Appl. Magn. Reson. 25, 113-119 (2003) Applled Magnetic Resonance 9 Springer-Verlag 2003 Printed in Austria Spatial Structure of Triglycine Determined by the Residual Dipolar Coupling Analysis V. V. Klochkov, B. I. Khairutdinov, A. V. Klochkov, V. G. Shtyrlin, and R.A. Shaykhutdinov Department of Chemistry, Kazan State University, Kazan, Russian Federation Received May 7, 2003; revised Ju[y 27, 2003 Abstract. The possibility to determine the relatively small organic compound conformations by the approach on the basis of the analysis of the residual dipolar couplings ~H-~3Cin the molecules par- tially aligned in lyotropic liquid crystalline media has been considered. This approach has been used in the nuclear magnetic resonance investigation of the triglycine structure in lyotropic medium (cetylpy- ridinium bromide/n-hexanol). The conformation of triglycine in solution has been established as trans- trans on the basis of the experimental data of observed couplings. 1 Introduction Traditionally, the determination of three-dimensional (3-D) structures of the rela- tively small organic compounds in solution is based on both 1-D nuclear mag- netic resonance (NMR) spectroscopy and modero NMR methods such as dynamic NMR spectroscopy [1, 2] and 2-D NMR spectroscopy [3, 4]. Note that nuclear Overhauser effect spectroscopy (NOESY) experiments allow one to determine the distances between magnetic nuclei of up to 0.5 nm and, hereby, to estabtish the 3-D structure of organic compounds in solution [3, 4]. The increase in the num- ber of atoms in a molecule results in the NMR spectral parameters which do not allow one to describe adequately the 3-D structure of organic compounds in solution. In this work an application of the approach for determination of the confor- mation of triglycine, a relatively small molecule, partially aligned in lyotropic liquid crystalline medium on the basis of an analysis of the residual dipolar cou- plings between magnetic nuclei 13C and 1H separated by one chemical bond (ID) is demonstrated. Since recently, this approach is actively used in the NMR in- vestigations of biochemical objects under the condition of slow motion (co0r c 87 1, r c is the correlation time, co o is the angular precession rate of magnetic nuclei) [5, 6]. It allows one to obtain independent information about the structure of