NMR and parity violation: low-temperature dependence in 1H CRAMPS and 13C CP/MAS ssNMR spectra of alanine enantiomer.
Life is based on L-amino acids and D-sugars rather than the enantiomeric D-amino acids and L-sugars. This broken symmetry is now believed to be a feature of fundamental physics-a result of symmetry-breaking induced by the weak force, which makes one enantiomer slightly more stable than the other. An amplification mechanism based on quantum mechanical tunneling could give rise to a second-order phase transition. In order to understand the transition mechanism, we measured the temperature dependence of 1H CRAMPS solid state NMR and 13C CP/MAS spectra of D- and L-alanine crystals from 295 K through to 220 K. Obvious difference of NMR behaviors between two enantiomers was observed in the phase transition which may be related to one suggested by Salam, caused biochirality among twenty amino acids.
Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China. wangwq@suh.ihep.ac.ch
Wen-Qing
WQ
Wang
Wei
W
Min
Zhi
Z
Liang
Li-Ying
LY
Wang
Lei
L
Chen
Feng
F
Deng
D000409:Alanine / Q000737:chemistry*; D003080:Cold Temperature; D003460:Crystallization; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011789:Quantum Theory; D013237:Stereoisomerism; D013696:Temperature
D000409:Alanine