MOLECULAR INTERACTION OF ISOALLOXAZINE DERIVATIVES. II

Abstract
Molecular interaction of isoalloxazine derivatives was examined in a variety of solvent systems. Two effects were encountered: hydrogen-bonding and interaction thought to have its basis in molecular charge transfer. Interaction with compounds which are charge-transfer donors but not hydrogen donors is increased greatly when the flavin is hydrogen-bonded to a solvent like water or to a solute such as trichloracetic acid. Previous studies of charge-transfer interaction in water solution were extended to include data for reduced flavin mononucleotide, and values of A H were determined for the interaction of riboflavin with L-tryptophan and with pentachlorophenolate. The results are discussed in relation to the chemistry of flavoproteins.