Chemistry Reference
In-Depth Information
H
H
OH
NH 2
O -
O
H
H
H
O -
O -
HO
HO
HO
N
H +
N
H +
N
H +
Pyridoxine (PN)
(vitamin B 6 )
Pyridoxamine (PM)
Pyridoxal (PL)
O
H
O
4'
H
H
O
OH
O
NH 2
O -
P
O -
H
H
5'
- O
4
3'
O
P
P
5
6
O -
3
2
- O
- O
O
O
- O
- O
- O
1
N
H +
H +
H +
Pyridoxine 5'-phosphate
(PNP)
Pyridoxamine 5'-phosphate
(PMP)
Pyridoxal 5'-phosphate (PLP)
FIGURE 12.10
The structure of pyridoxine and related compounds.
Vit B 6 can offer benefit in the transfer of signals from one nerve cell to another
with the participation of neurotransmitters, and be helpful in regulating the body's
clock and improving the immune system. The importance of PLP in the body can be
recognized by symptoms due to its deficiency. Generally, there is a decrease in appe-
tite and growth rate; with resulting dermatologic symptoms, muscle weakness, dental
and oral health issues, and hepatic steatosis. In term of vascular problems, deficiencies
cause arteriosclerosis, anemia, paralysis, convulsions, peripheral neuropathy, and
malformations. Vit B 6 deficiency will cause confusion, irritability, depression, and
mouth and tongue sores in our daily life. Conversely, an excess of Vit B 6 can lead to
difficulty in coordinating movement, numbness, and sensory changes.
Since PLP play a major role in amino acid metabolism, it is widely dispersed
throughout the plant and animal kingdoms. Common natural sources include rice,
fish, poultry, meat, potatoes, fruits (bananas) and vegetables (carrots), and other food
sources such as avocado, legumes, and whole grains. Various methods have been
used to isolate Vit B 6 from these sources.
HISTORICAL NOTE
Vit B 6 is a secondary metabolite. In 1934, Hungarian physician Paul György
noted that it cured skin disease in rats and 4 years later, Vit B 6 was isolated
from rice bran. The structure was elucidated by Harris and Folkers in 1939.
Subsequently, it was demonstrated that Vit B 6 mainly has two forms: pyridoxal
and pyridoxamine. All the forms of Vit B 6 are precursors of PLP, which is now
understood to play an important role as a cofactor of many essential enzymes
in the human body.
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