Procyanidin structure

Berke, B. and de Freitas, V.A.P., Influence of procyanidin structures on their ability to complex with oenin. Food Chem., 90, 3, 453, 2005. 

The strategy most widely used is the tentative qnantiiication of the procyanidin metabolites with respect to others with similar procyanidin structures. For example, the catechin and epicatechin metabolites were tentatively qnantified with its agly-cone, catechin and epicatechin, respectively. In UHPLC, the elution order of the catechin and epicatechin metabolites was considered to be the same as the elution order of catechin (first) and epicatechin (second) in their free forms. The different dimer isomer procyanidins were tentatively quantified with regard to the monomer catechin [30] or the commercial dimer [31-33,35,36,38]. 

Ottaviani JI, Actis-Givetta L, Villoido JJ, Fraga CG (2006) Procyanidin structure defines the extent and spectfieily of angiotensin I converting enzyme inhibition. Biochimie 88 359-365... 

Fig. 3. The regular structure of a procyanidin-type condensed tannin showing characteristic 4,8 interflavonoid bonds linking the flavonoid units.

The A-type proanthocyanidins are characterized by a second ether linkage between an A-ring hydroxyl group of the lower unit and C-2 of the upper unit. Since they are less frequently isolated from plants than the B-types, they have been considered unusual structures [18,19]. The first identified A-type proanthocyanidin was procyanidin A2 isolated from the shells of fruit of Aes-culus hippocastanum. Since then, many more A-type proanthocyanidins have been found in plants, including dimers, trimers, tetramers, pentamers and ethers [18,21]. 

Fig. 2.113. Structures of monomeric flavan-3-ols and procyanidin oligomers in apples. Reprinted with permission from A. Yanagida et al. [253].

Fig. 3.1 Structures of (a) catechin, (b) epicatechin, (c) epicatechin gallate, (d) general structure of PAs, and (e) procyanidin dimer...

Kusuda M, Inada K, Ogawa TO, Yoshida T, Shiota T, Shiota S, Tsuchiya T, Hatano T. (2006) Polyphenolic constituents structures of Zanthoxylum piper-itum fruit and the antibacterial effects of its polymeric procyanidin on methicillin-resistant Staphylococcus aureus. Biosci Biotechnol Biochem 70 1423-1431. 

FIGURE 2.11 The structures of the procyanidin dinners prominent in (from top to bottom) grape juice (procyanidin Bl), apple juice (procyanidin B2), and beer (procyanidin B3 and prodelphinidin B3). 

Franck, U., Neszmelyi, A., and Wagner, H., 2D-NMR structure elucidation of a procyanidin from... 

FIGURE 5.9 Hypothetical structures and thiolysis reaction of malvidin 3-glucoside-procyanidin B2 3 -gallate adducts. 

Thompson, R.S. et ah. Plant proanthocyanidins. Part. I. Introduction the isolation, structure, and distribution in nature of plant procyanidins. J. Chem. Soc. Perkin Trans. 11387, 1972. 

Balas, L. and Vercauteren, J., Extensive high-resolution reverse 2D NMR analysis for the structural elucidation of procyanidin oligomers. Magn. Reson. Chem. 32, 386, 1994. 

De Freitas, V. and Mateus, N., Structural features of procyanidin interactions with salivary proteins, J. Agric. Food Chem., 49, 940, 2001. 

A number of mixed procyanidins or prodelphinidin analogs with exceptionally complex structures have been identified from the roots of Clementsia semenovii and Rhodiala pamiroalaica. ° ° Owing to the space requirements for the naming of these macromolecules, these are listed in the text only. In addition, the authors stated that indicated eonfigurations are relative hence, it is unclear whether the proanthocyanidin community should indeed consider the structures of these compounds as well as those cited in Refs. 100-103, 105-107 as sufficiently defined. The analogs from C. semenovii are CS-3, 7-0-(6-<9-galloyl-(3-D-Glcp ... 

In addition to the contributions dealing with the isolation and structural elucidation of procyanidins, several excellent papers describing the synthesis and chemical manipulation of the proanthocyanidins in general have been published. These may be listed as follows ... 

X-ray and CD analysis. The structure of procyanidin B-1 was unequivocally confirmed by x-ray analysis of its deca-(9-acetyl derivative by Weinges, one of the pioneers in the field of proanthocyanidin chemistry. One of the most powerful methods to establish the absolute configuration at C-4 of the T-unit in dimeric A- and B-type proanthocyanidins remains the chiroptical method via application of the aromatic quadrant rule. This has been repeatedly demonstrated by the author s own work and several other contributions listed in Refs. 7-12. 

A mixed propelargonidin-prodelphinidin procyanidin pentamer, PZ-5, was identified in Ziziphm jujuba. Prodelphinidin polymers of undefined structure were also obtained from... 

Shaji, T. et al., Isolation and structure elucidation of some procyanidins from apple by low-temperature nuclear magnetic resonance, J. Agric. Food Chem., 51, 3806, 2003. 

Santos-Buelga, C., Kolodziej, H., and Treutter, D., Procyanidin trimers possessing a doubly linked structure from Aesculus hippocastanum. Phytochemistry, 38, 499, 1995. 

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