L-Glucosamine

Streptomyces Antibiotics. XV. N-Methyl-L-glucosamine. J. Amer. chem. Soc. 69, 3032 (1947). 

Amino-, Arylamino- und Benzylaminonitrilen D- und L-Glucosamin. Aminozuckersynthesen II. Liebigs Ann. Chem. 600, 115 (1956). 

The other component parts of streptomycin, namely L-streptose and the aminosugar 2-deoxy-2-methylamino-L-glucose (A -methyl-L-glucosamine), are also ultimately derived from o-glucose. Gentamicin Ci contains two aminosugars, L-garosamine and D-purpurosamine. 

Figure 2.2. Biosynthetic gene clusters for STR-related AGAs. Functionally related groups of genes are differentiated by the color code given below. NMLG, A-methyl-L-glucosamine. Related groups of genes are differentiated by the color code given below. See color plates.

Not much has been added to the biochemistry of STRs in the recent years. Therefore, we will only briefly treat the biosynthetic pathway here. Biosynthesis of the aminocyclitol (streptidine) and 6-deoxyhexose (streptose) moieties are well understood, with some remaining gaps in the enzymology. Much less is known about the residual biosynthetic phases, the formation of A-methyl-L-glucosamine, the condensation of subunits, and the late modification steps potentially coupled with export. ... 

The free nitriles of iV-methyl-L-glucosaminic acid and iV-methyl-L-mannosaminic acid have been prepared by Wolfrom, Thompson and Hooper by the Kiliani-Fischer cyanohydrin synthesis. 

In geringerem MaBe wurden bisher Pd-Katalysatoren ffir die katalytische Oxydation herangezogen. Beschrieben wird die Oxydation von L-Glucosamin zur L-Glucosaminsaure und von Glucosamin-6-phosphat 32) zur Saure unter Verwendung eines Pd/C-Katalysators. Glykol konnte... 

L-GIucosamine, pentaacetyl-N-methyl-, III, 354, 375, 382 a-D.L-Glucosamine, pentaacetyl-N-methyl-, III, 382... 

The synthesis of this substance, starting with methyl 2-acetamido-4,6-0-benzylidene-2-deoxy-a-D-glucoside, was performed as follows. The two isomers which were formed were separated on a Dowex 50 colunm, and one (Md +109°) was shown to be identical with natural muramic acid. The strong dextrorotation effectively ruled out the L-glucosamine configuration, and the configuration of the lactic moiety was deduced to be most likely d. The second isomer had [ ] +52° and differed, in its behavior on resin columns and in paper chromatography, from natural muramic acid. 

Amino-polyols, such as 1-aminodeoxy-D-sorbitol or D-(-l-)-glucosamine, as well as adenine, underwent selenenylation-acylation at the amino groups by dichloride 102 and thus their 2-benzisoselenazol-3(2//)-onyl derivatives 108 and 109 were obtained <2003SC1301> (Scheme 40). The organoselenium-modified /3-CDs 110 and 111 were synthesized in a similar way <2002HCA9>. 

It was pointed out that N-methyl-L-glucosaminic acid nitrile was only the second nitrile in the sugar series to be isolated in the cyanohydrin reaction and that extension of the general procedure by which it was prepared should result in the isolation of other members. The nitrile of N-methyl-L-glucosaminic acid showed the same unusual mutarotation as does that of the lower-melting form of D-gluconic acid nitrile. Wolfrom and Thompson have noted that N-methyl-L-glucosaminic acid nitrile hydrochloride was a much more stable compound than the free base. 

In the preparation of N-methyl-L-glucosaminic acid nitrile by treatment of an ethanol solution of N-methyl-L-arabinosylamine with hydrogen cyanide, it was to be expected that the epimeric N-methyl-L-man-nosaminic acid nitrile Avould also be formed. Wolfrom and Thompson" were able to isolate in crystalline condition the acetylated nitrile of N-methyl-L-mannosaminic acid from this reaction mixture. This compound was converted to crystalline N-methyl-L-mannosaminic acid. 

The reduction of N-methyl-L-glucosaminic acid lactone with sodium amalgam in sulfuric acid led to crystalline pentaacetyl-N-methyl-a-L-glucosamine" from which crystalline N-methyl-L-glucosamine (free base) was prepared." Pentaacetyl-N-methyl-/8-L-glucosamine and N-acetyl-N-methyl-L-glucosamine were also isolated. 

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. 

Hydrolysis of pentaacetylstreptobiosamic acid monolactone in refluxing 2.5 N hydrochloric acid yielded a crystalline compound derived from the streptose moiety. This compound was designated streptosonic acid monolactone and was further characterized as its diacetate. The hydrolyzate was shown to contain N-methyl-L-glucosamine. 

---