Amino Sugars from Natural Products

Of the sixteen theoretically possible 2-amino-2-deoxyaldohexoses derivatives of six have so far been found in natural products these have the d- 

2-Amino-%-deoxy derivative of Mode of synthesis Melting point, °C. Hydrochloride  

2-Amino-2-deoxy-D-mannose. Enzymic degradation of JV-acetylneura-minic acid (sialic acid) yields 2-amino-2-deoxy-D-mannose,50 identical with 

The amino sugar gives a reaction similar to that of 2-amino-2-deoxy-D-glucose in the Elson-Morgan test. 

A diaminodideoxyhexose of unknown structure constitutes the hexose moiety of a pentose hexoside (disaccharide) called neobiosamine which may be isolated66 from the antibiotic substances neomycin B and neomycin C. 

---

S-Amino-8-deoxy Sugars from Natural Products... 

Considerable work has been done in the field of chiral hosts capable of discriminating between enantiomeric guest molecules. A variety of chiral residues either synthetic or derived from natural products l (sugars, tartaric acid, amino acids etc.) have been fused to macrocyclic rings. In most cases, chiral primary ammonium cations have been the guest species of choice, although the complexation of chiral carboxylates has been examined to some extent 2]. 

The hydroxy groups in natural products like, for example, the macrolide antibiotics erythromycin, 1"1 and desmycosin, 2001 2011 as well as the 3-(hydroxymethyl)-2- or 3-cephems 2021 and derivatives of the amino sugar garamin 2031 have been converted into the carbamate function with CDI and amines. In the case of aminoglycoside antibiotics of the sisomicin series, thiocarbamates or dithiocarbamates have been prepared from alcohols or thiols using ImCSIm and amines.12041... 

The most practical method for preventing WOF in meat products is to add antioxidants prepared from natural precursors such as sugars and amino adds by heating them to produce constituents that not only act as antioxidants but serve to enhance meaty flavor as well. The resulting Maillard products have been known to have antioxidant activity in lipid systems (6-8). It is assumed that the antioxidative property of the Maillard reaction is assodated with the formation of low molecular weight reductones and high molecular weight melanoidins (6, 7, 9-13). 

J. Jurczak and A. Golebiowski, From a-amino acids to amino sugars, in Studies in Natural Products Chemistry, Vol. 4, A.-ur Rahman, ed., Elsevier, Amsterdam, 1989, p. 111. 

In this brief article, I will focus on the ways we have learned from the chemistry of the life process itself. However, I must first call attention to another part of natural chemistry that has an effect on chemical thinking the field called the Chemistry of Natural Products. Chemists have explored nature and have discovered several special types of chemicals sugars, fats, ter-penes, alkaloids, acetogenins, amino acids, heterocyclic coloring matters, macrocyclic lactones, steroid hormones, and so on. (2). These compounds have been produced by living organisms and they are secreted by or isolated from them. This field is concerned with the substances of nature and the biochemical processes by which they are formed. 

---