Identification and quantification of the glucose degradation product glucosone in peritoneal dialysis fluids by HPLC/DAD/MSMS.

Glucose degradation products (GDPs) formed during heat sterilization of peritoneal dialysis (PD) fluids exert cytotoxic effects and promote the formation of advanced glycation end-products in the peritoneal cavity. As a result, long-term application of continuous ambulatory peritoneal dialysis is limited. The composition and concentration of GDPs in PD fluids must be known to evaluate their biological effects. The present study describes a targeted screening for novel GDPs in PD fluids. For this purpose, dicarbonyl compounds were converted with o-phenylenediamine to give the respective quinoxaline derivatives, which were selectively monitored by HPLC/diode array detector. Glucosone was thereby identified as a novel major GDP in PD fluids. Product identity was confirmed by LC/MSMS analysis using independently synthesized glucosone as a reference compound. Furthermore, a method was developed to quantify glucosone in PD fluids by HPLC/UV after derivatization with o-phenylenediamine. The method's limit of detection was 0.6 microM and the limit of quantitation 1.1 microM. A linear calibration curve was obtained between 1.1 and 113.9 microM (R(2)=0.9999). Analyzed at three different concentration levels, recovery varied between 95.6% and 102.0%. The coefficient of variation ranged between 0.4% and 4.7%. The method was then applied to the measurement of glucosone in typical PD fluids. Glucosone levels in double chamber bag PD fluids varied between not detectable and 6.7 microM. In single chamber bag fluids, glucosone levels ranged between 28.7 and 40.7 microM.

Development and validation of an HPLC method to quantify 3,4-dideoxyglucosone-3-ene in peritoneal dialysis fluids.

A method was developed and validated to quantify 3,4-dideoxyglucosone-3-ene in peritoneal dialysis fluids by high-performance liquid chromatography with UV detection after derivatization with o-phenylenediamine. The advantages of this method compared with direct HPLC analysis are (i) the possibility of quantifying 3,4-dideoxyglucosone-3-ene simultaneously together with other glucose degradation products, (ii) the compatibility of the method with MS detection for unequivocal identification of the analyte and (iii) a bathochromic shift of the UV absorbance maximum which leads to higher selectivity. The validated method was used to measure 3,4-dideoxyglucosone-3-ene concentrations additionally to the glucose degradation products 3-deoxyglucosone, methylglyoxal, glyoxal, 5-hydroxymethylfurfural, 2-furaldehyde, formaldehyde and acetaldehyde in 19 commercial products for peritoneal dialysis.

A structure-permeability study of small drug-like molecules.

A systematic structure-permeability relationship study on a set of small drug-like molecules with log D values in the range -2.5 to 3 and carrying a diverse array of functionality reveals that the compounds with log D>0 and <3 are highly permeable. Surprisingly, several tetrazole derivatives were found to be substrates for efflux pump(s).