1. Grupo de Espectroscopia Molecular, Unidad Asociada CSIC Laboratorios de Espectroscopia y Bioespectroscopia Edificio Quifima. Parque Científico Universidad de Valladolid M. VARELA, C. CABEZAS AND J. L. ALONSO ROTATIONAL STUDY OF NATURAL AMINO ACID GLUTAMINE

2. AIM: SYSTEMATIC STUDY OF PROTEOGENIC AMINO ACIDS GLYALAVALILELEU PR O SERCYSTHRGLUASPASN PHETYR ME T TRP GLN HIS LYS AR G Aliphatic with non-polar side chain Aliphatic with polar side chain Aromatic side chain

3. CONFORMATIONAL STUDY OF GLUTAMINE: WHAT CAN WE EXPECT? R = –CH 2 CH 2 C(O)NH 2 Glutamine presents high flexibilityGreat number of low energy conformers Ab initio calculations predict up to 12 conformations in a energy window of 900 cm -1 ΔE MP2 /cm -1 1370850113011581071790 ΔG MP2 /cm -1 507669712747863865 ΔE MP2 /cm -1 179 0 3808581400959 ΔG MP2 /cm -1 0 106 140418669471

4. Glutamine presents high flexibilityGreat number of low energy conformers Glutamine possesses two 14 N nucleiVery complex hyperfine structure 14 N nucleus has non spherical nuclear charge distribution Q ≠ 0 Interaction with molecular electric field gradient CONFORMATIONAL STUDY OF GLUTAMINE: WHAT CAN WE EXPECT?

5. FT-MW Spectrometer Fabry-Pérot Resonator Picosecond Laser 4-10 GHz Frequency Range EXPERIMENTAL: LA-MB-FTMW SPECTROSCOPY

6. Jet Nd:YAG laser Rotary Diffusion pump Glutamine sample Laser Gas pulseLaser pulse EXPERIMENTAL: LA-MB-FTMW SPECTROSCOPY Ne

7. FT-MW spectrometer Polarization MW field Rotary Diffusion pump MW pulse Jet Ne EXPERIMENTAL: LA-MB-FTMW SPECTROSCOPY Gas pulseLaser pulse

8. Molecular emission FT Detection Frequency-domain Rotary Diffusion pump FT-MW spectrometer Time-domain EXPERIMENTAL: LA-MB-FTMW SPECTROSCOPY MW pulse Gas pulseLaser pulse Ne

9. RESULTS 3 03 -2 02 3 13 -2 12 3 12 -2 11 Wide frequency scans covering up to 4 GHz revealed the rotational signatures of only one rotamer

10. Conformer IConformer IIConformer IIIConformer IV 2023.72170.42456.42890.3 947.4898.9739.2683.6 903.9742.2665.5642.3 -0.60-0.40-1.65-0.71 1.960.66 0.90 -1.36-0.260.99-0.18 1.72-1.93-4.26-2.91 -3.761.992.492.33 2.04-0.061.770.58 ---- ---- ∆E/cm -1 1790380858 ∆G/cm -1 0106140418 RESULTS Rotamer A A/MHz2467.70941(14) B/MHz727.94433(22) C/MHz 655.81028(16) 14 N amide χ aa /MHz-1.5447(19) χ bb /MHz0.6267(15) χ cc /MHz0.9179(15) 14 N amine χ aa /MHz-4.0736(75) χ bb /MHz2.3760(94) χ cc /MHz1.6976(94) N 67 σ /kHz 2.4

11. PRESENT RESULTS: BROADBAND FTMW SPECTROSCOPY Experimental details in talk TD07 CP-FTMW + LASER ABLATION SOURCE

12. PRESENT RESULTS: BROADBAND FTMW SPECTROSCOPY 6-12 GHZ Broadband Rotational Spectrum with 40000 FID

13. 5 15 -4 14 5 05 -4 04 5 14 -4 13 5 23 -4 22 4 14 -3 13 4 04 -3 03 4 13 -3 12 4 23 -3 22 Rotamer A Rotamer B PRESENT RESULTS: BROADBAND FTMW SPECTROSCOPY

14. Conformer IConformer IIConformer IV 2023.72170.42890.3 947.4898.9683.6 903.9742.2642.3 -0.60-0.40-0.71 1.960.660.90 -1.36-0.26-0.18 1.72-1.93-2.91 -3.761.992.33 2.04-0.060.58 --- --- ∆E/cm -1 1790858 ∆G/cm -1 0106418 PRESENT RESULTS: BROADBAND FTMW SPECTROSCOPY Rotamer B A/MHz2124.4 (28) B/MHz847.8152 (72) C/MHz 805.666 (21) 14 N amide χ aa /MHz- χ bb /MHz- χ cc /MHz- 14 N amine χ aa /MHz- χ bb /MHz- χ cc /MHz- N 21 σ /kHz 5.0

15. SUMMARY So far, the rotational spectra of two conformers of Glutamine have been observed Investigation of the 14 N nuclear quadrupole hyperfine structure for rotamer II is needed to get the final assignment Probably more species will be identified in the broadband FTMW spectrum

16. ACKNOWLEDGMENTS Grant CTQ 2010- 19008 CSD 2009-00038 Molecular Astrophysics Grants VA070A08 and CIP13/01 Grupo de Espectroscopia Molecular (GEM) Laboratorios de Espectroscopia y Bioespectroscopia, Unidad Asociada CSIC, UVa,Valladolid, Spain