A chemical method for the determination of mannosidostreptomycin.

Several analytical methods have been suggested for the determination of mannosidostreptomycin (streptomycin B) (5, 6). Titus and Fried (6, 12) and Plaut and McCormack,’ who have utilized the quite specific and quite accurate but yet laborious counter-current distribution methods (previously described by Craig) for the isolation and determination of streptomycin B, have noted a number of difficulties that are encountered under certain experimental conditions. Another method is that described by Schenck et al. (10) who have combined the malt01 test (11) with the microbiological assay. Inasmuch as streptomycin B shows lower antibiotic activity against many microorganisms than does streptomycin A (6, 9), they assume that it is possible to apply simultaneous equations to the results obtained with these assay methods and thus determine the relative quantities of streptomycins A and B present in the preparations under examination. This is theoretically sound if all the antibiotic activity is derived from the streptomycins A and B present, and if streptomycin A and streptomycin B potencies are additive in antibiotic effect. However, this analytical system inherits the difficulties present in both of the methods, including the effect of miscellaneous materials such as metallic ions and carbohydrates on the malt01 assay and on the bioassay (2). Also, the bioassay requires a rather long incubation period. Consideration of chemical methods adaptable to the determination of streptomycin B suggested that the determination of the mannose moiety might serve satisfactorily. This determination could be combined with the malt01 analytical method (by which total streptomycin is measured), and the quantity of streptomycin A present in the sample determined by difference. The carbazole test has been used for the identification and estimation of mannose and other reducing sugars by several investigators (1, 3, 7, 8) and offered promise as a quantitative method (7)?