Structure determination of monohydrated trifolin (kaempferol 3-O-β-D-galactopyranoside) from laboratory powder diffraction data.
ABSTRACT The crystal structure of monohydrated trifolin (kaempferol 3-O-β-D-galactopyranoside) (an important biologically active compound, which was isolated from the aerial part of Consolida oliveriana) has been determined from conventional laboratory X-ray powder diffraction data. Variable counting time technique was used during measurement and crystal structure was solved by means of Monte Carlo algorithm. The final structure was achieved by Rietveld refinement using both constraints and restraints on interatomic bond lengths and angles. © 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 100:1588-1593, 2011.
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ABSTRACT: The p90 ribosomal S6 family of kinases (RSK) are potential drug targets, due to their involvement in cancer and other pathologies. There are currently only two known selective inhibitors of RSK, but the basis for selectivity is not known. One of these inhibitors is a naturally occurring kaempferol-α-L-diacetylrhamnoside, SL0101. Here, we report the crystal structure of the complex of the N-terminal kinase domain of the RSK2 isoform with SL0101 at 1.5 Å resolution. The refined atomic model reveals unprecedented structural reorganization of the protein moiety, as compared to the nucleotide-bound form. The entire N-lobe, the hinge region, and the αD-helix undergo dramatic conformational changes resulting in a rearrangement of the nucleotide binding site with concomitant formation of a highly hydrophobic pocket spatially suited to accommodate SL0101. These unexpected results will be invaluable in further optimization of the SL0101 scaffold as a promising lead for a novel class of kinase inhibitors.Biochemistry 07/2012; 51(33):6499-510. · 3.38 Impact Factor