Chemistry Reference
In-Depth Information
Table 10.19.
Pattern of
•
OH-radical attack (in %) on H
2
Ura and some of its methyl deriva-
tives. The
•
OH-balance is sometimes significantly below 100%, partly due to the inefficien-
cy of the method for the detection of oxidizing
C
(5)-yl radicals. (Schuchmann et al. 1984b)
Substrate
C
(5)
C
(6)
Methyl
Total
H
2
Ura
5
90
-
95
1MeH
2
Ura
≈
2
61
29
92
3MeH
2
Ura
≈
2
72
10
84
30
a
1,3Me
2
H
2
Ura
≈
2
≈
62
94
H
2
Thy
4
74
6
84
6MeH
2
Ura
≈
2
84
6
92
a
≈
22% at
N
(1)CH
3
and 8% at
N
(3)CH
3
In DNA, the
C
(1
H is hidden in the minor groove and hence difficult to access
by reactive free radicals such as
•
OH (Chap. 12.2). If the above type of reaction
would occur within DNA, it would lead to a tandem lesion (for their biological
importance see Chap. 12.5).
′
)
−
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