|Knothe, Gerhard - Gary|
Submitted to: Journal of the Chemical Society Perkin Transactions 2
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/19/1998
Publication Date: N/A
Interpretive Summary: Scientists and technologists need to know the composition of materials with which they work and have to be able to analyze mixtures of materials rapidly. Vegetable oils and their derivatives mainly constitute mixtures of various compounds called fatty acids. Such mixtures occur in many commercial products derived from vegetable oils. The method developed here will allow for rapid analyses of vegetable oil-derived mixtures by a mathematical equation which can "automate" the evaluation of such analyses.
Technical Abstract: The 13C-NMR shift values of saturated carbons in long chain compounds can be mathematically approximated by equations of the kind s = -ax-b + cx-d + e which are similar to those for the Lennard Jones potential. Here s is the chemical shift of a carbon atom and x is the position in the chain of this atom or a functional group influencing its shift value. Equations were determined for selected saturated carbons of methyl octadecanoate, cis- and trans- octadecenoic acids, methyl cis-octadecenoates, methyl oxooctadecanoates, methyl hydroxyoctadecanoates, methyl acetoxyoctadecanoates and methyl epoxyoctadecanoates. Excellent correlation (regression coefficients in most cases >0.99) of experimental and theoretical data was achieved. These equations can be used for predicting 13C NMR shift values of saturated carbons in long chain compounds.