Aqueous and methanolic extracts of several microalgae ( Ankistrodesmus sp., Spirogyra Euglena cantabrica , Caespitella pascheri ) cyanobacteria Nostoc commune Nodularia spumigena Leptolyngbya protospira Phormidiochaete Arthrospira platensis were screened for their radical scavenging activity against the stable 1,1-diphenyl-2-picrylhydrazyl. Despite fact that water was a more efficient solvent to extract greater amount extractable substances, it seems methanol selected group compounds with...

The methanol extracts of leaf skins and flowers Aloe vera from the Canary Islands were analyzed for their phenolic profiles screened antioxidant antimycoplasmic activities. use reversed phase high performance liquid chromatography (RP-HPLC) allowed identification 18 constituents. Leaf skin characterized by abundance catechin, sinapic acid quercitrin. Gentisic acid, epicatechin quercitrin most prominent compounds flowers. in vitro activities determined using 1,1-diphenyl-2-picrylhydrazyl...

Fourteen phenolic compounds were identified and quantified in extracts derived from vitro culture of Phaeodactylum tricornutum diatom growing natural seawater (control) containing the following added copper (Cu) iron (Fe) metals: Cu(II) (315 nmol L −1 790 ) Fe(III) (900 ). The cell concentration was 471% for last day (expressed as a percentage control) diatoms exposed to iron, while showed densities 80% 52.5% at concentrations 315 , respectively. Each extract revealed presence 14 compounds,...

Abstract This work is focused on the effect of lethal and sub-lethal copper (Cu) concentrations free amino acid polyphenol production by marine diatom Phaeodactylum tricornutum ( P. ) after 12, 18, 21 days exposure. The 10 acids (arginine, aspartic acid, glutamic histidine, lysine, methionine, proline, valine, isoleucine, phenylalanine) polyphenols (gallic protocatechuic p -coumaric ferulic catechin, vanillic epicatechin syringic rutin, gentisic acid) were measured RP-HPLC. Under doses Cu,...

The biochemical composition of three novel selected microalgae strains (Chlorophyta) was evaluated to confirm their potential possibilities as new sustainably produced biomass with nutritional, functional, and/or biomedical properties. Extracts from cultured Pseudopediastrum boryanum, Chloromonas cf. reticulata, and Chloroidium saccharophilum exhibited higher radical scavenging activity DPPH (1,1-diphenyl-2-picrylhydrazyl) when compared butylated hydroxytoluene (BHT), but lower than...

This study is focused on analysing polyphenols and carbohydrates released by Phaeodactylum tricornutum (P. tricornutum) diatoms cultured in natural seawater enriched with sublethal lethal Cu doses. concentrations of 0.31, 0.79 1.57 µM reduced cell densities 37, 82 91%, respectively, compared to the control. The total sum all identified cells grown under levels increased up 18.8 107.4 times, data from a control experiment. Four different vitro assays were used estimate antioxidant activities...

A single, unified convergent strategy for the stereocontrolled synthesis of trans-fused polyethers was developed. It demonstrated that epimerization and reductive intramolecular coupling hydroxy ketones in reactions with silane-Lewis acids (SI-LA) to generate ethers C-linked oxacycles is affected by its conformational preference a predictable manner. The obtained results make evident influence hydrogen bonding between hemiketal hydroxyl 1,3-diaxial C-O bond regular may confidently be...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRing-puckering geometrical models for five-membered ringsE. Diez, A. L. Esteban, F. J. Bermejo, and M. RicoCite this: Phys. Chem. 1980, 84, 24, 3191–3196Publication Date (Print):November 1, 1980Publication History Published online1 May 2002Published inissue 1 November 1980https://pubs.acs.org/doi/10.1021/j100461a012https://doi.org/10.1021/j100461a012research-articleACS PublicationsRequest reuse permissionsArticle Views186Altmetric-Citations29LEARN...

Three freshwater microalgae (Spirogyra sp., Cosmarium and blytii) collected from several locations in Gran Canaria have been studied to explore their potential as a novel source of bioactive compounds for biotechnological applications. Soluble carbohydrates were quantified after extraction with 3 M HCl at 100 °C, ranging 35.8 43.3 %, water room temperature, 19 22.8 %. Amino acids glutamic acid, proline aspartic acid by RP-HPLC. Glutamic was the most abundant, 12.2 3.63 mg g-1 dry biomass....

This paper presents the application of methodology flipped classroom in laboratory practices a basic subject chemistry taught first year degree XXX. The used consisted assigning student task preparing as an autonomous work, making available practice guide with theoretical foundations and experimental procedure, well collection explanatory videos on handling instrumental techniques required each practice. Before after face-to-face practical sessions, students had to solve both online quizzes....

Four new compounds, a sesquiterpene, eleganodiol (1), and three sesquiterpene lactones, eleganolactone A (2), B (3), elegain (4), were isolated from Gonospermum elegans along with 16 known compounds. The structures of 1, 2, 4 determined on the basis MS NMR studies their acetate derivatives (1a, 2a, 4a). structure derivative (3a) 3 was spectroscopic data interpretation by single-crystal X-ray diffraction. Compounds 2a 3a used to study biological activities HL-60 human promyelocytic leukemia...

Phytochemical research of two Tolpis species, T. proustii and lagopoda, led to the isolation three new compounds: 30-chloro-3β-acetoxy-22α-hydroxyl-20(21)-taraxastene (1), 3β,22α-diacetoxy-30-ethoxy-20(21)-taraxastene (2) 3β,28-dihydroxy-11α-hydroperoxy-12-ursene (3). The structures compounds were elucidated by means extensive IR, NMR, MS data comparison reported in literature. vitro antioxidant activities extracts assessed DPPH ABTS scavenging methods. cytotoxicity several known its...

The extracts of six common plants from the Canary Islands were screened for their antioxidant activities and compared with several phenolic compounds natural origin (quercetin, catechin, rutin gentisic acid) synthetic (butylated hydroxyanisole (BHA) butylated hydroxytoluene (BHT)). in vitro activity determined by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) method revealed that Plantago major L., Artemisia canariensis (Bess.) Lessing Bidens aurea (Dryand.) Sherff exerted greater than other...

Trans-substituted tetrahydropyrans with an acetylenic moiety at C-2 were synthesized from 2-formyloxy-3-(tert-butyldimethylsilyloxy)-tetrahydropyran by reaction substituted silylacetylenes in the presence of a Lewis acid.

Abstract. Global environmental changes strongly affect the growth and biochemical composition of microalgae. Cultures coccolithophore Emiliania huxleyi were grown under four different CO2-controlled pH conditions (7.75, 7.90, 8.10, 8.25) to improve understanding adaptive mechanisms these organisms through in phenolic compounds carbohydrate content ocean acidification (OA) scenarios. The highest algal biomass peaks, 1.07 (± 0.10) 1.04 0.06) × 108 cells L−1, observed microcosms with...

Abstract. Cultures of the coccolithophore Emiliania huxleyi were grown under four different CO2-controlled pH conditions (7.75, 7.90, 8.10, and 8.25) to explore variations in extra- intracellular polyphenols carbohydrates response ocean acidification scenarios. Acidification did not significantly affect final cell densities carbohydrate contents. Intra- extracellular phenolic compounds identified quantified by reverse-phase high-performance liquid chromatography (RP-HPLC), with highest...