Chemistry Reference
In-Depth Information
O
O
O
RN
O
X
X
X
N
C
+5
N
NH
NH
X
N
NH
O
O
O
O
X
X
R
O
Cr
5+
N
NH
2
R
N
NH
2
H
N
8-oxoG
nucleophilic
attack
ring opening
H
2
O
HO
-
HO
O
H
OO
O
N
O
N
NH
HN
N
acyl shift
NH
O
O
R
H
R
-
N
NH
2
O
NH
2
OH
R
N
NH
2
OH
Spiroiminodihydantoin, Sp
Figure 17.7
Formation of Sp from 8-oxoG via a two-electron, oxo atom transfer mechanism
69
O
OO
N
HN
N
NH
O
R
H
NH
2
R
N
NH
2
O
8-oxoG
Spiroiminodihydantoin, (Sp)
O
O
HN
HN
NH
NH
O
O
R
H
NH
2
R
N
2
Oxidized Guanidinohydantoin, (Gh
ox
)
Guanidinohydantoin, (Gh)
O
O
O
N
NH
2
NH
2
NH
2
N
RHN
N
RHN
Oxazolone (Oz)
Imidazalone (Iz)
O
N
O
O
O
NH
RN
HO
O
RHN
O
Parabanic Acid (Pa)
Oxaluric Acid (Oa)
Figure 17.8
Oxidative nucleobase lesions considered possible to arise from Cr(VI) exposure.
Only 8-oxoG and Sp have thus far been observed in cellular systems
