80044-64-0Relevant academic research and scientific papers
Proanthocyanidins from Lotus Corniculatus
Foo,Newman,Waghorn,Mcnabb,Ulyatt
, p. 617 - 624 (2007/10/03)
The chemical structure of the purified proanthocyanidin polymers of Lotus corniculatus was analysed by 13CNMR and by mild acid catalysed degradation in the presence of excess of phloroglucinol. The NMR data showed that the polymer was partially glycosidated with a number average Mr in the range 1800-2100 (six to seven flavanoid units). The products from phloroglucinol scission reaction indicated the extender flavan units to consist mostly of epicatechin (67%) and epigallocatechin (30%), with minor amounts of catechin and epiafzelechin units, which were linked together predominantly by C-4/C-8 interflavanoid bonds. The polymer chains were terminated mostly by catechin (83%) and, to a lesser extent, by epicatechin (16%). Copyright
POLYPHENOLIC COMPOUNDS FROM CROTON LECHLERI
Cai, Y.,Evans, F. J.,Roberts, M. F.,Phillipson, J. D.,Zenk, M. H.,Gleba, Y. Y.
, p. 2033 - 2040 (2007/10/02)
The blood-red sap of Croton lechleri was found to contain proanthocyanidins as major constituents which accounted for up to 90percent of the dried weight.In addition to (+)-catechin, (-)-epicatechin, (+)-gallocatechin, (-)-epigallocatechin and dimeric procyanidins B-1 and B-4, five novel dimers and trimers were isolated and characterized as catechin-(4α->8-epigallocatechin, gallocatechin-(4α->8)-epicatechin, gallocatechin-(4α->6)-epigallocatechin, catechin-(4α->8)-gallocatechin-(4α->8)-gallocatechin and gallocatechin-(4α->8)-gallocatechin-(4α->8)-epigallocatechin.Higher oligomers were also obtained.A new procedure combining chemical degradation with 1H NMR spectroscopy has been developed for determination of the composition and molecular size of oligomeric/polymeric proanthocyanidins.The oligomers of the sap were shown to have the mean degree of polymerization of 4,5-6 and 6-7, respectively, and Mr up to 2130.The heterogeneity of the oligomers was clearly indicated by the presence of a variety of flavan-3-ols as extension and terminal units.An exceptionally high content of gallocatechin and epigallocatechin in the oligomers was observed.Key Word Index: Croton lechleri; Euphorbiaceae; Sangre de Grado; Dragon's blood; polyphenol; proanthocyanidins; flavan-3-ols; procyanidins; prodelphinidins.
HYDROLYSABLE TANNINS AND PROANTHOCYANIDINS FROM GREEN TEA
Nonaka, Gen-Ichiro,Sakai, Ryo,Nishioka, Itsuo
, p. 1753 - 1756 (2007/10/02)
Two hydrolysable tannins were isolated from green tea, and their structures were characterized by chemical and spectral means as 1,4,6-tri-O-galloyl-β-D-glucose and 1-O-galloyl-4,6-(-)-hexahydroxydiphenoyl-β-D-glucose.In addition, a new proanthocyanidin gallate was isolated, together with the known procyanidins B-2, B-4 and C-1.The structure of the proanthocyanidin was established as epigallocatechin-(4β -> 8)-3-O-galloylepicatechin.Key Word Index - Thea sinensis; Theaceae; green tea; ellagitannin; gallotannin; proanthocyanidin; polyphenol.
Plant Proanthocyanidins. Part 7. Prodelphinidins from Pinus sylvestris
Gupta, Raj K.,Haslam, Edwin
, p. 1148 - 1150 (2007/10/02)
A dimeric prodelphinidin and a polymeric proanthocyanidin have been isolated from male flowers of Pinus sylvestris.Structural analyses of the dimer and the polymer are reported and a biomimetic synthesis of the dimer is noted.
