title: Synthesis, guest-binding, and reduction-responsive degradation properties of water-soluble cyclophanes having disulfide moieties.
abstract: Water-soluble cationic cyclophane having diphenyl disulfide moieties (1a) was synthesized as a reduction-responsive degradable host. The stoichiometry for the complex of 1a with anionic fluorescence guests, such as 4,4'-bis(1-anilinonaphthalene-8-sulfonate) (Bis-ANS) and 4-(1-pyrene)-butanoic acid (PBA), was confirmed to be 1:1 host:guest by a Job plot. The binding constants (K) of 1a toward Bis-ANS and PBA were evaluated to be 6.7 × 10(3) and 4.5 × 10(4) M(-1), respectively, as confirmed by fluorescence spectroscopy. Reduction of disulfide bonds of 1a by dithiothreitol gave its reduced form having poor guest-binding affinity that led to release of the entrapped guest molecules to the bulk aqueous phase. Meanwhile, anionic cyclophane 1b, which was derived from 1a by a reaction with succinic anhydride, binds cationic anticancer drugs, such as daunorubicin hydrochloride (DNR) and doxorubicin hydrochloride (DOX), with a K of 2.1 × 10(3) and 7.5 × 10(2) M(-1), respectively. A similar reduction-responsive guest release feature was observed when DNR and DOX were employed as a guest for complexation with 1b.
authors.affiliation: Department of Chemistry, Faculty of Science, Fukuoka University , 8-19-1 Nanakuma, Fukuoka 814-0180, Japan. hayashida@fukuoka-u.ac.jp
authors.forename: Osamu
authors.initials: O
authors.lastname: Hayashida
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Ichimura
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sato
authors.forename: Terutaka
authors.initials: T
authors.lastname: Yasunaga
mesh_terms: D001372:Aza Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D001665:Binding Sites; D004220:Disulfides / Q000737:chemistry*; D047028:Macrocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D012995:Solubility; D014867:Water / Q000737:chemistry
chemical_list: D001372:Aza Compounds; D004220:Disulfides; D047028:Macrocyclic Compounds; C525610:tetraaza(6.1.6.1)paracyclophane; D014867:Water