Uncommon species diversity values in epiphytic diatom assemblages of the kelp Eisenia arborea

Macroalgae are an ideal substratum for multiple species of diatoms that are ingested along with their hosts by many species of grazers including abalones (Haliotis spp.). Much of the diet of abalones along the western coast of the Baja California peninsula (Mexico) depends on blades of the kelp Macrocystis pyrifera that is heavily colonized by diatoms. Although the kelp Eisenia arborea (its ecological alternative) is an acceptable food-source for Haliotis spp., the epiphytic diatom flora living on this kelp was hitherto unknown. Thus, the association structure of the epiphytic diatoms growing on blades of E. arborea from the western coast of Baja California Sur (B.C.S.) was determined. We tested the hypothesis that the epiphytic diatom assemblages on blades of E. arborea collected at different dates would show low species diversity and taxa representing distinct stages of succession. We identified 99 diatom taxa that represent the first floristic list of diatoms living on E. arborea. Values of diversity (H´) were lower than usual and, together with an extremely high dominance of Pteroncola inane (a new record for the region), the structure of the diatom assemblage is regarded atypical, similar to those measured for assemblages from extreme environments. However, structure analysis did not permit distinction of succession stages in the epiphytic diatom assemblage

Macroalgas marinas del litoral rocoso Neovolcánico de Veracruz, México

Background and Aims: The rocky shore environments of the state of Veracruz are unique sites in which the macroalgal richness has been poorly studied, mainly due to the absence of complete floristic lists and a follow-up of the changes in algal populations. Hence, the goal of this work was to contribute to the knowledge of algae of Veracruz rocky shore environments located in Playa Paraíso, Playa Villa Rica and Playa Muñecos, which are influenced by the foothills of the Neovolcanic Belt.Methods: Seaweeds were collected during rainy (September 2016) and dry seasons (May 2017) on selected rocky shores named “Playa Paraíso” (PP), “Playa Villa Rica” (PVR) and “Playa Muñecos” (PM). Samples were preserved in a seawater and formaldehyde (4%) solution. External and internal morphometric observations were carried out on the thalli, and the species were determined according to specialized taxonomic literature.Key results: A total of 45 species were identified, from which 18 were Chlorophyta, 16 Rhodophyta and 11 Ochrophyta. The most representative families found were Corallinaceae, Rhodomelaceae, Cladophoraceae and Dictyotaceae. The highest richness of species was observed in PP during the dry season. New records are reported for the localities, of which Centroceras gasparrinii, Gracilaria apiculata and G. flabelliformis are new records for the state of Veracruz.Conclusions: The algal flora of the Neovolcanic rocky coast of Veracruz is tropical and houses 31% of the regional algal flora of the state. The new records in each of the localities reflect a gap in the knowledge of the algal richness of this area. As a consequence, it is suggested to continue recording species occurrence in the area in order to integrate the corresponding floristic lists.Antecedentes y Objetivos: Los ambientes de los litorales rocosos del estado de Veracruz, México, son sitios únicos en los que la riqueza específica macroalgal ha sido poco estudiada, ya que se carece de listados florísticos completos y de un seguimiento a los cambios en las poblaciones algales. El objetivo de este trabajo fue contribuir al conocimiento de algas de los ambientes rocosos veracruzanos ubicados en Playa Paraíso, Playa Villa Rica y Playa Muñecos, los cuales están influenciados por las estribaciones del Eje Neovolcánico.Métodos: Las algas se recolectaron durante la época de lluvias (septiembre 2016) y de secas (mayo 2017) en Playa Paraíso (PP), Playa Villa Rica (PVR) y Playa Muñecos (PM). Las muestras se preservaron en una solución de agua de mar y formol al 4%. Se realizaron observaciones morfométricas externas e internas de los talos y se determinaron las especies de acuerdo con literatura taxonómica especializada.Resultados clave: Se determinaron un total de 45 especies, de las cuales 18 fueron Chlorophyta, 16 Rhodophyta y 11 Ochrophyta. Las familias mejor representadas fueron Corallinaceae, Rhodomelaceae, Cladophoraceae y Dictyotaceae. La mayor riqueza de especies se observó en PP durante la época de secas. Se mencionan nuevos registros para las localidades de estudio; de éstos, Centroceras gasparrinii, Gracilaria apiculata y G. flabelliformis son nuevos registros para el estado de Veracruz.Conclusiones: La flora algal del litoral rocoso Neovolcánico de Veracruz es de tipo tropical y alberga 31% de la flora algal regional del estado de Veracruz. Los nuevos registros en cada una de las localidades reflejan que aún prevalece una brecha en el conocimiento de la riqueza algal de esta región. Por lo tanto, se sugiere continuar con el registro de especies en la zona con la finalidad de integrar los listados florísticos correspondientes

Análisis fitoquímico y actividad antidiabética, antibacteriana y antifúngica de hojas de Bursera simaruba (Burseraceae)

Background and Aims: Bursera simaruba leaves are traditionally used to treat various illnesses. Nonetheless, there are few reports on the description of the phytochemicals potentially responsible for such biological activities. Therefore, this study aimed to describe the antifungal, antibacterial, and antidiabetic potential by using in vitro experiments, and to contribute to the knowledge of the chemical composition of B. simaruba leaves. Methods: A methanolic extract (MeOH-Ex) of B. simaruba leaves was tested for antibacterial, antifungal, and antidiabetic activities, and different groups of secondary metabolites were detected by qualitative assays. Furthermore, phytochemical analysis of MeOH-Ex was carried out by ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-ESI+-MS-QTOF), and putative identifications were performed using public spectral databases. Key results: The MeOH-Ex of the leaves of B. simaruba qualitatively contains alkaloids, terpenes and steroids, saponins, tannins, coumarins and phenolic compounds, such as caffeic acid, chlorogenic acid, apigenin, kaempferol, phlorizin, quercitrin, quercetin-glucoside and apigenin-glycoside. In addition, burseran and yatein lignans were tentatively identified. MeOH-Ex exhibited low antifungal activity against Fusarium solani (16.3% mycelial growth inhibition) and a high antidiabetic effect by in vitro inhibition of α-amylase (87.7%) and α-glucosidase (75.9%) enzymes. Finally, chlorogenic acid standard exhibited a significant inhibition of α-amylase (49.5%) and α-glucosidase (85.1%) enzymes. Conclusions: The MeOH-Ex of B. simaruba leaves represents a source of secondary metabolites with potential antidiabetic activity. The phenolic compounds tentatively identified could play important roles in preventing disorders due to post-prandial hyperglycemia by inhibiting the enzymes α-amylase and α-glucosidase. Chlorogenic acid presence is highlighted as one of the main potential bioactive compounds in B. simaruba leaves.Antecedentes y Objetivos: Las hojas de Bursera simaruba se utilizan tradicionalmente para tratar diversas enfermedades. Sin embargo, existen pocos reportes sobre la descripción de los fitoquímicos potencialmente responsables de tales actividades biológicas. Por lo tanto, este estudio tuvo como objetivo describir el potencial antifúngico, antibacteriano y antidiabético mediante experimentos in vitro, así como contribuir al conocimiento de la composición química de las hojas de B. simaruba. Métodos: Se analizó la actividad antibacteriana, antifúngica y antidiabética de un extracto metanólico (MeOH-Ex) de hojas de B. simaruba, y se detectaron diferentes grupos de metabolitos secundarios mediante ensayos cualitativos. Además, el análisis fitoquímico de MeOH-Ex se determinó con cromatografía líquida de ultra alta resolución acoplada a espectrometría de masas de alta resolución (UHPLC-ESI+-MS-QTOF), y las identificaciones putativas se realizaron utilizando bases de datos espectrales públicas. Resultados clave: El MeOH-Ex de las hojas de B. simaruba contiene cualitativamente alcaloides, terpenos y esteroides, saponinas, taninos, cumarinas y compuestos fenólicos, tales como ácido cafeico, ácido clorogénico, apigenina, kaempferol, florizina, quercitrina, quercetina-glucósido y apigenina-glucósido. Además, se identificaron tentativamente los lignanos burseran y yatein. El MeOH-Ex exhibió una baja actividad antifúngica contra Fusarium solani (16.3% de inhibición del crecimiento micelial) y un alto efecto antidiabético por inhibición in vitro de las enzimas α-amilasa (87.7%) y α-glucosidasa (75.9%). Finalmente, el estándar de ácido clorogénico mostró una inhibición significativa de las enzimas α-amilasa (49.5%) y α-glucosidasa (85.1%). Conclusiones: El MeOH-Ex de las hojas de B. simaruba representa una fuente de metabolitos secundarios con potencial actividad antidiabética. Los compuestos fenólicos tentativamente identificados podrían desempeñar un papel importante en la prevención de trastornos por hiperglucemia posprandial al inhibir las enzimas α-amilasa y α-glucosidasa. Destaca la presencia de ácido clorogénico como uno de los principales compuestos bioactivos potenciales en las hojas de B. simaruba

Variación en la composición química y en la actividad biológica de Eisenia arborea (Laminariales: Ochrophyta).

impreso y digita

Comprehensive profiling and identification of bioactive components from methanolic leaves extract of Juniperus deppeana and its in vitro antidiabetic activity

Juniperus plant species are rich sources of bioactive secondary metabolites and are traditionally used for the treatment of several illnesses, including those related to hyperglycemia and diabetes. The major bioactive compounds identified in certain species of this genus are terpenes and phenolics. Juniperus deppeana Steud. is mainly used as a wood resource and its chemical composition has been partially established. Our goal was to perform a comprehensive profiling of a methanolic extract of leaves of J. deppeana and determine its potential as a source of α-amylase and α-glucosidase inhibitors. Terpene and phenolic compounds were putatively identified based on their accurate mass spectrometric data. Regarding terpenes, we found mainly diterpenes, specifically dehydroabietic acid-like, hinokiol-like, agathic acid-like, and dihydroxyabietatrienoic acid-like compounds. Isopimaric acid was also identified and its identity was confirmed by coelution with an authentic standard via comparing retention time, mass spectrum, and collisional cross section values. For phenolic compounds, we identified mainly compounds with a chemical structure similar to the biflavonoids amentoflavone and bilobetin. Besides, the methanolic extract of J. deppeana leaves show inhibition of α-amylase (IC50 = 85.11 ± 11.91 μg mL−1) and α-glucosidase (IC50 = 32.50 ± 3.40 μg mL−1) enzymes, demonstrating a potential alternative for the search of antidiabetic natural products.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author