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1

Determination of nalidixic acid using dispersive liquid-liquid microextraction followed by HPLC-UV

Daneshfar A, Lotfi H. J, Khezeli T

Acta Chromatographica

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2011

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Vol. 23, no. 4

567--577

EN

A fast, simple, and sensitive sample preparation procedure based on dispersive liquid-liquid microextraction (DLLME) followed by high-performance liquid chromatography and ultraviolet (HPLC-UV) detection was developed for the determination of nalidixic acid in a human urine sample. A mixture of extraction solvent (35 μL carbon tetrachloride) and disperser solvent (1.0 mL acetonitrile) were rapidly injected into an aqueous sample (5.0 mL) for the formation of cloudy solution; the analyte in the sample was extracted into the fine droplets of carbon tetrachloride. After extraction, phase separation was performed by centrifugation and the enriched analyte in the sedimented phase was determined by HPLC-UV. The influence of several important parameters on extraction efficiency of nalidixic acid was evaluated. Under optimized experimental conditions, the calibration graph was linear in the concentration range of 1–800 μg L-1 with the coefficient of determination being 0.9994. The limits of detection and quantification were 0.2 and 0.7 μg L-1, respectively. The relative standard deviations (RSDs) and accuracies were in the range of 1.1–8.7% and 92.7–104.9%, respectively. This procedure was successfully applied to the determination of nalidixic acid in spiked urine samples with satisfactory results. The relative recoveries of urine samples ranged from 103.1% to 105.1%, with RSDs varying from 0.8% to 2.4%.

2

Application of adsorptive cathodic stripping voltammetry for determination of trace amounts of Zinc using nolidixic acid as a chelating agent

Gholivand M. B., Pourhossein A., Shahlaei M.

Chemia Analityczna

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2009

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Vol. 54, No. 4

655-666

EN

A sensitive method for determination of trace zinc based on adsorptive preconcentration of zinc-nalidixic acid (NAL) complex onto the surface of a hanging mercury drop electrode (HMDE) has been described. Optimum conditions of determination were as follows: pH 8.7, 90 (imol L-1 NAL, accumulation potential —800 mV, and accumulation time 120 s. Under optimal conditions, a linear calibration graph in Zn range 15-2500 nmol L-1and detection limit of 5 nmol L-1 were obtained. Relative standard deviation for 80 nmol L-1 concentration was 2.3% (n = 10). The effect of positively and negatively charged ions on the peak height of Zn-NAL complex was evaluated. The method was applied to the determination of zinc in: spring water, tap water, seawater, dry tea, Tab. Sanatogen gold A-Z, and MIST certified reference material with satisfactory results.

PL

Opisano czułą metodę analizy śladów cynku. W metodzie zastosowano adsorpcyjne zatężanie kompleksu cynku z kwasem nalidyksowym (NAL) na wiszącej elektrodzie rtęciowej. Wyznaczono optymalne warunki oznaczania: pH = 8,7; stężenie NAL 90 (nmol L-1; potencjał zatężania —800 mV i czas zatężania 120 s. W optymalnych warunkach krzywa kalibrowania była liniowa w przedziale 15—2500 nmol L-1, a granica wykrywalności wynosiła 80 nmol L-1. Względne odchylenie standardowe przy stężeniu cynku 80 nmol L-1 wynosiło 2,3% (n= 10). Zbadano wpływ dodatnio i ujemnie naładowanych jonów na wysokość piku kompleksu. Opracowaną metodę zastosowano z powodzeniem do oznaczania cynku w: wodzie źródlanej, wodzie z kranu, wodzie morskiej, suchej herbacie. Tab. Sanatogen gold A-Z i materiale wzorcowym NIST.

3

Biologicznie aktywne pochodne 1,8-naftyrydyny

Suryło P., Kowalski P., Hołda M.

Wiadomości Chemiczne

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2003

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[Z] 57, 3-4

247--266

EN

This review attempts to briefly summarise the recent developments in the synthesis and application of 1,8-naphthyridine derivatives as biological active compounds. A large number of these compounds still evolves interest of chemists and pharmacologists. From among of one thousand papers, which appeared within the last fifteen years, most described applications of 1,8-naphthyridine derivatives as biologicaly active compounds. Nalidixic acid (1) was the first 1,8-naphthyridine derivative approved as the drug with antibacterial activity. There are many routes to the synthesis of nalidixic acid. The main routes are presented in the Schemes 1, 4, and 6. This compound was the first from the quinolone's family applied as the chemotherapeutic drug. Modification of the structure of nalidixic acid brought the discovery of a new group of most potent antibacterial compounds called fluoroquinolones. Enoxacine (16), esafloxacine (21), tosulfoxacine (22), trovafloxacine (23) and alatrofloxacine (24) are the examples of 1,8-naphthyridine derivatives belonging to that group. General reaction scheme of synthesis of 16 and 21 is similar to synthesis of nalidixic acid, while synthesis of the compounds 22, 23, and 24 presented in Scheme 8 is quite different. Moreover, many other 1,8-naphthyridine derivatives 31-40 have been intensively studied as antibacterial agents in vitro, but none of them has been applied as a drug. A number of 2- and 7-substituted 1,8-naphthyridines 41 showed some antimalarial activity in vivo, while the compounds of general structure 42 were found inactive. 2(4)-Piperazinyl-1,8-naphthyridines (45) have been pharmacologically investigated for their antyhipertensive activity. 1,8-Naphthyridines 46, bearing a phenyl group in position 2, were found to be selective antagonists for the A1 adenosine receptor subtype. A series of 1,8-naphthyridines 47-49 exhibited appreciable diuretic and antikaliuretic activity in rats. In search for potential anticancer compounds study such as SAR (structure activity relationship) and QSAR (quantity structure activity relationship) have been used. As the result of the research the structure of the compounds 50 has established as the most potent inhibitor of tubulin polymerization. The nitrobenzo-1,8-naphthyridines (52)constitute a group of potential interest for the design of new cytotoxins. Moreover, 1,8-naphthyridine derivatives have been found to be active as inhibitors of platelet aggregation agents 53-54 ; antiviral 56-57 and antialergic agents 62. These derivatives possess bronchodilating 64, antiflammatory and sedative properties 67.