High-performance liquid chromatography and capillary electrophoresis of L- and D-carnitine by precolumn diastereomeric derivatization.

A new method for the simultaneous assay of D- and L-enantiomers of carnitine is described. The method is based on precolumn derivatization with (+)-1-(9-fluorenyl)ethyl chloroformate [(+)FLEC] producing a diastereomeric derivative which can be detected both by UV absorbance and fluorescence detection. Also acyl esters of carnitine can be processed with this method, after alkaline hydrolysis. The D-enantiomer of carnitine and acylcarnitine can be detected at a concentration as low as 0.2% in the raw material and in pharmaceuticals. Assays can be carried out using an autoinjector either by HPLC or capillary electrophoresis (CE) because the derivative proved to be very stable. Its application is proposed for the routine assay of the enantiomeric excess of L-carnitine and their acyl esters in pharmaceutical products.

Synthesis and amnesia-reversal activity of a series of 7- and 5-membered 3-acylamino lactams.

A series of 3-(acylamino)-epsilon-caprolactams and 3-(acylamino)-2-pyrrolidinones was synthesized. Some of these compounds reversed at different degrees electroconvulsive shock- and Scopolamine-induced amnesia, using a step-through passive avoidance in mice. Classical nootropic drugs, i.e., Aniracetam, Oxiracetam, and Piracetam, were used as reference compounds. Within the analyses of data performed, we introduced a new parameter, the confrontation index (CI), which is a function of Mann-Whitney's U statistic. The CI permits a common scale of activity of substances to be generated, independently of probabilistic hypotheses, with higher scores representing higher activities. The most active compounds were characterized by the formylamino and [3-(trifluoromethyl)benzoyl]amino groups in the 3-position of the ring. None of the substances assayed showed any effect on spontaneous behavior and neurovegetative system.

In vivo and in vitro antilipolytic effects of some various substituted homocysteine-thiolactone-nicotinamides: structure-activity study.

The antilipolytic activity of homocysteine-thiolactone-nicotinamide (ST22) and in 2-chloro (ST71), 6-chloro (ST82) and 6-hydroxy (ST90) derivatives was investigated by evaluation of serum free fatty acids (FFA) and triglycerides (TG) (in vivo) and FFA release from adipose tissue (in vitro). Increased FFA levels in 17-hr fasted rats at 60 min following treatment with 7 . 10(-4) mol kg-1 p.o. were reduced by 70% (ST22), 60% (ST82) and 18% (ST71), whereas ST90 provoked no change; TG levels showed similar changes. Basal FFA release from epididymal rat adipose tissue at 60 min following treatment with 7 . 10(-4) mol kg-1 p.o. of ST22 and ST82 was reduced by 79 and 45%, respectively. Lipid mobilization induced by noradrenaline (NA) was diversely affected by the compounds according to the tests employed: with in vivo experiments, serum FFA levels were reduced by 60, 70, 10 and 5% at 60 min following treatment with ST22, ST82, ST71 and ST90, respectively (7 . 10(-4) mol kg-1 p.o.; NA bitartrate, 2 mg kg-1 s.c.); in vitro, ST22 produced no change, whereas the other compounds induced a significant mobilization of FFA. The results suggest that: (a) antilipolytic activity can be greatly modified when various substituents capable of influencing either the inductive (-I) or the resonance (+M) effect are introduced into the different positions of the pyridine ring; and (b) the lipolysis experiments did not evince any direct relationship between the effects obtained by the in vivo tests and those obtained by the in vitro tests.

Semisynthetic beta-lactam antibiotics. III. Cephalosporin derivatives in the furyl series. Chemical and microbiological properties.

The synthesis of a series of 7-acylamido cephalosporins having a substituted furyl moiety in the side chain is described. These new cephalosporins were examined in vitro for antibacterial activity and evaluated for resistance to inactivation by beta-lactamases.

Semisynthetic beta-lactam antibiotics. II Cephalosporin derivatives in the naphthalene series. Chemical and microbiological properties.

A seris of new 7-acylamidocephalosporins, containing a substituted naphthalene moiety in the side chain, has been prepared and tested for their in vitro antibacterial activity. Some observations are made on the structure-activity relationships.

Synthesis of 7-acylamidodesacetoxycephalosporanic acids and corresponding pivaloyloxymethyl esters. Chemical and microbiological properties.

A series of 7-acylamidodesacetoxycephalosporanic acids and analogous pivaloyloxymethyl esters have been prepared and tested in vitro for antibacterial activity. Those acids which exhibited a significant in vitro activity, were also studied in vivo and compared with the corresponding esters. Experiments performed on laboratory animals showed that, after oral administration, the esters were absorbed more efficiently than the corresponding acids.

Synthesis and pharmacological activity and some derivatives of 1-phenyl-1,2,3,4-tetrahydro-5H-1,4-benzodiazepin-5-one.

4-N-Alkylamino derivatives and corresponding ammonium quaternary salts of tetrahydro-1,4-benzodiazepin-5-one were synthesized and evaluated for psychotropic activity in mice by ip via. This study was also extended to some nitro and amino derivatives of tetrahydro-1,4-benzodiazepin-5-one. Compounds were devoid of tranquilizing activity and in comparison with two classical benzodiazepines, chlordiazepoxide and diazepam, they showed high toxicity and little or no effect on motor coordination, motor activity, and maximal electroshock. On some "in vitro" tests the compounds exhibited pharmacological properties when they were used at high concentrations.

A new cephalosporin derivative (ST-21) orally administered in laboratory animals.

The pivaloxymethyl ester of 7-(D-2-amino-2-phenylacetamido)-desacetoxicephalosporanic acid hydrochloride (ST-21) and cephalexin possess the same bacteridal activity. In fact, in the animal body ST-21 releases cephalexin. The acute toxicity study shows the good tolerance of both substances, whereas the tissue distribution is different, both after oral and i.v. administration. Cephalexin concentrations in some tissues of rats and rabbits, particularly in the lungs and kidneys, are higher and longer-lasting in the animals treated with ST-21 than in those receiving cephalexin, thus showing a different pattern of distribution in the body. For this reason ST-21 might be more suited for the treatment of lung and kidney infections.