Streptomycin hydrogenation

Dihydrostreptomycin sulfate may be prepared from streptomycin sulfate by catalytic hydrogenation (Merck, Pfizer, Cyanamid), electrolytic reduction (Schenley, Olin Mathieson), or by sodium boro hydride reduction (Bristol), or by isolation from a fermentation process (Takeda). 

Other chemicals which inhibit milk lipase include hydrogen peroxide, animal cephalin, sodium arsenite, diisopropyl fluorophosphate, 2,4 din-itro-l-fluorobenzene, p-hydroxymercuribenzoate, potassium dichromate, lauryl dimethyl benzyl ammonium chloride, aureomycin, penicillin, streptomycin, and terramycin (Schwartz 1974). 

Use of alkylamide phases, in which alkyl chains are attached to the silica surface via an alkylamide group, reduces interactions with free silanols, by an internal masking mechanism. Residual silanols interact by hydrogen bonding with the embedded amide groups and thus become less active toward analytes. The embedded polar amide groups lessen the hydrophobicity of these phases compared to that of C18 bonded phases prepared from the same silica. Improved peak shapes of ionizable compounds were reported and this stationary phase was successfully used under IPC conditions to analyze streptomycin and its dihydrostreptomycin derivative in food... 

Streptomycin trihydrochloride was hydrogenated in aqueous solution at atmospheric pressure using platinum as catalyst. - About one molar equivalent of hydrogen was absorbed to yield a product which formed a crystalline trihelianthate from which a white powder, designated... 

Hydrogenation of the crystalline streptomycin trihydrochloride-calcium chloride double salt in aqueous solution with platinum oxide catalyst at atmospheric pressure or with Raney nickel catalyst at 100-140 atmospheres and 150° also yielded dihydrostreptomycin. Acid hydrolysis of dihydrostreptomycin gave streptidine and N-methyl-L-glucosamine. Hence, the reduction involved the nitrogen-free moiety, streptose. 

Cleavage of streptomycin with ethyl mercaptan and hydrogen chloride yielded streptidine and a new derivative of streptobiosamine, ethyl thio-streptobiosaminide hydrochloride diethyl mercaptal. Treatment of methyl streptobiosaminide hydrochloride dimethyl acetal with ethyl mercaptan and hydrogen chloride readily yielded the same mercaptal hydrochloride. It thus was apparent that the relationship between these two compounds resided simply in the replacement of methoxy by thio-ethoxy groups on the same carbon skeleton. Acetylation of the mercaptal yielded two anomeric forms of ethyl tetraacetylthiostreptobiosaminide diethyl mercaptal. ... 

Now the hydrogenation of streptomycin to dihydrostreptomycin involved the reduction of the free carbonyl group to carbinol. Therefore, the allocation of the primary alcohol group so formed to the 1 or 6 posi-... 

Streptomycin B was inactivated by carbonyl reagents. On catalytic hydrogenation it absorbed one mole of hydrogen to form dihydrostrepto-mycin B. The hydrogenation did not cause any loss in activity. The activity of dihydrostreptomycin B was not impaired by carbonyl reagents and it did not yield maltol on treatment mth alkali. 

Polysaccharides Hydrogen bonds and dipole-dipole interactions with hydroxyl groups of the sugar molecules are assumed to be the main interactions. In some cases, the helical structure of dextrins might be responsible for chiral recognition. Heparin, dextran sulfate, dermatan sulfate, streptomycin sulfate, amylose, chondroitin sulfate C, laminaran, dextrin sulfopropyl, and kanamycin sulfate. Doxylamine, laudanosine, naproxen, oxamniquine, pheniramine, primaquine, timepidium, trimetoquinol, etc. 

Although no analogs of streptomycin exist in which the C5 position is altered, the structure of the complex suggests that very few, if any, modifications would be tolerated, because that hydroxyl group is also involved in a hydrogen bond with Lys45 of SI2. Similar restrictions are not expected for C2 modification, as there are no direct contacts between its hydroxyl group and the ribosome. 

Figure 6.2. Molecular interactions between streptomycin and 303 (E. cdU numbering, top) with various modifications tested for activity (bottom). Dashed lines indicate possible hydrogen bonds (some of which are salt bridges when suitably reinforced with favorable electrostatic potentials). Arrows point to permissible modifications arrows with an X point to non-permissible modifications. (a)Ringl. (b) Ring II. Dashed arrow points to modifications that results in compounds that are active ty an unknown mechanism, (c) Ring III.

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