Chlorogenic acid

Chlorogenic acid is a family of esters formed between certain trans cinnamic acids and (-)-quinic acid^[1] and is a major phenolic compound in coffee, found widespread in plants, and can be isolated from the leaves and fruit^[2]. This compound, long known as an antioxidant, also slows the release of glucose into the bloodstream after a meal.^[3]

Additional recommended knowledge

Daily Visual Balance Check

Daily Sensitivity Test

Essential Laboratory Skills Guide

Chemical properties

Structurally, chlorogenic acid (CGA) is the ester formed between certain trans cinnamic acid and (L)-quinic acid (1L-1(OH),3,4/5-tetrahydroxycyclohexanecarboxylic acid) ^[4]. Isomerisation of chlorogenic acid have been reported with 3 isomerisations of the quinic acid in position 3, (3-CQA), 4 (4-CGA) and 5 (5-CQA). Isomerisation at position 1 and 6 has not yet been reported.^[5]

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 µg/L, 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 Type 2 Diabetes Mellitus^[6] and cardiovascular disease^[7].

Pharmaceutical & industrial applications

This substance is claimed to have antiviral^[8], antibacterial^[9] and antifungal^[10] effects with relatively low toxicity and side effects, alongside properties that do not lead antimicrobial resistance. Potential uses are suggested in pharmaceuticals, foodstuffs, feed additives, and cosmetics.^{[citation needed]}

Chlorogenic acid is marketed under the tradename Svetol^® in Norway and the United Kingdom as a food active ingredient used in coffee, chewing gum, and mints to promote weight reduction. ^[11][12]

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 glucagon, a hyperglycemiant hormone. The studies also confirmed a reduction in blood glucose levels and an increase in the intrahepatic concentrations of glucose-6-phosphate and of glycogen.^[13]

References

1. ^ Clifford, M. N.; Johnston, K. L.; Knigh, S.; Kuhnert, N. (2003). "Hierarchical Scheme for LC-MSⁿ Identification of Chlorogenic Acids". Journal of Agriculture and Food chemistry 51: 2900-2911.
2. ^ Clifford, M. N. (2003). Methods in polyphenol analysis - The analysis and characterization of chlorogenic acids and other cinnamates.. C. Santos-Buelga & G. Williamson (Eds.) - Cambridge: Royal Society of Chemistry, 314–337. 
3. ^ Johnston, K. L.; Clifford, M.N., and Morgan, LM. (2003). "Coffee acutely modifies gastrointestinal hormone secretion and glucose tolerance in humans: glycemic effects of chlorogenic acid and caffeine." (HTML). American Journal of Clinical Nutrition 79 (4): 728–733. American Journal of Clinical Nutrition. ISSN: 0002-9165. Retrieved on 2007-05-26.
4. ^ Clifford, M. N. (1999). "Chlorogenic acids and other cinnamates – nature, occurrence and dietary burden.". Journal of the Science of Food and Agriculture 79: 362–372.
5. ^ Clifford, M. N.; KELLY L. JOHNSTON and SUSAN KNIGH and NIKOLAI KUHNERT (2003). "Hierarchical Scheme for LC-MSⁿ Identification of Chlorogenic Acids". Journal of Agriculture and Food chemistry 51: 2900-2911.
6. ^ Paynter, Nina P.; Hsin-Chieh Yeh, Sari Voutilainen, Maria Ines Schmidt, Gerardo Heiss, Aaron R. Folsom, Frederick L. Brancati and W. H. Linda Kao (2006). "Coffee and Sweetened Beverage Consumption and the Risk of Type 2 Diabetes Mellitus." (HTML). American Journal of Epidemiology 164 (11): 1075-1084. Oxford Journals. ISSN: 1476-6256. Retrieved on 2007-05-26.
7. ^ Morton, Lincoln W.; Rima Abu-Amsha Caccettah, Ian B Puddey and Kevin D Croft (2000). "Chemistry And Biological Effects Of Dietary Phenolic Compounds: Relevance To Cardiovascular Disease." (HTML). Clinical and Experimental Pharmacology and Physiology 27 (3): 152-159. Blackwell Publishing. Retrieved on 2007-05-26.
8. ^ Jassim, S.A.A.; M.A. Naji (2003). "Novel antiviral agents: a medicinal plant perspective" (HTML). Journal of Applied Microbiology 95 (3): 412-427. Blackwell Publishing. Retrieved on 2007-05-26.
9. ^ RODRIGUEZ DE SOTILLO, d.; M. HADLEY and M. HADLEY (1998). "Potato Peel Extract a Nonmutagenic Antioxidant with Potential Antimicrobial Activity" (PDF). Journal of Food Science 63 (5): 907. Blackwell Publishing. Retrieved on 2007-05-26.
10. ^ Bowels, Bobby L.; Arthur J. Miller (1994). "Caffeic Acid Activity Against Clostridium botulinum Spores" (HTML). Journal of Food Science 59 (4): 905. Blackwell Publishing. Retrieved on 2007-05-26.
11. ^ Ventures, Energix. Coffee Slender, How does it work.. Retrieved on 2007-05-26.
12. ^ Ventures, Energix. Studier viser at Coffeeslender virker!. Retrieved on 2007-05-26.
13. ^ Harding, Anna. Coffee can be good for you, experts say. Retrieved on 2007-05-26.