Anisotropy of the fluorescence from the monomer, five oligomers, and a polymer of epicatechin

✍ Scribed by Donghwan Cho; Wayne L. Mattice; Lawrence J. Porter

• Publisher: Wiley (John Wiley & Sons)
• Year: 1990
• Tongue: English
• Weight: 343 KB
• Volume: 29
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.360290109

✦ Synopsis

The steady-state fluorescence anisotropy r has been measured at 25°C for dilute solutions of epicatechin units connected by interflavan bonds with 4b -+ 8 stereochemistry. The molecules studied are monodisperse oligomers from the monomer through the hexamer, and a polydisperse sample with a number-average degree of polymerization x, of 10. The hexamer and smaller oligomers have been removed from the polydisperse sample. All samples have a very small value of r in 1,4-dioxane and in methanol. Higher values of r are seen in ethylene glycol and in glycerol. In the latter two solvents, the monomer has significantly higher r than any species with x,, > 1. This observation is interpreted as evidence for the presence of excitation migration from one monomer to another in the dimer and species of higher x,.