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Prof. Dr. Natividad Chaves Lobón
Universidad de Extremadura, Badajoz, Spain

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Research Keywords & Expertise

0 Allelopathy
0 ecophysiology
0 Plant-plant interaction
0 Ecological function of metabolism secondary
0 Plant-animal interaction

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Journal article
Published: 15 January 2020 in Antioxidants
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Plants have a large number of bioactive compounds with high antioxidant activity. Studies for the determination of the antioxidant activity of different plant species could contribute to revealing the value of these species as a source of new antioxidant compounds. There is a large variety of in vitro methods to quantify antioxidant activity, and it is important to select the proper method to determine which species have the highest antioxidant activity. The aim of this work was to verify whether different methods show the same sensitivity and/or capacity to discriminate the antioxidant activity of the extract of different plant species. To that end, we selected 12 species with different content of phenolic compounds. Their extracts were analyzed using the following methods: 2,2-di-phenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity assay, ferric reducing (FRAP) assay, Trolox equivalent antioxidant capacity (ABTS) assay, and reducing power (RP) assay. The four methods selected could quantify the antioxidant capacity of the 12 study species, although there were differences between them. The antioxidant activity values quantified through DPPH and RP were higher than the ones obtained by ABTS and FRAP, and these values varied among species. Thus, the hierarchization or categorization of these species was different depending on the method used. Another difference established between these methods was the sensitivity obtained with each of them. A cluster revealed that RP established the largest number of groups at the shortest distance from the root. Therefore, as it showed the best discrimination of differences and/or similarities between species, RP is considered in this study as the one with the highest sensitivity among the four studied methods. On the other hand, ABTS showed the lowest sensitivity. These results show the importance of selecting the proper antioxidant activity quantification method for establishing a ranking of species based on this parameter.

ACS Style

Natividad Chaves; Antonio Santiago; Juan Carlos Alías. Quantification of the Antioxidant Activity of Plant Extracts: Analysis of Sensitivity and Hierarchization Based on the Method Used. Antioxidants 2020, 9, 76 .

AMA Style

Natividad Chaves, Antonio Santiago, Juan Carlos Alías. Quantification of the Antioxidant Activity of Plant Extracts: Analysis of Sensitivity and Hierarchization Based on the Method Used. Antioxidants. 2020; 9 (1):76.

Chicago/Turabian Style

Natividad Chaves; Antonio Santiago; Juan Carlos Alías. 2020. "Quantification of the Antioxidant Activity of Plant Extracts: Analysis of Sensitivity and Hierarchization Based on the Method Used." Antioxidants 9, no. 1: 76.

Journal article
Published: 21 July 2016 in Molecules
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In previous studies, secondary metabolites in the leaf exudate of Cistus ladanifer, specifically aglycone flavonoids and diterpenes, were demonstrated to play an ecophysiological role. They protect against ultraviolet radiation, have antiherbivore activity, and are allelopathic agents. Their synthesis in the plant was also found to vary quantitatively and qualitatively in response to various environmental factors. In view of these findings, the present work was designed to clarify whether within a single population there are differences among individuals subject to the same environmental conditions. To this end, we analyzed the leaves of 100 individuals of C. ladanifer. The results showed the existence of intrapopulational variation, since, although all the individuals had the same composition of secondary chemistry, the amounts were different. The individuals of a given population of C. ladanifer differ from each other even when growing under similar conditions. According to the ammount of flavonoids and diterpenes observed in each individual, it was possible to distinguish four different groups of individuals. Most individuals, evenly distributed within the population, had low concentrations of the studied compounds, whilst other individuals synthesized greater amounts and were randomly distributed among the former. Given the functions of flavonoids and diterpenes in this species, the quantified intra-population variation may involve greater plasticity for the species in the face of environmental changes.

ACS Style

Cristina Valares Masa; Juan Carlos Alías Gallego; Natividad Chaves Lobón; Teresa Sosa Díaz. Intra-Population Variation of Secondary Metabolites in Cistus ladanifer L. Molecules 2016, 21, 945 .

AMA Style

Cristina Valares Masa, Juan Carlos Alías Gallego, Natividad Chaves Lobón, Teresa Sosa Díaz. Intra-Population Variation of Secondary Metabolites in Cistus ladanifer L. Molecules. 2016; 21 (7):945.

Chicago/Turabian Style

Cristina Valares Masa; Juan Carlos Alías Gallego; Natividad Chaves Lobón; Teresa Sosa Díaz. 2016. "Intra-Population Variation of Secondary Metabolites in Cistus ladanifer L." Molecules 21, no. 7: 945.

Journal article
Published: 26 July 2012 in Plants
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The exudate of Cistus ladanifer L. consists mainly of two families of secondary metabolites: flavonoids and diterpenes. The amount of flavonoids present in the leaves has a marked seasonal variation, being maximum in summer and minimum in winter. In the present study, we demonstrate that the amount of diterpenes varies seasonally, but with a different pattern: maximum concentration in winter and minimum in spring-summer. The experiments under controlled conditions have shown that temperature influences diterpene production, and in particular, low temperatures. Given this pattern, the functions that these compounds perform in C. ladanifer are probably different.

ACS Style

Juan Carlos Alías; Teresa Sosa; Cristina Valares; José Carlos Escudero; Natividad Chaves. Seasonal Variation of Cistus ladanifer L. Diterpenes. Plants 2012, 1, 6 -15.

AMA Style

Juan Carlos Alías, Teresa Sosa, Cristina Valares, José Carlos Escudero, Natividad Chaves. Seasonal Variation of Cistus ladanifer L. Diterpenes. Plants. 2012; 1 (1):6-15.

Chicago/Turabian Style

Juan Carlos Alías; Teresa Sosa; Cristina Valares; José Carlos Escudero; Natividad Chaves. 2012. "Seasonal Variation of Cistus ladanifer L. Diterpenes." Plants 1, no. 1: 6-15.

Journal article
Published: 19 August 2010 in Plant and Soil
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A lower herb richness and diversity in the presence of Cistus ladanifer is attributed to the allelochemicals exudate from its leaves and stem. The objective of the present study was to determine allelopathic activities of C. ladanifer exudates and the persistence of potential allelochemicals in soil environment. The results showed that the aglycone flavonoids degrade very slowly in the soil, remaining a very long time with no further external input. Although the amounts of aglycone flavonoids in soils are low (of the order of μg/g soil), their high persistence may facilitate inhibition of the germination and growth of other species or an indirect effect by altering the soil’s characteristics, providing a possible explanation for the phytotoxic activity attributed to C. ladanifer.

ACS Style

Teresa Sosa; Cristina Valares; Juan Carlos Alías; Natividad Chaves Lobón. Persistence of flavonoids in Cistus ladanifer soils. Plant and Soil 2010, 337, 51 -63.

AMA Style

Teresa Sosa, Cristina Valares, Juan Carlos Alías, Natividad Chaves Lobón. Persistence of flavonoids in Cistus ladanifer soils. Plant and Soil. 2010; 337 (1-2):51-63.

Chicago/Turabian Style

Teresa Sosa; Cristina Valares; Juan Carlos Alías; Natividad Chaves Lobón. 2010. "Persistence of flavonoids in Cistus ladanifer soils." Plant and Soil 337, no. 1-2: 51-63.