuclear leukocytes.
Chlorogenic acid and caffeic acid are antioxidants in vitro and might therefore contribute to the prevention of cardiovascular disease.
Pharmaceutical & industrial applications This substance can be used as anti-infectious active ingredient, it has wide anti-virus, anti-bacteria effects, and has relatively lower toxicity and side-effects. It has obvious anti-infectious effects, and does not like to lead Anti-microbial resistance. Due to its obvious anti-infectious effects, it not only can be used in pharmaceutical field but can be used widely in many other fields like food, feed additives, cosmetics also.
Recent studies Chlorogenic acid has been proven in animal studies in vitro to inhibit the hydrolysis of the glucose-6-phosphate enzyme in an irreversible fashion. This mechanism allows chlorogenic acid to reduce hepatic glycogenolysis (transformation of glycogen into glucose) and to reduce the absorption of new glucose. In addition, in vivo studies on animal subjects have demonstrated that the administration of chlorogenic acid lessens the hyperglycemic peak resulting from the glycogenolysis brought about by the administering of glucagen, a hyperglycemiant . The studies also confirmed a reduction in blood glucose levels and an increase in the intrahepatic concentrations of glucose-6-phosphate and of glycogen.
References Molecule of the Week - chlorogenic acid. Chlorogenic acid. URL accessed on September 5, 2005. China Great Vista Chemicals. Chlorogenic acid. URL accessed on September 5, 2005. |
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1. J Nutr. 2006 May;136(5):1192-7. Related Articles, Links
Chlorogenic acid is absorbed in its intact form in the stomach of rats.
Lafay S, Gil-Izquierdo A, Manach C, Morand C, Besson C, Scalbert A.
Unite des Maladies Metaboliques et Micronutriments, INRA de Clermont-Ferrand/Theix, 63122 Saint Genes Champanelle, France.
The bioavailability of chlorogenic acid, a major polyphenol of the human diet that is particularly abundant in coffee and various fruits, was explored in rats. To identify the form under which it is absorbed through the gut mucosa and the site of absorption along the gastrointestinal tract, rats were fed a diet supplemented with chlorogenic acid (0.25%, wt:wt). Chlorogenic acid and its metabolites were estimated in the stomach, small intestine and cecal contents as well as in bladder urine and plasma by HPLC with coulometric detection at several time points (1.5, 3, 4.5, and 7 h) after the beginning of the meal. Minor hydrolysis of chlorogenic acid (<1%) occurred in the stomach and small intestine contents, whereas 15-32% of ingested chlorogenic acid was hydrolyzed into caffeic acid in the cecum. Chlorogenic acid and caffeic acid appeared early (at 1.5 h) in plasma and urine, suggesting an absorption of chlorogenic acid into the upper part of the gastrointestinal tract. Gastric absorption of chlorogenic acid was further examined by infusing chlorogenic acid in the ligated stomach of food-deprived rats. After 30 min of infusion, intact chlorogenic acid was found in the gastric vein and aorta. No other metabolites could be detected by HPLC-electrospray ionization-MS-MS. These results show for the first time that chlorogenic acid is quickly absorbed in the rat stomach in its intact form.
PMID: 16614403 [PubMed - in process] |
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2. Cancer Cell Int. 2006 Mar 27;6:7. Related Articles, Links
The chemopreventive properties of chlorogenic acid reveal a potential new role for the microsomal glucose-6-phosphate translocase in brain tumor progression.
Belkaid A, Currie JC, Desgagnes J, Annabi B.
Laboratoire dOncologie Moleculaire, Departement de Chimie, Centre BIOMED, Universite du Quebec a Montreal, Montreal, Quebec, Canada. annabi.borhane@uqam.ca.
ABSTRACT : BACKGROUND : Chlorogenic acid (CHL), the most potent functional inhibitor of the microsomal glucose-6-phosphate translocase (G6PT), is thought to possess cancer chemopreventive properties. It is not known, however, whether any G6PT functions are involved in tumorigenesis. We investigated the effects of CHL and the potential role of G6PT in regulating the invasive phenotype of brain tumor-derived glioma cells. RESULTS : RT-PCR was used to show that, among the adult and pediatric brain tumor-derived cells tested, U-87 glioma cells expressed the highest levels of G6PT mRNA. U-87 cells lacked the microsomal catalytic subunit glucose-6-phosphatase (G6Pase)-alpha but expressed G6Pase-beta which, when coupled to G6PT, allows G6P hydrolysis into glucose to occur in non-glyconeogenic tissues such as brain. CHL inhibited U-87 cell migration and matrix metalloproteinase (MMP)-2 secretion, two prerequisites for tumor cell invasion. Moreover, CHL also inhibited cell migration induced by sphingosine-1-phosphate (S1P), a potent mitogen for glioblastoma multiform cells, as well as the rapid, S1P-induced extracellular signal-regulated protein kinase phosphorylation potentially mediated through intracellular calcium mobilization, suggesting that G6PT may also perform crucial functions in regulating intracellular signalling. Overexpression of the recombinant G6PT protein induced U-87 glioma cell migration that was, in turn, antagonized by CHL. MMP-2 secretion was also inhibited by the adenosine triphosphate (ATP)-depleting agents 2-deoxyglucose and 5-thioglucose, a mechanism that may inhibit ATP-mediated calcium sequestration by G6PT. CONCLUSION : We illustrate a new G6PT function in glioma cells that could regulate the intracellular signalling and invasive phenotype of brain tumor cells, and that can be targeted by the anticancer properties of CHL.
PMID: 16566826 [PubMed - in process] |
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3: J Agric Food Chem. 2006 Mar 22;54(6):1957-69. Related Articles, Links
Characterization by LC-MS(n) of four new classes of chlorogenic acids in green coffee beans: dimethoxycinnamoylquinic acids, diferuloylquinic acids, caffeoyl-dimethoxycinnamoylquinic acids, and feruloyl-dimethoxycinnamoylquinic acids.
Clifford MN, Knight S, Surucu B, Kuhnert N.
Center for Nutrition and Food Safety, School of Biomedical and Molecular Sciences, University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom. m.clifford@surrey.ac.uk
LC-MS4 has been used to detect and characterize in green coffee beans 12 chlorogenic acids not previously reported in nature. These comprise three isomeric dimethoxycinnamoylquinic acids (7-9) (Mr 382), three caffeoyl-dimethoxycinnamoylquinic acids (22, 24, and 26) (Mr 544), three diferuloylquinic acids (13-15) (Mr 544), and three feruloyl-dimethoxycinnamoylquinic acids (28, 30, and 32) (Mr 558). Structures have been assigned on the basis of LC-MS4 patterns of fragmentation and relative hydrophobicity and, in the case of the dimethoxycinnamoylquinic acids, by comparison with authentic standards. Several new structure-diagnostic fragmentations have been identified for use with diacyl-chlorogenic acids, for example, m/z 299 and 255 for C4 caffeoyl, m/z 313 and 269 for C4 feruloyl, nearly equal elimination of both cinnamoyl residues for vic-3,4-diacyl, and an increasing ratio of "dehydrated" ions to "non-dehydrated" ions at MS2 with increasing methylation of those cinnamoyl residues. Possible mechanisms have been proposed to account for the fragmentations observed. The mass spectrometric resolution of six isomeric chlorogenic acids (Mr 544) in a crude plant extract by fragment-targeted LC-MS2 and LC-MS3 experiments illustrates the analytical power and advantage of ion trap mass spectroscopy. |
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