title: Effect of molecular chirality and side chain bulkiness on angiogenesis of haloacetylcarbamoyl-2-nitroimidazole compounds.
abstract: BACKGROUND
  Angiogenesis is required for tumor growth and metastasis, and is an exciting target for cancer treatment. We designed and synthesized antiangiogenetic TX agent (TX-1898, -1900), and analyzed their structural features. TXs have a chiral center and S- and R-enantiomers. Conformation analysis and molecular dynamics simulation were undertaken.
  
  
  METHODS
  Molecular models of TXs were constructed using InsightlI-Discover. Conformation analysis was performed with CONFLEX, and z-matrix data were extracted to calculate molecular orbital (MO) parameters (i.e. solvation free energy (dGW)). Their molecular dynamics were simulated with the Discover3 module, and the total energy and dihedral angles were estimated.
  
  
  RESULTS
  The methyl-including TXs (Group 1: TX-1863, -1878, -1866, -1879) had 130-229 conformers (-1.26-14.6 kcal/mol). The t-butyl-including group (Group 2: TX-1880, -1881, -1882, -1883) had 244 - 294 conformers (3.69 - 16. 76 kcal/mol), and the p-t-butylphenyl-containing TXs (Group 3: TX-1897, -1899, -1898, -1900) had 584 - 711 conformers (-7.48 -5.18 kcal/mol). The dGWprofile of nine samples, which were extracted from these conformers, were examined and one minimum dGW point was observed in the haloacetylcarbamoyl-2-nitroimidazole TXs (Group 1 -3).
  
  
  CONCLUSIONS
  TX-1898 exhibited significant antiangiogenic activity. The order of antiangiogenic activity was as follows: TX-1898 (93% at 5 microg/pellet) > TX-1900 (82% at 5 microg/pellet) > TX-1897 (64% at 10 microg/pellet) > TX-1899 (58% at 10 microg/pellet). The chiral center has an important role for orienting the molecular characteristics.
authors.affiliation: Faculty of Pharmacy, Chiba Institute of Science, 3 Shiomi-cho, Choshi, Chiba, Japan. kohkura@sag.bekkoame.ne.jp
authors.forename: Kazuto
authors.initials: K
authors.lastname: Ohkura
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Uto
authors.forename: Hideko
authors.initials: H
authors.lastname: Nagasawa
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Hori
mesh_terms: D020533:Angiogenesis Inhibitors / Q000737:chemistry*; D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D002642:Chick Embryo; D003198:Computer Simulation; D003510:Cyclohexanes / Q000737:chemistry; D004730:Endothelium, Vascular / Q000187:drug effects; D009593:Nitroimidazoles / Q000737:chemistry*; D000077609:O-(Chloroacetylcarbamoyl)fumagillol; D011487:Protein Conformation; D051381:Rats; D012717:Sesquiterpenes / Q000737:chemistry; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D020533:Angiogenesis Inhibitors; D003510:Cyclohexanes; D009593:Nitroimidazoles; D012717:Sesquiterpenes; C496997:TX-1898; D000077609:O-(Chloroacetylcarbamoyl)fumagillol