The antioxidant capacity related to the phenolic composition of monospecific honeybee-collected pollen extract from the mesquite tree (Prosopis juliflora) from Durango, Mexico, was evaluated in an in vitro-biological system (as inhibitor of lipid peroxidation on mouse hepatic microsomal preparations) and in an in vivo system (on homogenized liver of bromobenzene-intoxicated mice) by quantification of thiobarbituric acid-reactive substances (TBARS). The comparison of results obtained from these two different systems was also made. The results obtained suggest that pollen of P. juliflora is an important source of flavonoids, which can be considered as natural antioxidants. Mesquite pollen extracts showed antioxidant activity related to the flavonol concentration in both the in vitro-biological system and the in vivo system with a lower activity in the latter of these systems. Under in vivo conditions and in those in which a state of oxidation in not induced, a high concentration of flavonols in the extract of mesquite pollen can have a pro-oxidant effect. r

BackgroundFruits of wild species of the genus Physalis are consumed as food and calyces and leaves are used in traditional medicine. The phenolic composition of the species of this genus have been scarcely studied. To contribute to a better knowledge for the use of all the potential of these wild species of plants, leaves, fruits, and calyces of five wild species of the genus were analyzed for their phenolic composition and antioxidant properties.ResultsImportant tissue- and species-dependent variations were found. Calyces of Physalis subulata showed the highest contents of phenolics (176.58 mg of gallic acid equivalents/g dry tissue), flavonoids (39.63 mg/g dry tissue), and phenolic acids (50.57 mg of quercitrin equivalents/g dry tissue), and its leaves displayed the highest total antioxidant capacity (3.59 mg of ascorbic acid equivalents/mL) and one of the highest reduction powers (0.54 µg of ascorbic acid equivalents/mL). A high performance liquid chromatography with photodiode array detection analysis revealed a total of 28 phenolic compounds in foliar tissues (mainly kaempferol-3-O-glycosides), 16 in fruits (mainly phenolic acids), and 16 in calyces (mainly kaempferol-3-O-glycosides); the profiles of these compounds in the three types of tissue were species-specific.ConclusionsThe studied species of Physalis are important sources of phenolics with relevant antioxidant activity. The current results indicate that phenolic profiles are valuable specific chemical markers and can be relevant as food tracing and authenticity indicators for plant-based preparations involving species of Physalis.

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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.

In this work, a new, easy and rapid method of analyzing phenolic compounds in pollen extract, based on capillary electrophoresis coupled with electrospray ionization time-of-flight-mass spectrometry (CE-ESI-TOF-MS), has been developed. A systematic investigation of separation parameters has been performed with respect to resolution, sensitivity, analysis time and peak shape. The electrophoretic parameters and electrospray conditions must be optimized to obtain reproducible analyses. Using this method, several important phenolic compounds such as acetin-glucoside, 7-O-methylherbacetin-3-sophoroside, galloyl-glucose, quercetin-3-sophoroside, apigenin-6,8-di-C-glycoside, quercetin-3-rutinoside, genistein-7-O-beta-D: -glucoside, luteolin-7-O-glucoside, apigenin-7-O-glucoside and 2',4',6'-trihydroxy-3'-formyldihydrochalcone have been determined directly from pollen extract. The efficiency, the rapidity, the small amounts of sample required, and the high resolution of CE coupled with the sensitivity, the selectivity, the accurate masses and the true isotopic patterns obtained using TOF-MS point to the potential of this approach for identifying the phenolic compounds present in pollen.

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The family Verbenaceae hosts important species used in traditional medicine of many countries. The taxonomic controversies concerning the specific delimitation of several of its species make it difficult to guarantee the botanical origin of herbal preparations based on species of this family. To contribute to the development of both specific chemomarkers and a quality control tool to authenticate the botanical origin of herbal preparations of Verbenacea species, we determined the foliar HPLC-DAD phenolic profiles and the antioxidant properties of 10 wild species of this family occurring in Mexico. The contents of phenols and flavonoids varied significantly among species. Priva mexicana showed the highest levels of total phenolics (53.4 mg g -1 dry tissue) and Verbena carolina had the highest levels of flavonoids (17.89 mg g -1 dry tissue). Relevant antioxidant properties revealed by antiradical and reducing power were found for the analyzed species. These properties varied significantly in a species-dependent manner. The phenolic compounds accumulated were flavones and phenolic acids. Flavones were the only type of flavonoids found. The results of a cluster analysis showed that the compounds were accumulated in species-specific profiles. The phenolic profiles are proposed as valuable chemomarkers that can become a useful tool for the quality control concerning the botanical origin of herbal medicinal preparations based on the species analyzed. In addition, phenolic profiles could contribute importantly to solve the taxonomic controversies concerning species delimitation in the family Verbenaceae.Keywords: Verbenacea, antioxidant activity, chemomarkers, flavones, phenolic profiles. Compostos fenólicos das folhas de dez especies selvagem de Verbenaceae como antioxidantes e quimiomarcadores específicos ResumoA família Verbenaceae compreende importantes espécies utilizadas na medicina popular de muitos países. As dificuldades taxonômicas relativas à delimitação específica de muitas das suas espécies face difícil a verificar a origem botânico das preparações herbales baseadas nas espécies desta família. Para fazer uma contribuição ao desenvolvimento de indicadores taxonômicos e dum método de controle de qualidade para verificar a origem botânico de preparações herbales das espécies de Verbenaceae, os perfis fenólicos, obtidos pares HPLC-DAD, e as atividades antioxidantes das folhas de 10 espécies selvagens Mexicanas desta família foram determinados. Os conteúdos dos compostos fenólicos totais e dos flavonoides foram significativamente diferentes entre as espécies. Priva mexicana apresentou a maior quantidade de compostos fenólicos totais (53.4 mg g -1 amostra seca) e Verbena carolina apresentou a maior quantidade de flavonoides (17.89 mg g -1 amostra seca). Verifica-se importantes propriedades antioxidantes, como os resultados dos ensaios da capacidade antiradical e do poder redutor indicaram. As propriedades antioxidantes foram significativamente diferentes entre as espécies. Verificou-se que os compostos fe...

A review is presented about the studies that have been carried out on the phenolic composition of the species of the genus Agave in order to show which species of the genus has been analyzed, what is the potential of the species of Agave as source of phenolics with important biological activities, and what is the significance of the phenolic profiles as chemotaxonomic markers in the genus. The results of the analysis of a dozen of Agave species reveal an important richness of phenolic compounds, including flavonoids, homoisoflavonoids, and phenolic acids, and a broad diversity of biological activities associated to those compounds, as antioxidant, antibacterial, antifungal, antinematod, and immunomodulatory capabilities. The phenols of Agave also have a major potential as specific chemotaxonomic markers.