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X-ray, structural assignment and molecular docking study of dihydrogeodin from Aspergillus Terreus TM8

A re-cultivation of the thermophilic fungus Aspergillus terreus TM8, and working up of its extract afforded the dichloro-benzophenone derivative, dihydrogeodin (1) in addition to the butyrolactones I (2), V (3) and VI (4). A literature surveying revealed one recent structural assignment trial for dihydrogeodin (1), however, with some inaccuracies. We report herein a full assignment of dihydrogeodi

Diverse polyketides and alkaloids from Penicillium sp. KHMM : structural elucidation, biological and molecular docking studies

As a continuation of our earlier research concerning the investigation of microbial bioactive secondary metabolites from the terrestrial Penicillium sp.KH Link 1809 isolate KHMM, the fungus was re-cultivated on a large scale to explore its bioactive compounds intensively. Fifteen compounds, including seven alkaloids (1-7), one sesquiterpene (8), an acetylenic system (9), two sterols, and sphengoli

Ergostane-type steroids from the Cameroonian ‘white tiama’ Entandrophragma angolense

Two new ergostane-type steroids named tiamenones A and B (1–2) were isolated from the bark of Entandrophragma angolense (Meliaceae) along with ten known compounds identified as 20S-hydroxy-4,6,24(28)-ergostatrien-3-one (3), 3β,7α,20β-trihydroxyergosta-5,24(28)-diene (4), 3β,5α-dihydroxyergosta-7,22-diene (5), stigmasterol, β-sitosterol, β-amyrin, oleanolic acid, asperphenamate, sucrose and daucost

Synthesis, in vitro cytotoxicity activity against the human cervix carcinoma cell line and in silico computational predictions of new 4-arylamino-3-nitrocoumarin analogues

A new series of 4-arylamino-3-nitrocoumarin analogues (4–18) have been synthesized and characterized by sophisticated spectroscopic techniques (1H NMR, 13C NMR) and mass spectrometry. All the new synthesized compounds were evaluated for their in vitro cytotoxic activity against the human cervix carcinoma cell line (KB-3-1) using resazurin assay with (+)-griseofulvin as the positive control (IC50 =

Phenothiazine-Biaryl-Containing Fluorescent RGD Peptides

Cyclic RGD peptides are well-known ligands of integrins. The integrins αVβ3 and α5β1 are involved in angiogenesis, and integrin αVβ3 is abundantly present on cancer cells, thus representing a therapeutic target. Hence, synthetic and biophysical studies continuously are being directed towards the understanding of ligand-integrin interaction. In this context, the development of versatile synthetic s

Structure of apo flavin-dependent halogenase Xcc4156 hints at a reason for cofactor-soaking difficulties

Flavin-dependent halogenases regioselectively introduce halide substituents into electron-rich substrates under mild reaction conditions. For the enzyme Xcc4156 from Xanthomonas campestris, the structure of a complex with the cofactor flavin adenine dinucleotide (FAD) and a bromide ion would be of particular interest as this enzyme exclusively brominates model substrates in vitro. Apo Xcc4156 crys

Three phragmalin-type limonoids orthoesters and the structure of odoratone isolated from the bark of Entandrophragma candollei (Meliaceae)

The phytochemical exploration of the Entandrophragma candollei stem bark extract led to the isolation and identification of twenty compounds including three undescribed phragmalin-class limonoids named encandollens C–E (1–3), the undescribed protolimonoid 5 together with sixteen known compounds. The structures of all the isolated compounds were determined by interpretation of their spectroscopic a

Two novel, flavin-dependent halogenases from the bacterial consortia of botryococcus braunii catalyze mono-and dibromination

Halogen substituents often lead to a profound effect on the biological activity of organic compounds. Flavin-dependent halogenases offer the possibility of regioselective halogenation at non-activated carbon atoms, while employing only halide salts and molecular oxygen. However, low enzyme activity, instability, and narrow substrate scope compromise the use of enzymatic halogenation as an economic

Degrowth

This article examines the idea of degrowth, a concept in political ecology used to envision a democratically planned downscaling of production and consumption in affluent regions of the world as a means to avoid ecological breakdown, decrease inequality, and improve quality of life. Since its inception at the beginning of the 2000s in France, the idea of degrowth has sparked a worldwide social mov

Between pace-making and pace-taking : Urban cycle logistics in an ‘accelerated polity’

The purpose of this study is to explore the concept of social acceleration by examining how cities are trying to speed up, maintain or slow down the pace of societal change. Through studies of cycle logistics policies and actions in cities in Denmark, Norway, the UK, the Netherlands, and Germany, we show how these balance between acting as pace-makers and pace-takers, as well as what the consequenThe purpose of this study is to explore the concept of social acceleration by examining how cities are trying tospeed up, maintain or slow down the pace of societal change. Through studies of cycle logistics policies andactions in cities in Denmark, Norway, the UK, the Netherlands, and Germany, we show how these balance be-tween acting as pace-makers and pace-takers, as well as what the consequenc

Turning the tanker? Exploring the preconditions for change in the global petrochemical industry

Meeting the goals set out in the Paris Agreement will require rapid and deep reductions of greenhouse gas emissions (GHG) across all sectors of the global economy. Like all major societal transformations, this climate transition will impact both social and technical aspects of society and, depending on how it evolves, will reallocate social and economic benefits and costs differently. Recognising

Two local minima for structures of [4Fe–4S] clusters obtained with density functional theory methods

[4Fe–4S] clusters are essential cofactors in many proteins involved in biological redox-active processes. Density functional theory (DFT) methods are widely used to study these clusters. Previous investigations have indicated that there exist two local minima for these clusters in proteins. We perform a detailed study of these minima in five proteins and two oxidation states, using combined quantu