scholarly journals Inhibition of staphylococcal α-toxin. The effect of aromatic polysulphonic acids on the lethal effect of α-toxin in mice

1968 ◽  
Vol 108 (1) ◽  
pp. 49-55 ◽  
Author(s):  
J. P. Arbuthnott ◽  
I. R. W. Lominski ◽  
Margaret Robson Wright
Keyword(s):  
Lethal Effect ◽  
Haemolytic Activity ◽  
Compound Viii ◽  
Test Compound ◽  
Inhibitory Activities ◽  
Related Compounds ◽  
Group 1

1. Certain aromatic polysulphonic acids, previously tested for inhibition of the haemolytic activity of staphylococcal α-toxin, together with some additional related compounds, were tested as possible inhibitors of α-toxin in mice. 2. Compounds that inhibited the haemolytic activity of α-toxin at concentrations of 0·16mm or less [compounds (I), (II), (IV), (V), (VII) and (VIII)] were found to inhibit the lethal effect of α-toxin. 3. With the exception of compound (VIII), amounts of 1mg. were required to inhibit 4 LD50 of toxin when the test compounds were premixed with α-toxin before injection; comparable inhibition with 0·3mg. of compound (VIII) was achieved without prolonged premixing. 4. Mixtures of α-toxin and compounds (I) and (II) containing an excess of test compound showed markedly diminished inhibitory activities. 5. The ‘half-molecule’ analogues of group 1 [compounds (III) and (XVIII)] were non-inhibitory. 6. Compounds (I)–(V), when administered separately from α-toxin by the same route (intraperitoneal), were active only when injected almost simultaneously with toxin, whereas compounds (VII) and (VIII) were strikingly inhibitory when injected 15min. before or after the toxin. 7. Compound (VIII) failed to inhibit the lethal effect of α-toxin when injected by a different route (intravenous).

scholarly journals Phytogrowth-Inhibitory Activities of .BETA.-Dolabrin and .GAMMA.-Thujaplicin, Hinokitiol-Related Compounds and Constituents of Thujopsis dolabrata Sieb. et Zucc. var hondai MAKINO.

2000 ◽  
Vol 23 (5) ◽  
pp. 645-648 ◽  
Author(s):  
Yoshikazu SAKAGAMI ◽  
Yoshihiko INAMORI ◽  
Nami ISOYAMA ◽  
Hiroshi TSUJIBO ◽  
Toshihiro OKABE ◽  
...  
Keyword(s):  
Inhibitory Activities ◽  
Related Compounds

Development of Enzyme Immunoassay for Captan and Its Degradation Product Tetrahydrophthalimide in Foods

1993 ◽  
Vol 76 (2) ◽  
pp. 381-386 ◽  
Author(s):  
W Harvey Newsome ◽  
Jupiter M Yeung ◽  
Peter G Collins
Keyword(s):  
Detection Limit ◽  
Human Serum Albumin ◽  
Degradation Product ◽  
Protein Concentration ◽  
Polyclonal Antibodies ◽  
Enzyme Linked Immunosorbent Assay ◽  
Test Compound ◽  
Coefficients Of Variation ◽  
Spacer Arm ◽  
Related Compounds

Abstract A simple, sensitive, and precise enzyme-linked immunosorbent assay (ELISA) is described for the quantitation of captan as its degradation product tetrahydrophthalimide (THPI) in foods using polyclonal antibodies. Three hapten analogues of THPI with different alky I spacer arm lengths were synthesized. Immunogens and coating proteins were prepared by coupling these haptens to human serum albumin and ovalbumin, respectively. A 5-carbon spacer arm appeared to be optimum for the production of antibodies. Heterologous coating proteins did not improve the sensitivity, but reduction of homologous coating protein concentration did improve the sensitivity, resulting in a concentration of test compound required to inhibit binding by 50% of 15.5 ng/mL The antiserum is specific for captan, captafol, and THPI, but not other structurally related compounds. The minimum detection limit was 1 ng/mL; the linearity was 1-200 ng/mL. The overall recoveries of captan and THPI from 11 commodities spiked at 4 levels were 92 and 100%, respectively. The intra-assay and interassay coefficients of variation were 9.1 and 16.8% for apple blanks and 5.9 and 4.2% for apple spiked with 3 ppm THPI, respectively. The ELISA described is suitable for measuring captan and THPI at levels comparable to those typically found in fruit.

scholarly journals Inhibitory activities and inhibition specificities of caffeic acid derivatives and related compounds toward 5-lipoxygenase.

1989 ◽  
Vol 37 (4) ◽  
pp. 1039-1043 ◽  
Author(s):  
Masanori SUGIURA ◽  
Youichiro NAITO ◽  
Yasunari YAMAURA ◽  
Chikara FUKAYA ◽  
Kazumasa YOKOYAMA
Keyword(s):  
Caffeic Acid ◽  
Caffeic Acid Derivatives ◽  
Inhibitory Activities ◽  
Related Compounds

Growth-inhibitory activities of some 1,4-naphthoquinones and related compounds on Staphylococcus aureus and Escherichia coli

1968 ◽  
Vol 14 (6) ◽  
pp. 661-666 ◽  
Author(s):  
G. J. Leahy ◽  
D. J Currie ◽  
H. L. Holmes ◽  
J. R. Maltman
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Electron Transport ◽  
Electron Transport Chain ◽  
Growth Inhibitory ◽  
Transport Chain ◽  
Half Wave ◽  
Inhibitory Activities ◽  
Related Compounds

Growth-inhibitory activities of some or all of 98 1,4-naphthoquinones and 16 related compounds on Escherichia coli and two strains of Staphylococcus aureus were determined alone or in combination. These values, when plotted against their polarographic half-wave potentials and those of their C2-n-butylthio analogs support the hypothesis that these compounds, or the products resulting from their reaction with a protein nucleophile, function by short-circuiting one or other of the quinones present in the electron-transport chain.

scholarly journals Comparative evaluation of the inhibitory activities of the novel penicillanic acid sulfone Ro 48-1220 against beta-lactamases that belong to groups 1, 2b, and 2be.

1997 ◽  
Vol 41 (2) ◽  
pp. 475-477 ◽  
Author(s):  
L S Tzouvelekis ◽  
M Gazouli ◽  
E E Prinarakis ◽  
E Tzelepi ◽  
N J Legakis
Keyword(s):  
Inhibitory Activity ◽  
Comparative Evaluation ◽  
The Novel ◽  
Beta Lactamases ◽  
Penicillanic Acid ◽  
Inhibitory Activities ◽  
Group 1

The inhibitory activity of the penicillanic acid sulfone Ro 48-1220 against group 1, 2b, and 2be beta-lactamases was evaluated. Ro 48-1220 inhibited TEM and SHV as effectively as clavulanate and tazobactam. It also inhibited group 1 beta-lactamases at lower concentrations than tazobactam. Ro 48-1220, at a concentration of 4 micrograms/ml, protected ceftriaxone and ceftazidime against strains producing group 1 and 2be beta-lactamases.

Induction of drug-metabolizing enzymes of rat liver by derivatives of coumarin

1970 ◽  
Vol 48 (4) ◽  
pp. 232-240 ◽  
Author(s):  
George Feuer
Keyword(s):  
Lipid Solubility ◽  
Induction Effect ◽  
Drug Metabolizing Enzymes ◽  
Test Compound ◽  
Hydroxylase Activity ◽  
Metabolizing Enzymes ◽  
Oral Doses ◽  
Derivatives Of ◽  
Related Compounds ◽  
Enzyme Inducers

The ability of coumarin and 35 structurally related compounds to induce coumarin 3-hydroxylase was examined in the liver of the rat. After seven daily oral doses of 1 mmole/kg of the test compound, the hydroxylase activity with coumarin or 4-methylcoumarin as substrate was increased 13- to 14-fold by 8-(2″-butenyloxy-3″-methyl)-furo-(2′:3′–6:7) coumarin; 4- to 8-fold by 4-methylcoumarin; 6-fold by 6-acetyl-4,8-dimethyl-7-hydroxycoumarin; 2- to 5-fold by 7,8-dihydroxy-4-methylcoumarin; 2- to 3-fold by 6,7-dihydroxy-4-methylcoumarin, 7-hydroxy-4-methylcoumarin, 4,8-dimethyl-7-hydroxycoumarin, 3-isopropyl-7-methoxy-4-methyl coumarin, 3-chloro-7-methoxy-4-methylcoumarin, and 3-carboxycoumarin. Nearly all enzyme inducers contained the 4-methyl substituent. 4-Methylcoumarin and 6,7-dihydroxy-4-methyl coumarin elicited a greater induction on the hydroxylation of 4-methylcoumarin than on that of coumarin. The other coumarin derivatives brought about no consistently greater effect on either hydroxylase. No correlation was found between the induction effect and the lipid solubility of the inducer. 4-Methylcoumarin exerted a greater induction effect on coumarin 3-hy droxylase than on nitroanisole or codeine demethylase and hexobarbitone or butylated hydroxy toluene oxidases. Other known enzyme inducers (hexobarbitone, 17-methyltestosterone, and 20-methylcholanthrene) also increased hydroxylase activity in a manner comparable to that of 4-methylcoumarin.

scholarly journals New inhibitors of methane production by rumen micro-organisms. Development and testing of inhibitors in vitro

1975 ◽  
Vol 34 (3) ◽  
pp. 429-446 ◽  
Author(s):  
J. W. Czerkawski ◽  
Grace Breckenridge
Keyword(s):  
Methane Production ◽  
Trichloroacetic Acid ◽  
Physical State ◽  
Pivalic Acid ◽  
Relative Activity ◽  
State Density ◽  
Inhibitory Activities ◽  
Micro Organisms ◽  
Related Compounds

1. A procedure is described for assaying in vitro the activity of various inhibitors of methane production by rumen micro-organisms.2. Methods of preparation of various inhibitors are described together with attempts to characterize these compounds by determining their physical properties (physical state, density, chromatographic behaviour), their hydrolysis by rumen contents and their relative potency as inhibitors.3. The results of preliminary studies with trichloroethanol and its ester with pivalic acid are given.4. The inhibitory activities of several groups of related compounds are reported. These include the polyhalogenated alcohols and their esters with pivalic acid, the esters of trihalogenated alcohols and monobasic fatty acids from C2to C16and the trihalogenated alcohol esters of dibasic acids. The results of experiments with esters of alcohols and polyhalogenated carboxylic and sulphonic acids are also given.5. It is concluded that the mechanism of action of the inhibitors might be similar to that of known polyhalogenated methane analogues (e.g. chloroform). The relative activity of various compounds might be partly governed by the ease of their absorption into the microbial cells and by the extent to which the esters can be hydrolysed by rumen contents.6. The results show that some substances are very poor inhibitors, unless they are esterified (e.g. trichloroacetic acid) but on the whole the esters in which the polyhalogen grouping is on the alcohol portion of the molecule are better inhibitors than those in which it is on the acid portion of the molecule.

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