LC/MS characterization of impurities and degradation products of a potent antitumor peptidic dimer, CU201.

Compound CU201 [SUIM-(d-Arg-Arg-Pro-Hyp-Gly-Igl-Ser-d-Igl-Oic-Arg)(2), where SUIM=suberimidyl; Hyp=trans-4-hydroxyproline; Igl=alpha-(2-indanyl)-glycine; Oic=octahydroindole-2-carboxylic acid], is a dimeric analog of the potent bradykinin antagonist peptide B9430. It blocks the G(alphaq,11) signal of the heterotrimeric G proteins, stimulates c-Jun kinases, and induces apoptosis in lung cancer cells with neuroendocrine features. CU201 shows potent inhibition for small-cell lung cancer cells in vitro (ED(50)=0.

Separation of polyethylene glycol-modified proteins by open tubular capillary electrochromatography.

This study involves the characterization of six polyethylene glycol-modified proteins by open tubular capillary electrochromatography, a high-resolution, versatile and reproducible technique for the analysis of biomolecules and pharmaceuticals. Optimized conditions were obtained with respect to type of capillary modification (cholesterol and octadecyl), applied voltage (+20 and -20 kV), buffer pH (2.14-8.