From owner-chemistry*- at -*ccl.net Thu Oct 2 09:22:00 2008 From: "Michel PETITJEAN michel.petitjean*_*cea.fr" To: CCL Subject: CCL: Chirality assignment test cases Message-Id: <-37833-081002084744-9051-SBgfL4AAwvdLnfLZmnNIzQ+/-server.ccl.net> X-Original-From: "Michel PETITJEAN" Content-class: urn:content-classes:message Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="iso-8859-1" Date: Thu, 2 Oct 2008 14:45:03 +0200 MIME-Version: 1.0 Sent to CCL by: "Michel PETITJEAN" [michel.petitjean---cea.fr] =20 Dear Mark, Simple test cases should appear in stereo nomenclature books = (IUPAC,...), and the references cited may contain interesting chiral molecules = exemplifying the rules. Inositols, chiral fullerenes, highly bridged graph-symmetric structures, non-planar graphs structures, etc., would surely be nice test cases. I hope that the CSD contains the connection tables of some of these = molecules. The "known" chirality is an ambiguous concept: apart in a few simple = situations, how can we know if the CIP assignment of chirality is possible, if not by running some CIP flag assignment program ? If the CIP rules are expressed rigorously, the CIP algorithm AND its = input data must be unambiguous, and then the CIP algorithm must be programmable. Assuming that the data and the algorithm are defined, the implementation = can be tested. Invariance of the result upon random renumbering of the connection table = is also a good test. Programming the CIP rules is an exciting project. Prelog himself proposed to revise them many years ago. I wish you good luck. Michel Petitjean DSV/iBiTec-S/SB2SM (CNRS URA 2096) CEA Saclay, bat. 528 91191 Gif-sur-Yvette Cedex, France. Phone: +331 6908 4006 / Fax: +331 6908 4007 E-mail: michel.petitjean*|*cea.fr http://petitjeanmichel.free.fr/itoweb.petitjean.html -------- Message d'origine-------- De: Mark Mackey M.Mackey,+,cresset-bmd.com = [mailto:owner-chemistry*|*ccl.net] Date: mer. 01/10/2008 18:42 =C0: Michel PETITJEAN Objet : CCL: Chirality assignment test cases =20 Hi all. I'm testing some old chirality assignment code (using the Cahn-Ingold-Prelog rules). It would be really useful if there was a data set of test cases with known chirality, ranging from the simple (amino acids) right up to the really nasty ones. Does anyone out these have such a thing? It's mind-bendingly tedious drawing in and assigning test cases by hand... --=20 Dr Mark Mackey Director, Development Cresset BioMolecular Discovery Ltd