C11(R)
N
H
N11
CA1
N
H
2
NB1
N
H
NC1
C21(R)
O
H
O21
C31(S)
N
H
N31
CD1
N
H
2
NE1
N
H
NF1
C41(R)
O
O41
C51(R)
O
H
O51
C61(S)
O
H
O61
C12(R)
C22(S)
C32(S)
O
H
O32
CG2
O
OG2
C42(S)
CH2
O
O42
O
O13
C13(S)
C23(S)
N
H
N23
CI3
C33(S)
O
H
O33
C43(R)
O
H
O43
C53(S)
O
O53
C63
O
H
O63