Sulfated cyclodextrins (CDs) are multiply negatively charged molecules widely used as chiral selectors in capillary electrophoresis (CE). In some of their applications, the effective charge numbers of their molecules were observed to be lower than the numbers of the attached sulfated groups due to strong binding of counterions. However, degree of reduction of the theoretical charge was not quantified. For that reason, in this study, capillary isotachophoresis (CITP) and capillary zone electrophoresis (CZE) were applied for the determination of the effective charge numbers and actual ionic mobilities of two kinds of sulfated CDs: single isomer sulfated α-, β-, and γ-CDs (SI-CDs) and randomly highly sulfated α-, β-, and γ-CDs (HS-CDs). The effective charge numbers of the SI-CDs and HS-CDs were determined from the length of their ITP zones, the ionic mobilities determined by CZE, and molar concentrations of their solutions applied for CITP analysis, and from the same parameters of reference compounds, formic acid for SI-CDs and dichloroacetic acid for HS-CDs. The determined effective charge numbers of the SI-CDs were equal to or only slightly lower than the numbers of sulfate groups in their molecules but the effective charge numbers of randomly HS-CDs were significantly (22.2%-27.8%) reduced as compared to the average numbers of sulfate groups in their molecules. In accordance with a lower number of sulfate groups in SI-CDs than in HS-CDs, the absolute values of the actual ionic mobilities of SI-CDs (35.5-37.5) × 10-9 m2 V-1 s-1 were lower than those of HS-CDs (43.5-44.1) × 10-9 m2 V-1 s-1.

• Keywords
• capillary isotachophoresis, capillary zone electrophoresis, charge number, counterion condensation, effective charge,
• MeSH
• Cyclodextrins * chemistry   analysis   MeSH
• Electrophoresis, Capillary methods   MeSH
• Isomerism MeSH
• Isotachophoresis * methods   MeSH
• Sulfates * chemistry   MeSH
• Stereoisomerism MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Cyclodextrins * MeSH
• Sulfates * MeSH

The problem of a growing resistance of bacteria and other microorganisms to conventional antibiotics gave rise to a search for new potent antimicrobial agents. Insect antimicrobial peptides (AMPs) seem to be promising novel potential anti-infective therapeutics. The dipeptide β-alanyl-tyrosine (β-Ala-Tyr) is one of the endogenous insect toxins exhibiting antibacterial activity against both Gram-negative and Gram-positive bacteria. Prior to testing its other antimicrobial activities, it has to be prepared in a pure form. In this study, we have developed a capillary zone electrophoresis (CZE) method for analysis of β-Ala-Tyr isolated from the extract of the hemolymph of larvae of the fleshfly Neobellieria bullata by reversed-phase high-performance liquid chromatography (RP-HPLC). Based on our previously described correlation between CZE and free-flow zone electrophoresis (FFZE), analytical CZE separation of β-Ala-Tyr and its admixtures have been converted into preparative purification of β-Ala-Tyr by FFZE with preparative capacity of 45.5 mg per hour. The high purity degree of the β-Ala-Tyr obtained by FFZE fractionation was confirmed by its subsequent CZE analysis.

• Keywords
• antimicrobial peptides, beta-alanyl-tyrosine, capillary zone electrophoresis, free-flow zone electrophoresis, peptide analysis, peptide purification,
• MeSH
• Anti-Infective Agents chemistry   isolation & purification   MeSH
• Dipeptides chemistry   isolation & purification   MeSH
• Electrophoresis methods   MeSH
• Hemolymph chemistry   MeSH
• Larva chemistry   MeSH
• Sarcophagidae chemistry   MeSH
• Chromatography, High Pressure Liquid MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• alanyltyrosine MeSH Browser
• Anti-Infective Agents MeSH
• Dipeptides MeSH