title: Preparation and function of poly(acrylic acid)s modified by supramolecular complex composed of porphinatoiron and a cyclodextrin dimer that bind diatomic molecules (O2 and CO) in aqueous solution.
abstract: Poly(acrylic acid) (PAA) is modified by 5-(4-β-alanylaminophenyl)-10,15,20-tris(4-sulfonatophenyl) porphinatoiron(III) to yield iron porphyrin-bearing PAAs (FeP(n)s) through a condensation reaction. FeP(n)s were further functionalized by Py3CD, which is a per-O-methylated β-cyclodextrin (CD) dimer with a pyridine linker and includes the porphyrin pendants to form ferric hemoCD-P(n)s. Ferrous hemoCD-P(3), having three porphyrin chromophores in a polymer chain, is shown to bind molecular oxygen (P(1/2)=7.9±1.4 Torr) in aqueous solution at pH 7.0 and 25 °C, affording oxy-hemoCD-P(3). Oxy-hemoCD-P(3) is biphasically autoxidized to ferric hemoCD-P(3), with 27% of the dioxygen adducts being rapidly oxidized. The rate of autoxidation of oxy-hemoCD-P(15), having 15 porphyrin chromophores in a polymer chain, was much faster than that of oxy-hemoCD-P(3), thus suggesting self-catalyzed autoxidation of oxy-hemoCD-P(n)s. Oxy-hemoCD-P(n)s are markedly stabilized by catalase, thereby indicating that hydrogen peroxide generated from oxy-hemoCD-P(n) accelerates the autoxidation. Most of the hemoCD-P(3) molecules injected into the femoral vein of a rat remained in the body, though about 16% of the hemoCD-P(3) molecules were excreted in the urine as a carbon monoxide adduct.
authors: Department of Molecular Chemistry and Biochemistry, Doshisha University, Kyotanabe, Kyoto 610-0321, Japan. kkano@mail.doshisha.ac.jp
authors: Koji
authors: K
authors: Kano
authors: Toshiro
authors: T
authors: Ochi
authors: Sayuri
authors: S
authors: Okunaka
authors: Yusuke
authors: Y
authors: Ota
authors: Keiichi
authors: K
authors: Karasugi
authors: Takunori
authors: T
authors: Ueda
authors: Hiroaki
authors: H
authors: Kitagishi
mesh_terms: D000179:Acrylates; D000818:Animals; D001802:Blood Substitutes / Q000032:analysis / Q000138:chemical synthesis / Q000493:pharmacokinetics / Q000494:pharmacology; D002248:Carbon Monoxide / Q000737:chemistry* / Q000378:metabolism; D002374:Catalase / Q000737:chemistry / Q000378:metabolism; D003692:Delayed-Action Preparations / Q000032:analysis / Q000138:chemical synthesis* / Q000493:pharmacokinetics / Q000494:pharmacology; D017377:Diatoms / Q000737:chemistry* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D008665:Metalloporphyrins / Q000032:analysis / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry* / Q000378:metabolism; D011108:Polymers / Q000032:analysis / Q000737:chemistry; D011725:Pyridines / Q000737:chemistry; D051381:Rats; D012996:Solutions / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013481:Superoxides / Q000737:chemistry / Q000378:metabolism; D014867:Water / Q000737:chemistry; D047392:beta-Cyclodextrins / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000179:Acrylates; D001802:Blood Substitutes; D003692:Delayed-Action Preparations; D008665:Metalloporphyrins; D011108:Polymers; D011725:Pyridines; D012996:Solutions; D047392:beta-Cyclodextrins; D014867:Water; D013481:Superoxides; D002248:Carbon Monoxide; D007501:Iron; D002374:Catalase; D010100:Oxygen