Chemistry Reference
In-Depth Information
HBA Distributions
50
40
30
20
10
0
0
1
2
3
4
5
6
>6
Count
Maybridge
ChemBridge
ActiveSight
Figure 9.4
Hydrogen bond acceptor (HBA) distributions for ActiveSight, ChemBridge and
Maybridge fragment libraries.
HBD Distributions
35
30
25
20
15
10
5
0
0
1
2
3
4
5
6
>6
Count
Maybridge
ChemBridge
ActiveSight
Figure 9.5
Hydrogen bond donor (HBD) distributions for ActiveSight, ChemBridge and
Maybridge fragment libraries.
ActiveSight indicates that their small compound library is obtained from fragments
of 'drug-like' molecules.
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7
]
As seen by the molecular weight (Figure 9.1) and flexibility
(Figure 9.7) distributions, these compounds are very small and rigid compared with the
other two vendors. Most of the ActiveSight fragments consist of a single rigid core decor-
ated with small side-chains. While nearly 95% of their molecules are less than 200 Da with
cores of benzenes, benzimidazoles, cyclohexanes, furans, indoles, indazoles, naphthalenes,
piperidines, pteridines, purines, pyrazoles, pyridines, pyrimidines, oxazoles, isoxazoles,
quinolines, isoquinolines, quinazolines and thiazoles, the fragments provide a fairly large
range of functionality, as witnessed by the distribution of HBAs and HBDs, shown in
Figures 9.4 and 9.5, but with 75% of the fragments having a zero net charge (Figure 9.6).
