title: A revised conformational code for the exhaustive analysis of conformers with one-to-one correspondence between conformation and code: application to the VCD analysis of (S)-ibuprofen.
abstract: A revised conformational code for the exhaustive analysis of conformers of all classes of molecules is proposed and applied to the vibrational circular dichroism (VCD) analysis of (S)-ibuprofen. The revised code can strictly define the conformation of compounds with relatively high-symmetry substituents and is especially useful for visualizing conformational changes in ligands and proteins. The conformational analysis of (S)-ibuprofen using the code in the solution state reveals that the four energetically preferred conformations, ibut-3alpha2alpha sigma(phpa-3alpha sigma2alpha), ibut-3alpha2alpha tau(phpa-3alpha tau2alpha), ibut-2beta3beta tau(phpa-3alpha tau2alpha), and ibut-2beta3beta sigma(phpa-3alpha sigma2alpha), exist in the monomer and dimer forms. In CDCl(3) solution, the dimer form is stabilized as the "U"-shape, and the ease of crystallization is largely ascribed to the conformation of phpa-3alpha2alpha for (S)-ibuprofen. The new version of the conformational code has the possibility to be used as a tool for the exhaustive analysis of conformers of all kinds of chemical compounds, conformome analysis, and in the future for metabolome, proteome, and genome analyses.
authors.affiliation: National Institute of Advanced Industrial Science and Technology, AIST Tsukuba West, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan. izumi.h@aist.go.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Izumi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ogata
authors.forename: Laurence A
authors.initials: LA
authors.lastname: Nafie
authors.forename: Rina K
authors.initials: RK
authors.lastname: Dukor
mesh_terms: D002942:Circular Dichroism; D007052:Ibuprofen / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D015242:Ofloxacin / Q000737:chemistry; D013055:Spectrophotometry, Infrared; D009626:Terminology as Topic
chemical_list: D015242:Ofloxacin; D007052:Ibuprofen