Regiospecific analysis of diricinoleoylacylglycerols in castor (Ricinus communis L.) oil by electrospray ionization-mass spectrometry

Jiann Tsyh Lin, Arthur Arcinas

Research output: Contribution to journalArticle

25 Scopus citations

Abstract

HPLC fractions of diricinoleoylacylglycerols containing one non-ricinoleoyl chain from castor oil were used to identify the regiospecific location of this non-ricinoleoyl chain on the glycerol backbone using electrospray ionization-MS3 of lithium adducts. The regiospecific ions used were from the loss of α,β-unsaturated fatty acid specific at the sn-2 position. The content of 1,3-diricinoleoyl-2-oleoyl-sn-glycerols (ROR) among the three stereospecific isomers, RRO, ROR and ORR, was about 91%. The contents of other 1,3-diricinoleoyl-2-acyl-glycerols among the three stereospecific isomers were as follows: 1,3-diricinoleoyl-2-linoleoyl-sn-glycerol, 95%; 1,3-diricinoleoyl-2-linolenoyl-sn-glycerol, 96%; 1,3-diricinoleoyl-2-stearoyl- sn-glycerol, 96%; 1,3-diricinoleoyl-2-palmitoyl-sn-glycerol, 78%; and 1,3-diricinoleoyl-2-lesqueroloyl-sn-glycerol, 31%. These non-hydroxyl fatty acids were mostly at the sn-2 position of triacylglycerols in castor oil. These results suggest that phospholipase A2 hydrolysis of phosphatidylcholine (PC) containing non-hydroxyl fatty acid at the sn-2 position is either blocked or partially blocked in vivo. Phospholipase A2 hydrolysis of 2-lesqueroloyl-PC is not blocked and is similar to that of 2-ricinoleoyl-PC. Transgenic inhibition of phospholipase C hydrolysis of PC might be used to block the incorporation of non-hydroxyl fatty acids into triacylglycerols, thus increasing the content of ricinoleate in seed oil.

Original languageEnglish (US)
Pages (from-to)2209-2216
Number of pages8
JournalJournal of Agricultural and Food Chemistry
Volume55
Issue number6
DOIs
Publication statusPublished - Mar 21 2007
Externally publishedYes

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Keywords

  • Castor oil
  • Diricinoleoylacylglycerols
  • Diricinoleoyloleoylglycerol
  • LC-MS
  • Phospholipase A
  • Phospholipase C
  • Regiospecific analysis
  • Ricinoleate
  • Ricinus communis L.
  • Triacylglycerols

ASJC Scopus subject areas

  • Chemistry(all)
  • Agricultural and Biological Sciences(all)

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