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

▪ The exoskeleton of lobster and crab is a rich source of chitin, which is a

repeating polymer of glucosamine units.

Preparation: It can be obtained from chitin by strong acid hydrolysis.

Fate of glucosamine in the body:

Through a complex pathway it eventually leads to formation of

glycosaminoglycans, which then form large aggregating proteoglycans with

hylauronic acid to form the matrix in cartilage. Therefore, glucosamine is a

fundamental molecule for the synthesis of cartilage.

Uses:

1) Clinically, glucosamine is used for knee and hip osteoarthritis.

2) Research also shows positive results with the use of both glucosamine and

chondroitin to treat osteoarthritis.

3) It may help regenerate the damaged cartilage in osteoarthritis joints.

Attention: The hypothesis that glucosamine may cause insulin resistance is of

concern. The metabolic steps that glucosamine goes through in the body can be

overloaded and block the normal movement of glucose. This can cause insulin

resistance in cells exposed to large doses of glucosamine. However, the research

in this area is contradictory. The preliminary results from the study of the effects

of normal, recommended doses of glucosamine in healthy adults shows no

incidence of insulin resistance.

2) Thiosugars

▪ The replacement of an oxygen atom in a monosaccharide by sulfur gives rise to

thiosugars.

▪ In occurs naturally in seeds of black mustard (Brassica nigra) as

thioglycosides, e.g. sinigrin.

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