On Tue, Oct 28, 2008 at 5:38 PM, Robert DeLisle <[email protected]> wrote:
> I agree with Nik an additional 2 pence. In fact, while reading Greg's
> original note, my thoughts were essentially identical to Nik's comments.
Excellent. Here's an altered proposal based on Nik's comments.
The definition of NumHAcceptors will be modified (modifications
discussed below). I won't make any changes to the NOCount or NHOHCount
descriptors or introduce new names for them. The new names would
conceivably break existing code and wouldn't really contribute to
clarity of future code, so the change doesn't seem worth making.
For the purposes of fixing the more complex HAcceptor descriptor I
propose the following SMARTS:
HAcceptorSmarts = Chem.MolFromSmarts('[$([O,S;H1;v2]-[!$(*=[O,N,P,S])]),\
$([O,S;H0;v2]),$([O,S;-]),\
$([N;v3;!$(n-...@[o,N,P,S])]),\
$([nH0,o,s;+0]),\
$(F-a)]')
There are two changes here relative to the current definition: the
third line and the last one.
The third line includes nitrogens that have three neighbors and that
are not connected to another atom that has a non-ring double bond to
O, N, P, or S. The last line includes Fs that are connected to an
aromatic atom.
Comments?
-greg
