OESetComment

void OESetComment(OEMolBase &mol, const char *c)
void OESetComment(OEMolBase &mol, const std::string &c)

Attaches a text comment to a molecule. This comment will be written to the comment field of the .mol2 and .sdf molecular formats. It will also be conserved in OEBinary format. This property may be retrieved using the OEGetComment function.