Guayule (Parthenium argentatum), a shrub native to the arid region of the U.S. southwest and Mexico belonging to the Asteraceae family, is a source of high quality, hypoallergenic natural rubber with applications in pharmaceutical, tire, and food industries. Production of rubber results in a substantial amount of resin-containing residues which contain a wide variety of secondary metabolites (sesquiterpene esters, triterpene alcohols, fatty acids, etc.). In order to enhance the economic viability of guayule as an industrial crop, value-added use of the residues is needed and has the potential to reduce gross rubber production costs. The main objective of this research is the characterization of guayule resin using rapid and accurate analytical techniques to identify compounds of potential commercial value. Guayule resin is inherently complex and includes many high-molecular-weight and non-volatile compounds that are not easy to observe using traditional chromatographic techniques. The combination of two mass spectroscopy techniques: gas chromatography mass spectroscopy (GC-MS) and high-resolution Fourier transform ion cyclotron resonance mass spectroscopy (FT-ICR MS), were used to characterize the composition of the extracted resin from guayule (Parthenium argentatum). FT-ICR MS was used to characterize hundreds of compounds with over a wide range of molecular weights and degrees of aromaticity at higher levels of mass accuracy than other forms of mass spectrometry. GC-MS was used to identify volatile compounds like mono- and sesquiterpene compounds.
Keywords: Complex mixtures; Guayule; Mass spectroscopy; Natural resin; Parthenium argentatum; Terpenes.
© 2020 The Author(s).