Molecular species of acylglycerols incorporating radiolabeled fatty acids from castor (Ricinus communis L.) microsomal incubations.
Sixty-one molecular species of triacylglycerols (TAG) and diacylglycerols produced from castor microsomal incubations incorporating six different (14)C-labeled fatty acids have been identified and quantified. The preference for incorporation into TAG was in the order ricinoleate > oleate > linoleate > linolenate > stearate > palmitate. Ricinoleate was the major fatty acid incorporated, whereas stearate, linolenate, and palmitate were incorporated at low levels. Twenty-one molecular species of acylglycerols (HPLC peaks) in castor oil have also been assigned. The levels of TAG in castor oil are RRR (triricinolein) >> RR-TAG >> R-TAG > no R-TAG. The levels of the molecular species within the groups of RR-TAG, RL-TAG, and LL-TAG individually are ricinoleate > linoleate > oleate > linolenate, stearate, and palmitate. The results of the labeled fatty acid incorporation are consistent with ricinoleate being preferentially driven into TAG and oleate being converted to ricinoleate in castor oil biosynthesis.
Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 800 Buchanan Street, Albany, California 94710, USA. jtlin@pw.usda.gov
Jiann-Tsyh
JT
Lin
Jennifer M
JM
Chen
Lucy P
LP
Liao
Thomas A
TA
McKeon
D002250:Carbon Radioisotopes; D002368:Castor Oil / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004075:Diglycerides / Q000032:analysis / Q000378:metabolism*; D005227:Fatty Acids / Q000032:analysis / Q000378:metabolism*; D007553:Isotope Labeling; D008861:Microsomes / Q000737:chemistry*; D019301:Oleic Acid / Q000032:analysis / Q000378:metabolism; D012277:Ricinoleic Acids / Q000032:analysis / Q000378:metabolism; D012278:Ricinus / Q000648:ultrastructure*; D014280:Triglycerides / Q000032:analysis / Q000378:metabolism*
D002250:Carbon Radioisotopes; D004075:Diglycerides; D005227:Fatty Acids; D012277:Ricinoleic Acids; D014280:Triglycerides; D019301:Oleic Acid; D002368:Castor Oil; C030521:ricinoleic acid