(-)-Armepavine, a benzylisoquinoline alkaloid isolated from Papaver caucasicum, was examined by gradient-enhanced 2D NMR spectroscopy and X-ray diffraction analysis. Unambiguous 1H, 13C, and 15N NMR assignment of the title alkaloid is reported.
A new similarity index for automated comparison of powder diagrams is proposed. In contrast to traditionally used similarity indices, the proposed method is valid in cases of large deviations in the cell constants. The refinement according to this index closes the gap between crystal structure prediction and automated crystal structure determination. The opportunities of the new procedure have been demonstrated by crystal structure solution of un-indexed powder diagrams of some organic pigments (PY111, PR181 and Me-PR170).
3P-094 High resolution and precise X-ray crystal structure determination of Cyctochrome c Oxidase(The 46th Annual Meeting of the Biophysical Society of Japan)