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(1) Racemization
N
N N
N
NH
2
O
HO OH
S
OOC
H
2
N
+
_
H
(S)
(S)
(S, S) SAMe
(R, S) SAMe
Bio-Inactive Form
Bio-Active Form
N
N N
N
NH
2
O
HO OH
S
OOC
H
2
N
+
_
H
(S)
(R)
CH
3
CH
3
Reversible
Conversion
Positive Points about
(R, S) SAMe:
•
It is still SAMe;
•
It is not harmful;
•
It is reversible to
Bioactive (S, S)
SAMe;
•
It is possible that (R,
S) is a
Time Release
form of (S, S).
Challenge: SAMe’s Extreme Instability
(2) Degradation
SAMe
S
-Adenosyl-L-
Homocysteine (SAH)
Adenosine
(ADE)
5’-Deoxy-5’-
Methylthioadenosine
(DMTA)
• • • • • •
Loss is –
permanent, Irreversible
and Significant
Challenge: SAMe’s Extreme Instability