Gas chromatographic determination of diisopyramide in the presence of some butyrophenones in human plasma.

A gas chromatographic procedure with flame ionization detection for the simultaneous determination of diisopyramide and butyrophenones in plasma was developed and evaluated. The quantitative analysis of diisopyramide and butyrophenones (BTPs) was performed in gas chromatograph equipped with packed column (glass column packed with 3% of phenylmethyl silicone-20% ph.), with previous Solid Phase Extraction (SPE) of drugs in C18 minicolumns. For all the drugs considered the accuracy of the proposed method has been evaluated through the recovery test which fell in the range 93-99%, once the absence of matrix interferences has been verified. The precision, expressed as coefficient of variation (CV%), has been of the order of 4%. A 15 m x 0.32 mm i.d. crosslinked, 5% phenylmethyl silicone-coated fused-silica column was also quantitatively utilized and samples were injected using the on-column mode.

Simultaneous determination of propranolol or metoprolol in the presence of butyrophenones in human plasma by gas chromatography with mass spectrometry.

A method has been developed for the simultaneous gas chromatographic determination of propranolol or metoprolol and butyrophenones butyrophenones in human plasma in vitro. The drugs were extracted from plasma by solid-phase extraction. Calibration graphs were linear in the 50-300-ng/mL range. The recovery of the compounds was 80-90%. The sensitivity of the method was adequate for the determination of the drugs at toxic concentrations and at therapeutic levels. It is a simple, rapid, and reproducible method for the simultaneous determination of propranolol or metoprolol and some butyrophenones. The minimum detectable concentration was 50 ng/mL with a flame ionization detector and 10 ng/mL with a mass spectrometer detector.

Simultaneous determination of propranolol or metoprolol in the presence of benzodiazepines in the plasma by gas chromatography.

A method for the simultaneous gas chromatographic determination of propranolol and metoprolol and some benzodiazepines in human plasma is described. After the addition of an internal standard, plasma samples were adjusted to pH 8.5 and extracted by SPE chromatography. The analysis was performed by GC with packed and capillary columns, using a FID detector. The quantitative recovery was reported. The assay response was linear in concentration range 50-300 ng/mL for propranolol-benzodiazepine and 100-350 ng/mL for metoprolol-benzodiazepine mixtures.

Antimicrobial activity of basic cholane derivatives. X. Synthesis of 3 alpha- and 3 beta-amino-5 beta-cholan-24-oic acids.

A simple and convenient route to 3 alpha- and 3 beta-amino-5 beta-cholan-24-oic acids was developed via Leuckart-Wallach amination reduction and subsequent acid hydrolysis. Two epimeric formylamino derivatives were produced (alpha and beta), approximately in a 1:1 ratio, as determined by 13C nuclear magnetic resonance spectroscopy. The two isomers were separated by making use of their different solubilities in ethyl ether. The absolute configuration of the two amino acids was assigned by comparison with authentic reference samples.

Antimicrobial activity of basic cholane derivatives. Part IX.

Twenty new compounds derived from deoxycholic acid have been synthesized. They contain two basic functions: at C-24 (benzylamino, morpholino, diethanolamino, N,N-diethylethylenediamino, N-methylpiperazino) and at beta-C-3 (amino, methylamino, ethylamino, benzylamino). The compounds showed interesting antimicrobial activity, as expressed in terms of the low M.I.C. values (0.9-31-micrograms/ml) against five Gram(+) and four Gram(-) strains, two fungi and one yeast. The compounds inhibit the production of a fluorescent pigment in Pseudomonas aeruginosa: this result suggests that the ability to cross the bacterium cell membrane is the first step of activity. A discussion in terms of structure-activity relationship is reported.

Simultaneous determination of quinidine and butyrophenones in human plasma by GC-MS.

This report describes a sensitive GC and HRGC-MS procedure for the simultaneous determination of Quinidine and some bytyrophenone drugs in human plasma. The quantitative response is linear from 50-250 ng/ml using Pipamperone as international standard. It is suitable for clinical analysis at therapeutic levels.

Antimicrobial activity of basic cholane derivatives, VIII.

Two series of new compounds derived from deoxycholic acid have been synthesized: 3,12-dioxo-5 beta-cholan-24-N-substituted amides and their 3 beta-amino and 3 beta-N-alkylamino derivatives. The first series of five compounds 1-5 carries at C-24 the residue of benzylamine, morpholine, diethanolamine, N,N-diethyl-ethylenediamine, and N-methylpiperazine. The second series of twenty compounds 1A-D - 5A-D was prepared by means of reductive amination starting from the compounds of the first series. This reaction proved to be regioselective and stereospecific: it attacks only C-3 of the steroid moiety and introduces the following axial beta-oriented substituents: amino, methylamino, ethylamino, and benzylamino. The compounds of the first series showed moderate scattered antimicrobial activity; while introduction of the 3 beta-amino and 3 beta-N-alkylamino residue greatly increased activity towards Gram (+) strains; even yeast and fungi appear to be sensitive towards this last series of compounds. The results have been discussed with respect to the nature of the substituents both at C-3 and C-24, the highest activity being associated to the hydrophobicity of these residues.

[Derivatives of lithocholic acid with antibacterial and antifungal activity. IV]. / Derivati dell'acido litocolico ad attività antibatterica ed antifungina. Nota IV.

A series of N-substituted amides of litocholic acid and some N-substituted derivatives of 3 alpha-hydroxy-24-amino-5 beta- cholane were prepared and their in vitro antibacterial and antifungal activity determined against a variety of gram-positive and gram-negative strains and two kinds of mycetes . Some of the tested compounds showed an interesting activity against gram-positive strains and mycetes .

[Bile acid derivatives with antimicrobial activity]. / Derivati di acidi biliari ad attività antimicrobica.

A series of condensation products of cholic and dehydrocholic acids with (L)-aminoacids was prepared and tested in vitro for antimicrobial activity. The derivatives of cholic acid with basic aminoacids showed significant activity, especially marked when (L)-arginine was the condensed aminoacid.

[Pollution levels of the anesthetic agent fluorurate (gas chromatography study)]. / Tassi di inquinamento da agente anestetico fluorurato (Indagine gas-cromatografica).

Using a simple, highly sensitive technique, the rate of pollution due to enflurane in an operating theatre with two beds and two respirators but without an air exchange system has been measured. After much debate and after seven serious cases of viral hepatitis among medical staff, the facility was closed because it was judged to be unusable and because the surgical department using it was moved elsewhere.