Isolation and chemical characterization of agelaiatoxin8 (AvTx8) from Agelaia vicina wasp venom and its biological effects on GABA neurotransmission

2017 ◽  
Vol 31 (10) ◽  
pp. e21941 ◽  
Author(s):  
Andrea B. Pizzo ◽  
Renê O. Beleboni ◽  
Ruither O. Gomes Carolino ◽  
Luciana de Oliveira ◽  
Antonio Miranda ◽  
...  
Keyword(s):  
Biological Effects ◽  
Chemical Characterization ◽  
Wasp Venom ◽  
Gaba Neurotransmission

Chemical characterization of organic microcontaminant sources and biological effects in riverine sediments impacted by urban sewage and pulp mill discharges

Chemosphere ◽  
2013 ◽  
Vol 90 (2) ◽  
pp. 611-619 ◽  
Author(s):  
S. Chamorro ◽  
V. Hernández ◽  
V. Matamoros ◽  
C. Domínguez ◽  
J. Becerra ◽  
...  
Keyword(s):  
Biological Effects ◽  
Chemical Characterization ◽  
Pulp Mill ◽  
Urban Sewage ◽  
Riverine Sediments

Biological effects and chemical characterization of Iris schachtii Markgr. extracts: A new source of bioactive constituents

2018 ◽  
Vol 112 ◽  
pp. 448-457 ◽  
Author(s):  
Andrei Mocan ◽  
Gokhan Zengin ◽  
Adriano Mollica ◽  
Ahmet Uysal ◽  
Erdogan Gunes ◽  
...  
Keyword(s):  
Biological Effects ◽  
Chemical Characterization ◽  
Bioactive Constituents

scholarly journals Mediation of Elicitin Activity on Tobacco Is Assumed by Elicitin-Sterol Complexes

2001 ◽  
Vol 12 (9) ◽  
pp. 2825-2834 ◽  
Author(s):  
Hanan Osman ◽  
Sébastien Vauthrin ◽  
Vladimir Mikes ◽  
Marie-Louise Milat ◽  
Franck Panabières ◽  
...  
Keyword(s):  
Binding Sites ◽  
Defense Mechanisms ◽  
Specific Binding ◽  
Biological Effects ◽  
Chemical Characterization ◽  
Site Directed Mutagenesis ◽  
Specific Binding Sites ◽  
Biological Responses ◽  
Kinetics Of

Elicitins secreted by phytopathogenic Phytophthoraspp. are proteinaceous elicitors of plant defense mechanisms and were demonstrated to load, carry, and transfer sterols between membranes. The link between elicitor and sterol-loading properties was assessed with the use of site-directed mutagenesis of the 47 and 87 cryptogein tyrosine residues, postulated to be involved in sterol binding. Mutated cryptogeins were tested for their ability to load sterols, bind to plasma membrane putative receptors, and trigger biological responses. For each mutated elicitin, the chemical characterization of the corresponding complexes with stigmasterol (1:1 stoichiometry) demonstrated their full functionality. However, these proteins were strongly altered in their sterol-loading efficiency, specific binding to high-affinity sites, and activities on tobacco cells. Ligand replacement experiments strongly suggest that the formation of a sterol-elicitin complex is a requisite step before elicitins fasten to specific binding sites. This was confirmed with the use of two sterol-preloaded elicitins. Both more rapidly displaced labeled cryptogein from its specific binding sites than the unloaded proteins. Moreover, the binding kinetics of elicitins are related to their biological effects, which constitutes the first evidence that binding sites could be the biological receptors. The first event involved in elicitin-mediated cell responses is proposed to be the protein loading with a sterol molecule.

Olfactory and Chemical Characterization of Indoor Air-Towards a Psychophysical Model for Air Quality

1981 ◽  
Author(s):  
Birgitta Berglund ◽  
Ulf Berglund ◽  
Thomas Lindvall ◽  
Helene Nicander-Bredberg
Keyword(s):  
Air Quality ◽  
Indoor Air ◽  
Chemical Characterization

PURIFICATION AND PARTIAL CHEMICAL CHARACTERIZATION OF SHEEP NEUROPHYSIN

1973 ◽  
Vol 74 (2) ◽  
pp. 226-236 ◽  
Author(s):  
Michel Chrétien ◽  
Claude Gilardeau
Keyword(s):  
Amino Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Chemical Characterization ◽  
Terminal Amino Acid ◽  
Amino Acid Determination ◽  
Pituitary Glands ◽  
Terminal Amino ◽  
Partial Chemical ◽  
Acid Determination

ABSTRACT A protein isolated from ovine pituitary glands has been purified, and its homogeneity assessed by NH2- and COOH-terminal amino acid determination, ultracentrifugation studies, and polyacrylamide gel electrophoresis after carboxymethylation. Its chemical and immunochemical properties are closely similar to those of beef and pork neurophysins, less similar to those of human neurophysins. It contains no tryptophan (like other neurophysins) or histidine (like all except bovine neurophysin-I and human neurophysins). It has alanine at the NH2-terminus and valine at the COOH-terminus. Its amino acid composition is similar to, but not identical with those of porcine and bovine neurophysins.

Laboratory Methods for the Physico-Chemical Characterization of Recombinant Allergens as Reference Standards

Alergologia ◽  
2020 ◽  
Vol 1 (4) ◽  
pp. 7
Author(s):  
Mariana Vieru ◽  
Florin-Dan Popescu ◽  
Laura Haidar ◽  
Carmen Bunu-Panaitescu
Keyword(s):  
Chemical Characterization ◽  
Reference Standards ◽  
Recombinant Allergens ◽  
Laboratory Methods ◽  
Physico Chemical

PHYTOCHEMICAL SCREENING, ANTIOXIDANT, ANTI-CYTOTOXIC AND ANTICANCER EFFECTS OF GALINSOGA PARVIFLORA AND VERNONIA POLYANTHES (ASTERACEAE) EXTRACTS

2020 ◽  
Vol 8 (10) ◽  
pp. 84-98
Author(s):  
Sula M. V. Feleti ◽  
Renê L. Aleluia ◽  
Suiany V. Gervásio ◽  
Jean Carlos V. Dutra ◽  
Jessica R. P. Oliveira ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Phenolic Acids ◽  
Unsaturated Fatty Acids ◽  
Biological Effects ◽  
Human Lymphocytes ◽  
Chemical Characterization ◽  
Total Content ◽  
Ags Cells ◽  
Ft Icr Ms ◽  
Ft Icr

The study was designed to investigate the chemical composition and the biological effects of G. parviflora and V. polyanthes ethanolic extracts in vitro. Total content of phenols, flavonoids and tannins was quantified by spectrophotometry; chemical characterization was permed by mass spectrometry (ESI (-) FT-ICR MS and APCI (+) FT-ICR MS analysis). Antioxidant activities were determined by FRAP and Fe2+ chelating methods. Extracts cytotoxicity was evaluated in human lymphocytes, sarcoma-180 (S-180) and human gastric adenocarcinoma (AGS) cells, by MTT assay. V. polyanthes presented higher total content of tannins and G. parviflora presented higher amount of phenols and flavonoids. Chemical characterization showed the presence of flavonoids, phenolic acids and sesquiterpene lactones in V. polyanthes extract, and steroids, phenolic acids and fatty acids (Poly Unsaturated Fatty Acids - PUFA) in G. parviflora extract. V. polyanthes extract stood out in the Fe2+ chelation test. G. parviflora extract did not present outstanding antioxidant results in the tested protocols. Both species showed a tendency to promote cytotoxicity in human lymphocyte cells. Regarding the antiproliferative effect, both species were able to reduce S-180 cell viability and G. parviflora extract showed high antiproliferative potential in the assay with AGS cells. These findings reinforce the medicinal use of these plants, as well as suggest their potential use for the development of new drugs and for the treatment of cancers.

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