Open AccessCarbon-13 Relaxation and Proton Nuclear Magnetic Resonance Studies of Prostaglandin F 2α
Author(s) -
Woodrow W. Conover,
Josef Fried
Publication year - 1974
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.71.6.2157
Subject(s) - dihedral angle , resonance (particle physics) , chemistry , relaxation (psychology) , chemical shift , ring (chemistry) , proton , nuclear magnetic resonance , nuclear magnetic resonance spectroscopy , carbon fibers , crystallography , stereochemistry , materials science , molecule , hydrogen bond , atomic physics , organic chemistry , physics , composite material , psychology , social psychology , quantum mechanics , composite number
Carbon magnetic resonance T1 relaxation and chemical shift measurements at 22.63 MHz establish hydrophobic aggregation of prostaglandin F2α in phosphate buffer solutions between 0.05 and 0.2 M. Analysis of the proton magnetic resonance spectra of prostaglandin F2α at 270 MHz by double resonance techniques yield all the proton-proton coupling constants for the five-membered ring indicating a favored half-chair conformation for the ring in which the dihedral angle for the C-8 and C-12 protons is close to 180°. Effective correlation times derived from carbon magnetic resonance T1 values for all the carbon atoms show segmental motion for ring carbon C-10 and in the aliphatic portions of both side chains, while the double bonded portions of the side chains and the ring carbons act as a more rigidly interconnected network. Chemical shift changes in the carbon magnetic resonance and proton magnetic resonance spectra upon aggregation suggest that the 5-6 double bond, C-7, and C-9 participate in the aggregation process.