A novel vector calibration method, hyperplane intercept, is proposed for grey analytical systems to resolve the concentrations of the chemical components from the multi-component data gained from attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. This method is capable of quantifying a particular component known to be present in the mixture without having to know t...

We report a combined quantum mechanical/molecular mechanical (QM/MM) study of the effect of mutations of the Phe434 residue in the active site of cyclohexanone monooxygenase (CHMO) on its enantioselectivity toward 4-hydroxycyclohexanone. In terms of our previously established model of the enzymatic Baeyer-Villiger reaction, enantioselectivity is governed by the preference toward the equatorial ...

Using gas chromatography-mass spectrometry, we investigated the urinary excretion of organic acids of 278 newborn babies in a special care unit to obtain reference data and monitor metabolism. In 101 of 584 urine samples analyzed, we found isomers of cyclohexanediol. trans-1,2-Cyclohexanediol was always most abundant, with small amounts of 1,3- and 1,4-cyclohexanediol and, sometimes, traces of ...

Coincidence Doppler broadening spectroscopy was applied to study n-hexane (C6H14), cyclohexane (C6H12) and cyclohexanone (C6H10O), at solid, as well as liquid states. The experiments were performed in parallel with traditional positron annihilation lifetime spectroscopy. Significant positron trapping by oxygen was observed in cyclohexanone; the oxygen effect is stronger in liquid state than in ...

This paper presents a systematic computational study of the mechanism of cyclohexanone-monomer co-initiation in high-temperature homopolymerization of methyl acrylate (MA) and methyl methacrylate (MMA). Previous experimental studies of spontaneous thermal homopolymerization of MA and MMA showed higher monomer conversion in the presence of cyclohexanone than xylene. However, these studies did no...

Curcumin is the major phenolic compound present in turmeric (Curcuma longa L.). Curcumin and 15 novel analogs were investigated for their antioxidant and selected biological activities. Strong relationships between the structure and evaluated activity revealed that the compounds with specific functional groups and carbon skeleton had specific biological profiles. Among the compounds tested, the...

A series of chiral pyrrolidinyl-sulfamide derivatives have been identified as efficient bifunctional organocatalysts for the direct Michael addition of cyclohexanone to a wide range of nitroalkenes. The desired Michael adducts were obtained in high chemical yields and excellent stereoselectivities (up to 99/1 dr and 95% ee).

Carbon nanotubes (CNTs)-supported Pt nanoparticles were prepared with selective deposition of Pt nanoparticles inside and outside CNTs (Pt–in/CNTs and Pt–out/CNTs). The effects of Pt loading and reaction solvents on phenol hydrogenation were investigated. The Pt nanoparticles in Pt–in/CNTs versus Pt–out/CNTs are smaller and better dispersed. The catalytic activity and reuse stability toward phe...