Pharmacognosy with the Basics of Plant Biochemistry - Kovalyov, V. M. 2004

Special Part
Carbohydrates
Oligosaccharides

Oligosaccharides (oligosides) are low-molecular-weight carbohydrate polymers. Depending on the number of monosaccharide residues making up the molecule, they are classified as Disaccharides (or bioses), trisaccharides (or trioses), tetrasaccharides (or tetroses), pentasaccharides (or pentoses), hexasaccharides (or hexoses), as well as heptoses, octoses, nonoses, and decoses, respectively. Compounds containing more than 10 monosaccharide residues are classified as Polysaccharides. Oligosaccharides—predominantly in the form of di- and trisaccharides—are widely distributed both in a free state and as Structural components of complex Proteins, mucopolysaccharides, Glycolipids, Glycosides, and other biologically significant substances found in microorganisms, plants, and animals.

The properties of oligosaccharides depend on the CHARACTERISTICS OF THE constituent Monosaccharides. Most oligosaccharides serve as a source of energy. Some of them are produced on a large scale, such as sucrose from sugar beets and sugar cane, and lactose from milk, among others.

Sucrose (beet sugar, cane sugar, 4-O-α-D-glucopyranosyl-$eta$-O-fructofuranoside), C₁₂H₂₂O₁₁, is a disaccharide carbohydrate and the most common sugar of plant origin. Sucrose is synthesized in plant leaves via Photosynthesis from D-glucopyranose and D-fructofuranose. Sugar beet roots (up to 24%) and sugar cane stalks (up to 20%) have the highest sucrose content.

Sucrose is readily assimilated by the body and represents a valuable food product. In pharmacy, sugar syrup is used as a flavoring and corrective agent, and powdered sugar is utilized in tablet manufacturing. The pharmaceutical industry produces syrups of rosehip, marshmallow ROOT, iron-supplemented aloe, and others. There is also a complex preparation known as Alsucral (Venter, sucralfate), in which sucrose sulfate is combined with aluminum hydroxide.

Maltose (malt sugar, 4-O-α-D-glucopyranosyl-α-D-glucopyranose). The glucose residues are linked via the 1 $ ightarrow$ 4 carbon atoms. The aldehyde group of the second residue remains free, which is why maltose undergoes all reactions characteristic of reducing monosaccharides. Maltose is produced by the Hydrolysis of Starch in the form of starch syrup (molasses), which is used in the food industry and for technical purposes.

Lactose (milk sugar, 4-O-β-D-galactopyranosyl-α-D-glucopyranose). It is a component of mammalian milk, from which it is commercially obtained. It exhibits reducing properties. The production of fermented dairy products relies on the Fermentation of lactose to produce lactic acid. Lactose is widely used in the food industry, medicine, and bacteriology.

Cellobiose (4-O-β-D-glucopyranosyl-α-D-glucopyranose) differs from maltose by having a β-glycosidic bond between the glucose molecules. It is obtained from Cellulose.

Other homodisaccharides are known that are built from D-glucose residues but possess Different types of linkages, such as sophorose (1 → 2) and gentiobiose (1 → 6). They are frequently found as components of flavonoid glycosides.

Rutinose (6-O-α-L-rhamnopyranosyl-D-glucopyranose) is a disaccharide that forms the sugar moiety of rutin, a well-known flavonol widely distributed in plants.

Primulaverose (6-O-β-D-xylopyranosyl-D-glucopyranose) is a disaccharide isolated from the hydrolysis products of various phenolic glycosides (such as primulaverosides, primulalverosides, monotropitoside, etc.).