Prodelphinidins

Proanthocyanidins are an important group of di- to oligomeric flavonoids in plants. Four proanthocyanidins (procyanidin B3, prodelphinidin B4, ECG-(4 8)-ECG and GC-(4 8)-EGCG) were determined quantitatively in tea. The amounts in fresh tea leaves were between 1 and 2 g/kg per compound (Nakabayashi, 1991). The occurrence of proanthocyanidins may serve as a criterion for the differentiation between fermented and non-fermented teas (Kiehne et al, 1997). 

Proanthocyanidins (PAs), also known as condensed tannins, are oligomeric and polymeric flavan-3-ols. Procyanidins are the main PAs in foods however, prodelphinidins and propelargonidins have also been identified (Gu and others 2004). The main food sources of total PAs are cinnamon, 8084 mg/100 g FW, and sorghum, 3937 mg/100 g FW. Other important sources of PAs are beans, red wine, nuts, and chocolate, their content ranging between 180 and 300 mg/100 g FW. In fruits, berries and plums are the major sources, with 213.6 and 199.9 mg/100 g FW, respectively. Apples and grapes are intermediate sources of PAs (60 to 90 mg/100 g FW), and the content of PAs in other fruits is less than 40 mg/100 g FW. In the majority of vegetables PAs are not detected, but they can be found in small concentrations in Indian squash (14.8 mg/ 100 g FW) (Gu and others, 2004 US Department of Agriculture, 2004). 

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). 

Chart 8.1.S Shikimates (skeletons) widespread on land (5max=57, av=43 5//ftnax=0.48, av=0.39). Tannins lignans epigallocathechin gallate (Asian black tea. Camellia sinensis L.) Kuntze, Theaceae, Ang. MI) procyanidins and prodelphinidins (widespread in plants) soluble hydrolyzable tannins gallotannin (myrobalan. East Indian trees, Terminalia spp., oak, Quercus spp., Lithocarpus spp., and sumac, Rhus spp.) ellagitannin (Myrtaceae). 

Qa dan, F., Petereit, F., and Nahrstedt, A., Prodelphinidin trimers and characterization of a proanthocyanidin oligomer from Cistus albidus, Pharmazie, 58, 416, 2003. 

ESI-MS in the positive ion mode enabled to detect [M + H] ions up to the galloylated pentamer. Analysis of wine proanthocyanidins showed the presence of additional series of species with 16 mass unit differences to signals given by grape seed procyanidins. These were attributed to the presence of (epi)gallocatechin units in mixed procyanidin prodelphinidin... 

As discussed above, the development of mild MS techniques has led to further progress in the determination of proanthocyanidin size distribution. In particular, ESI-MS studies have demonstrated that prodelphinidin and procyanidin units coexist within the polymers, where they seem distributed at random. A list of mass signals attributed to proanthocyanidins detected in grape or wine extracts is given in Table 5.2. 

Foo, L. and Porter, L., Prodelphinidin polymers definition of structural units. J. Chem. Soc. Perkin Trans. /1186, 1978. 

The location of the interflavanyl bond in dimers and oligomers is denoted within parentheses as in carbohydrates. The orientation of the interflavanyl bond at C-4 is denoted as a or (3 as in the lUPAC rules. Thus, the familiar procyanidin B-1 (5) is named epicatechin-(4(3 8)-catechin, the analogous prodelphinidin (6) is named epigallocatechin-(4(3 —> 8)-catechin, and the 2S analog (7) is named e t-catechin-(4(3 6)-e t-epiafzelechin. 

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 ... 

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

The limited numbers of new propelargonidins are listed in Table 11.7. This is in addition to the mixed procyanidin-propelargonidin tetramer, davallin (Table 11.5), " the mixed propelargonidin-procyanidin trimer, epiafzelechin-(4(S 8)-epicatechin-(4(S 8)-catechin (Table 11.5), and the mixed propelargonidin-prodelphinidin-procyanidin pentamer... 

McGraw, G.W., Steynberg, J.P., and Hemingway, R.W., Condensed tannins a novel rearrangement of procyanidins and prodelphinidins in thiolytic cleavage. Tetrahedron Lett., 34, 987, 1993. 

Tits, M. et al., Prodelphinidins from Ribes nigrum, Phytochemistry, 31, 971, 1992. 

Prodelphinidins main constituten is epigallocatechin, which has three hydroxyl groups (3 , 4 , 5 ) in the B-ring. 

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