Junji Aoki

Improvement of blood compatibility on cellulose dialysis membrane I. Grafting of 2-methacryloyloxyethyl phosphorylcholine on to a cellulose membrane surface

A methacrylate with a phospholipid polar group, 2-methacryloyloxyethyl phosphorylcholine (MPC), was grafted on cellulose membrane for haemodialysis in an aqueous medium using cerium ion (Ce4+) as an initiator. The effects of the concentrations of MPC and Ce4+, and degassing of feed solution on the grafting of MPC on the surface and the membrane properties such as permeability and mechanical strength were examined. The grafted MPC composition depended on the concentrations of both the monomer and initiator in the feed solution. When the grafted MPC distribution was controlled by the monomer concentration, the permeability of the membrane decreased with an increase in grafted MPC distribution. On the other hand, the permeability was not changed from the original membranes value when the MPC distribution was regulated by Ce4+ concentration. The tensile strength of the membrane did not change during the grafting of MPC and this indicated that the grafting had taken place in the amorphous region of the cellulose. These results suggested that this method is a promising way to improve the blood compatibility of a cellulose membrane without having an adverse effect on the haemodialysis membrane.

Improvement of blood compatibility on cellulose dialysis membrane: 2. Blood compatibility of phospholipid polymer grafted cellulose membrane

The blood compatibility of a cellulose haemodialysis membrane whose surface was grafted with a methacrylate having a phospholipid polar group, 2-methacryloyloxyethyl phosphorylcholine, was evaluated with attention to platelet adhesion to the membrane surface and complement activation induced by the membrane. When the original cellulose membrane came in contact with platelet-rich plasma for 30 min, numerous platelets adhered to the surface and aggregated. On the other hand, the membrane grafted with 2-methacryloyloxyethyl phosphorylcholine effectively suppressed platelet adhesion and activation. This effect became more pronounced with increasing surface distribution. Especially, the 2-methacryloyloxyethyl phosphorylcholine grafted membranes, whose distribution exceeded 0.27, completely inhibited platelet adhesion, even when the contact time was 180 min. Moreover, the complement activation was also reduced with increased 2-methacryloyloxyethyl phosphorylcholine distribution on the surface of the membrane.

High photo-response organic materials: tetrabenzo-[a,cd,j,lm]perylene and diphenanthra[4,5,6-abcd, 4,5,6-jklm]perylene

Abstract The photoconductivity of evaporated thin films of tetrabenzo[ a,cd,j,lm ] perylene and diphenanthra[4,5,6- abcd , 4,5,6- jklm ]perylene were observed. These compounds, particularly the latter, were found to show a very high photo-response even under a high vacuum. The time response of the photocurrent is very sharp under a high vacuum, so that the reliable spectral response of the photocurrent could be observed. The photocurrents increase successively by exposing the films to oxygen, but no effect is observed by exposing them to nitrogen and sulphur hexafluoride (SF 6 ).

Conformation of condensed polycyclic aromatic hydrocarbons Part III. The molecular and crystal structure of tribenzo [a,h,rst] phenanthra [1,2,10-cde] pentaphene: a simple analysis of the in-plane distortions due to overcrowding

Abstract The crystal and molecular structure of tribenzo [ a,h,rst ] phenanthra [1,2,10- cde ] pentaphene was determined by X-ray diffraction with final agreement factor R=0.057 for 2842 reflections. The molecule is largely distorted from a planar structure owing to a steric repulsion between the overcrowded hydrogen atoms. The deviations of the atoms from the mean plane of the whole molecule range from −1.78 to 1.52 A. The molecule has an approximate twofold axis perpendicular to the mean molecular plane and takes a saddle form. A simple analysis of the out-of-plane and in-plane distortions shows that the latter should not be neglected.

Structure determination by MS, NMR and UV spectra of bromo and nitro derivatives of 1-azabenzanthrone

Abstract 3-Bromo-1-azabenzanthrone and 9-nitro-1-azabenzanthrone have been identified by their mass, 1 H (HH COSY) and 13 C (ADEPT) NMR, and UV spectra. The position of the nitro group has also been confirmed by mass and UV spectra of 9-nitro-1-azabenzanthrone derivatives: two isomers of pyridino-1-azabenzanthrones. The changeable substitution position of the nitro group on 1-azabenzanthrone is speculated as resulting from some kind of solvent effect for an electrophilic reaction.

Synthesis and physical properties of azapolycyclic hydrocarbons. Part 1. Preparation of 1-azabenzanthrone and its condensation products and their structural determination

Preparation of 1 -azabenz[de]anthrone (27) was carried out by making use of a German Patent reaction. An improved procedure gave (27) easily and rapidly. Compound (27) underwent self-condensation via a zinc-catalysed method or an alkali-fusion procedure. The zinc-catalysed condensation product was separated into four isomers; 3,12-diazatetrabenzo[a,cd,j,lm]perylene (7), 3,15-diazabenzo[rst]phe-nanthro[1,10,9-cde]pentaphene (4), 5,17-diazadibenzo[a,rst]naphtho[8,1,2-cde]pentaphene (3), and 5,10-diazabenzo[rst]phenaleno[1,2,3-de]pentaphene (6). The major component was (3). The reduced product after alkali-fusion condensation of (27) was separated into four isomers; (7), (3), (6), and 5,14-diazadinaphtho[1,2,3-cd:1′,2′,3′-lm]perylene (2). The major component was (2).The structures of the isomers were assigned from their oxidation products, m.p., u.v.–visible, i.r., and mass spectra. According to our assignments, (6) and possibly 5,14-diazatetrabenzo-[a,cd,lm,o] perylene (10) are new structural isomers of fused nanocyclic compounds whose parent aromatic hydrocarbons have not been prepared, though (10) has not actually been isolated.

Electrostatic repulsion between localized charges on hetero-atoms in a doubly charged ion and mechanism of ionization and fragmentation. Electron impact mass spectra of benzanthrone, 1-azabenzanthrone, 8-azabenzanthrone and their 3-bromo substituents

Abstract Electron impact mass spectra and ionization efficiency curves of fragment ions were taken for six benzanthrone homologues, i.e., benzanthrone, 1-azabenzanthrone, 8-azabenzanthrone, 3-bromobenzanthrone, 3-bromo-1-azabenzanthrone and 3-bromo-8-azabenzanthrone. The main fragmentation reactions were the elimination of CO and subsequently of HCN from the molecular ion Mi+ (i = 1,2) based on the observation of metastable ions and the value of appearance energies of fragment ions. The intensity of a doubly charged ion [MCOHCN (or C2H2 in benzanthrone)]2+ compared with an ion (MCO)2+ is strong for 8-azabenzanthrones, intermediate for 1-azabenzanthrones and weak for benzanthrones. This fact suggests that positive charges are localized on oxygen, nitrogen or other hetero-atoms immediately after the formation of a doubly charged molecular ion, that they exclude each other because of strong repulsion at short distances, and that this repulsive force promotes the above fragmentation. Approximate values of the first and second ionization potentials were interpreted from the easily achieved emission of non-bonding electrons from heteroatoms in the outer surface of molecules, which is correlated with the results of molecular orbital calculations.

Time Dependence of the Crystallization of Tetrabenzo [a, cd, j, lm]perylene Evaporated Film as a Function of Purity

Abstract The rate of crystallization from the amorphous state of Tetrabenzo[a, cd, j, lm]perylene(TBP) film under various temperature conditions was examined as a function of the purity of the specimen. On the basis of the absorption and fluorescence spectra of TBP film, the rate of crystallization of TBP film evaporated at room temperature was found to be decreased with increasing impurity of the specimen. The rate of crystallization of TBP, with an impurity level of 10−6 mol/mol, was decreased at temperatures below the glass transition temperature (135-140°C), while the crystalline thin film was immediately obtained at temperatures above the glass transition point. On the other hand, crystalline thin films of the purest TBP (10−8 mol/mol impurity contents) prepared by our methods (J. Chem. Soc. Jpn., 1979 (4), 443) could be obtained immediately after sample preparation independent of the substrate temperature.

Convenient Synthesis of 7H-Naphtho-[1,8-gh]quinolin-7-one

Abstract 7H-Naphtho[1,8-gh]quinolin-7-one was prepared by the glycerol condensation of 3-aminophenalenone in good yields. This method provides a new and convenient synthesis of the compound. NMR spectra of its related compounds were measured, and the rapid interchange between two equivalent α-enone structures was found, which is well known as the phenomenon for the formation of carboxylic acid dimer or hydrogen difluoride ion. GRAPHICAL ABSTRACT

Studies of Alkali Fusion of Benzanthrone By-Producing Isoviolanthrone A

The relation between the yields of three isomers of violanthrone--violanthrone A (VOA), violanthrone B (VOB), and isoviolanthrone A (isoVOA)--and the condition of the alkali fusion of benzanthrone have been studied. When the method of alcoholic alkali fusion was applied to benzanthrone at low temperature, the major product was VOB. On the other hand, it was reported by Di Raddo et al. (2) that isoVOA was not obtained as a by-product under proper conditions (alkali fusion at high temperature) of synthesizing VOA. However, the result by the present authors is that 6 ∼ 7 percent of the A compound is isoVOA.