Spatial Models of Sugars and Their Compounds

Introduction

Sugar molecules are widespread in nature and play an important role in all living organisms. Sugars are found in nucleic acids, in fruit sikes (“grape sugar”), as well as in human and animal blood (“blood sugar”). They are part of many glycolipids and glycoproteins. Sugars are used by plants to transport and store carbohydrates in soluble form. Sugarcane and sugar beets are rich in sugars (cane and beet sugar). Bees using sugar from flower nectar produce honey. This class of compounds includes simple sugars (monosaccharides) and their polymers - oligosaccharides and polysaccharides. The classification of monosaccharides is based on the number of carbon atoms in the molecule (pentoses, hexoses, etc.), as well as on the chemical nature of the carbonyl group (aldoses and ketoses). A small fraction of sugar molecules (less than 0.1%) in living organisms is linear. The vast majority of monosaccharide molecules are present in living organisms with the formation of rings of carbon atoms containing one oxygen atom in the ring (pyranoses are rings with five carbon atoms and one oxygen atom, furanoses are rings with four carbon atoms and one oxygen atom). The linear forms of monosaccharides are usually depicted in the form of Fischer projections, and the cyclic forms of monosaccharides are depicted in the form of Haworth projections (Metzler, 1980; Lehninger, 1982; Koolman and Roehm, 2013). Neither projection gives a spatial image of monosaccharide molecules. Although it is clear that spatial images of molecules allow us to understand their structure, location in space and the possibility of their participation in various chemical reactions in living organisms. Speaking about spatial models of molecules, we mean the definition of which spatial forms are formed by the atoms of molecules in the form of a convex body or a set of convex bodies. The structure of these bodies determines their dimension in accordance with the Euler - Poincaré equation (Poincaré, 1895). Given the large dimensionality of molecules, it is often useful for ease of use to construct their three - dimensional images based on their images of higher dimensionality, without forgetting that their complete models have higher dimensionality (Zhizhin, 2019 c). In this paper, these approaches are used to analyze spatial models of molecules of various sugars and their compounds.