Rolitetracycline

Tetracycline antibiotics represent one of the most successful classes of pharmaceuticals and are extensively used around the world for human and veterinary health. Ozone-based processes have emerged as a selective water treatment process for many pharmaceuticals. The primary objective of this study was to determine the reaction kinetics for transformation of five tetracycline antibiotics (i.e., chlortetracycline, doxycycline, oxytetracycline, rolitetracycline, and tetracycline) by ozone across the pH2 to 9 range. The apparent second-order rate constant for tetracycline was on the order of 1-6 × 10(4) M(-1) s(-1) at low pH, and 0.6-2.0 × 10(6) M(-1) s(-1) at near neutral pH. The apparent second-order rate constants did not fit a conventional pKa-based model, presumably due to the complex acid/base speciation of tetracycline antibiotics. A model that considers the net charge on tetracycline molecules in solution provided a nice fit to experimental data for all five tetracyclines.

We have developed a sensitive CE method to determine eight tetracyclines (TCs) (chlortetracycline, demeclocycline, doxycycline, methacycline, minocycline, oxytetracycline, TC, and rolitetracycline (RTC)) in honey samples. The running buffer was 150 mM sodium borate (pH 9.8) and 2.5% 2-propanol with 15 s hydrodynamic injection at 25 kV. We have also developed an SPE procedure with a C18 cartridge as a clean-up step. Analytes were detected at 360 nm in less than 16 min. LODs ranged in honey from 23.9 microg/kg for TC to 49.3 microg/kg for RTC. Seven samples of Spanish honey of different floral origins were examined. None of them showed contamination with these antibiotics using the proposed method.

A novel monoclonal antibody (MAb) against oxytetracycline (OTC) was generated and characterized. The MAb was used in the development of an enzyme-linked immunosorbant assay (ELISA)-based detection system. An OTC-bovine serum albumin (BSA) conjugate was prepared and used in the immunization of mice. A conventional somatic cell fusion technique was used to generate MAb-secreting hybridomas denoted 2-4F, 7-3G, and 11-11A. An indirect competitive ELISA (icELISA) was applied to measure the sensitivity and specificity of each MAb in terms of its 50% inhibitory concentration (IC50) and percentage of cross-reactivity, respectively. MAb 2-4F exhibited the highest sensitivity, with an IC50 of 7.01 ng/ml. This MAb showed strong cross-reactivity to rolitetracycline, but no cross-reactivity to other unrelated antibiotics. When MAb 2-4F was used to detect OTC from shrimp samples, the recoveries were in the range of 82%-118% for an intra-assay and 96%-113% for an inter-assay.

A new synthesis way of haptens for tetracyclines (tetracycline, chlortetracycline and oxytetracycline) based on the formation of their carboxamido and diazo derivatives that maintain the tetracyclic nucleus and possess an aromatic or aliphatic spacer arm--in order to create a degree of heterology in the chemical structure--is described. The haptens were used to successfully raise polyclonal antibodies and a reliable and sensitive indirect competitive enzyme-linked immunosorbent assay (ELISA) for tetracycline was set up. After the optimization of physical and chemical parameters (pH, salt, detergent concentration, and time), a detection limit of 0.4 ng mL(-1) for tetracycline was reached. The optimized ELISA showed cross-reactivity to rolitetracycline (91%), oxytetracycline (30%), methacycline (14%), and chlortetracycline (10%). The analytical potential of the immunoassay was demonstrated by the excellent recoveries obtained (mean value ranging between 79% and 108%) when determining tetracycline residues in honey samples with a simple preparation procedure.