A-type proanthocyanidin explained

A type proanthocyanidins are a specific type of proanthocyanidins, which are a class of flavonoid. Proanthocyanidins fall under a wide range of names in the nutritional and scientific vernacular, including oligomeric proanthocyanidins, flavonoids, polyphenols, condensed tannins, and OPCs. Proanthocyanidins were first popularized by French scientist Jacques Masquelier.[1]

Distribution in plants

A-type linkage is a less common feature in proanthocyanidins with both 4β→8 (B-type) and 2β→O→7 interflavanoid bonds.[2]

A-type proanthocyanidin glycosides can be isolated from cocoa liquor.[3]

Dimers

Other A-type proanthocyanidins can be found in cranberries,[2] cinnamon,[4] peanut skins[5] [6] and Geranium niveum.[7]

Chemistry

B-type procyanidins (catechin dimers) can be converted to A-type procyanidins by radical oxidation.[8] Fragmentation patterns for A-type proanthocyanidins include heterocyclic ring fission (HRF), retro-Diels-Alder (RDA) fission, benzofuran-forming fission (BFF) and quinone methide fission (QM).[9]

Metabolism

The metabolism of type-A proanthocyanidins is significant since a large number of metabolites are detected in urine and feces soon after ingestion of foods rich in polymers, indicating rapid elimination and absence of physiological effect. Polymeric type-A proanthocyanidins are depolymerized into epicatechin units in the small intestine, then cleaved into smaller phenolic acids with no known biological role.[10]

Research

In vitro, A-type proanthocyanidins isolated from cranberry juice cocktail demonstrated anti-adhesion activity against E. coli binding to urinary tract epithelial cells, whereas B-type proanthocyanidins from grape exhibited minor activity.[11] In humans, a 2014 review indicated there was insufficient clinical evidence that cranberry type-A proanthocyanidins are effective in lowering the risk of urinary tract infections (UTIs),[12] while a 2023 review concluded that long-term consumption of cranberry products may reduce the risk of UTIs in certain groups.[13]

Notes and References

  1. 10767669 . Oligomeric proanthocyanidin complexes: history, structure, and phytopharmaceutical applications . 2000 . Fine . AM . 5 . 2 . 144–51 . Alternative Medicine Review . 22 September 2009 . https://web.archive.org/web/20091104202815/http://www.chiroonline.net/_fileCabinet/opc.pdf . 4 November 2009 . dead .
  2. 17182824 . 2007 . Neto . CC . Cranberry and its phytochemicals: a review of in vitro anticancer studies . 137 . 1 Suppl . 186S–193S . The Journal of Nutrition. 10.1093/jn/137.1.186S . free .
  3. Hatano . T . Miyatake . H . Natsume . M . Osakabe . N . Takizawa . T . Ito . H . Yoshida . T . Proanthocyanidin glycosides and related polyphenols from cacao liquor and their antioxidant effects . Phytochemistry . 59 . 7 . 2002 . 11909632 . 10.1016/S0031-9422(02)00051-1 . 749–58.
  4. New identification of proanthocyanidins in cinnamon (Cinnamomum zeylanicum L.) using MALDI-TOF/TOF mass spectrometry . María Luisa Mateos-Martín . Elisabet Fuguet . Carmen Quero . Jara Pérez-Jiménez . Josep Lluís Torres . 2012 . Analytical and Bioanalytical Chemistry . 402 . 3 . 1327–1336 . 10.1007/s00216-011-5557-3 . 22101466 . 10261/88579.
  5. de Camargo . A. C. . Regitano-d'Arce . M. A. B. . Gallo . C. R. . Shahidi . F. . 2015 . Gamma-irradiation induced changes in microbiological status, phenolic profile and antioxidant activity of peanut skin . Journal of Functional Foods . 12 . 129–143 . 10.1016/j.jff.2014.10.034. free .
  6. A-type proanthocyanidins from peanut skins . Hongxiang Lou . Yamazaku Y. . Sasaku T. . Uchida M. . Tanaka H. . Oka S. . 1999 . Phytochemistry . 51 . 2 . 297–308 . 10.1016/S0031-9422(98)00736-5 .
  7. 10346950 . 1999 . Calzada . F . Cerda-García-Rojas . CM . Meckes . M . Cedillo-Rivera . R . Bye . R . Mata . R . Geranins a and B, new antiprotozoal A-type proanthocyanidins from Geranium niveum . 62 . 5 . 705–9 . 10.1021/np980467b . Journal of Natural Products.
  8. 10.1016/S0040-4039(99)02097-3 . Conversion of procyanidin B-type (catechin dimer) to A-type: Evidence for abstraction of C-2 hydrogen in catechin during radical oxidation . 2000 . Kondo . Kazunari . Kurihara . Masaaki . Fukuhara . Kiyoshi . Tanaka . Takashi . Suzuki . Takashi . Miyata . Naoki . Toyoda . Masatake . Tetrahedron Letters . 41 . 4 . 485–488.
  9. 10.1002/jms.1411. The mass spectral analysis of isolated hops A-type proanthocyanidins by electrospray ionization tandem mass spectrometry. 2008. Li. Hui-Jing. Deinzer. Max L.. Journal of Mass Spectrometry. 43. 10. 1353–63. 18416438.
  10. Profile of urinary and fecal proanthocyanidin metabolites from common cinnamon (Cinnamomum zeylanicum L.) in rats . María Luisa Mateos-Martín . Jara Pérez-Jiménez . Elisabet Fuguet . Josep Lluís Torres . 2012 . Mol. Nutr. Food Res. . 56 . 4 . 671–675 . 10.1002/mnfr.201100672 . 22383303 . 10261/88578.
  11. 16055161. Phytochemistry. 2005. 66. 18. 2281–91. A-type cranberry proanthocyanidins and uropathogenic bacterial anti-adhesion activity. Howell AB, Reed JD, Krueger CG, Winterbottom R, Cunningham DG, Leahy M. 10.1016/j.phytochem.2005.05.022.
  12. Scientific Opinion on the substantiation of a health claim related to CranMax® and reduction of the risk of urinary tract infection by inhibiting the adhesion of certain bacteria in the urinary tract pursuant to Article 14 of Regulation (EC) No 1924/20061. EFSA Journal. 2014. 12. 5. 3657. 10.2903/j.efsa.2014.3657. free.
  13. Williams . Gabrielle . Hahn . Deirdre . Stephens . Jacqueline H. . Craig . Jonathan C. . Hodson . Elisabeth M. . 2023-04-17 . Cranberries for preventing urinary tract infections . The Cochrane Database of Systematic Reviews . 4 . 4 . CD001321 . 10.1002/14651858.CD001321.pub6 . 1469-493X . 10108827 . 37068952.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "A-type proanthocyanidin".

Except where otherwise indicated, Everything.Explained.Today is © Copyright 2009-2024, A B Cryer, All Rights Reserved. Cookie policy.