Control of protein synthesis in mammalian cells by aminoacylation of transfer ribonucleic acid.

The dependence of protein synthesis on the intracellular content of aminoacylated tRNA has been studied in mouse ascites tumor cells deprived for various amino acids. A remarkable reduction in net protein synthesis has been found only after a drastic decrease in aminoacylation of tRNA. The quantitative correlation of protein synthesis with the degree of aminoacylation suggests that a moderate amino acid starvation primarily influences the rate of elongation at the codon concerned. These results are in contrast to the findings previously reported for HeLa cells. Some crucial steps during the determination of intracellular aminoacyl-tRNA have been investigated. The reliability of the method employed has been discussed on a theoretical basis.     

Fluoromethylcyclopropylamine derivatives as potential in vivo toxicophores – A cautionary disclosure

Fluorination of metabolic hotspots in a molecule is a common medicinal chemistry strategy to improve in vivo half-life and exposure and, generally, this strategy offers significant benefits. Here, we report the application of this strategy to a series of poly-ADP ribose glycohydrolase (PARG) inhibitors, resulting in unexpected in vivo toxicity which was attributed to this single-atom modification.     

Pyridine-2-propanoic acids: Discovery of dual PPARalpha/gamma agonists as antidiabetic agents

A series of novel pyridine-2-propanoic acids was synthesized. A structure-activity relationship study of these compounds led to the identification of potent dual PPARalpha/gamma agonists with varied isoform selectivity. Based on the results of efficacy studies in diabetic (db/db) mice, and the desired pharmacokinetic parameters, compound (S)-13 was selected for further profiling.     

Inhibitors of epidermal growth factor receptor tyrosine kinase: optimisation of potency and in vivo pharmacokinetics

The structure-activity and structure-property relationships of anilinoquinazoline inhibitors of EGFR were investigated. Strategies to lower volume of distribution and shorten half-life through structure and pKa modulation are discussed.     

Noninvasive recovery and detection of possum Trichosurus vulpecula DNA from bitten bait interference devices (WaxTags)

The brushtail possum is a major agricultural and ecological pest in New Zealand. A novel noninvasive DNA sampling tool for detecting its presence (WaxTags, or WT) was tested. DNA was recovered from saliva left on WT, and two lengths (407 bp and 648 bp) of the cytochrome c oxidase I (COI) barcoding region were amplified by polymerase chain reaction (PCR). PCR products were considered (+) when a DNA band was clearly visible by electrophoresis. Different factors that might affect PCR (+) were investigated with captive possums: (i) both extraction protocols of the QIAGEN DNeasy Blood and Tissue Kit, (ii) effect of an overnight or longer delay of up to 3 weeks before DNA extraction on both COI amplicons, and (iii) effect of the individual, order and magnitude of the bite. Extraction protocols were not significantly different. The effect of the overnight delay was not significant, and amplification of the short amplicon was significantly higher (100%) than for the long fragment (48%). After a two or 3‐week delay, the short amplicon had 94% and 56% PCR (+), success rates, respectively. Individual, order and magnitude of a bite had no significant effect. The delay trial was repeated with WT from the wild, for which PCR (+) rate of the short amplicon was 63%, regardless of freshness. Four microsatellites were amplified from captive WT samples. We conclude that DNA from saliva traces can be recovered from WT, a potential new tool for noninvasive monitoring of possums and other wildlife.