Search results for "010404 medicinal & biomolecular chemistry"
showing 10 items of 373 documents
Phytotoxic Lignans from Artemisia arborescens
2018
A systematic bioassay-guided fractionation of methylene chloride extracts of the aerial part of Artemisia arborescens was performed in order to identify its phytotoxic compounds Two lignans were isolated, sesamin and ashantin, that inhibited growth of Agrostis stolonifera (bentgrass), a monocot, and Lactuca sativa (lettuce), a dicot, at 1 mg mL–1. In a dose-response screening of these lignans for growth inhibition against Lemna paucicostata (duckweed), ashantin was the most active with an IC50 of ca. 224 μM. The mode of action of these compounds is still unknown. In mosquito larvicidal bioassays the pure compounds sesamin and ashantin did not cause mortality at the highest dose of 125 mg/L…
1-(2′-Bromobenzyl)-6,7-dihydroxy-N-methyl-tetrahydroisoquinoline and 1,2-Demethyl-nuciferine as Agonists in Human D2 Dopamine Receptors
2020
Certain D2-like dopamine receptor (DR) agonists are useful therapeutically as antiparkinsonian drugs, whereas D2-like DR antagonists or partial agonists are proven effective as antipsychotics. Two ...
Indole alkaloids from the coprophilous fungus Aphanoascus fulvescens
2019
Abstract The Ascomycete fungus Aphanoascus fulvescens isolated from goose dung was investigated for its secondary metabolites, yielding five new indole alkaloids okaramines V–Z (1–5) and eleven known derivatives (6–16). Their structures were determined by 1D, 2D NMR spectra and HRMS data. Compounds 6, 8, 11 and 12 showed significant to moderate cytotoxicity against the mouse lymphoma cell line L5178Y with IC50 values ranging from 4.0 to 14.7 μM. Preliminary structure-activity relationships are discussed.
Prediction of Aquatic Toxicity of Benzene Derivatives to Tetrahymena pyriformis According to OECD Principles
2016
Background: Many QSAR studies have been developed to predict acute toxicity over several biomarkers like Pimephales promelas, Daphnia magna and Tetrahymena pyriformis. Regardless of the progress made in this field there are still some gaps to be resolved such as the prediction of aquatic toxicity over the protozoan T. pyriformis still lack a QSAR study focused in accomplish the OECD principles. Methods: Atom-based quadratic indices are used to obtain quantitative structure-activity relationship (QSAR) models for the prediction of aquatic toxicity. Our models agree with the principles required by the OECD for QSAR models to regulatory purposes. The database employed consists of 392 substitut…
Triterpenoid Saponins From the Stem Bark of Pentaclethra eetveldeana
2019
Two previously undescribed triterpenoid saponins together with 4 known ones were isolated from the stem bark of Pentaclethra eetveldeana De Wild. & Th. Dur. Their structures were elucidated by spectroscopic methods including 1D and 2D NMR experiments in combination with mass spectrometry as 3- O-β-D-glucopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→3)]-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→4)]-α-L-arabinopyranosyloleanolic acid and 3- O-β-D-glucopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→3)]-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→4)]-α-L-arabinopyranosylhederagenin.
Chemical Composition and Antibacterial Activity of Extracts of Helleborus bocconei Ten. subsp. intermedius
2007
Helleborus bocconei Ten. subsp. intermedius (Ranunculaceae) is a Sicilian medicinal plant used for the treatment of pneumonia affecting cows and horses and for the removal of human decayed molars. The goal of our study was to assess the biological activity of Helleborus bocconei subsp. intermedius by testing its extracts for their activity against bacteria known to cause respiratory diseases. The two more active extracts (light petroleum from roots and aerial parts), as well as the dichloromethane extracts, were analyzed by GC/MS and their composition is reported.
GC and GC/MS analysis of the essential oil of Salvia hierosolymitana boiss. Growing wild in Lebanon
2007
The essential oil of the aerial parts of Salvia hierosolymitana Boiss. (Lamiaceae), growing wild in Lebanon, was obtained by hydrodistillation and analysed by GC and GC-MS. Ninety-two compounds, representing 92.7% of the oil, were identified. The major components were hexadecanoic acid (15.5%), phytol (5.4%), hexahydrofarnesyl acetone (4.6%), (Z,Z)-9,12-octadecadienoic acid (4.5%) and 4-vinylguaiacol (4.4%).
Fragment- and negative image-based screening of phosphodiesterase 10A inhibitors.
2019
A novel virtual screening methodology called fragment- and negative image-based (F-NiB) screening is introduced and tested experimentally using phosphodiesterase 10A (PDE10A) as a case study. Potent PDE10A-specific small-molecule inhibitors are actively sought after for their antipsychotic and neuroprotective effects. The F-NiB combines features from both fragment-based drug discovery and negative image-based (NIB) screening methodologies to facilitate rational drug discovery. The selected structural parts of protein-bound ligand(s) are seamlessly combined with the negative image of the target's ligand-binding cavity. This cavity- and fragment-based hybrid model, namely its shape and electr…
Cytotoxic Bufadienolides from the Leaves of Melianthus major
2020
Melianthus major is a medicinal plant endemic to South Africa. Its leaf extract led to the isolation of five new bufadienolides, 2β-acetoxy-3,5-di-O-acetylhellebrigenin (1), 2β-acetoxy-3-O-acetylhellebrigenin (2), 2β-acetoxy-14-deoxy-15β,16β-epoxymelianthugenin (4), 2β-acetoxy-14-deoxy-15β,16β-epoxymelianthusigenin (5), and 2β-hydroxymelianthusigenin (6), and four known analogues. The structures of the compounds were elucidated using NMR and HRESIMS data analyses. The relative configurations were defined by single-crystal X-ray crystallography and NOESY correlations. The isolated compounds exhibited strong cytotoxicity against MCF-7 breast cancer cells and sensitive CCRF-CEM and multidrug-r…
The Diterpenoids of the Genus Marrubium (Lamiaceae)
2006
The occurrence and chemical structures of labdane diterpenoids from the genus Marrubium are reviewed and the published 13C NMR spectroscopic data for these compounds is presented. The pharmacological activities and biogenesis of these diterpenoids are also reported.