VITAMIN

1
?????? Power Point ??????????????? ???????????????
???????? (506221) ??????? (Vitamin) ??.??.
???????? ?????? ????????????????
????????????????? ??????????????????????
2
VITAMIN

• FAT (LIPID) SOLUBLE VITAMIN
• WATER SOLUBLE VITAMIN

3
FAT (LIPID) SOLUBLE VITAMIN
CH3
CH2 C- CH3 CH CH2
H2C C CH CH 2

• Vitamin A
• Vitamin D
• Vitamin E
• Vitamin K

ISOPRENE UNIT
( 2-methylbutadiene)
4
A2
????? Stryer, 1995
5
WATER SOLUBLE VITAMIN

• Vitamin B complex
• Vitamin C (ascorbic acid)

6
VITAMIN B COMPLEX

• Vitamin B1 (thiamin)
• Vitamin B2 (riboflavin)
• Pantothenic acid (B5)
• Nicotinic acid (niacin), Nicotinamide
  (niacinamide) (B3)

• Vitamin B6 (pyridoxal, pyridoxine, pyridoxamine)
• Lipoic acid
• Biotin
• Vitamin B12 (cobalamin)
• Folic acid

7
????? Stryer, 1995
8
???????? ??? Vitamin A
Retinal, retinene, retinadehyde, aldehyde form
(-CHO)
Retinoic acid, acid form (-COOH)
Retinol , alcohol form (-CH2OH)
Retinyl palmitate, ester form (storage form)
????? http//www.indstate.edu/thcme/mwking/vitam
ins.html
9
11-cis-retinal
????? http//www.indstate.edu/thcme/mwking/vitam
ins.html
????? Lehninger et al, 1993
10
??????? b-carotene????????????? ??????????
b-carotene 2 molecules of retinaldehyde
(provitamin form of vitamin A)
b-carotene
b -carotene dioxygenase
O2 , bile salts
2 Retinaldehyde
NAD,FAD
retinaldehyde reductase
NADPH H(NADH H) NADP(NAD)
Retinol
Retinoic acid
( plasma transport by binding to albumin )
( plasma transport by binding to apo-RBP )
11
??????????????? retinal ??????????????? ??????????
????? retinol ?????????????????
????? Murray et al, 1996
12
Retinol
Palmitic acid
Retinyl palmitate
small intestine
Chylomicrons
blood circulation
Retinol
Storage as a lipid ester
liver
RBP
(aporetinol binding protein)
Retinol-RBP complex
blood circulation
CRBP(cellular retinol binding protein)
Retinol
Complex
extrahepatic tissues
13
Aporetinol - Binding Protein (RBP)
1. ?????????????????????? 2. ?????????? 1
polypeptide chain , M.W. 21,000 D 3. ????? all
- trans - retinol ( 1 molecule retinol / 1
molecule RBP ) 4. ???????????????? retinol,
?????????????? oxidation 5. RBP-retinol complex
?? specific receptor ??? cell membrane ???
target organ
14
??????????Vitamin A ?? Visual Process
EYE
RHODOPSIN
light
visual excitation
dark
ALL-trans-RETINAL OPSIN
OPSIN 11-cis-RETINAL
retinal isomerase
dehydrogenase
11-cis-RETINOL
ALL-trans-RETINOL
RBP
BLOOD CIRCULATION
RBP-ALL-trans-RETINOL
RBP
LIVER
ALL-trans-RETINOL PALMITATE
H2O ALL-trans-RETINYL PALMITATE
esterase
15
????? Murray et al, 1996
16
Lys
aldehyde group
17
Depletion in b - carotene ( vitamin A
deficiency)
Increased risk of cancer
b - carotene effective antioxidant , is
suspected to reduce the
risk of cancers known to
be initiated by the production of
free radicals
Reduce the risk of lung cancer in smokers
Increased b - carotene intake
18
????? Murray et al, 1996
Conjugated alkyl structure of b-carotene
ROO . organic peroxide free radical (peroxyl
free radical)