PLANT PHYSIOLOGY , Vol 113, Issue 4 1343-1349, Copyright © 1997 by American Society of Plant Biologists
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BIOCHEMISTRY AND ENZYMOLOGY |
In Vivo Studies of the Biosynthesis of [alpha]-Eleostearic Acid in the Seed of Momordica charantia L
L. Liu, E. G. Hammond and B. J. Nikolau
Department of Food Science and Human Nutrition (L.L.,E.G.H., B.J.N.) and Department of Biochemistry and Biophysics (E.G.H., B.J.N.), Iowa State University, Ames, Iowa 50011
In vivo radiotracer experiments using 14C-labeled acetate, oleate,
linoleate, and linolenate were conducted to investigate the biosynthesis of
[alpha]-eleostearic acid in the seeds of Momordica charantia. With the
exception of [14C]linolenate, all of these precursors radioactively labeled
[alpha]-eleostearate. Kinetics of the time course of metabolism of the
radioactive precursors indicate that linoleate is the acyl precursor of
[alpha]-eleostearate and that its conversion to [alpha]-eleostearate occurs
while the acyl moiety is esterified to PC. Pulse-chase experiments with
14C-labeled acetate or linoleate provided additional corroborative evidence
that linoleoyl PC is the precursor of [alpha]-eleostearoyl PC.
