M. Husak et al., X-RAY ABSOLUTE STRUCTURE OF NICERGOLINE (FORM-I) - QUANTITATIVE-ANALYSIS OF NICERGOLINE PHASE MIXTURE - FORM-I FORM-II, Collection of Czechoslovak Chemical Communications, 59(7), 1994, pp. 1624-1636
The structure of semisynthetic ergot derivative nicergoline (form I) w
as determined from X-ray single crystal diffraction data. The tide alk
aloid imethylergoline-8beta-methanol-5'-bromonicotinate, C24H26BrN3O3)
crystallizes in the triclinic space group P1, with a = 7.729(7), b =
8.695(4), c = 17.030(8) angstrom, alpha = 100.90(4), beta = 98.67(5),
gamma = 93.04(5)-degrees, Z = 2. A structural comparison of nicergolin
e forms I and II was made. The quantitative analyses of some model pha
se mixtures form I/form II were carried out using both Rietveld full p
rofile fitting method and linear regression of the peak intensity-conc
entration dependence. Results obtained are in good mutual agreement. T
he smallest limit of detection of form II in binary mixture with form
I is about 3% as found from powder diffraction study.