Dehydration of Tetracycline

Intermediate precision study on a capillary electrophoretic method for chlortetracycline

“…CTC can be epimerized at position C4 to form 4-epichlortetracycline (ECTC). Due to the presence of a hydroxyl group at C-6 position, TC and CTC are subjected to dehydration under acid conditions forming anhydrotetracycline (ATC) and anhydrochlortetracycline (ACTC) [12,13]. Unlike other tetracyclines, CTC is not stable in alkaline medium.…”

Transfer of tetracyclines across the H2O|1,2-dichloroethane interface: Analysis of degraded products in strong acid and alkaline solutions

“…Two different isosbestics points are defined at k = 294 and 390 nm, which proves that a process of species interconversion occurs. The increase in the absorption peaks at k = 270 and 428 nm correlates with the absorption peaks observed in the AHTC spectra [11]. In order to emphasize such correlation, this figure also shows the spectrum obtained at 20 h of degradation, which can be compared with the AHTC spectrum shown in Fig.…”

“…These compounds are known to be highly unstable in solution. The main factors affecting their stability are extreme acidity or alkalinity of the solution, light, temperature, and the presence of molecular oxygen [4][5][6][7][8][9][10][11][12][13]. Stability of tetracyclines has been studied by different methods and complex schemes of degradation have been considered [4,9,12].…”

Anhydrotetracycline oxygenase activity and biosynthesis of tetracyclines in streptomyces aureofaciens

“…Principle of the method: the UV/visible spectrum of ATC differs from those of DHTC/DHCTC and TC/CTC by having an absorbance maximum at 435 nm (Schlecht and Frank, 1975;McCormick etal, 1958). With the oxygenation of ATC a decrease in the absorbance level at 440 nm is directly proportional to the amount of ATC transformed.…”

“…Chemicals: Sephadex G-25 (medium) was obtained from Pharmacia, Sweden; NADP + and glucose-6-phosphate from Reanal, Hungary; glucose 6-phosphate dehyda'ogenase from Boehringer, BRD; ATC was prepared according to Schlecht and Frank (1975).…”