Flavonoid composition and antioxidant capacity of the edible flowers ofAgave durangensis(Agavaceae)

Abstract

The antioxidant properties and the flavonoid composition of extracts of different hydrophobicity prepared from the entire edible flowers of Agave durangensis were evaluated. Separately, total extracts of tepals and anthers-pollen were analyzed in the same manner. The high performance liquid chromatography with photodiode array detection (HPLC-DAD) analysis revealed a total of eight flavonols (five quercetin glycosides and three kaempferol glycosides), varying in number and concentration in the different extracts. The total extracts of the entire flowers showed the highest flavonoid content (1210.4 µg/g dry extract) and the most complex flavonoid profile (eight compounds). All the extracts showed important antioxidant activity, which was not evidently associated with their flavonoid content. The total extracts of tepals showed the highest antioxidant properties (total antioxidant capacity, free radical scavenging activity, and iron reducing capacity: 30.2 mg ascorbic acid equivalents, EC 50 = 0.074 µg/mL, and IC 50 = 43.28 µg/mL, respectively). The flowers of A. durangensis represent an important source of antioxidant flavonols.Keywords: Agave durangensis; edible flowers; flavonoid profiles; antioxidant capacity; flavonol glycosides Se evaluaron las propiedades antioxidantes y composición fenólica de extractos de diferente hidrofobicidad de flores comestibles enteras de Agave durangensis. Separadamente, se analizaron extractos crudos de tépalos y anteras-polen. El análisis de HPLC-DAD reveló en total ocho flavonoles (cinco glicósidos de quercetina y tres glicósidos de canferol), que variaron en número y concentración en los extractos. Los extractos totales de las flores enteras tuvieron el contenido más alto de flavonoides (1210,4 µg/g extracto seco) y el perfil de flavonoides más complejo (ocho compuestos). Todos los extractos mostraron importante actividad antioxidante, no claramente asociada al contenido de flavonoides. Los extractos crudos de tépalos mostraron las propiedades antioxidantes más altas (capacidad antioxidante total, capacidad bloqueadora de radicales libres, y capacidad reductora de fierro: 30,2 mg de equivalentes de ácido ascórbico, EC 50 = 0,074 µg/mL, e IC 50 = 43,28 µg/mL, respectivamente). Las flores de A. durangensis representan una fuente importante de flavonoles antioxidantes.

Phytochemistry investigation and antioxidant activity of four edible Verbenaceae of Burkina Faso

“…Contrary to its decoction content which is 7.03 mg EAG/dry extract but it presented the best activity (0.05 EQ/g dry extracts). Our results are in disagreement with those of Barriada-Bernal et al [27]. According to our former investigation [9], it was difficult to establish a clear correlation between the flavonoids rate and the DPPH* reduction.…”

“…In fact, with a total phenolic content of 44.74 mg EAG/g extracts (butanolic fraction of V. diversifolia), we observed a best activity on TAC than ethyl acetate fraction which gave 131.32 mg EAG/g extracts. These results corroborate with those of Barriada-Bernal et al [27] who evaluated antioxidant activities against the total flavonoids contents. They don't found a clear correlation betweentotal antioxidant capacity and the total flavonoids content.…”

“…Concerning total flavonoid content,we note a correlation between theircontents and ion ferric reducing activity. These results are corroborated [27], [36]. While looking of close ions proportioning using atomic absorption method, we realize that among the four plants species, L. chevalieri presented the strongest content of ions ferrous (5.661 g/kg).…”

Micropropagation of Agave salmiana: Means to Production of Antioxidant and Bioactive Principles

“…From a nutraceutical point of view, recent reports have highlighted that Agave and its by-products have bioactivity due to the content of different metabolites, such as “aguamiel”, the sap of the plant, which contains fructans and saponins (Santos-Zea et al, 2012; Leal-Díaz et al, 2015). The phytochemicals found in Agave include phenolic compounds, such as kaempferol and quercetin, in various glycosylated forms (Almaráz-Abarca et al, 2013; Barriada-Bernal et al, 2014), and saponins, as glycosides of hecogenin, diosgenin, chlorogenin, kammogenin, and gentrogenin (Yokosuka and Mimaki, 2007; Pérez et al, 2014). Previous studies have reported an increase in bioactivity of diverse micropropagated plants compared to wild-type (WT) plants (García-Pérez et al, 2012; Dakah et al, 2014), suggesting that the micropropagation of A. salmiana could result in this advantage.…”

Seed Vigor Variation of <i>Agave durangensis</i> Gentry (Agavaceae)

“…The differences between the free radical scavenging activities exhibited by the seeds of each natural population of Agave durangensis can be due to the variations in phenol contents (Table 6) and the types of phenols accumulated, which were different in the seeds of each population ( Table 7). The particular phenol profile is a relevant feature to determine the antioxidant properties of any plant tissue or structure [49]. Seed phenols form complexes with carbohydrates and lipids, enhancing the stability of those organic compounds in the endosperm under oxidative stress conditions, avoiding the beginning of a tandem oxidative degradation caused by oxygen reactive species [50].…”