Mass spectrometric study to characterize thioisoindole derivatives of aminoglycoside antibiotics

Abstract

Aminoglycoside antibiotics are widely used to treat serious Gram-negative and Gram-positive bacterial infections. The lack of a UV chromophore presents a problem in the analysis of aminoglycosides. Derivatization with 1,2-phthalic dicarboxaldehyde (OPA) in the presence of a thiol made it possible to introduce a UV chromophoric thioisoindole moiety. A qualitative mass spectrometry study was carried out to confirm the molecular identity of the products formed. The conditions described earlier to derivatize gentamicin and kanamycin yielded products in which all primary amino groups are fully derivatized. On the other hand, with tobramycin and amikacin, there was also formation of incompletely derivatized products that contained one thioisoindole group less than the fully derivatized product. This study has therefore brought an additional insight into the nature of the OPA-aminoglycoside derivatives studied.

Ordered mesoporous silica and aluminosilicate-type matrix for amikacin delivery systems

“…The drug uptake (the drug content in the hybrid) was evaluated by UV-vis spectroscopy via a derivatization method using o-phthaldialdehyde (OPA) [33,34]. Briefly, the derivatization reagent was prepared from 10 mg OPA, 200 lL absolute ethanol, 10 lL DTT 2 M aqueous solution, and 20 mL sodium carbonate buffer solution, pH 10.5.…”

Block ionomer complexes containing cationic antibiotics to kill intracellular Brucella melitensis in vitro

“…A calibration curve was prepared relating the absorbance at 340 nm to the concentration of gentamicin–phthalaldehyde–mercaptoethanol derivatives in solution. The derivative is soluble and stable in aqueous solutions and absorbs strongly in the UV, and it has been shown that all three primary amines on gentamicin react . The calibration curve had a linear regression correlation of 99.7%.…”

“…To characterize the concentration of drug incorporated in the BICs, the gentamicin was released from the isolated complexes with base, and the released gentamicin, which contains three primary amines, was derivatized with phthalaldehyde in the presence of mercaptoethanol. This derivatization has been used extensively by others as a sensitive method to quantify primary amines . A calibration curve was prepared relating the absorbance at 340 nm to the concentration of gentamicin–phthalaldehyde–mercaptoethanol derivatives in solution.…”

“…This derivatization has been used extensively by others as a sensitive method to quantify primary amines. [40][41][42][43][44] A calibration curve was prepared relating the absorbance at 340 nm to the concentration of gentamicinphthalaldehyde-mercaptoethanol derivatives in solution. The derivative is soluble and stable in aqueous solutions and absorbs strongly in the UV, and it has been shown that all three primary amines on gentamicin react.…”

The use of laser-induced fluorescence or ultraviolet detectors for sensitive and selective analysis of tobramycin or erythropoietin in complex samples

“…However when determination of the drug was required, particularly in biological fluids, its detection was complicated because of low detection sensitivity due to the poor chromophore effects and when chemical derivatization was used, poor stability of the determination was found. The literature showed a mass spectrometric [2], spectrofluorimetric [3,4], spectrophotometric and colorimetric methods [5][6][7] for TOB analysis. But each of these methods is not ideal to efficiently detect TOB at trace level.…”