Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An insoluble graft copolymer consisting of the covalently bound polyoxyethylene to cross-linked polystyrene (HO-POE-PS) was prepared by anionic polymerization of ethylene oxide on the resin. The copolymer was then converted to the corresponding amino-polymer (H2N-POE-PS) and the latter was employed as the solid carrier for peptide synthesis. Although HO-POE-PS has successfully been employed as a carrier for peptide synthesis by the standard shaking procedure using t-butoxycarbonyl-amino acids, now we deemed it of interest to test its suitability for the continuous flow synthesis. Thus, the C-terminal octapeptide of the porcine insulin B chain (B23-30) was prepared by this procedure using a photolabile anchoring group and fluoren-9-ylmethoxycarbonyl-amino acids. All the reactions were carried out in a continuous flow manner in a steel column under pressure using a high-performance liquid chromatography (HPLC) system. At the end of the synthesis, a sample of the protected peptide was cleaved from the support by photolysis. For the cleavage of another sample, an aqueous solution of sodium carbonate was employed. The protected peptide was purified on silica gel and Sephadex-LH 20. All the protecting groups of a sample of the octapeptide were removed with piperidine/dimethylformamide and trifluoroacetic acid and the deblocked peptide was purified by ion-exchange chromatography. The free peptide was shown to be homogeneous by thin-layer chromatography, HPLC, and electrophoresis. The identify of the free octapeptide was confirmed by amino-acid analysis, 13C-nuclear magnetic resonance measurement and field-desorption mass spectrometry. The peptide was also shown to be free of racemization.
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PMID:Continuous flow peptide synthesis on aminopolyoxyethylene-polystyrene graft copolymer using Fmoc-strategy. 304 90

A liquid chromatographic (LC) method for determining furazolidone in finished feeds and premixes was collaboratively studied. Finished feed sample is extracted with acetone-water (93 + 7) on a Goldfisch apparatus, extracting solvent is removed, and the residual material is dissolved in warm DMF. A solution of tetraethylammonium bromide is added, the fat layer is removed, and the sample is clarified by filtration and injected onto a reverse phase LC system with detection at 365 nm. Premixes, extracted by shaking with DMF and diluted so that the final furazolidone concentration is about 55 micrograms/mL, are chromatographed and detected the same as finished feed samples, using a mobile phase of acetonitrile-2% acetic acid (20 + 80). Ten commercial feed samples were preweighed and supplied to 14 collaborators. The 5 matched pairs were chosen to represent the following allowed levels: 0.0055, 0.022, 0.033, 2.2, and 22%. Two familiarization samples at the 0.0055 and 11% levels were also supplied. Instructions called for a single analysis of each sample. Two results were eliminated by the Dixon test. The coefficients of variation, following treatment by the ranking test, ranged from 2.0 at the 22% level to 6.5 at the 0.0055% level. Calculated F-values are not significant (P greater than 0.01) except for the 0.0055% level samples extracted overnight. This method has been adopted official first action.
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PMID:Liquid chromatographic method for determination of furazolidone in premixes and complete feeds: collaborative study. 405 21

Furazolidone is separated from finished feeds by acetone-water extraction on a Goldfisch apparatus. Extracting solvent is removed, and the residue is dissolved in dimethylformamide-5% tetraethylammonium bromide (1 +1), clarified, and chromatographed on a reverse phase C1 column. The mobile phase is CH3CN-2% acetic acid (20 + 80) with detection at 365 nm. The method was tested for linearity, recovery, and ruggedness, and compared with the AOAC colorimetric assay by using field samples containing 0.0055-0.055% furazolidone. Precision data suggest a cumulative relative standard deviation of 1.43% within days and 1.78% between days. The ruggedness test predicts a between-laboratory relative standard deviation of 3.67%. Recovery was 97.5 +/- 2.0% and linearity was excellent (r2 = 0.9994) up to 0.06% furazolidone. Premixes are extracted by shaking with dimethylformamide. An aliquot of the extract is diluted (1 + 1) with 5% tetraethylammonium bromide, clarified, and chromatographed.
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PMID:High performance liquid chromatographic determination of furazolidone in feed and feed premixes. 728 7

A novel methacrylate monomer containing a quinolone moiety was synthesized and homopolymerized in N,N-dimethylformamide (DMF) by using azobisisobutyronitrile (AIBN) as an initiator. The new monomer was copolymerized with poly(ethylene glycol) methyl ether methacrylate (MPEGMA) in DMF using the same initiator. The monomer, homopolymer, and copolymer were characterized by elemental analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), size exclusion chromatography (SEC), FTIR, (13)C NMR, and (1)H NMR. The antibacterial activities of the monomer as well as polymers were investigated against Staphylococcus aureus and Escherichia coli, which are representative of Gram-positive and Gram-negative bacteria, respectively. All compounds showed excellent antibacterial activities against these two types of bacteria. The antibacterial activities were determined using the shaking flask method, where 25 mg/mL concentrations of each compound were tested against 10(5) CFU/mL bacteria solutions. The number of viable bacteria was calculated by using the spread plate method, where 100 microL of the incubated antibacterial agent in bacteria solutions were spread on agar plates and the number of viable bacteria was counted after 24 h of incubation period at 37 degrees C.
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PMID:Synthesis, characterization, and antibacterial activities of novel methacrylate polymers containing norfloxacin. 1563 60

Iridium is preconcentrated from the large volume of its aqueous solution using 1-(2-pyridylazo-2-naphthol) (PAN) on microcrystalline naphthalene in the pH range of 4.5-6.0. The solid mass after filtration is dissolved with 5 ml of dimethylformamide (DMF) and the metal determined by first derivative spectrophotometry. The detection limit is 20 ppb (signal to noise ratio = 2) and the calibration curve is linear over the concentration range 0.25-75.0 mug in 5 ml of the final DMF solution with a correlation coefficient of 0.9996 and relative standard deviation of +/- 1.1%. Various parameters such as the effect of pH, volume of aqueous phase, choice of solvent, reagent and naphthalene concentration, shaking time and interference of a number of metal ions on the determination of trace amount of iridium have been studied in detail to optimize the conditions for its determination in synthetic samples corresponding to various standard alloys and environmental samples.
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PMID:Derivative spectrophotometric determination of iridium after preconcentration of its 1-(2-pyridylazo)-2-naphthol complex on microcrystalline naphthalene. 1896 20

A new class of homologous gelators, LG12 -(CH2 )n -BSA, composed of bipyridinyl groups, L-glutamic moieties having double dodecyl chains, and linked alkyl spacers with different lengths were synthesized. It was found that these gelators could immobilize medium-polarity solvents readily and the behaviors of these gels showed a dependence on the spacer length. Of all the gels, the LG12 -(CH2 )11 -BSA gels exhibited self-healing property and multiple-stimulus responsibility, such as heating, shaking, and sonication. The investigation of CD spectra indicated that the supramolecular chirality, which was attributed to the chiral transfer from the chiral center to the assemblies, was also closely related to the length of methylene spacers. The longer the alkyl spacers, the weaker the transmitted supramolecular chirality. Only LG12 -(CH2 )1 -BSA gelators, which had the shortest spacers, formed right-handed nanoscale chiral twists owing to crowded hydrogen bonding interactions. Moreover, the high-polarity solvent DMF was found to be able to regulate the chiral twist as well as its pitch length readily.
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PMID:Multiple-stimulus-responsive supramolecular gels and regulation of chiral twists: the effect of spacer length. 2583 65

The synthetic methodology is carried out in multistep which was initiated as phase I by utilizing Fischer esterification methodology of 2-phenylacetic acid (1) to ethyl-2-phenylacetate (2). The ester was reacted with hydrazine hydrate form 2-phenylacetohydrazide (3) which underwent ring closure with carbon disulfide in alcoholic base to achieve 5-benzyl-1,3,4-oxadiazole-2-thiol (4). Phase II, involved the reaction of electrophiles with 2-bromoacetylbromide (5) with arylated/arenylated amines (6a-e) in aqueous alkaline medium under vigorous shaking to generate N-substituted-2-bromoacetamides (7a-e). Finally in phase III, the parent oxadiazole reacted with N-substituted-2-bromoacetamides and in DMF/LiH to yield 2-[(5-benzyl-1,3,4-oxadiazole-2yl)sulfanyl]-N-(arylated/arenylated) acetamides (8a-e). All the derivatives were screened for their anti-enzymatic potential against acetyl/butyrylcholinesterase and lipoxygenase and for the antibacterial activity. They were found to be weak enzyme inhibitors and also possessed weak antibacterial action with the exception of 8e, which demonstrated prominent anti-enzymatic and antibacterial activity, which may be attributed to the presence of 3,4-dimethoxyphenylacetamide moiety. The LD50 data revealed that most of the N-substituted derivatives were found to be less cytotoxic.
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PMID:Synthesis of 2-[(5-benzyl-1,3,4-oxadiazole-2yl)sulfanyl]-N-(arylated/arenylated) acetamides as antibacterial and acetyl cholinesterase inhibitors. 2908 97

A fluorescent metallogel (1 %w/v) has been synthesized from deprotonation of non-fluorescent adipic acid derived ligand H4AL with LiOH followed by coordination with Cd2+ in DMF. The Cd2+ not only induces the coordination complex formation, but, it leads to aggregation, nanofibre formation of about ~10 nm average diameter and gelation. Metallogel was also found to be reversibly stimuli-responsive towards heating and mechanical shaking whereas resistant for ultrasound. The involvement of chelation enhanced fluorescence (CHEF), aggregation induced emmision (AIE) and aggregation caused quenching (ACQ) during the course of gelation has been well established by fluorescence experiments. Further, corrdination complex involved in metallogel formation has been well characterized by ESI-MS and Job's plot. The synthesized metallogel has true gel phase material is proved by a detailed rheological studies. The mechanism of gelation is well established by using FTIR, UV-vis, fluorescence, lifetime measurement, Job's plot, ESI-mass, PXRD and TEM techniques.
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PMID:Cd2+-induced Fluorescent Metallogel: A case of CHEF and ACQ phenomenon. 3113 4