Page 57 - PG 504-theoretical notes-phyto-1-2024-2025..

Clinical pharmacy PharmD program Third level Phytochemistry-1 (PG-504)

2) D-Apiose:

• It is a rare pentose having an unusual branched chain structure.

• It is present in the leaves and seeds of parsley in the form of glycoside known

as apiin. It is obtained by hydrolysis of apiin or by synthesis.

Note: Branched chain monosaccharides are also found in antibiotics (e.g.,

streptose, dihydrostreptose and others), as well as in several plants (e.g.,

hamamelose in witch-hazel).

3) D-Xylose (Wood sugar):

• It is found in straws, corn cobs, and wood.

• It can be prepared by a. boiling woody materials with acids. i.e. HCl , to

hydrolyze the xylan rich polymer of hemicellulose which is broken down to
yield xylose. /Or b. fermenting glucose by yeast, filter. The remaining

solution is concentrated and D-xylose is crystallized out.

• Used as: 1. foods for diabetics. 2. Diagnostic agent in disorders due to intestinal

malabsorption or/: Crohn’s disease; Radiation enteritis or Pellagra

4) D-Ribose:

D-Ribose (Cytoplasm) and D-desoxyribose (Nucleus) constitute the
sugar part of ribonucleic acids (RNA) and deoxyribonucleic acids (DNA). They

occur in the furanose form.

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