Receptor-bound conformation of cilengitide better represented by its solution-state structure than the solid-state structure.

The X-ray crystal and NMR spectroscopic structures of the peptide drug candidate Cilengitide (cyclo(RGDf(NMe)Val)) in various solvents are obtained and compared in addition to the integrin receptor bound conformation. The NMR-based solution structures exhibit conformations closely resembling the X-ray structure of Cilengitide bound to the head group of integrin αvβ3. In contrast, the structure of pure Cilengitide recrystallized from methanol reveals a different conformation controlled by the lattice forces of the crystal packing.

Step-by-step synthesis of the endohedral stannaspherene [Ir@Sn12]3- via the capped cluster anion [Sn9Ir(cod)]3-.

The endohedral stannaspherene cluster anion [Ir@Sn(12)](3-) was synthesized in two steps. The reaction of K(4)Sn(9) with [IrCl(cod)](2) (cod: 1,5-cyclooctadienyl) in ethylenediamine (en) solution first yielded the [K(2,2,2-crypt)](+) salt (2,2,2-crypt: 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.