N
X
C
Hal
O
N
S
P Si
Natural
Products
Solvents
C
C
C
C C
C
243
5.13 Natural Products
243
5.13 Natural Products
5.13.1 Amino Acids
Chemical Shifts and Coupling Constants (δ in ppm, J in Hz)
+
H 3 N
O –
O
+
H 3 N
OH
O
+
H 3 N
OH
O
+
H 3 N
O
–
O
+
H 3 N
OH
O
+
H 3 N
OH
O
+
H 3 N
O
–
O
+
H 3 N
O
–
O
7.47
7.33
7.38
4.32
4.28
3.72
≈2
1.70
≈2
1.70
1.11
0.94
1.10
0.95
3.60
2.60
2.26
1.25
0.98 1.03
7.41
4.28
1.86
1.46
4.49
3.76
3.54
3 J ab 5.7
3 J ab 5.7
3 J bc 4.2
3 J cd 6.9
3 J ab 5.5
3 J bc ≈6.7
3 J bd ≈6.7
3 J eg 6.1
3 J ef 5.7
(in TFA)
(in TFA)
(in TFA)
(in TFA)
(in H 2 O, pH 7.0)
(in H 2 O, pH 7.0)
(in H 2 O, pH 7.0)
(in H 2 O, pH 7.0)
(in H 2 O, pH 7.0)
a
a
e
g
f
a
b
b
b
b
c
c
d
e
d
c,d
+
H 3 N
O
–
O
+
H 3 N
OH
O
7.35
4.41
3.66
2.28
1.97
1.55
1.70
1.25,
1.46
1.10
0.93
1.21
1.00
3 J ab 5.5
3 J bc 3.6
3 J cd 7.0
3 J ce 6.1
3 J cf 8.4
2 J ef -13.6
3 J eg 7.0
3 J fg 7.0
3 J bc 4.0
(in TFA)
a
c
c
b
b
d
g
e
f
3 J bc 4.3
3 J cd 7.0
3 J ce 7.0