Fungicidal activity of new O-derivatives of phenylpyridylketoximes.

Some alkyl- and acylderivatives of phenylpyridylketoximes were prepared and tested in vitro and in vivo against fungal plant pathogens of different taxonomic classes. The tested compounds exhibited remarkable activities, especially when an ethyl group was present on the oxime function.

Design of chiral LC separations for calcium antagonists on alpha 1-acid glycoprotein and ovomucoid columns.

Three chiral calcium antagonist drugs, gallopamil and two dihydropyridine derivatives, have been successfully separated within short retention times using both the alpha 1-acid glycoprotein chiral stationary phase (Chiral-AGP) and the ovomucoid column (Ultron ES-OVM). Aqueous buffer at defined pH is modified by the addition of an organic component, in order to modulate the retention properties of each system. Optimization of pH and organic modifier is carried out using the modified simplex method, with Kaiser's peak separation function as a criterion. The influence of pH and percentage of organic modifier on retention, selectivity, resolution and column performance are discussed for the two dihydropyridines analysed on Chiral-AGP and Ultron ES-OVM stationary phases. A new method is proposed as a new chiral system suitability test for these protein-based phases, utilizing a racemic mixture of closely eluting verapamil enantiomers as a probe.

High-performance liquid chromatographic determination of alpha-tocopheryl nicotinate in cosmetic preparations.

alpha-Tocopheryl nicotinate (alpha-TN) accelerates blood circulation and stimulates hair follicle cells, hence it is an active ingredient in a broad range of cosmetic products. A reversed-phase high-performance liquid chromatographic method was developed to determine alpha-TN in cosmetic preparations with alpha-tocopheryl acetate as internal standard. The method was found to be rapid, precise and specific.

High-performance liquid chromatography post-column derivatization with fluorescence detection to study the influence of ambroxol on dipalmitoylphosphatidylcholine levels in rabbit eustachian tube washings.

In this work an appropriate high-performance liquid chromatography method was set up to guarantee specificity, sensitivity, precision and accuracy in analyzing dipalmitoylphosphatidylcholine (DPPC) in rabbit eustachian tube washings, as well as to determine its varying levels after administration of ambroxol chloride. The procedure is based on a post-column derivatization with fluorescence detection using 1,6-diphenyl-1,3,5-hexatriene which exhibits increased fluorescence in a lipid environment. DPPC was chromatographed on a Hypersil C18. The mobile phase for the isocratic elution consisted of 40 mmol/l choline chloride in methanol-tetrahydrofuran (97:3). Ambroxol was given to a group of New Zealand white rabbits at a dose of 30 mg/kg. A second group receiving vehicle only acted as controls.

HPLC determination of K-hetacillin and Na-dicloxacillin in oily suspension.

A simple and rapid high performance liquid chromatographic method was developed for separation and identification of K-hetacillin and Na-dicloxacillin in oily suspensions for veterinary practice. The method is precise, accurate and applicable to the analysis of commercial dosage form.

Trends of organochlorine residues in eggs of birds from Italy, 1977 to 1985.

All the eggs, collected in Italy in 1982 and 1983, of two species of passerine birds, three gulls, four terns and the night heron, contained DDE and, with lower frequencies, other organochlorine contaminants. Organochlorines were more concentrated in the species of higher trophic level. DDE contamination showed a decreasing trend from 1978 to 1985 in one passerine, two terns and in the heron. After 1980-1982, the level of contamination was below the critical threshold beyond which reproduction is affected, eggshell thickness was only slightly or not reduced; therefore, the current impact of organochlorines on these birds is probably negligible. Detrimental effects may have occurred during the 1970s, when some of the eggs were contaminated beyond the critical threshold.