Wm. Craig Byrdwell, phd

Resources for Lipid Analysis in the 21st Century

For a conveniently printable .pdf version of these structures (2 pages), click HERE

© 2006-2011

The figures and tables on this website are copyrighted in 2006-2011 by William Craig Byrdwell.  If you use these tables please reference




Masses of neutral molecules are given.  Protonated molecules, [M+H]+, observed by mass spectrometry, are one mass unit higher than the neutral masses.


For more information on the structures of Vitamin D isomers, see:


Nomenclature of Vitamin D,

Pure & Appl. Chem., 54:1511-1516 (1982).



For pairs of isomers in which both forms are possible, the most commonly cited isomer is listed first.



E = ‘entgegen’ (opposite) = trans

Z = ‘zusammen’ (together) = cis



For more information on

cis / trans isomers, see:


Wikipedia E / Z Notation page


or the


Wikipedia cis / trans Isomerism page