Quantitative analysis of amino acids by HPLC in dried blood and urine in the neonatal period: Establishment of reference values.

Quantitative analysis of amino acids in blood and urine is primarily indicated for the diagnosis of amino acid disorders. The high-performance liquid chromatography (HPLC) technique is frequently used for this detection. The frequency of sample collection on filter paper has been increasing exponentially, and there are many advantages attributed to processing biological samples in this way.

Selective activity of Mucor plumbeus reductase towards (-)-camphorquinone.

The biotransformation of 1R-(-)-camphorquinone, achieved by growing cells of four fungi species isolated from soil (Mucor plumbeus, Lecanicillium muscarium, Thamnostylum sp. and Syncephalastrum racemosum), was investigated in optimized culture media for each species. Fungi were grown aerobically under shaking and their activities with respect to camphorquinone were monitored for 20 days by gas chromatography coupled to mass spectrometry (GCMS).

Synergistic bactericidal activity of Eremanthus erythropappus oil or beta-bisabolene with ampicillin against Staphylococcus aureus.

The activity of Eremanthus erythropappus oil (EO) and some of its compounds and their potential synergistic interaction with ampicillin against different strains of Staphylococcus aureus were investigated. Determination of chemical composition of EO by gas chromatography-mass spectrometry (GC/MS) and bioguided chemical fractionation led to the identification of beta-bisabolene as the main active compound. A synergistic bactericidal activity of EO or beta-bisabolene with ampicillin against Staphylococcus aureus was observed in a time-kill assay.