Synthesis and Structure of 2‐Substituted Thieno[3′,2′:5,6]pyrido[4,3‐d]pyrimidin‐4(3H)‐one Derivatives

A series of new 2‐substituted 3‐(4‐chlorophenyl)‐5,8,9‐trimethylthieno[3′,2′: 5,6]pyrido[4,3‐d]pyrimidin‐4(3H)‐ones 8 were synthesized via an aza‐Wittig reaction. Phosphoranylideneamino derivatives 6a or 6b reacted with 4‐chlorophenyl isocyanate to give carbodiimide derivatives 7a or 7b , respectively, which were further treated with amines or phenols to give compounds 8 in the presence of a catalytic amount of EtONa or K₂CO₃. The structure of 2‐(4‐chlorophenoxy)‐3‐(4‐chlorophenyl)‐5,8,9‐trimethylthieno[3′,2′: 5,6]pyrido[4,3‐d]pyrimidin‐4(3H)‐one ( 8j ) was comfirmed by X‐ray analysis.     

Syntheses and Characterizations of Two Palladium(II) Complexes of 5‐Mercapto‐1‐methyltetrazole

Reaction of PdCl₂(CH₃CN)₂ with the sodium salt of 5‐mercapto‐1‐methyltetrazole (MetzSNa) in methanol solution affords an interesting dinuclear palladium complex [Pd₂(MetzS)₄ ] ( 1 ). However, treatment of PdCl₂(CH₃CN)₂ with neutral MetzSH ligand in methanol solution produces a mononuclear palladium complex [Pd(MetzSH)₄]Cl₂ ( 2 ). Both complexes were characterized by IR, ¹HNMR, UV‐Vis spectroscopy as well as X‐ray crystallography. Single‐crystal X‐ray diffraction analyses of two complexes lead to the elucidation of the structures and show that 1 possesses an asymmetric structure: one Pd atom is tetracoordinated by three sulfur atoms and one nitrogen atom to form PdS₃N coordination sphere, the other Pd atom is tetracoordinated by three nitrogen atoms and one sulfur atom to form PdSN₃ coordination sphere. The molecules of 1 are associated to 1‐D infinite linear chain by weak intermolecular Pd···S contacts in the crystal lattice. In 2 , the Pd atom lies on an inversion center and has a square‐planar coordination involving the S atoms from four MetzSH ligands. The two chloride ions are not involved in coordination, but are engaged in hydrogen bonding.     

Hyperoxygenation enhances the tumor cell killing of photofrin-mediated photodynamic therapy

Tumor hypoxia, either preexisting or as a result of oxygen depletion during photodynamic therapy (PDT) light irradiation, can significantly reduce the effectiveness of PDT-induced cell killing. To overcome tumor hypoxia and improve tumor cell killing, we propose using supplemental hyperoxygenation during Photofrin-PDT. The mechanism for the tumor cure enhancement of the hyperoxygenation-PDT combination is investigated using an in vivo-in vitro technique. A hypoxic tumor model was established by implanting mammary adenocarcinoma in the hind legs of mice. Light irradiation (200 J/cm2 at either 75 or 150 mW/cm2), under various oxygen supplemental conditions (room air, carbogen, 100% normobaric or hyperbaric oxygen), was delivered to animals that received 12.5 mg/kg Photofrin 24 h before light irradiation. Tumors were harvested at various time points after PDT and grown in vitro for colony formation analysis. Treated tumors were also analyzed histologically. The results show that when PDT is combined with hyperoxygenation, the hypoxic condition could be improved and the cell killing rate at various time points after PDT could be significantly enhanced over that without hyperoxygenation, suggesting an enhanced direct and indirect cell killing associated with high-concentration oxygen breathing. This study further confirms our earlier observation that when a PDT treatment is combined with hyperoxygenation it can be more effective in controlling hypoxic tumors.     

CoMFA, CoMSIA, and molecular hologram QSAR studies of novel neuronal nAChRs ligands-open ring analogues of 3-pyridyl ether

3-Pyridyl ethers are excellent nAChRs ligands, which show high subtype selectivity and binding affinity to alpha4beta2 nAChR. Although the quantitative structure-activity relationship (QSAR) of nAChRs ligands has been widely investigated using various classes of compounds, the open ring analogues of 3-pyridyl ethers have been less involved in these studies due to the greater flexibility of this kind of molecule. In this study, two three-dimensional QSAR techniques and one two-dimensional QSAR technique were used to correlate the molecular structure with the biological activity of 64 analogues of 3-pyridyl ethers. Three different QSAR models were established. Their performances in the QSAR studies of open ring analogues of 3-pyridyl ethers were evaluated by the statistical values in the corresponding models. All models exhibited satisfactory predictive power. Of these models, the HQSAR behaved optimally in terms of the statistical values with q2=0.845, r2=0.897. Finally, graphic interpretation of three different models provided coincident information about the interaction of the ligand-receptor complex and supplied useful guidelines for the synthesis of novel, potent ligands.     

Novel approach to synthesizing hydrophobically associating copolymer using template copolymerization: the synthesis and behaviors of acrylamide and 4-(omega-propenoyloxyethoxy) benzoic acid copolymer

Hydrophobically associating copolymers of acrylamide (AM) with a small amount of 4-(omega-propenoyloxyethoxy) benzoic acid (PEBA, <2.5%) were synthesized by template copolymerization in the presence of poly(allylammonium chloride) (PAAC) as a template in an aqueous medium. These template copolymers exhibited remarkable thickening properties due to the effective hydrophobic association, which were similar to those copolymers with a multiblock structure obtained by the micellar process. The pH of the reaction medium and the molecular weight of the template strongly influenced the thickening properties of the products. In the experimental range, the higher the PEBA content, the larger the thickening capacity of these hydrophobic copolymers. The aggregate behaviors of these copolymers were studied by fluorescence, transmission electron microscopy (TEM), and light scattering techniques. The apparent critical interpolymer aggregate concentration (cac) of the copolymer solution was about 0.5 g/dL. As the concentration of the copolymer became higher than the cac, the aggregates changed their morphology from small hollow spheres to big flower-shaped aggregates. All the above results indicated that the template copolymerization gave access to a very simple and powerful means for the preparation of hydrophobically associating copolymers and other functional polymer materials.     

Electrocatalytic Oxidation of Dopamine by Ferrocene in Lipid Film Cast on a Glassy Carbon Electrode

ＩｎｔｒｏｄｕｃｔｉｏｎＤＡｉｓｏｎｅｏｆｅｓｓｅｎｔｉａｌｐａｒｔｉｃｉｐａｎｔｓｉｎｔｈｅｎｅｕｒｏ ｔｒａｎｓｍｉｓｓｉｏｎｐｒｏｃｅｓｓｉｎｍａｍｍａｌｉａｎｃｅｎｔｒａｌｎｅｒｖｏｕｓｓｙｓ ｔｅｍ .ＡｌｏｓｓｏｆＤＡ ｃｏｎｔａｉｎｉｎｇｎｅｕｒｏｎｓｍａｙｒｅｓｕｌｔｉｎｓｏｍｅｓｅｒｉｏｕｓｄｉｓｅａｓｅｓｕｃｈａｓＰａｒｋｉｎｓｏｎｉｓｍ .1Ｓｉｎｃｅｉｔｓｄｉｓｃｏｖ ｅｒｙｉｎｔｈｅ 195 0ｓ ,ＤＡｈａｓｂｅｅｎｏｆｉｎｔｅｒｅｓｔｔｏｎｅｕｒｏｓｃｉｅｎ ｔｉｓｔｓａｎｄｃｈｅｍ…     

Activated carbon oxygen content influence on water and surfactant adsorption

This research investigates the adsorption properties of three activated carbons (AC) derived from coconut, coal, and wood origin. Each carbon demonstrates different levels of resistance to 2 M NaOH treatment. The coconut AC offers the greatest and wood AC the least resistance. The influence of base treatment is mapped in terms of its effects on specific surface area, micropore volume, water adsorption, and dodecanoic acid adsorption from both water and 2 M NaOH solution. A linear relationship exists between the number of water molecules adsorbed at the B-point of the water adsorption isotherm and the oxygen content determined from elemental analysis. Surfactant adsorption isotherms from water and 2 M NaOH indicate that the AC oxygen content effects a greater dependence on affinity for surfactant than specific surface area and micropore volume. We show a linear relationship between the plateau amount of surfactant adsorbed and the AC oxygen content in both water and NaOH phases. The higher the AC oxygen content, the lower the amount of surfactant adsorbed. In contrast, no obvious relationship could be drawn between the surfactant amount adsorbed and the surface area.     

Three New Triterpenoids from Lycopodium japonicum Thunb

Three new triterpenoids, (3β,8β,14α,21α)‐26,27‐dinoronocerane‐3,8,14,21‐tetrol ( 1 ), (3β,8β,14α,21β)‐26,27‐dinoronocerane‐3,8,14,21‐tetrol ( 2 ), and lycopodiin A ( 3 ), together with four known compounds, lycoclavanol ( 4 ), lycoclaninol ( 5 ), α‐onocerin ( 6 ), and 3‐epilycoclavanol ( 7 ), were isolated from Lycopodium japonicum Thunb (Lycopodiaceae). Their structures were established by means of spectroscopic analyses. Compounds 3 and 7 showed moderate antitumor activity. Compounds 4 and 6 exhibited acetylcholinesterase inhibition activity.     

O-二异丙氧磷酰基丝氨酸(或苏氨酸或酪氨酸)的合成

介绍一种简单方便地合成O-二异丙氧磷酰基丝氨酸(或苏氨酸或酪氨酸)的方法.其中O-二异丙氧磷酰基-L-丝氨酸(或苏氨酸)可从对应的N-磷酰化-L-丝氨酸(或苏氨酸)利用磷酰基N→0迁移的性质并在超声辅助下合成,而N-二异丙氧磷酰基-L-丝氨酸(或苏氨酸)的合成由L-丝氨酸(或苏氨酸)在次氯酸钠的水溶液中高收率地获得.O-二异丙氧磷酰基酪氨酸的合成可通过铜盐同时保护氨基和羧基,使用二异丙基磷酰氯为磷酰化试剂磷酰化,用硫化氢脱铜保护制备.     

Construction and Analysis of N-phosphoryl Peptide Libraries

N-Phosphoryl peptide libraries were constructed by transformation from homo-oligopeptide libraries, which was synthesized by self-assembly of amino acids with the assistance of phosphorus oxychloride. Electrospray ionization mass spectrometry (ESI-MS) was used to monitor the reaction.