Inhibitory activity and bactericidal kinetics of mecillinam/ampicillin combinations against enterobacteriaceae, pseudomonas and acinetobacter

1. The effect of a number of aromatic polysulphonic acids on the kinetics of haemolysis of rabbit erythrocyte suspensions by crude staphylococcal α-toxin was studied at pH8·6 and 6·8. 2. All of the inhibitory compounds caused an increase in the prelytic lag time (τ) of the sigmoid haemolysis curves, an increase in the time to reach 50% haemolysis (t½) and a decrease in the maximum rate of haemolysis (Rmax.). The most inhibitory compounds caused a 50% decrease in Rmax. at concentrations between 0·1 and 0·2mm. 3. The effect of pH varied considerably: compounds (I) and (II) were almost equally inhibitory at both pH values, compounds (IV) and (IX) were more inhibitory at pH6·8 than at pH8·6, and compounds (VII), (VIII), (X), (XI) and (XII) were more inhibitory at pH8·6. 4. Increased time of premixing α-toxin with compound (I) caused increased inhibition. 5. An attempt was made, where possible, to relate the inhibitory activity to the structure of the test compound.

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Transformationen von trans-2-Hexenal durch Botrytis cinerea PERS. als Entgiftungsmechanismen / Transformations of trans-2-Hexenal by Botrytis cinerea PERS. as Detoxification Mechanisms

Zeitschrift für Naturforschung C ◽

10.1515/znc-1987-1-210 ◽

1987 ◽

Vol 42 (1-2) ◽

pp. 64-68 ◽

Cited By ~ 4

Author(s):

Irene Urbasch

Keyword(s):

Botrytis Cinerea ◽

Gas Phase ◽

Aqueous Phase ◽

Inhibitory Activity ◽

Transformation Products ◽

Antibiotic Activity ◽

Lower Toxicity ◽

Main Components ◽

Kinetics Of ◽

Detoxification Mechanisms

Abstract The metabolization of trans-2-hexenal - one of the main components of plant wound gases with antibiotic activity - was investigated for 5 different isolates of Botrytis cinerea PERS. The transformation products as well as the kinetics of their formation were analyzed. Isolates exclusively mycelium forming (Bc 1 and Bc 13) transformed tr-2-hexenal into tr-2- hexenol, while sporulating isolates (Bc 3, Bc 9 and Bc 10) converted tr-2-hexenal to hexanol-1. Basically the metabolization of tr-2-hexenal proceeded in the same way via the aqueous phase as in the gas phase. The transformation products tr-2-hexenol and hexanol-1 showed significantly lower toxicity against the tested B. cinerea isolates than tr-2-hexenal. In each isolate the end product of tr-2- hexenal conversion had the weakest inhibitory activity. The transformation reactions thus represent detoxification mechanisms for these fungi.

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Porcine Pancreatic Lipase Inhibitory Agent Isolated from Medicinal Herb and Inhibition Kinetics of Extracts from Eleusine indica (L.) Gaertner

Journal of Pharmaceutics ◽

10.1155/2016/8764274 ◽

2016 ◽

Vol 2016 ◽

pp. 1-9 ◽

Cited By ~ 3

Author(s):

Siew Ling Ong ◽

Siau Hui Mah ◽

How Yee Lai

Keyword(s):

Pancreatic Lipase ◽

Inhibitory Activity ◽

Hexane Fraction ◽

Inhibition Mechanism ◽

Porcine Pancreatic Lipase ◽

Active Components ◽

Reference Drug ◽

Spectral Techniques ◽

Eleusine Indica ◽

Kinetics Of

Eleusine indica (Linnaeus) Gaertner is a traditional herb known to be depurative, febrifuge, and diuretic and has been reported with the highest inhibitory activity against porcine pancreatic lipase (PPL) among thirty two plants screened in an earlier study. This study aims to isolate and identify the active components that may possess high potential as an antiobesity agent. Of the screened solvent fractions of E. indica, hexane fraction showed the highest inhibitory activity of 27.01±5.68% at 100 μg/mL. Bioactivity-guided isolation afforded three compounds from the hexane fraction of E. indica, namely, β-sitosterol, stigmasterol, and lutein. The structures of these compounds were elucidated using spectral techniques. Lutein showed an outstanding inhibitory activity against PPL (55.98±1.04%), with activity 60% higher than that of the reference drug Orlistat. The other compounds isolated and identified were β-sitosterol (2.99±0.80%) and stigmasterol (2.68±0.38%). The enzyme kinetics of E. indica crude methanolic extract on PPL showed mixed inhibition mechanism.

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Comparison of the gastric exocrine inhibitory activity and plasma kinetics of somatostatin-28 and somatostatin-14

Regulatory Peptides ◽

10.1016/0167-0115(83)90625-0 ◽

1983 ◽

Vol 5 ◽

pp. 6

Author(s):

B.H. Hirst ◽

J.M. Conlon ◽

J. Holland ◽

B. Shaw ◽

D.H. Coy

Keyword(s):

Inhibitory Activity ◽

Plasma Kinetics ◽

Kinetics Of ◽

Somatostatin 14

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Kinetics of α -glucosidase inhibitory activity and phytochemical analysis of Piper crocatum Ruiz & Pav. leaves ethanol extract

International Journal of Research in Pharmaceutical Sciences ◽

10.26452/ijrps.v11ispl4.4416 ◽

2020 ◽

Vol 11 (SPL4) ◽

pp. 2032-2036

Author(s):

Muhammad Alfarabi ◽

Maria Bintang ◽

Suryani ◽

Mega Safithri ◽

Waras Nurcholis

Keyword(s):

Inhibitory Activity ◽

Ethanol Extract ◽

Diabetes Type 2 ◽

Diabetes Type ◽

Phytochemical Analysis ◽

Inhibitory Effects ◽

Phenol Compounds ◽

Significant Function ◽

Kinetics Of

α-Glucosidase is an enzymes group that playing essential roles in the digestion of polysaccharide. Inhibitor of a-glucosidase can decrease polysaccharide digestion rate and therefore plays a significant function in preventing the development of diabetes (type 2). Piper crocatum Ruiz & Pav. is an essential herb applied traditionally in Indonesia to treat diabetes mellitus. This work evaluated the a-glucosidase inhibitory activity of P. crocatum leaves ethanol extract. Phytochemical component of the extract was also analyzed. The α-glucosidase inhibitory activity of the P. crocatum leaves ethanol extract was examined by reacting its different concentrations with α-glucosidase and p-nitrophenyl glucopyranoside. Kinetics of the α-glucosidase inhibition was determined using a Lineweaver-Burke plot. Phytochemical in the extract was determined using GC-MS. Ethanol extract of P. crocatum leaves exhibited moderate α-glucosidase inhibitory activity compared with acarbose. Phytochemical analyses showed the presence of stilbene, linolenic acid, phenol, phytosteroid, and α-tocopherol. The competitive action of P. crocatum leaves ethanol extract is due to its inhibitory effects on α-glucosidase. The stilbene and phenol compounds indicated responsible for anti-diabetic activity from P. crocatum leaves ethanol extract.

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Bromotyrosine Alkaloids with Acetylcholinesterase Inhibitory Activity from the Thai Sponge Acanthodendrilla sp

Natural Product Communications ◽

10.1177/1934578x1501001135 ◽

2015 ◽

Vol 10 (11) ◽

pp. 1934578X1501001 ◽

Cited By ~ 2

Author(s):

Natchanun Sirimangkalakitti ◽

Opeyemi J. Olatunji ◽

Kanokwan Changwichit ◽

Tongchai Saesong ◽

Supakarn Chamni ◽

...

Keyword(s):

Inhibitory Activity ◽

Nmr Assignments ◽

Therapeutic Potential ◽

2D Nmr ◽

Inhibition Kinetics ◽

Ache Inhibitory Activity ◽

First Time ◽

Kinetics Of ◽

Resolution Mass ◽

C Nmr

Twenty bromotyrosine alkaloids, including a new compound, 13-oxosubereamolline D (5), were isolated from the Thai sponge Acanthodendrilla sp. Their structures were determined by analyses of 1D- and 2D-NMR, high-resolution mass, and circular dichroism data. The complete 1H and 13C NMR assignments of 5,7β-dichlorocavernicolin (19) and 5,7α-dichlorocavernicolin (20) are described herein for the first time. The acetylcholinesterase (AChE) inhibitory activity of all isolated compounds was evaluated. Only homoaerothionin (7) and fistularin 1 (10) exhibited inhibitory activity against human recombinant AChE ( hrAChE) with IC50s of 4.5 and 47.5 μM, respectively. The hrAChE inhibition kinetics of 7, the most potent alkaloid, showed increased K m and unchanged V max values, suggesting its competitive mode of inhibition. The spirocyclohexadienylisoxazole and the length of the alkyl diamine linkage were proposed as the crucial parts for its strong inhibitory activity. This finding indicates a therapeutic potential for 7 in acetylcholine-related diseases, most importantly Alzheimer's disease.

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A novel class of protein from wheat which inhibits xylanases1

Biochemical Journal ◽

10.1042/bj3380441 ◽

1999 ◽

Vol 338 (2) ◽

pp. 441-446 ◽

Cited By ~ 59

Author(s):

W. Russell McLAUCHLAN ◽

Maria T. GARCIA-CONESA ◽

Gary WILLIAMSON ◽

Martinus ROZA ◽

Peter RAVESTEIN ◽

...

Keyword(s):

Triticum Aestivum ◽

Aspergillus Niger ◽

Molecular Mass ◽

Active Site ◽

Inhibitory Activity ◽

Basic Protein ◽

Recombinant Enzyme ◽

Terminal Sequence ◽

Xylanase Inhibitor ◽

Kinetics Of

We have purified a novel class of protein that can inhibit the activity of endo-β-1,4-xylanases. The inhibitor from wheat (Triticum aestivum, var. Soisson) is a glycosylated, monomeric, basic protein with a pI of 8.7–8.9, a molecular mass of 29 kDa and a unique N-terminal sequence of AGGKTGQVTVFWGRN. We have shown that the protein can inhibit the activity of two family-11 endo-β-1,4-xylanases, a recombinant enzyme from Aspergillus niger and an enzyme from Trichoderma viride.The inhibitory activity is heat and protease sensitive. The kinetics of the inhibition have been characterized with the A. niger enzyme using soluble wheat arabinoxylan as a substrate. The Km for soluble arabinoxylan in the absence of inhibitor is 20±2 mg/ml with a kcat of 103±6 s-1. The kinetics of the inhibition of this reaction are competitive, with a Ki value of 0.35 µM, showing that the inhibitor binds at or close to the active site of free xylanase. This report describes the first isolation of a xylanase inhibitor from any organism.

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Inhibition Kinetics of Sida rhombifolia L. Extract Toward Xanthine Oxidase by Electrochemical Method

Indonesian Journal of Chemistry ◽

10.22146/ijc.21270 ◽

2014 ◽

Vol 14 (1) ◽

pp. 71-77 ◽

Cited By ~ 3

Author(s):

Dyah Iswantini ◽

Muammar Yulian ◽

Sri Mulijani ◽

Trivadila Trivadila

Keyword(s):

Xanthine Oxidase ◽

Crude Extract ◽

Inhibitory Activity ◽

Electrochemical Method ◽

Competitive Inhibition ◽

Ethanol Extract ◽

Inhibition Kinetics ◽

Ic50 Value ◽

Kinetics Of ◽

Sida Rhombifolia

Sida rhombifolia L. is a traditional medicinal plant that has been known with potential as antigout. The previous research suggested that flavonoids crude extract of S. rhombifolia had an inhibitory activity toward xanthine oxidase by 71% and a spectrophotometric measurement showed that the type of flavonoids crude extract inhibition was a competitive inhibition. The purpose of the research was to investigate the type of inhibition kinetic of S. Rhombifolia’s ethanol extract by electrochemical method and to compare the measurements of linearity and sensitivity between spectrophotometric and electrochemical methods. The results showed that the yield of S. Rhombifolia’s ethanol extract was 9.82% with the inhibitory activity ranging from 13.64% to 82.69% (5.00-200 mg L-1) and IC50 value was 91.15±5.74 mg L-1. Allopurinol as a control showed the inhibitory activity of 15.26-70.95% (0.10-4.00 mg L-1) and IC50 value was 2.45±2.21 mg L-1. Inhibition kinetics of the ethanol extract caused a KM increase and unchange of VMAX. Based on the data, the type of inhibition kinetics was a competitive inhibition, with an inhibitor affinity (α) value of 3.18. Linearity of xanthine oxidase activity assay by electrochemical and spectrophotometric methods showed the range of 0.01-1.00 mM (R2 = 0.978) and 0.05-0.70 mM (R2 = 0.977) respectively. The sensitivity of electrochemical method was reported higher (0.95 μA mM-1) than the spectrophotometric method (0.007 min-1).

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