Biological effectiveness of quillay (Quillaja saponaria) extracts for the control of yellow aphids (Melanaphis sacchari) in sorghum

Objective: To evaluate and define a plant extract for the control of the yellow aphid in order to prevent environmental contamination and improve crop profitability. Design/Methodology/Approach: In a sorghum plot —located in the municipality of Jantetelco, Morelos— with a high incidence of yellow aphids, three doses —2-, 4-, and 6-mL L-1 of water of Quillaja saponaria extract, 0.2-mL L-1 of water of Imidacloprid, and 10-mL L-1 of water of calcium polysulfide—, as well as an absolute control, were evaluated. The applications were carried out using a 15-L manual spray backpack, which had been previously calibrated and had a fan nozzle. A randomized block experimental design—with six treatments and four repetitions— was used. The experimental unit was made up of five 5-m long rows with 0.70 m between rows, resulting in a 17.5 m2 total area per experimental unit. The three central furrows were the useful plot, leaving 0.5 m at each end of the furrow. The total size of the experimental plot was 420 m2. Results: The biological effectiveness during the samplings was as follows: both the Quillaja saponaria (6-, 4- and 2-mL L-1 water doses) and Imidacloprid treatments had a 100% effectiveness. Study limitations/implications: This study was carried out in sorghum crops. Findings/conclusions: Treatments based on Quillaja saponaria extracts on M. sacchari in sorghum crops showed 100% biological effectiveness from the first application and no phytotoxicity was observed in any treatment

INVESTIGATION OF THE POSSIBILITY OF USING THE METHOD OF DIFFERENTIAL SPECTROPHOTOMETRY FOR THE ANALYSIS OF OVERLAPPING ABSORPTION BANDS OF TRITERPENE SAPONINS CHROMOPHORES AND THEIR QUANTITATIVE DETERMINATION IN AQUEOUS SOLUTIONS

A detailed analysis of the absorption spectra of mono- and bidesmoside triterpene glycosides was performed. It is suggested that the maximum in the region of 198–208 nm is attributed to the absorption of the double bond in the cyclohexene ring of the aglycone. The second less seen maximum at a wavelength of 280 nm is observed in the spectrum of saponin Quillaja Saponaria and is almost completely absent in the spectrum of saponin Mukorossi Sapindus. Identification of this maximum is extremely difficult, since its presence can be due to both the aldehyde group in the aglycone and the hydroxyl and carboxyl groups in the carbohydrate molecules. Using the method of differential spectrophotometry, a method for decomposing the UV spectrum of saponins into its constituent components is proposed and justified. A spectral analysis was performed, including the assignment of the absorption bands to the functional groups of the studied compounds. The possibility of estimating changes in the spectral properties of glycoside solutions with changes in the acidity of the medium is considered. The possibility of a bathochromic shift of the maximum absorption of the aglyconic part of saponin depending on the microenvironment (the structure of the carbohydrate part) and changes in the pH of the solution is established. It is shown that the bands at 274, 280.5 nm correspond to n-π* transitions of carbonyl and carboxyl groups and are determined only in the regions of high concentrations in Quillaja Saponaria saponin solutions. Based on the results obtained, calibration models for the quantitative determination of saponins in solutions are proposed. The regression analysis of the calibration equations is carried out, the main statistical indicators are calculated.

Estrategias de manejo de plantas leñosas en ambientes de altura: Área Natural Protegida Laguna del Diamante (Mendoza, Argentina)

Los sitios arqueológicos de altura en el Centro Oeste Argentino y Chile Central se caracterizan por estar localizados en ambientes altoandinos, presentar recintos pircados, cerámica afín a complejos culturales de la cuenca Maipo-Mapocho de Chile Central, evidencias de caza de camélidos y procesamiento de plantas silvestres y cultivadas. En este trabajo se presenta el estudio antracológico de dos sitios ubicados en el Área Natural Protegida Laguna del Diamante (3.200 m snm), con evidencias de ocupación humana entre 2.100 años aP y tiempos históricos. Para caracterizar cuali-cuantitativamente el registro antracológico de LD-S2 y LD-S4 se utilizaron métodos estándar. Se identificaron siete taxa vegetales. Las estrategias de manejo de plantas leñosas detectadas estuvieron orientadas a la recolección de maderas locales (familia Asteraceae y Adesmia sp.), junto con otras de pisos altitudinales inferiores, tanto de Chile Central (Acacia aff. caven, Persea lingue y Quillaja saponaria) como de Argentina (Prosopis aff. alpataco), así como de un taxón que crece en ambos flancos cordilleranos (Ochetophila sp.). Los resultados obtenidos se integraron con estudios previos sobre fuentes y artefactos de obsidiana y análisis isotópicos y cerámicos. Todos muestran un acceso predominante de sociedades de la cuenca cordillerana del río Maipo a Laguna del Diamante.

A High-Content Screen for the Identification of Plant Extracts with Insulin Secretion-Modulating Activity

Bioactive plant compounds and extracts are of special interest for the development of pharmaceuticals. Here, we describe the screening of more than 1100 aqueous plant extracts and synthetic reference compounds for their ability to stimulate or inhibit insulin secretion. To quantify insulin secretion in living MIN6 β cells, an insulin–Gaussia luciferase (Ins-GLuc) biosensor was used. Positive hits included extracts from Quillaja saponaria, Anagallis arvensis, Sapindus mukorossi, Gleditsia sinensis and Albizia julibrissin, which were identified as insulin secretion stimulators, whereas extracts of Acacia catechu, Myrtus communis, Actaea spicata L., Vaccinium vitis-idaea and Calendula officinalis were found to exhibit insulin secretion inhibitory properties. Gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) were used to characterize several bioactive compounds in the selected plant extracts, and these bioactives were retested for their insulin-modulating properties. Overall, we identified several plant extracts and some of their bioactive compounds that may be used to manipulate pancreatic insulin secretion.

Geographic Area of Collection Determines the Chemical Composition and Antimicrobial Potential of Three Extracts of Chilean Propolis

The biological properties of chilean propolis have been described and include antibacterial, antifungal and antibiofilm activities. Propolis has a strong antimicrobial potential. Clinical experiences with synthetic antibiotics indicated the need to discover new sources of bioactive compounds associated with ethnopharmacological knowledge or natural sources such as propolis. The microscopic analysis of pollen grains from plants allows us to determine the botanical origin of the propolis samples. In Angol, sample pollen grains were obtained from fodder plants (Sorghum bicolor; Lotus sp.) and trees, such as Acacia sp., Pinus radiata, Eucalyptus sp. and Salix babylonica. Propolis from the Maule region contains pollen grains from endemic plants such as Quillaja saponaria. Finally, the sample obtained from Melipilla presented a wider variety of pollen extracted from vegetable species.Colorimetric assays performed to quantify the total polyphenols present in Chilean propolis samples established that PCP2 (Angol sample) showed high amounts of phenolics compounds, with significant statistical differences in comparison with the other samples. The main compounds identified were pinocembrin, quercetin and caffeic acid phenethyl ester (CAPE). The Angol sample showed a high content of polyphenols.Studies that determine the influence of geographical and floral variables on the chemical composition of propolis are a valuable source of information for the study of its biological properties.

The Phagosome–Lysosome Fusion Is the Target of a Purified Quillaja saponin Extract (PQSE) in Reducing Infection of Fish Macrophages by the Bacterial Pathogen Piscirickettsia salmonis

Piscirickettsia salmonis, the etiological agent of Piscirickettsiosis, is a Gram-negative and facultative intracellular pathogen that has affected the Chilean salmon industry since 1989. The bacterium is highly aggressive and can survive and replicate within fish macrophages using the Dot/Icm secretion system to evade the host’s immune response and spread systemically. To date, no efficient control measures have been developed for this disease; therefore, the producers use large amounts of antibiotics to control this pathogen. In this frame, this work has focused on evaluating the use of saponins from Quillaja saponaria as a new alternative to control the Piscirickettsiosis. It has been previously reported that purified extract of Q. saponaria (PQSE) displays both antimicrobial activity against pathogenic bacteria and viruses and adjuvant properties. Our results show that PQSE does not present antimicrobial activity against P. salmonis, although it reduces P. salmonis infection in an in vitro model, promoting the phagosome–lysosome fusion. Additionally, we demonstrate that PQSE modulates the expression of IL-12 and IL-10 in infected cells, promoting the immune response against the pathogen and reducing the expression of pathogen virulence genes. These results together strongly argue for specific anti-invasion and anti-intracellular replication effects induced by the PQSE in macrophages.