77450-03-4Relevant articles and documents
Accessible chiral linker to enhance potency and selectivity of neuronal nitric oxide synthase inhibitors
Jing, Qing,Li, Huiying,Roman, Linda J.,Martasek, Pavel,Poulos, Thomas L.,Silverman, Richard B.
supporting information, p. 56 - 60 (2014/02/14)
The three important mammalian isozymes of nitric oxide synthase (NOS) are neuronal NOS (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS). Inhibitors of nNOS show promise as treatments for neurodegenerative diseases. Eight easily synthesized compounds containing either one (20a,b) or two (9a-d; 15a,b) 2-amino-4-methylpyridine groups with a chiral pyrrolidine linker were designed as selective nNOS inhibitors. Inhibitor 9c is the best of these compounds, having a potency of 9.7 nM and dual selectivity of 693 and 295 against eNOS and iNOS, respectively. Crystal structures of nNOS complexed with either 9a or 9c show a double-headed binding mode, where each 2-aminopyridine headgroup interacts with either a nNOS active site Glu residue or a heme propionate. In addition, the pyrrolidine nitrogen of 9c contributes additional hydrogen bonds to the heme propionate, resulting in a unique binding orientation. In contrast, the lack of hydrogen bonds from the pyrrolidine of 9a to the heme propionate allows the inhibitor to adopt two different binding orientations. Both 9a and 9c bind to eNOS in a single-headed mode, which is the structural basis for the isozyme selectivity.
Design and stereoselective synthesis of four peptide nucleic acid monomers with cyclic structures in backbone
Watanabe, Akiko,Kiyota, Naotoshi,Yamasaki, Tetsuo,Tanda, Kazuhiro,Miyagoe, Tatsunori,Sakamoto, Masanori,Otsuka, Masami
experimental part, p. 1132 - 1139 (2011/11/05)
Four isomers of the monomer of peptide nucleic acid (PNA) were derived from (2S,4R)-4-hydroxyproline; they had different stereochemistries at the C 2 and C4 positions in the pyrrolidine ring. These different backbone conformations corresponding to four different stereochemistries were realized through a combination of inversions at the C2 and the C4 positions in pyrrolidine ring. The obtained backbone frameworks were reacted with N-benzoyl thymine to give the corresponding PNA monomers. Spectroscopic comparison of the resultant monomers confirmed their stereochemistries.
Transition-Metal-Catalyzed Asymmetric Organic Synthesis via Polymer-Attached Optically Active Phosphine Ligands. 5. Preparation of Amino Acids in High Optical Yield via Catalytic Hydrogenation
Baker, Gregory L.,Fritschel, Scott J.,Stille, John R.,Stille, John K.
, p. 2954 - 2960 (2007/10/02)
Two new optically active phosphinopyrrolidine monomers were prepared by the reaction of (2S,4S)-4-(diphenylphosphino)-2-pyrrolidine and (2R,4R)-4-(diphenylphosphino)-2-pyrrolidine with acryloyl chloride to give N-acryloyl-(2S,4S)-4-(diphenylphosphino)-2-pyrrolidine (1) and N-acryloyl-(2R,4R)-4-(diphenylphosphino)-2-pyrrolidine (2).Copolymerization of 1 and 2 with hydrophilic comonomers and a divinyl monomer provided cross-linked insoluble polymers containing 3-5percentof 1 or 2 that would swell in polar solvents.Exchange of rhodium (I) onto the polymer gave catalysts which were active for the asymmetric hydrogenation of N-acyl α-amino acids in high optical yields, the phosphine derived from the enantiomer of the naturally occurring 4-hydroxyproline giving (S)-amino acids.The catalysts could be reused with no loss in selectivity by simple filtration.
