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Solutions for Carbohydrates and Nucleic Acids
OH
NH2
N
NN
N
NH2
O
H
N
N
O
OH
H
OH
OH
N
NN
H
O
O
N
H
N
N
OH
O
H
N
NN
N
H
NH2
O
H
OH
NH2
N
H
N N
N
guanine:
uracil:
cytosine:49
R2NH2
R
N
R
H
H+
H+
R
N
R
H
HH
OHOH
H
CH2 O
OH H
C
H
HH
OHOH
H
CH2 O
OH
R
N
R
H
HH
OHOH
H
CH2 O
OH
C
H
HH
OHOH
H
CH2 OHO
H2O
H2OO
H
H
HH
OHOH
H
CH2 O
OH
H
O
H
H
HH
OHOH
H
CH2 O
OH
N
H
HH
OHOH
H
CH2 O
OH
N
N
N
NH2
N
N
NH2
O
H
HH
OHOH
H
CH2 O
OH
N
N
NH2
O
H
HH
OHOH
H
CH2 O
OH
cytidine
50 Aminoglycosides, including nucleosides, are similar to acetals: stable to base, cleaved by acid.
(a)
3° aliphatic 
amine— 
strong base
hemiacetal form
of ribose
(b)
site of 
protonation; weak 
base adenosine
See discussion on next page.
616