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Comphensive Guide to Accessory Nutrients and Essential Oils


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Meschino Health Comprehensive Guide to Accessory Nutrients and Essential Oils
Accessory Nutrients and Essential Oils
Glucosamine Sulfate
General Considerations
Glucosamine-6-phosphate is the precursor from which all proteoglycans are synthesized. Proteoglycans are found in
the synovial fluid of joints, the vitreous humor of the eye, arterial walls, as well as bone and cartilage. They are major
components of the extracellular matrix or ground substance, a gelatinous material that forms a meshwork between
cells. Proteoglycans are proteins that contain many chains of glycosaminoglycans (formerly called
mucopolysaccharides).
Glycosaminoglycans are long, unbranched polysaccharides composed of repeating disaccharide units. The repeating
disaccharides usually contain an uronic acid or a glucuronic acid, and a hexosamine, and are frequently sulfated. All
hexosamines are derived from glucosamine-6-phosphate. Hence the synthesis of glucosamine-6-phosphate is
essential to the production of ground substance throughout our lives. This extracellular matrix is more than glue that
holds cells together. It also serves as a barrier to microorganisms from reaching cells. Because they are long and
negatively charged, glycosaminoglycans chains repel each other. As well, the proteoglycans occupy a very large
space and act as “molecular sieves”, determining which substances approach and leave cells. Their properties also
give resilience to substances such as cartilage, permitting compression and reexpansion (shock absorbing function)
There are at least seven types of glycosaminoglycans, which differ from each other based upon the monosaccharides
present in their repeating disaccharide units:
1. Chondroitin sulfate
2. Dermatan sulfate
3. Heparin
4. Heparin sulfate
5. Hyaluronic acid
6. Keratan sulfate I
7. Keratan sulfate II
Except for hyaluronic acid, the glycosaminoglycans are linked to proteins, usually attached covalently to serine or
threonine residues, and are hence also referred to as proteoglycans. Keratan sulfate I is attached to asparagine. The
synthesis of all glycosaminoglycans is dependent upon the presence of glucosamine-6-phosphate.
Glucosamine-6-phosphate
The body normally synthesizes glucosamine-6-phosphate by the transfer of an amino group from the amide of
glutamine to fructose 6-phosphate. Glucosamine can then be N-acetylated by an acetyltransferase enzyme to yield N-
acetyl glucosamine-6-phosphate and N-acetyl galactosamine, which are then linked to UDP. Both N-acetyl
glucosamine and N-acetyl galactosamine are used as monosaccharides to form various glycosaminoglycans. The
glycosaminoglycans in joint cartilage are comprised of repeating units of glucuronic acid and N-acetyl galactosamine. It
appears that as some people age, they lose the ability to manufacture sufficient levels of glucosamine-6-phosphate,
and thus, there is a reduction in the synthesis of N-acetyl galactosamine and N-acetyl glucosamine. The result is that
cartilage loses its ability to act as a shock absorber and erosion of cartilage and ground substance can lead to
osteoarthritis. Radioisotope studies using C14 glucosamine indicate that glucosamine supplementation is a good
substrate for a kinase enzyme which yields glucosamine-6-phosphate, which can then be used to form
glycosaminoglycans.
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