STRUCTURAL CHARACTERIZATION OF OXIDIZED LUMIFLAVIN HYDROCHLORIDE HYDRATE - COMPARISON WITH THE HYDROGEN-BONDING AT THE COFACTOR OF FLAVOPROTEINS

In order to examine the possibility of hydrogen bonding around the fla vin ring, an X-ray diffraction study of the title compound was underta ken. Crystals of lumiflavin hydrochloride hydrate [2(C13H12N4O2)4 HCl 7 H2O] are triclinic, space group P (1) over bar, Z = 2, a = 11.064(1) , b = 17.903(1), c = 9.891(1)Angstrom, alpha = 111.9(6), beta = 96.4(8 ), gamma = 91.6(7)degrees. We present the crystal structure of this co mpound and compare it with other flavin derivatives and with the struc ture of the active site of some flavoproteins.