Browsing Chemistry by Issue Date

Now showing items 1-20 of 336

Non-aqueous titration of hydroxamic acids

Stamey, T. W.; Christian, Robert (Elsevier, 1966-01-01)

Benzohydroxamic acid is titrated with 0.1M tetrabutyl-anunonium hydroxide in nine non-aqueous solvents with three different indicating electrodes. The best results are obtained using dimethylformamide as solvent and ...
Borate complexes of benzohydroxamic acid and some of its derivatives

Fields, Alan R.; Daye, Barbara M.; Christian, Robert (Elsevier, 1966-07-01)

Ultraviolet spectrophotometric measurements in dilute aqueous solution give pK(a) values of 8.78, 8.27, 8.96 and 8.68, respectively, for benzohydroxamic, N-phenylbenzohydroxamic, p-methoxybenzohydroxamic and N-methyl-p-m ...
A microprocessor-controlled photon counter for pulsed optically detected magnetic resonance

Power, R. K.; Nishimura, A. M. (American Institute of Physics, 1979-08-01)

In pulsed optically detected magnetic resonance (ODMR) spectroscopy, a lock-in amplifier is used to monitor the signal which is phase-matched to the duty cycle of an applied sequence of pulses. However, since the desired ...
Affinity chromatography of glucose dehydrogenase

Carper, W. Robert; Groutas, William C.; Coffin, D. B. (Springer, 1988-01-15)

Porcine liver beta-D-glucose dehydrogenase, a multi-functional protein, has been purified to apparent homogeneity. The enzyme has been separated from the endoplasmic reticulum using Triton X-114 and further purified using ...
Results compared for tricyclic antidepressants as assayed by liquid chromatography and enzyme immunoassay

Dorey, R. Cameron; Preskorn, Sheldon H.; Widener, Pamela K. (P.B. Hoeber, 1988-11-01)

The tricyclic antidepressants amitriptyline, nortriptyline, imipramine, and desipramine in serum of patients taking one of the drugs were quantified in two laboratories by high-performance liquid chromatography (HPLC) and ...
High-performance liquid chromatographic analysis of DNA composition and DNA modification by chloroacetaldehyde

Singhal, Ram P.; Landes, J. P. (Elsevier, 1988-12-23)

The separation of common and modified deoxyribonucleosides derived from DNA hydrolyzates was examined under different chromatographic conditions on silica-based octadecyl (C18) columns, involving hydrophobic interactions ...
Inhibition of human leukocyte elastase by derivatives of N-hydroxysuccinimide. A structure-activity-relationship study

Groutas, William C.; Brubaker, Michael J.; Stanga, Michael A.; Castrisos, J. C.; Crowley, J. P.; Schatz, E. J. (American Chemical Society, 1989-07-01)

A series of compounds derived from 3-alkyl-N-hydroxysuccinimide have been synthesized and their inhibitory activity toward human leukocyte elastase has been investigated. Compounds having an isobutyl or isopropyl group at ...
Hydantoin derivatives. A new class of inhibitors of human leukocyte elastase

Groutas, William C.; Stanga, Michael A.; Castrisos, J. C.; Schatz, E. J. (Informa Healthcare, 1990-01-01)

Derivatives of hydantoin have been found to inactivate human leukocyte elastase irreversibly. Chymotrypsin and cathepsin G are also inhibited by these compounds.
Inhibitors of human leukocyte proteinase-3

Groutas, William C.; Hoidal, John R.; Brubaker, Michael J.; Stanga, Michael A.; Venkataraman, Radhika; Gray, B. H.; Rao, Narayanam V. (American Chemical Society, 1990-04-01)
Ionic inhibitors of human leukocyte elastase: pyridinium and phenyl carboxylate derivatives of 3-alkyl-N-hydroxysuccinimide

Groutas, William C.; Stanga, Michael A.; Castrisos, J. C.; Schatz, E. J.; Brubaker, Michael J. (John Wiley and Sons, 1990-10-01)

A series of pyridinium and phenyl carboxylate derivatives of 3-alkyl-N-hydroxysuccinimide has been synthesized; the compounds have been shown to be highly effective, time-dependent inactivators of human leukocyte elastase. ...
N,N,N',N'-tetramethyl-1,4-phenylenediamine: a facile electron donor and chromophoric substrate for dopamine beta-monooxygenase

Wimalasena, Kandatege; Wimalasena, D. Shyamali (Elsevier, 1991-03-29)

Dopamine beta-monooxygenase is shown to catalyze the oxidation of N,N,N',N'-tetramethyl-1,4-phenylenediamine (TMPD) to its cation radical in the presence of a regular substrate and molecular oxygen. The enzyme-mediated ...
Inhibition of human leukocyte elastase by phosphate esters of N-hydroxysuccinimide and its derivatives: direct observation of a phosphorylated enzyme by 31P nuclear magnetic resonance spectroscopy

Groutas, William C.; Venkataraman, Radhika; Brubaker, Michael J.; Stanga, Michael A. (American Chemical Society, 1991-04-30)

A series of phosphate esters derived from N-hydroxysuccinimide and 3-alkyl-N-hydroxysuccinimide have been synthesized and found to be potent time-dependent irreversible inhibitors of human leukocyte elastase (HLE). The ...
Microcapsules through polymer complexation. I: Complex coacervation of polymers containing a high charge density

Wen, Shao; Yin, X. N.; Stevenson, William T.K. (Elsevier, 1991-05-01)

Acidic and basic methacrylate co- and ter-polymers based on (respectively) methacrylic acid (MAA) and dimethylaminoethyl methacrylate (DMAEMA) were prepared by solution free radical polymerization and structurally characterized ...
Microcapsules through polymer complexation. II. By complex coacervation of polymers containing a low charge density

Shao, W.; Yin, X. N.; Stevenson, William T.K.; Alexander, Holly (Elsevier, 1991-07-01)

Relationships between ionizable group content, structure and molecular weight, solubility and solution behaviour, and the efficacy of ionic complex formation through complex coacervation, have been established for a range ...
Continuous spectrophotometric assays for dopamine beta-monooxygenase based on two novel electron donors: N,N-dimethyl-1,4-phenylenediamine and 2-aminoascorbic acid

Wimalasena, Kandatege; Wimalasena, D. Shyamali (Elsevier, 1991-09-02)

Based on the novel chromophoric electron donors, N,N-dimethyl-1,4-phenylenediamine (DMPD) and 2-amino-2-deoxy-L-ascorbic acid (2-aminoascorbic acid), two sensitive, convenient, and continuous spectrophotometric assays for ...
Boronate affinity chromatography

Singhal, Ram P.; DeSilva, S. S. (Springer, 1992-01-01)
Inhibitors of human neutrophil cathepsin G: structural and biochemical studies

Groutas, William C.; Brubaker, Michael J.; Venkataraman, Radhika; Epp, Jeffrey B.; Stanga, Michael A.; McClenahan, Jerald J. (Elsevier, 1992-04-01)

The interaction of a series of sulfonate and phosphate esters derived from N-hydroxysuccinimide with human leukocyte cathepsin G was investigated. The synthesized compounds were found to be time-dependent inhibitors of the ...
Enantioselective inhibition of human leukocyte elastase

Groutas, William C.; Brubaker, Michael J.; Venkataraman, Radhika; Stanga, Michael A. (Elsevier, 1992-08-15)

(RS)-Diethyl-2-benzyl-succinate was resolved using alpha-chymotrypsin. The two enantiomers were then elaborated to yield (S)-(+) and (R)-(-)-3-benzyl-N-[(methyl-sulfonyl)oxy]succinimide and the inhibitory activity of the ...
Separation of dideoxyribonucleosides in trace amounts by automated liquid chromatography and capillary electrophoresis

Singhal, Ram P.; Hughbanks, D.; Xian, Jun (Elsevier, 1992-09-18)

No satisfactory high-performance liquid chromatographic (HPLC) method is currently available for the separation of the major dideoxyribonucleosides (ddNs) and their derivatives. A method involving HPLC has been developed ...
Human neutrophil proteinase 3: mapping of the substrate binding site using peptidyl thiobenzyl esters

Brubaker, Michael J.; Groutas, William C.; Hoidal, John R.; Rao, Narayanam V. (Elsevier, 1992-11-16)

A series of peptidyl thiobenzyl esters was used to map the active site of human leukocyte proteinase 3. The steady-state kinetics parameters reveal the following features regarding the substrate specificity of proteinase ...