Drawing Oligosaccharides

Drawing oligosaccharides from their names involves understanding the basic structures of carbohydrates, the numbering system used to describe the positions of the different functional groups, and the conventions used to represent the different types of linkages between the monosaccharides. Here are some examples of how to draw different types of oligosaccharides from their names:

1. Maltose: Maltose is a disaccharide composed of two glucose units linked by an α-1,4-glycosidic bond. To draw maltose, you would start with a glucose molecule and add another glucose molecule to it by linking the first carbon atom of the second glucose to the fourth carbon atom of the first glucose with an α-1,4-glycosidic bond. The resulting structure would look like this:

       HOCH2(1)--(4)O--C6H10O5(1)--(4)O--C6H10O5

2. Sucrose: Sucrose is a disaccharide composed of glucose and fructose linked by a β-1,2-glycosidic bond. To draw sucrose, you would start with a glucose molecule and add a fructose molecule to it by linking the second carbon atom of the fructose to the first carbon atom of the glucose with a β-1,2-glycosidic bond. The resulting structure would look like this:

       HOCH2(1)--O--C6H10O5(2)--O--C6H12O6(2)--O--CH2OH

3. Lactose: Lactose is a disaccharide composed of glucose and galactose linked by a β-1,4-glycosidic bond. To draw lactose, you would start with a glucose molecule and add a galactose molecule to it by linking the fourth carbon atom of the glucose to the first carbon atom of the galactose with a β-1,4-glycosidic bond. The resulting structure would look like this:

       HOCH2(1)--(4)O--C6H10O5(1)--(4)O--C6H12O6(1)--O--CH2OH

4. Maltotriose: Maltotriose is a trisaccharide composed of three glucose units linked by α-1,4-glycosidic bonds. To draw maltotriose, you would start with a glucose molecule and add two more glucose molecules to it by linking the first carbon atom of the second glucose to the fourth carbon atom of the first glucose, and the first carbon atom of the third glucose to the fourth carbon atom of the second glucose, with α-1,4-glycosidic bonds. The resulting structure would look like this:

       HOCH2(1)--(4)O--C6H10O5(1)--(4)O--C6H10O5(1)--(4)O--C6H10O5

5. Isomaltose: Isomaltose is a disaccharide composed of two glucose units linked by an α-1,6-glycosidic bond. To draw isomaltose, you would start with a glucose molecule and add another glucose molecule to it by linking the first carbon atom of the second glucose to the sixth carbon atom of the first glucose with an α-1,6-glycosidic bond. The resulting structure would look like this:

       HOCH2(1)--(6)O--C6H10O5(1)--(4)O--C6H10O5