TY - JOUR
T1 - Influence of functional groups on the C
α-C
β chain of L-phenylalanine and its derivatives
AU - Ganesan, Aravindhan
AU - Brunger, Michael
AU - Wang, Feng
PY - 2010/7/1
Y1 - 2010/7/1
N2 - L-phenylalanine (L-phe) consists of three different functional groups, i.e., phenyl, carboxyl (-COOH) and amino (-NH2), joining through the C
α-C
β bridge. Substitution of these groups produces 2-phenethylamine (PEA) and 3-phenylpropionic acid (PPA). Electronic structures of L-phe, PEA and PPA together with smaller "fragments" L-alanine and benzene were determined using density functional theory (DFT), from which core and valence shell ionization spectra were simulated. Comparison of the spectra reveals that core shell ionization energies clearly indicate that the carbon bridge is significantly affected by their functional group substitutions particularly at the Ca site. In the valence space, quite unexpectedly, the frontier orbitals are concentrated on the benzene group although some energy splitting is observed. The orbitals which significantly affect the C
α-C
β carbon backbone are from the inner valence shell in the ionization energy region of 20-26 eV of the molecules.
AB - L-phenylalanine (L-phe) consists of three different functional groups, i.e., phenyl, carboxyl (-COOH) and amino (-NH2), joining through the C
α-C
β bridge. Substitution of these groups produces 2-phenethylamine (PEA) and 3-phenylpropionic acid (PPA). Electronic structures of L-phe, PEA and PPA together with smaller "fragments" L-alanine and benzene were determined using density functional theory (DFT), from which core and valence shell ionization spectra were simulated. Comparison of the spectra reveals that core shell ionization energies clearly indicate that the carbon bridge is significantly affected by their functional group substitutions particularly at the Ca site. In the valence space, quite unexpectedly, the frontier orbitals are concentrated on the benzene group although some energy splitting is observed. The orbitals which significantly affect the C
α-C
β carbon backbone are from the inner valence shell in the ionization energy region of 20-26 eV of the molecules.
KW - Amino acids
KW - Functional groups
KW - L-phenylalanine
KW - Valence ionization spectra
UR - http://www.scopus.com/inward/record.url?scp=78650296388&partnerID=8YFLogxK
U2 - 10.1016/j.nima.2010.02.122
DO - 10.1016/j.nima.2010.02.122
M3 - Article
VL - 619
SP - 143
EP - 146
JO - Nuclear Instruments and Methods in Physics Research Section A-Accelerators Spectrometers Detectors and Associated Equipment
JF - Nuclear Instruments and Methods in Physics Research Section A-Accelerators Spectrometers Detectors and Associated Equipment
SN - 0168-9002
IS - 1-3
ER -