A novel synthetic route to fused propenochlorin and benzochlorin photodynamic therapy probes

Reaction of meso-(2-formylvinyl)octaethylporphyrin with (CH3)3SiCN-Cu(OTf)2 produced unexpected 10(3)-trimethylsiloxyl and 10(3)-hydroxyl fused propenochlorins which, in H2SO4, underwent subsequent migration of the 8-ethyl group to the 10(3)-position of the exocyclic benzene ring to form a novel benzochlorin.     

Functionalization of OEP-based benzochlorins to develop carbohydrate-conjugated photosensitizers. Attempt to target beta-galactoside-recognized proteins

meso-(2-Formylvinyl)octaethylporphyrin on reaction with cyanotrimethylsilane in the presence of various catalysts [copper triflate [Cu(OTf)(2)], indium triflate [In(OTf)(3)], or magnesium bromide diethyl etherate (MgBr(2).Et(2)O)] produced a mixture of the intermediate 3-hydroxy-3-cyanopropenoporphyrin, the corresponding trimethylsilyl ether derivative, and the unexpected propenochlorins. The yields of the reaction products were found to depend on the reaction conditions and the catalysts used. The intermediate porphyrins on treatment with concentrated sulfuric acid yielded the free-base cyanobenzochlorins in major quantity along with several other novel benzochlorins as minor products. Reduction of ethyl-3-hydroxy-1-pentenoate-porphyrin with DIBAL-H/NaBH(4) and subsequent acid treatment provided the corresponding free-base 10(3)-(2-hydroxyethyl)benzochlorin, which upon a sequence of reactions gave a free-base benzochlorin bearing a carboxylic acid functionality in good yield. It was then condensed with a variety of carbohydrates (glucosamine, galactosamine, and lactosamine), and the related conjugates were screened using the galectin-binding-ability assay. Among the carbohydrate conjugates investigated, the lactose and galactose analogues displayed the galectin-binding ability with an enhancement of about 300-400-fold compared to lactose. In preliminary studies, all photosensitizers (with or without carbohydrate moieties) were found to be active in vitro [radiation-induced fibrosarcoma (RIF) tumor cells]. However, the cells incubated with lactose (known to bind to beta-galactoside-recognized proteins) prior to the addition of the photosensitizers containing the beta-galactose moiety (e.g., galactose and lactose) produced a 100% decrease in their photosensitizing efficacy. Under similar experimental conditions, benzochlorin without a beta-galactoside moiety or the related glucose conjugate did not show any inhibition in its photosensitizing efficacy. These results in combination with the galectin-binding data indicate a possible beta-galactoside-recognized protein specificity of the galactose- and lactose-benzochlorin conjugates.     

Crystallographic characterization of N,N′-diarylformamidines bearing an alkoxy substituent at either the meta- or ortho-position

Crystal structures of four diphenylformamidines bearing phenyl substituents ortho-CH₃O (1), ortho-C₂H₅O (2), meta-CH₃O (3), and meta- ⁿ BuO (4) are reported. In each of the structures, formamidine exists as an unsymmetrical cyclic hydrogen bond dimer, and the geometry of the amidine unit is consistent with the localized C–N and C=N bonds. Interesting conformations due to the orientation of aryl groups were also observed. Crystal Data: 1, orthorhombic, Pbca, a = 11.297(1) Å, b = 15.092(1) Å, c = 16.380(2) Å, V = 2792.6(4) ų, Z = 8; 2, triclinic, P , a = 9.651(1) Å, b = 11.974(1) Å, c = 14.583(2) Å, = 101.789(2)°, = 99.320(2)°, = 99.048(2)°, V = 1595.9(3) ų, Z = 4; 3, orthorhombic, Pbca, a = 15.562(2) Å, b = 8.626(1) Å, c = 20.110(2) Å, V = 2699.4(5) ų, Z = 8; 4, monoclinic, P2₁/c, a = 14.525(2) Å, b = 15.534(2) Å, c = 8.818(1) Å, = 93.113(2)°, V = 1986.6(4) ų, Z = 4.     

铜离子与黄酮类配合物的促氧化作用

本文研究了3种结构相关的黄酮类化合物:黄芩素(Baicalein)、黄芩苷(Baicalin)和汉黄芩素(Wogonin)与Cu2 的配位作用,考察了其络合金属离子的结构特征,并且检测了黄酮类化合物与Cu2 形成配合物后的促氧化活性.用紫外分光光度法扫描黄酮类化合物与Cu2 形成配位后的吸光曲线变化;用电泳法检测了黄酮类化合物与Cu2 形成配合物后对DNA链的氧化损伤.结果表明,这3种黄酮主要是通过A环鳌合Cu2 .黄芩素和汉黄芩素与Cu2 形成配合物后不具有促氧化作用,而黄芩苷与Cu2 形成配合物后仍然具有一定的促氧化作用,能够导致DNA的氧化损伤.     

Structural modifications of plumieride isolated from Plumeria bicolor and the effect of these modifications on in vitro anticancer activity

Plumieride was isolated as one of the major components from the biologically active methanolic extract of the bark of Plumeria bicolor (family Apocynaceae). For investigating the effect of substituents on cytotoxic activity it was modified into a series of compounds. Replacing the methyl ester functionality of plumieride with alkyl amides of variable carbon units improved the cytotoxic activity, and a correlation between overall lipophilicity and cytotoxic activity was observed. In plumieride, the glucose moiety was converted into a di- and trisaccharide by following the protection and deprotection approach, and the resulting compounds produced enhanced cytotoxicity. However, these compounds were found to be less effective than plumeiride containing a dodecyl (12 carbon units) amide group. Among all of the derivatives, the naturally occurring plumieride showed the least cytotoxicity (50% cell kill = 49.5 microg/mL), and the dodecyl amide analogue of plumieridepentaacetate produced the best efficacy (50% cell kill = 11.8 microg/mL). The di- and trisaccharide analogues were found to be slightly less effective than the dodecyl derivative (50% cell kill = 15-17 microg/mL). The in vitro cytotoxicity of the plumieride analogues was determined in radiation-induced fibrosarcoma (RIF) tumor cells.     

华北型煤田岩溶陷落柱侧壁厚壁筒突水模式研究

岩溶陷落柱作为一种特殊地质体,在华北型煤田广泛发育和分布,本文就华北型煤田岩溶陷落柱侧壁厚壁筒突水模式及判据进行了研究,这对华北型煤田煤矿安全生产有着重要意义。     

常德-张家界高速公路慈利东互通段膨胀土工程特性及改性研究

在对常德—张家界高速公路慈利东互通段工程地质综合测试、补充勘探的基础上 ,通过对膨胀土及其改良土进行了系统的试验研究 ,如自由膨胀率、有荷膨胀量、收缩、胀缩总率、颗粒分析、压缩、抗剪强度、承载比试验 ,评价了该段膨胀土的工程特性 ,对于指导膨胀土路基的设计与施工 ,具有重要的意义     

A palladium-catalyzed approach to allenic aromatic ethers and first total synthesis of terricollene A

A palladium-catalyzed C–O bond formation reaction between phenols and allenylic carbonates to give 2,3-allenic aromatic ethers with decent to excellent yields under mild reaction conditions has been described. A variety of synthetically useful functional groups are tolerated and the synthetic utility of this method has been demonstrated through a series of transformations of the allene moiety. By applying this reaction as the key step, the total syntheses of naturally occurring allenic aromatic ethers, eucalyptene and terricollene A (first synthesis; 4.5 g gram scale), have been accomplished.

A palladium-catalyzed C–O bond formation reaction between phenols and allenylic carbonates to give 2,3-allenic aromatic ethers with decent to excellent yields under mild reaction conditions has been described.     

Synthesis and characterization of PNIPAM‐b‐(PEA‐g‐PDEA) double hydrophilic graft copolymer

A series of well‐defined double hydrophilic graft copolymers, consisting of poly(N‐isopropylacrylamide)‐b‐poly(ethyl acrylate) (PNIPAM‐b‐PEA) backbone and poly(2‐(diethylamino)ethyl methacrylate) (PDEA) side chains, were synthesized by successive atom transfer radical polymerization (ATRP). The backbone was firstly prepared by sequential ATRP of N‐isopropylacrylamide and 2‐hydroxyethyl acrylate at 25 °C using CuCl/tris(2‐(dimethylamino)ethyl)amine as catalytic system. The obtained diblock copolymer was transformed into macroinitiator by reacting with 2‐chloropropionyl chloride. Next, grafting‐from strategy was employed for the synthesis of poly(N‐isopropylacrylamide)‐b‐[poly(ethyl acrylate)‐g‐poly(2‐(diethylamino)ethyl methacrylate)] (PNIPAM‐b‐(PEA‐g‐PDEA)) double hydrophilic graft copolymer. ATRP of 2‐(diethylamino)ethyl methacrylate was initiated by the macroinitiator at 40 °C using CuCl/hexamethyldiethylenetriamine as catalytic system. The molecular weight distributions of double hydrophilic graft copolymers kept narrow. Thermo‐ and pH‐responsive micellization behaviors were investigated by fluorescence spectroscopy, ¹H NMR, dynamic light scattering, and transmission electron microscopy. Unimolecular micelles with PNIPAM‐core formed in acidic environment (pH = 2) with elevated temperature (≥32 °C); whereas, the aggregates turned into vesicles in basic surroundings (pH ≥ 7.2) at room temperature. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5638–5651, 2008     

离子色谱法测定电厂凝水处理模拟系统高纯水中的全铁

研究了用离子色谱法测定电厂凝水处理系统中高纯水中全铁的方法，用过硫酸铵将水样中的铁全部转化成Fe^3 ，再用浓缩柱浓缩样品，离子色谱法分析Fe^3 ，得到全铁的含量，检出限为1μg/L。