Development and validation of method for TH588 and TH287, potent MTH1 inhibitors and new anti-cancer agents, for pharmacokinetic studies in mice plasma.

MTH1 is a protein that is required for cancer cell survival and is overexpressed in cancer cells. TH588 and TH287 are two new compounds that inhibit the MTH1 protein. The inhibitors were tested in pharmacokinetic studies on mice.

MTH1 inhibition eradicates cancer by preventing sanitation of the dNTP pool.

Cancers have dysfunctional redox regulation resulting in reactive oxygen species production, damaging both DNA and free dNTPs. The MTH1 protein sanitizes oxidized dNTP pools to prevent incorporation of damaged bases during DNA replication. Although MTH1 is non-essential in normal cells, we show that cancer cells require MTH1 activity to avoid incorporation of oxidized dNTPs, resulting in DNA damage and cell death.

Evaluation of a direct high-capacity target screening approach for urine drug testing using liquid chromatography-time-of-flight mass spectrometry.

In this study a rapid liquid chromatography-time-of-flight mass spectrometry method was developed, validated and applied in order to evaluate the potential of this technique for routine urine drug testing. Approximately 800 authentic patient samples were analyzed for amphetamines (amphetamine and methamphetamine), opiates (morphine, morphine-3-glucuronide, morphine-6-glucuronide, codeine and codeine-6-glucuronide) and buprenorphines (buprenorphine and buprenorphine-glucuronide) using immunochemical screening assays and mass spectrometry confirmation methods for comparison. The chromatographic application utilized a rapid gradient with high flow and a reversed phase column with 1.

Development of a two-dimensional liquid chromatography system for isolation of drug metabolites.

The separation, isolation and identification of drug metabolites from complex endogenous matrices like urine, plasma and tissue extracts are challenging tasks. Metabolites are usually first identified by mass spectrometry and tentative structures proposed from product ion spectra. In many cases mass spectrometry cannot be used to determine positional isomers and metabolites have to be fractionated in microgram amounts for analysis by NMR.

Experimental design as a tool when evaluating stationary phases for the capillary electrochromatographic separation of basic peptides.

Two different capillary electrochromatography (CEC) stationary phases, Hypersil phenyl and Hypersil C(18), have been characterised with respect to their ability to separate the four basic peptides H-Tyr-(D)Ala-Phe-Phe-NH(2) (TAPP), H-Tyr-(D)Ala-Phe-NH(2) (TAP), H-Phe-Phe-NH(2) (PP) and H-Phe-NH(2) (P). Optimal separation conditions were first established separately for the two phases by applying experimental design in a stepwise procedure. The first step comprised a study to acquire basic knowledge about the variables, their influence on the response and their respective experimental domains for each of the two stationary phases.

Experimental design-based development of a rapid capillary electrophoresis method for determining impurities in the tetrapeptide H-Tyr-(D)Arg-Phe-Phe-NH2.

A capillary electrophoresis (CE) method has been developed and validated for separating the tetrapeptide H-Tyr-(D)Arg-Phe-Phe-NH2 and nine related substances. The method was developed using experimental design in a four-step procedure, in which eight variables were investigated in a total of 47 experiments. The preferred background electrolyte (BGE) consisted of 0.

Enantiomeric separation of TAPP, H-Tyr-(D)Ala-Phe-Phe-NH(2), by capillary electrophoresis using 18-crown-6-tetracarboxylic acid as a chiral selector.

A capillary electrophoresis method for the enantiomeric separation of the tetrapeptide H-Tyr-(D)Ala-Phe-Phe-NH(2) (TAPP), has been developed and validated. The preferred background electrolyte (BGE) consisted of 0.1 M aqueous phosphoric acid adjusted to pH 3.

Stability study of a new antidote drug combination (Atropine-HI-6-Prodiazepam) for treatment of organophosphate poisoning.

The main purpose of this study was to investigate the chemical stability of a new antidote combination for the treatment of organophosphate poisoning. The antidote combination was packed (enclosed) in two plastic compartments separated by a barrier film. One of them contained a powder oxime cholinesterase reactivator (HI-6-monohydrate 1-[[[4-(aminocarbonyl)pyridinio]methoxy]methyl]-2-[(hydro xyimino)meth yl]-pyridinium dichloride).