NAME

     obrotate — batch-rotate dihedral angles matching SMARTS patterns

SYNOPSIS

     obrotate 'SMARTS-pattern' filename atom1 atom2 atom3 atom4 angle

DESCRIPTION

     The obrotate program rotates the torsional (dihedral) angle of a specified bond in molecules
     to that defined by the user. In other words, it does the same as a user setting an angle in
     a molecular modelling package, but much faster and in batch mode (i.e. across multiple
     molecules in a file).

     The four atom IDs required are indexes into the SMARTS pattern, which starts at atom 0
     (zero). The angle supplied is in degrees. The two atoms used to set the dihedral angle
     <atom1> and <atom4> do not need to be connected to the atoms of the bond <atom2> and <atom3>
     in any way.

     The order of the atoms matters -- the portion of the molecule attached to <atom1> and
     <atom2> remain fixed, but the portion bonded to <atom3> and & <atom4> moves.

EXAMPLES

     Let's say that you want to define the conformation of a large number of molecules with a
     pyridyl scaffold and substituted with an aliphatic chain at the 3-position, for example for
     docking or 3D-QSAR purposes.

     To set the value of the first dihedral angle to 90 degrees:
           obrotate 'c1ccncc1CCC' pyridines.sdf 5 6 7 8 90

     Here 6 and 7 define the bond to rotate in the SMARTS patter, i.e., c1-C and atoms 5 and 8
     define the particular dihedral angle to rotate.

     Since the atoms to define the dihedral do not need to be directly connected, the nitrogen in
     the pyridine can be used:
           obrotate 'c1ccncc1CCC' pyridines.sdf 4 6 7 8 90

     Keep the pyridyl ring fixed and moves the aliphatic chain:
           obrotate 'c1ccncc1CCC' pyridines.sdf 5 6 7 8 90

     Keep the aliphatic chain fixed and move the pyridyl ring:
           obrotate 'c1ccncc1CCC' pyridines.sdf 8 7 6 5 90

SEE ALSO

     obabel(1), obchiral(1), obfit(1), obgrep(1), obprop(1).

     The web pages for Open Babel can be found at: <http://openbabel.org/>

     A guide for constructing SMARTS patterns can be found at:
     <http://www.daylight.com/dayhtml/doc/theory/theory.smarts.html>

AUTHORS

     The obgrep program was contributed by Fabien Fontaine

     Open Babel is developed by a cast of many, including currrent maintainers Geoff Hutchison,
     Chris Morley, Michael Banck, and innumerable others who have contributed fixes and
     additions.  For more contributors to Open Babel, see <http://openbabel.org/wiki/THANKS>

COPYRIGHT

     Copyright (C) 1998-2001 by OpenEye Scientific Software, Inc.
     Some portions Copyright (C) 2001-2005 by Geoffrey R. Hutchison and other contributors.

     This program is free software; you can redistribute it and/or modify it under the terms of
     the GNU General Public License as published by the Free Software Foundation version 2 of the
     License.

     This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
     without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
     See the GNU General Public License for more details.