Cyclische Phenyl‐carbamate des Miotin‐Typs und ihre Wirkung auf die Acetylcholinesterase

Amstutz, René; Enz, Albert; Marzi, M.; Boelsterli, Jakob; Walkinshaw, Malcolm D.

doi:10.1002/hlca.19900730323

Cited by 22 publications

(8 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To our knowledge, low volatility may slow the mass transfer from the matrix to the headspace, resulting in the need for a higher temperature to give detectable amounts of analyte. The high boiling point and molecular weight of tramadol led to slow evaporation [21], Fig. 2.…”

Section: Optimization Of the Spme Conditionsmentioning

confidence: 99%

Rapid determination of tramadol in human plasma by headspace solid-phase microextraction and capillary gas chromatography–mass spectrometry

Sha

Shen

Duan

2005

Journal of Pharmaceutical and Biomedical Analysis

View full text Add to dashboard Cite

Section: Optimization Of the Spme Conditionsmentioning

confidence: 99%

Rapid determination of tramadol in human plasma by headspace solid-phase microextraction and capillary gas chromatography–mass spectrometry

Sha

Shen

Duan

2005

Journal of Pharmaceutical and Biomedical Analysis

View full text Add to dashboard Cite

“…The limit of quantification (LOQ) was defined as the lowest concentration of the extracted standard sample with EXPERIMENTAL Drugs and reagents. Rivastigmine, (Amstutz et al, 1990) (internal standard) were from Novartis Pharma AG, Basel Switzerland. The structures of the three chemical entities are show in Fig.…”

Section: Sample Preparationmentioning

confidence: 99%

A simple, rapid and sensitive method for simultaneous determination of rivastigmine and its major metabolite NAP 226‐90 in rat brain and plasma by reversed‐phase liquid chromatography coupled to electrospray ionization mass spectrometry

Enz

Chappuis

Dattler

2003

Biomedical Chromatography

Self Cite

View full text Add to dashboard Cite

A simple and sensitive reversed-phase liquid chromatography coupled with electrospray-mass spectrometry was developed and validated for the simultaneous determination of rivastigmine, a cholinesterase inhibitor, and its major metabolite NAP 226-90 in rat plasma and brain homogenates. Rivastigmine and NAP 226-90 were extracted from plasma and brain by ethyl acetate and, after drying under nitrogen, re-dissolved in acetonitrile and separated isocratic by HPLC on a C(18) column and quantified by single ion monitoring mass spectrometer. The mean (+/-SD) extraction efficiency for rivastigmine in plasma and brain was 93 +/- 2 and 95 +/- 2% (n = 5) of NAP 226-90 in a drug range of 10-100 pmol/mL or pmol/g. The method proved to be linear within the tested range (regression coefficient, r = 0.9999, n = 5). Intra- and inter-day precision coefficients of variation and accuracy bias were acceptable (within 15%, n = 5) over the entire range for both compounds using plasma or brain samples. The limits of quantification were 0.5 pmol/mL plasma and 2.5 pmol/g brain for rivastigmine and 1 pmol/mL plasma and 5 pmol/g brain for NAP 226-90, respectively. The analytical technique was used to determine the concentrations of rivastigmine and its metabolite NAP 226-90 in rat plasma and brain after oral drug administration. The concentrations of the parent drug and its major metabolite were compared to a pharmacodynamic parameter, the ex vivo inhibition of acetylcholinesterase.

show abstract

“…Moreover, if a β‐lactamase were to be acylated by a dihydrobenzoxazinone, the presence of this atom should also stabilize the acyl enzyme. A derivative of the parent heterocycle, 3,4‐dihydro‐3‐methyl‐6‐nitro‐2 H ‐1,3‐benzoxazin‐2‐one 3 , is known to react with chymotrypsin,4 whereas several of its analogues or homologues result in the production, with cholinesterases, of stabilized carbamoyl‐bound enzymes 5,6…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Hydrolysis, and Evaluation of 3-Acylamino-3,4-dihydro-2-oxo-2H-1,3-benzoxazinecarboxylic Acids and Linear Azadepsipeptides as Potential Substrates/Inhibitors of β-Lactam-Recognizing Enzymes

et al. 2001

View full text Add to dashboard Cite

The title compounds can be considered as stabilized aza analogs of previously studied dihydrobenzopyranones and linear depsipeptides, which behave as substrates or inhibitors of β-lactamases. Treatment of substituted hydrazides 9b and 9bЈ with a phosgene substitute resulted in a series of N-methylated 3-acylamino-3,4-dihydro-2-oxo-2H-1,3-benzoxazine-7-and -8-carboxylic acids 2b and 2bЈ. However, in the case of the corresponding free NH hydrazide 9a(m), a competitive cyclization gave instead a stable 4H-1,3,4-oxadiazol-5-one 10a. To avoid this unwanted cyclization, an N-(p-methoxy)-benzylated hydrazide 9bЈЈ was prepared. After formation of the benzoxazinone ring with carbonyldiimidazole, the removal of this new N 1 -hydrazide protecting group was achieved with methanesulfonic acid in trifluoroacetic acid to give the expected 3-phenacetamido-3,4-dihydro-2-oxo-2H-

show abstract

Cyclische Phenyl‐carbamate des Miotin‐Typs und ihre Wirkung auf die Acetylcholinesterase

Cited by 22 publications

References 12 publications

Rapid determination of tramadol in human plasma by headspace solid-phase microextraction and capillary gas chromatography–mass spectrometry

Rapid determination of tramadol in human plasma by headspace solid-phase microextraction and capillary gas chromatography–mass spectrometry

A simple, rapid and sensitive method for simultaneous determination of rivastigmine and its major metabolite NAP 226‐90 in rat brain and plasma by reversed‐phase liquid chromatography coupled to electrospray ionization mass spectrometry

Synthesis, Hydrolysis, and Evaluation of 3-Acylamino-3,4-dihydro-2-oxo-2H-1,3-benzoxazinecarboxylic Acids and Linear Azadepsipeptides as Potential Substrates/Inhibitors of β-Lactam-Recognizing Enzymes

Contact Info

Product

Resources

About