Internalization and stability of a thymidylate synthase Peptide inhibitor in ovarian cancer cells.

Information on the cellular internalization and stability of the ovarian cancer cell growth inhibitor peptide, LSCQLYQR (LR), is vital for lead optimization. Ad-hoc-synthesized LR/fluorescent-probe conjugates were used to monitor the internalization of the peptide. Mass spectrometry was used to identify adducts resulting from the thiol reactivity of the cysteine residue in LR.

Development of an in vitro liquid chromatography-mass spectrometry method to evaluate stereo and chemical stability of new drug candidates employing immobilized artificial membrane column.

A stopped-flow HPLC method was developed to evaluate configurational and chemical stability of pharmaceutical compounds employing immobilized artificial membranes (IAM) column to simulate conditions that pharmaceutical compounds will meet in vivo. The method was applied to recent developed chiral 5-arylbenzothiadiazine derivatives possessing high positive allosteric modulatory (PAM) activity on AMPA receptor. In particular the stopped-flow HPLC method developed used a chiral column to separate single enantiomer of the compounds that are forced into an IAM column where configurational and chemical stability was evaluated in simulated gastrointestinal fluids (pH 1.

2-Acyl-dimedones as UV-active protective agents for chiral amino acids: enantiomer separations of the derivatives on chiral anion exchangers.

2-Acetyldimedone and 12 related compounds were employed as UV-active pre-column derivatizing agents for amino acids. Direct enantioseparation of the products was achieved using chiral anion exchanger stationary phases in polar-organic mobile phase mode. Under basic conditions, the reagents´ cyclic β-tricarbonyl motifs can give rise to exo- and endocyclic enols through tautomerization.

Simultaneous measurement of adenosine, dopamine, acetylcholine and 5-hydroxytryptamine in cerebral mice microdialysis samples by LC-ESI-MS/MS.

A rapid and sensitive liquid chromatography/tandem mass spectrometry (LC-MS/MS) method has been developed for the simultaneous measurement of adenosine (ADE), dopamine (DA), acetylcholine (ACh) and 5-hydroxytryptamine (5-HT) in mouse brain microdialysates. High method sensitivity (LLOQ of 0.05nM) was achieved by optimization of chromatographic and mass spectrometric parameters.

An improved LC-S/MS method for the quantitation of adenosine concentration in mice brain microdialysates.

A sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the determination of adenosine concentrations in mouse brain microdialysis samples was developed. High method sensitivity (LLOQ of 1.25 fmol) was achieved by on-line switching column.