The Use of Leaves from Young Trees of Quillaja saponaria (Molina) Plantations as a New Source of Saponins

Abstract

The Use of Leaves from Young Trees of Quillaja saponaria (Molina) Plantations as a New Source of Saponins. Quillaja saponaria is an endemic tree in Chile. It has been extensively exploited for the extraction of saponins, which are used in mining, agriculture, and in the pharmaceutical and food industries. The overexploitation of native adult Quillaja forests has necessitated the establishment of plantations. Until now, biomass had been obtained from wood and bark of native adult trees, excluding the use of leaves due to their low biomass contribution to the whole tree, and also because industrial production lines have been designed for wood and bark and not for leaves that contain different compounds (e.g., chlorophyll). In this study, we propose using complete trees from young plantations, including the leaves. Quantification of saponins in the leaves of 24 three-year-old Quillaja trees from a plantation was carried out during the four seasons of one year. Our results showed that leaves represent 27.8% of the weight of the whole young trees and that leaves contain on average 2.58% of saponins. Considering that this amount is similar to that found in wood, we argue that leaves could contribute up to one-third of the saponins of young trees, making its processing key to attain good yields. Significant differences were observed in saponin contents during the four seasons. On average, the lowest concentration was found during winter (July = 1.39% dry weight) and the highest in autumn (April = 4.49%), suggesting that abiotic factors may have an affect on saponin production. A comparison among the 24 trees showed significant differences in saponin concentration (0.90% to 4.71%), supporting the need to select consistently superior saponin-producing trees. These results contribute to the understanding of a more sustainable production of Quillaja extracts, showing a potential to use whole young trees from plantations rather than only the wood and bark from native Quillaja forests.Hojas de árboles jóvenes de Quillaja saponaria (Molina) de plantaciones, como nueva fuente de saponinas. El árbol Quillaja saponaria, endémico de Chile, ha sido ampliamente explotado para la extracción de saponinas, las cuales son utilizadas en la minería, la agricultura y diversas industrias como la farmacéutica y la de alimentación. La sobreexplotación de los bosques nativos ha planteado la necesidad de establecer plantaciones. Hasta la fecha, la biomasa se ha obtenido de la madera y corteza de árboles adultos nativos, excluyendo el uso de las hojas debido a su baja contribución (respecto del árbol total) y también porque las líneas de producción industrial han sido diseñadas específicamente para madera y corteza, no para las hojas que contienen diferentes compuestos, como la clorofila. En este estudio, se propone el uso de árboles completos de plantaciones jóvenes, incluyendo las hojas. Se realizaron cuantificaciones de saponinas en hojas de 24 árboles de una plantación de tres años de edad durante las cuatro estaciones de un año. Nuestros re...

Saponin production from Quillaja genus species. An insight into its applications and biology

“…Currently, natural forests are the principal source (98 %) of raw material. The total area in Chile comprising QS (within the sclerophyllous forest) has been estimated at 230,000 ha with a biomass production of 2 t ha -1 every 15 years (San Martín, 2000;Schlotterbeck et al, 2015). The sustainable limit of natural forests has been estimated at 27,000 t yr -1 .…”

“…The sustainable limit of natural forests has been estimated at 27,000 t yr -1 . Nevertheless, it is estimated that 48,000 tons are required to sustain market demands by 2019-2020, challenging its self-renewal ability (Schlotterbeck et al, 2015). The International Union for Conservation of Nature (IUCN) qualifies this species under no risk of conservation (LC) (BGCI, 2018).…”

“…Efforts for domesticating this species have been made since the middle of the last century in Chile. Important knowledge has been generated about silvicultural management focused on propagation, productive improvement of natural forests, and establishment of plantations (San Martin et al, 2000;Prehn et al, 2003;Jordan and Roveraro, 2004;Schlotterbeck et al, 2015;Vidal et al, 2016).…”

“…In Chile, annual exportation of QS extracts, bark, and wood powder registered 20.6 million U.S. dollars in 2018 (INFOR, 2019). Along with the increasing demand for QS extract, pressure on natural forests has increased in the last decades, with a prediction of an overexploitation trend for the next years (Schlotterbeck et al, 2015). Since the identification of saponins as the main metabolites in Quillaja species, many studies have investigated their composition and applications, mainly on QS and, to a lesser extent, on QB.…”

Effect of saponins of Quillaja saponaria extracts in combination with Pseudomonas protegens to control Gaeumannomyces graminis var. tritici in wheat

“…Quillay (Quillaja saponaria Mol. ; Quillajaceae) is an endemic Chilean evergreen tree distributed from Valparaíso Region (30° S lat) to La Araucanía Region (38° S lat) (Schlotterbeck et al, 2015), which is rich in bidesmosidic saponins into its bark, leaves, and parts of the trunk (Donoso et al, 2011;Schlotterbeck et al, 2015). Saponins are secondary triterpenoid metabolites produced in many plant species, some with antifungal activity (Augustin et al, 2011;Ahmed et al, 2012).…”