Search results for "4-D"
showing 10 items of 955 documents
Estimation of the density of the protocatechuate-degrading bacterial community in soil by real-time PCR
2008
Summary The β-ketoadipate pathway is the major route for degradation of aromatic compounds by various soil microorganisms. Protocatechuate 3,4-dioxygenase, a key enzyme of this pathway and which is encoded by pcaGH genes, catalyses the ring cleavage of protocatechuate. Microorganisms harbouring pcaGH genes are widely distributed in the environment but little is known about their relative abundance within the total microflora. Hence, this paper reports the development of a real-time PCR assay to quantify the bacterial pcaH sequence that encodes the β sub-unit of the protocatechuate 3,4-dioxygenase. This real-time PCR assay was linear over seven orders of magnitude with a calculated efficienc…
Design of pharmacophoric group containing 1,4-dihydropyridine derivatives and determination of spectrum of pharmacological activities
2017
Vairākkārtīgi ir uzsvērts, ka 1,4-dihidropiridīna cikls ir viens no farmakoloģiski priviliģētām struktūrām, kas iedarbojas uz jonu kanāliem un dažādiem receptoriem, un kuru modificējot, sintezējot tās struktūras analogus, variējot aizvietotājus molekulā, būtu iespējams iegūt dažādus farmakoloģiski aktīvus savienojumus. Pētījumā ir sintezēti jauni, mērķtiecīgi dizainēti, farmakoforas grupas saturoši 1,4-dihidropiridīna atvasinājumi, sistemātiski mainot farmakoforās grupas (piridīniju un/vai propargil) un to atrašanās vietu molekulā. Izvērtēts sintezēto savienojumu farmakoloģiskās darbības spektrs (aktivitāte uz kalcija kanāliem, antiradikālā aktivitāte un reducējošā kapacitāte), veidots stru…
Diastereoselective synthesis of 6-functionalized 4-aryl-1,3-oxazinan-2-ones and their application in the synthesis of 3-aryl-1,3-aminoalcohols and 6-…
2010
Abstract Halocyclocarbamation of benzyl N -(1-phenyl-3-butenyl)carbamates afforded 6-functionalized 4-aryl-1,3-oxazinan-2-ones with moderate to excellent diastereoselectivity depending on the N -substituent. Importantly, in contrast to reported cyclocarbamations of homoallylic carbamates, which are generally trans -diastereoselective, cyclization of N -unsubstituted Cbz-protected homoallylamines led to cis -1,3-oxazinan-2-ones, predominantly. The use of N -benzylated and in situ prepared N -silylated derivatives resulted however in trans -selectivity. Transition states are proposed to explain the stereochemical influence of the N -substituent on the cyclocarbamations. The functionalized 1,3…
Study of interaction of antimutagenic 1,4-dihydropyridine AV-153-Na with DNA-damaging molecules and its impact on DNA repair activity
2018
Background1,4-dihydropyridines (1,4-DHP) possesses important biochemical and pharmacological properties, including antioxidant and antimutagenic activities. It was shown that the antimutagenic 1,4-dihydropyridine AV-153-Na interacts with DNA. The aim of the current study was to test the capability of the compound to scavenge peroxynitrite and hydroxyl radical, to test intracellular distribution of the compound, and to assess the ability of the compound to modify the activity of DNA repair enzymes and to protect the DNA in living cells against peroxynitrite-induced damage.MethodsPeroxynitrite decomposition was assayed by UV spectroscopy, hydroxyl radical scavenging—by EPR spectroscopy. DNA b…
Pyrazole[3,4-d]pyrimidine derivatives loaded into halloysite as potential CDK inhibitors
2021
Uncontrolled cell proliferation is a hallmark of cancer as a result of rapid and deregulated progression through the cell cycle. The inhibition of cyclin-dependent kinases (CDKs) activities is a promising therapeutic strategy to block cell cycle of tumor cells. In this work we reported a new example of nanocomposites based on halloysite nanotubes (HNTs)/pyrazolo[3,4-d]pyrimidine derivatives (Si306 and Si113) as anticancer agents and CDK inhibitors. HNTs/Si306 and HNTs/Si113 nanocomposites were synthesized and characterized. The release kinetics were also investigated. Antitumoral activity was evaluated on three cancer cell lines (HeLa, MDA-MB-231 and HCT116) and the effects on cell cycle ar…
Five years experience on 3,4-diaminopyridine phosphate in Lambert-Eaton syndrome: Case reports
2017
Abstract Rationale: To report our experience on 7 patients (4 males and 3 females), affected by nonparaneoplastic Lambert–Eaton myasthenic syndrome, treated with 3,4-diaminopyridine phosphate (3,4-DAPP) either alone or in combination with other immunosuppressants or steroids. Patient concerns: Patients have been evaluated at specific timepoints (ie, baseline and last 5 year follow-up), with neurological examination, autoantibodies against presynaptic voltage-gated Cav2.1 (P/Q type) calcium ion channel (VGCC) dosage, neurophysiological evaluation focusing on the increased amplitude of the compound muscle action potential (cMAP) after maximum voluntary effort, quantitative myasthenia gravis (…
Inhibition of FcεRI-mediated Activation of Rat Basophilic Leukemia Cells by Clostridium difficile Toxin B (Monoglucosyltransferase)
1996
Abstract Treatment of rat basophilic leukemia (RBL) 2H3-hm1 cells with Clostridium difficile toxin B (2 ng/ml), which reportedly depolymerizes the actin cytoskeleton, blocked [3H]serotonin release induced by 2,4-dinitrophenyl-bovine serum albumin, carbachol, mastoparan, and reduced ionophore A23187-stimulated degranulation by about 55-60%. In lysates of RBL cells, toxin B 14C-glucosylated two major and one minor protein. By using two-dimensional gel electrophoresis and immunoblotting, RhoA and Cdc42 were identified as protein substrates of toxin B. In contrast to toxin B, Clostridium botulinum transferase C3 that selectively inactivates RhoA by ADP-ribosylation did not inhibit degranulation…
Release of endogenous 3,4-dihydroxyphenylethylamine and its metabolites from the isolated neurointermediate lobe of the rat pituitary gland. Effects …
1986
: Isolated rat neurointermediate lobes were incubated in vitro. The release of 3,4-dihydroxyphenylethylamine (dopamine, DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and methoxyphenylethanol (MOPET) was determined by HPLC with electrochemical detection. Under resting conditions, the outflow of metabolites was 35–50 times that of DA. HVA accounted for 50%, DOPAC for 45%, and MOPET for 5% of the metabolites. Although an equivalent of 40–50% of the tissue DA content was released per hour as metabolites, the tissue DA content was not reduced after 110 min of incubation. The spontaneous outflow of DA and its metabolites was not affected by the DA uptake inhibitor GBR 12921 (1…
Presynaptic regulation of the electrically evoked release of endogenous dopamine from the isolated neurointermediate lobe or isolated neural lobe of …
1988
Isolated neurointermediate lobes (NILs) or isolated neural lobes (NLs) of the rat pituitary gland were incubated in Krebs-HEPES solution which contained pargyline and the dopamine uptake inhibitor GBR 12921. The release of endogenous dopamine was determined by HPLC with electrochemical detection. Electrical stimulation of the pituitary stalk induced a frequency-dependent release of dopamine. The release of dopamine from the combined NIL evoked by stimulation at 15 Hz was increased by 130% in the presence of the dopamine D2 receptor antagonist, (-)-sulpiride; the (+)-enantiomer of sulpiride had virtually no effect. When the stimulation frequency was 3 Hz (-)-sulpiride caused an increase in d…
2,4-Dimetoksibenzaldehīda kondensācija ar etilcianoacetātu jonu šķidrumu vidēs
2019
2,4-Dimetoksibenzaldehīda kondensācija ar etilcianoacetātu jonu šķidrumu vidēs. Maševska Z., zinātniskais vadītājs prof., Dr.h.ķīm. Zicmanis A. Maģistra darbs, 54 lappuses, 14 attēli, 10 tabulas, 66 literatūras avoti, 19 pielikumi. Latviešu valodā. Darbā apkopota literatūra par jonu šķidrumu iegūšanas metodēm, to attīrīšanu, toksiskajām īpašībām, fizikāli-ķīmiskajām īpašībām. Apkopota informācija par Knēvenāgela kondensācijas reakcijas principiem. Sintezēti 17 strukturāli atšķirīgi jonu šķidrumi. Veiktas Knēvenāgela kondensācijas reakcijas jonu šķidrumu vidēs, izvērtēti iegūtie rezultāti. Iegūtie rezultāti salīdzināti ar citiem līdzīgiem pētījumiem.