Location: Bioproducts ResearchTitle: Molecular species of triacylglycerols in the rubber particles of Parthenium argentatum and Hevea brasiliensis
Submitted to: Biocatalysis and Agricultural Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/12/2018
Publication Date: 7/18/2018
Citation: Hathwaik, U.I., Lin, J.T., McMahan, C.M. 2018. Molecular species of triacylglycerols in the rubber particles of Parthenium argentatum and Hevea brasiliensis. Biocatalysis and Agricultural Biotechnology. 16:107-114. https://doi.org/10.1016/j.bcab.2018.07.019.
Interpretive Summary: Natural rubbers are obtained after latex coagulation. Hevea latex is mostly from South-east Asia and its rubber is mostly (~70%) used to make tires. Guayule rubber (U.S. domestic rubber) can be used to make medical devices and has the potential to replace imported Hevea rubber and/or synthetic rubber from petroleum. The type and amount of rubber particle lipids are important because they affect the biosynthesis of rubber and the physical properties of the rubber. We report here the identification and quantification of many intact molecular species of triacylglycerols in the rubber particles of Hevea and guayule. We also proposed the structure of a new fatty acid in the rubber particles of guayule.
Technical Abstract: Molecular species of triacylglycerols (TAG) in the lipid extracts of the rubber particles of guayule (Parthenium argentatum) and Hevea (Hevea brasiliensis) were compared using LC-MS. The contents of the molecular species of acylglycerols in guayule rubber particle lipid extract in decreasing order were as: LLnLn (4.56%), LLLn (3.64%), LLn-OH20:0 (2.36%), LnLnLn (1.91%), LLnP(1.31%), LLP (1.25%), LLn-OH20:1 (0.80%), LLL (0.62%). L, linoleic acid; Ln, linolenic acid; P, palmitic acid; OH20:1, monohydroxy FA with 20 carbon atoms and one double bond. The highest contents of these FA constituents were Ln (9.21%) and L (9.07%). The normal FA among the total FA was about 88%, and hydroxy FA about 12%. The contents of the molecular species of TAG in Hevea rubber particle lipid extract in decreasing order were: 308-308-308 (20.6%), 308-308-O(4.9%), 308-308-L (3.6%), 308-308-S (2.8%), 308-308-324 (2.4%), 308-OL (1.5%) and LLL (1.3%). 308 and 324 were the furan FA with the masses of 308 and 324. O, oleic acid; S, stearic acid. Furan FA 308 was 10,13-epoxy-11-methyloctadeca-10,12-dienoic acid identified earlier. We proposed the structure of furan FA with the mass 324 as 10,13-epoxy-11-carboxyl-12-methylhexadeca-10,12-dienoic acid. The contents of FA from Hevea in decreasing order were: 308(30.8%), L (3.5%), O (2.4%), S (1.0%), 324 (1.0%), 19:2 (0.1%), 20:1 (0.1%), OH18:2 (0.1%). Furan FA among the total FA was about 82%, normal FA about 18% and hydroxy FA about 0.2%. This is the first report of the intact molecular species of TAG containing furan FA. It is also the first report of hydroxy FA in either species.