Search results for "Assay"
showing 10 items of 2241 documents
Steroidal saponins from Dioscorea preussii.
2014
Abstract Three new steroidal saponins, named diospreussinosides A–C (1–3), along with two known ones (4, 5) were isolated from rhizomes of Dioscorea preussii. Their structures were elucidated mainly by 1D and 2D NMR spectroscopic analysis and mass spectrometry as (25S)-17α,25-dihydroxyspirost-5-en-3β-yl-O-α- l -rhamnopyranosyl-(1 → 4)-α- l -rhamnopyranosyl-(1 → 4)-β- d -glucopyranoside (1), (25S)-17α,25-dihydroxyspirost-5-en-3β-yl-O-α- l -rhamnopyranosyl-(1 → 4)-α- l -rhamnopyranosyl-(1 → 4)-[α- l -rhamnopyranosyl-(1 → 2)]-β- d -glucopyranoside (2), and (24S,25R)-17α,24,25-trihydroxyspirost-5-en-3β-yl-O-α- l -rhamnopyranosyl-(1 → 4)-α- l -rhamnopyranosyl-(1 → 4)-[α- l -rhamnopyranosyl-(1 → …
Shikonin reduces oedema induced by phorbol ester by interfering with IκBα degradation thus inhibiting translocation of NF-κB to the nucleus
2010
Background and purpose In the present paper we studied the effect of shikonin on ear oedema induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), and determined the mechanisms through which shikonin might exert its topical anti-inflammatory action. Experimental approach Acute ear oedema was induced in mice by topical application of TPA. The in vitro assays used macrophages RAW 264.7 cells stimulated with lipopolysaccharide. Cyclooxygenase-2, inducible nitric oxide synthase, protein kinase Calpha, extracellular signal-regulated protein kinase (ERK), phosphorylated ERK (pERK), c-Jun N-terminal kinase (JNK), pJNK, p38, p-p38, p65, p-p65, inhibitor protein of nuclear factor-kappaB (NF-kappaB) …
New ursolic and betulinic derivatives as potential cytotoxic agents.
2003
Fifteen new ursolic and betulinic triterpenoids, bearing various functionalities at C-3 and C-28 were synthesized as potential cytotoxic agents. All compounds were obtained by a hemisynthetic route via ursolic and betulinic acids. Preliminary screening of these compounds on human HT 29 colon cancer cells revealed inhibitory activity for three of them. Beta-D-Glucopyranosyl-3beta-hydroxyurs-12(13)-en-28-oate 1c, 3beta-3-(3-pyridyl)-prop-2-enoyloxyurs-12(13)-en-28-oic acid 1i and the potassium salt of 3beta-cinnamoyloxylup-20(29)-en-28-oic acid 2d demonstrated cytotoxic activity in the micromolar range: 8.0, 45.0 and 8.0 microM, respectively.
Aaptamine Derivatives from the Indonesian Sponge Aaptos suberitoides
2013
Four new aaptamine derivatives (1-4) along with aaptamine (5) and three related compounds (6-8) were isolated from the ethanol extract of the sponge Aaptos suberitoides collected in Indonesia. The structures of the new compounds were unambiguously determined by one- and two-dimensional NMR and by HRESIMS measurements. Compounds 3, 5, and 6 showed cytotoxic activity against the murine lymphoma L5178Y cell line, with IC(50) values ranging from 0.9 to 8.3 μM.
Research Letter: Structural Combination of Established 5-HT2A Receptor Ligands: New Aspects of the Binding Mode
2010
MH.MZ, MDL 100907, and altanserin are structurally similar 4-benzoyl-piperidine derivatives and are well accommodated to receptor interaction models. We combined structural elements of different high-affinity and selective 5-HT(2A) antagonists, as MH.MZ, altanserin, and SR 46349B, to improve the binding properties of new compounds. Three new derivatives were synthesized with a 4-benzoyl-piperidine moiety as the lead structure. The in vitro affinity of the novel compounds was determined by a [³H]MDL 100907 competition binding assay. The combination of MH.MZ and SR 46349B resulted in a compound (8) with a moderate affinity toward the 5-HT(2A) receptor (K(i) = 57 nm). The remarkably reduced af…
Cytotoxicity of some Cameroonian spices and selected medicinal plant extracts
2011
Abstract Ethnopharmacological relevance Several medicinal plants and spices are used traditionally to treat cancers in Cameroon. Aim Methanol extracts from thirty-four spices and plants, with related ethnobotanical use were investigated for their in vitro cytotoxicity on the human pancreatic cancer cell line MiaPaCa-2, leukemia CCRF-CEM cells and their multidrug resistant (MDR) subline CEM/ADR5000, and the normal human umbilical vein endothelial cells (HUVECs). In addition the anti-angiogenic properties of the most active extracts were investigated. Material and methods The MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay was used for cyto…
Dinoflagellates from marine algal blooms produce neurotoxic compounds: effects on free calcium levels in neuronal cells and synaptosomes
2000
In this report, evidence is presented that the marine unicellular eukaryotic dinoflagellates can cause neurotoxicity very likely by an increase in intracellular free calcium ions ([Ca(2+)](i)). Determinations of the effects of culture supernatants from different clones of the dinoflagellate Alexandrium sp. isolated from algal blooms on the viability of rat primary neuronal cells revealed that all clones tested were toxic for these cells. In addition, all Alexandrium clones tested, except for A. ostenfeldii BAH ME-141, were found to be toxic for rat pheochromocytoma PC12 cells. No toxicity was observed for culture supernatants from Gonyaulax and Coolia monotis. Calcium ions are important in …
Inhibition of human P450 enzymes by natural extracts used in traditional medicine
2008
Different medicinal plants are widely used in Cuba and Mexico to treat several disorders. This paper reports in vitro inhibitory effects on the P450 system of herbal products commonly used by people in Cuba and Mexico in traditional medicine for decades. Experiments were conducted in human liver microsomes. The catalytic activities of CYP1A1/2, 2D6, and 3A4 were measured using specific probe substrates. The Heliopsis longipes extract exhibited a concentration-dependent inhibition of the three enzymes, and similar effects were produced by affinin (an alkamide isolated from the H. longipes extract) and two catalytically reduced alkamides. Mangifera indica L. and Thalassia testudinum extracts,…
Die Konzentration von Noradrenalin und Adrenalin in den einzelnen Abschnitten des Herzens
1959
1. A method for the assay of noradrenaline and adrenaline in small pieces of heart tissue is described. The amines were extracted with acid ethanol and separated by paper chromatography. The regions containing the amines were eluted and the amount of amines in the eluates was determined by bioassay. Noradrenaline was assayed on the blood pressure of the pithed rat. Adrenaline was assayed on the isolated atropinized rat's uterus stimulated with oxytocin. 2. The identity of the substances tested by bioassay with noradrenaline and adrenaline was confirmed by a number of chemical and pharmacological tests. 3. The concentration of catechol amines in different parts of the heart was studied in ca…
Approach of the State Pharmacopeia of Ukraine to analytical procedures validation on the example of chloride ions assay in peritoneal dialysis soluti…
2019
The objective of this study was to develop and validate an alternative analytical procedure for the total chloride assay in solutions for peritoneal dialysis (PD). The proposed analytical procedure was validated according to the requirements of the International Conference on Harmonization (ICH) Guideline: Topic ICH Q2(R1) and the approach of the State Pharmacopeia of Ukraine (SPU). The analytical procedure was specific. The li-nearity of the procedure was evaluated in the concentration range of 76 to 114 mmol/L of chloride ions (80-120% of the stated content (95 mmol/L)) with the regression equation y = 1.0029 ∑ X -0.2269 and a correlation coefficient of 0.9989. The y-intercept of the regr…