Argentatin Content in Guayule Leaves (<i>Parthenium argentatum</i> A. Gray)
María Mercedes García-Martínez,
Beatriz Gallego,
Guayente Latorre,
María Engracia Carrión,
Miguel Ángel De la Cruz-Morcillo,
Amaya Zalacain,
Manuel Carmona
Affiliations
María Mercedes García-Martínez
Instituto Técnico Agronómico Provincial de Albacete (ITAP), Parque empresarial Campollano, 2ª Avenida, 61, 02007 Albacete, Spain
Beatriz Gallego
Instituto de Toxicología de la Defensa, Hospital Central de la Defensa Gómez Ulla, Gta Ejército 1, 28047 Madrid, Spain
Guayente Latorre
E.T.S.I. Agronómica, de Montes y Biotecnología (ETSIAMB), Cátedra de Química Agrícola, Universidad de Castilla-La Mancha, Avda. de España s/n, 02071 Albacete, Spain
María Engracia Carrión
Institute for Regional Development (IDR), Food Quality Research Group, Universidad de Castilla-La Mancha Campus Universitario s/n, 02071 Albacete, Spain
Miguel Ángel De la Cruz-Morcillo
Institute for Regional Development (IDR), Food Quality Research Group, Universidad de Castilla-La Mancha Campus Universitario s/n, 02071 Albacete, Spain
Amaya Zalacain
E.T.S.I. Agronómica, de Montes y Biotecnología (ETSIAMB), Cátedra de Química Agrícola, Universidad de Castilla-La Mancha, Avda. de España s/n, 02071 Albacete, Spain
Manuel Carmona
Institute for Regional Development (IDR), Food Quality Research Group, Universidad de Castilla-La Mancha Campus Universitario s/n, 02071 Albacete, Spain
Approximately one-third of the waste biomass from the cultivation of guayule (Parthenium argentatum A. Gray) for natural rubber production is leaf tissue; however, whether it can be valorized is not known. Guayulins and argentatins are potential high-value products that can be recovered from guayule resin during rubber/latex processing. Argentatins are highly abundant in guayule stem resin; however, unlike the guayulins, their occurrence in leaves has not been investigated. The present study determined the content of argentatins and isoargentatins A and B in the leaves of a pure guayule accession (R1040) and two hybrids (CAL-1 and AZ-2) under conditions of irrigation and non-irrigation. The resin content in leaves was ~10%, which provides a suitable starting point for economic exploitation. The highest production of argentatins occurred in plants under irrigation, with yields of 4.2 and 3.6 kg ha−1 for R1040 and AZ-2, respectively. The R1040 accession had the highest percentage of resin and the greatest total argentatin content (24.5 g kg−1 dried leaf), principally due to the abundance of argentatin A. Contrastingly, CAL-1 consistently showed the lowest argentatin content based on dried leaf weight and production (0.6 kg ha−1). The substantial abundance of argentatins in guayule leaves suggests the potential for future exploitation.
