Chemical characterization, antioxidant activity and morphological traits in the leaves of guayule (Parthenium argentatum A. Gray) and its hybrids

In the rubber extraction process, guayule leaves represent an important biomass waste by-product, up to 32%, whose exploitation might contribute valorization of whole plant. The any its bioactive compounds or use as antioxidant seems be most feasible alternative. This study relates morphology individual content 35 (of 50 tentatively identified), determination overall phenolic and activity. morphological traits allowed classification accessions (27) into three main groups according size shape leaf, being related their hybridization. environment growing conditions modified leaf phenotype for USDA germplasm with respect recent USA studies. heterogeneity found by different authors in requires a standardization procedure. Of two analysis protocols, Total Polyphenol Index (TPI) Folin–Ciocalteau reagent (Folin) after extracting at 1 24 h, TPI h was selected since it faster simpler than others correlated better activity determined 2,2-diphenyl-picrylhydrazyl (DPPH). greater quantities corresponded chlorogenic acid family, but no influence morphology. On other hand, smaller concentrations such gallic acid, isomer ferulic quercetagetin methyl ether glucuronide correlate aspects