#pentose

• Aldose — A class of monosaccharides (simple sugars) that contain an aldehyde carbonyl functional group (-CHO) in their molecule, necessarily located at the first carbon atom of the chain. Distinct from ketoses, aldoses are solid, crystalline, water-soluble substances with a sweet taste, classified based on the number of carbon atoms into aldotrioses, aldotetroses, aldopentoses, and aldohexoses (such as glucose and galactose).
• Arabinose — A monosaccharide containing five carbon atoms belonging to the pentose class, frequently encountered in the plant kingdom as a major structural component of complex polysaccharides in cell walls, such as plant gums, pectins, and hemicelluloses. Unlike most natural sugars that occur predominantly as the D-isomer, arabinose is notable because its L-isomer is the most widespread and biologically active form in nature.