Dihydrostreptomycin analysis

Li, Y. M., Debremaeker, D., Van Schepdael, A., Roets, E., and Hoogmartens, J. (2000). Simultaneous analysis of streptomycin, dihydrostreptomycin and their related substances by capillary zone electrophoresis. J. Liq. Chromatogr. Relat. Technol. 23, 2979—2990. 

Analysis of bovine and swine kidney and muscle pairs from suspect Canadian slaughter animals has indicated an average difference in residue levels of 150/L and 164/L, respectively, for dihydrostreptomycin (20). Although dihydros-treptomycin is eliminated with the milk soon after its intramuscular administration to lactating cows, reaching residue levels in the range 0.05-0.13 ppb, it is not absorbed when given by the intramammary route and, thus, care must be taken to obey recommended withdrawal periods to avoid residues in milk. 

In traditional electrophoresis, separation efficiency is limited by thermal diffusion and convection. Owing to long analysis times and low efficiencies, these procedures never enjoyed wide usage. Problems have arisen when trying to differentiate between structurally related drug residues such as streptomycin and dihydrostreptomycin, tetracyclines, lincomycin and clindamycin, and erythromycin and oleandomycin (83, 84). To overcome these problems, anticonvective media, such as polyacrylamide or agarose gels, have also been used. 

An indirect competitive ELISA has been also developed for the determination of streptomycin and dihydrosticptomyciri in milk (24). Prior to the analysis, the milk sample was skimmed and treated with oxalic acid. The antiserum was raised in rabbits using streptomycin linked to a bacterial protein as the antigen. To perform the test, microtiter plates were coated with streptomycin, and antiserum and milk samples were mixed to be added in the wells where they were incubated for 1 h. Depending on the amount of residues in the sample, more or less antibody remained available for binding to the streptomycin coat. A pig antirabbit antibody-enzyme conjugate was subsequently added and incubated for 90 min. Using a suitable substrate, streptomycin and dihydrostreptomycin could be detected down to 1.6 ppb, whereas quantification could be made possible up to 100 ppb when samples were used undiluted. 

The absolute configuration of the streptidine moiety was determined by Dyer and A. W. Todd by applying Reeves s copper-complexing method to N,N -diacetyl-4-deoxystreptamine, derived from streptomycin by degradation. Moreover, the same conclusion was reached by Tatsuoka and coworkers on applying the Reeves method to 2,6-di-O-methylstreptamine derived from dihydrostreptomycin this revealed that the streptobiosamine moiety is attached to C-4 in the R configuration. The absolute structure of streptomycin was confirmed by an X-ray analysis of streptomycin oxime selenate. ... 

S. Umezawa and coworkers have now achieved a total synthesis of dihydrostreptomycin, and derivatives resistant to adenylylation or phosphorylation (described in the next Section) and which inhibit resistant organisms wiU presumably be synthesized. In this connection, a paper on the X-ray analysis of streptomycin oxime may be mentioned. 

Shin-ichi K, Analysis of impurities in streptomycin and dihydrostreptomycin hy hydrophilic interaction chromatog-raphy/electrospray ionization quadrupole ion trap/time-of-flight mass spectrometry. Rapid Commun. Mass Spectrom. 2009 23(6) 907-914. 

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