The pigments characteristic of black tea infusions are of two general types' associated with the theaflavin fraction and the thearubigin fraction. The thearubigins have been recognised as polymeric proanthocyanidins . 2 The theaflavin fraction contains a considerable number of compounds which are
The constitution of theaflavin
β Scribed by A.G. Brown; C.P. Falshaw; E. Haslam; A. Holmes; W.D. Ollis
- Publisher
- Elsevier Science
- Year
- 1966
- Tongue
- French
- Weight
- 417 KB
- Volume
- 7
- Category
- Article
- ISSN
- 0040-4039
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β¦ Synopsis
The recent publication1 describing (a) thedetermination of the molecular weight of thkaflavin acetate, (b) the deuterirrm analysis of theaflavin delaeroacetate, and (c) the interpretation of the NMR spectrum of the theaflavinmethanol solvate, makes it desirable for us to report our evidence regarding the constitution of theaflavin. Our results are in certain respects more extensive and more detailed than those reported by Gianturco ei al. ' and --No.11 HO IV; R=OtI
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## Abstract Theaflavin, theaflavin monogallate and theaflavin digallate were isolated from black tea leaves and studied by 1D and 2D NMR techniques, thus allowing unambiguous assignment of the ^1^H and ^13^C resonances of these complexes. Earlier studies have not yielded ^13^C data of equal reliabi
## Abstract An efficient deuterium labelling of theaflavin, aiming at radiolabelling of theaflavin, was accomplished for the first time by using 4βdeuteriumβlabelled __epi__βcatechin as the precursor and the resulting Dβlabelled theaflavin was fully characterized by ^1^H NMR, ^13^C NMR, IR spectros
A crystalline orange-red polyphenol, which has been named theaflavin, has been known for some time to be present in black tea.
The objective of the current study is to characterize the reaction products of theaflavin 3,3%-digallate, one of the major characteristic polyphenols of black tea, with hydroxyl radicals generated by hydrogen peroxide, with the aim of gaining insights into specific mechanisms of antioxidant reaction