RESUMO
The crystal structure of byakangelicin, one of furanocoumarin aldose reductase inhibitors, was determined by X-ray diffraction method. The crystal is triclinic, with a = 8.114(1), b = 10.194(1), c = 11.428(1)A, a = 111.50(1), beta= 95.57(1), gamma = 112.52(1) degrees , Dx = 1.41, Dm = 1.39 g/cm3, space group P1 and Z = 2. The intensity data were collected by omega-2theta scan method with CuK(a) radiations. The structure was solved by direct method and refined by full matrix least-squares procedure to the final R-value of 0.056. There are two molecules with different conformations in an asymmetric unit. The molecules are kept by two intermolecular O-HO type hydrogen bonds and van der Waal's forces in the crystal. The absolute configuration of the molecules was estimated to S-form by the 'Eta refinement' procedure.
