title: 13C and 15N-chemical shift anisotropy of ampicillin and penicillin-V studied by 2D-PASS and CP/MAS NMR.
abstract: The principal values of the chemical shift tensors of all 13C and 15N sites in two antibiotics, ampicillin and penicillin-V, were determined by 2-dimensional phase adjusted spinning sideband (2D-PASS) and conventional CP/MAS experiments. The 13C and 15N chemical shift anisotropies (CSA), and their confidence limits, were evaluated using a Mathematica program. The CSA values suggest a revised assignment of the 2-methyl 13C sites in the case of ampicillin. We speculate on a relationship between the chemical shift principal values of many of the 13C and 15N sites and the beta-lactam ring conformation.
authors.affiliation: Division of Inorganic Chemistry, Luleâ University of Technology, Luleâ, S-971 87, Sweden. Oleg.Antzutkin@km.luth.se
authors.forename: O N
authors.initials: ON
authors.lastname: Antzutkin
authors.forename: Y K
authors.initials: YK
authors.lastname: Lee
authors.forename: M H
authors.initials: MH
authors.lastname: Levitt
mesh_terms: D000667:Ampicillin / Q000737:chemistry*; D016880:Anisotropy; D009682:Magnetic Resonance Spectroscopy; D008961:Models, Structural; D010404:Penicillin V / Q000737:chemistry*
chemical_list: D000667:Ampicillin; D010404:Penicillin V