Synthesis of (Z)-(2′R)-1-O-(2′-methoxynonadec-10′-enyl)-sn-glycerol,a new analog of bioactive ether lipids

An unsaturated 2-methoxy-substituted 1-O-alkylglycerol, (Z)-(2′R)-1-O-(2′-methoxynonadec-10′-enyl)-sn-glycerol, a new analog of bioactive ether lipids, was synthesized from oleic acid and 2,3-isopropylidene-sn-glycerol. The two key steps of this synthesis were the conversion of oleyl aldehyde to a monounsaturated epoxide using Matteson’s method followed by hydrolytic kinetic resolution and a nucleophilic epoxide opening by 2,3-isopropylidene-sn-glycerol in the presence of potassium tert-butoxide in anhydrous DMF, which appeared to be a good reagent for this purpose. Furthermore, the diol by-product of the HKR process was also easily converted back to the starting epoxide thus almost doubling the amount of target molecule.     

Synthesis of halogenated 1-O-alkylglycerols from ricinoleic acid derivatives

Abstract

Resistance to the existing drugs and increasing numbers of diseases result in identifying new drug candidates with new forms of activity. As marine organisms are well known to provide a wide range of original compounds, Herein, we report the synthesis of new non-natural brominated, iodinated and chlorinated-substituted 1-O-alkylglycerols 5–7, analogs of a prominent 1-O-alkylglycerol (AKG) of the natural shark liver oil (SLO) mixture, namely the AKGs 18:1, n-9.     

Analysis of 10 urinary BTEX metabolites using LC–MS/MS

Benzene, toluene, ethylbenzene, and xylene (BTEX) are a group of volatile organic compounds that are ubiquitous in the environment due to numerous anthropogenic sources. Exposure to BTEX poses a health hazard by increasing the risk for damage to multiple organs, neurocognitive impairment and birth defects. Urinary BTEX metabolites are useful biomarkers for the evaluation of BTEX exposure, because of the ease of sampling and their longer physiological half-lives compared with parent compounds. A method that utilizes LC–MS/MS was developed and validated for simultaneously monitoring of 10 urinary BTEX metabolites. During the sample preparation an aliquot of urine was diluted with an equal volume of 1% formic acid; internal standard solution was added, and then the sample was centrifuged and analyzed. The analytes were separated on the Kinetex-F5 column by applying a linear gradient, consisting of 0.1% formic acid and methanol. The method was validated according to the FDA Bioanalytical Method Validation Guidance for Industry. The mean method's accuracies of the spiked matrix were 81–122%; the inter-day precision ranged from 4 to 20%; the limits of quantitation were 0.5–2 μg/L. The method was used for the evaluation of baseline levels of urinary BTEX metabolites in 87 firefighters.     

Theoretical prediction and experimental validation of the angle-of-arrival probability density of a laser beam in a strong plane-flame turbulence

The propagation of a laser beam through a plane turbulent flame is studied using geometrical optics approximation. The random fluctuations of the refractive index caused by a strong thermal turbulence in the flame create random perturbations of the laser beam direction. From the Markovian process model applied along the whole random path of the beam, the theoretical probability density of the laser beam angle-of-arrival is derived from the analytical solution of the Einstein-Fokker-Kolmogorov equation, which we have determined in terms of a series expansion of spherical harmonics. An experimental setup and a method for measuring this probability density are described. The experimental results obtained are shown to agree with the theoretical predictions.