Synthesis and antiproliferative activity of multisubstituted N-fused heterocycles against the Hep-G2 cancer cell line

Abstract  

Pyrrolo[1,2-a]imidazole and pyrrolo[2,1-b]thiazole derivatives were synthesized in a one-pot procedure by [3 + 2] cycloaddition reactions of the corresponding imidazolium ylides and thiazolium ylides with an alkene followed by oxidative aromatization of the primary cycloadducts under the action of the mild oxidant tetrakispyridinecobalt(II) dichromate. Antiproliferative activity of 14 new bicyclic N-fused heterocycles against the human hepatocellular liver carcinoma (Hep-G2) cell line were examined by the MTT method. Some of the compounds showed favorable antiproliferative activity, especially compound 3i displayed potent antiproliferative activities with an IC₅₀ value of 0.36 μg/cm³.     

Polycyclic aromatic hydrocarbons (PAHs) pollution recorded in annual rings of gingko (Gingko biloba L.): Regression analysis and comparison to other pollutants

Further interesting information about contamination recorded in gingko annual rings is revealed in this paper. The degradation degrees of varied PAHs in gingko trunk, range 2.4 to 3.4%, are evaluated by using regression analysis and confirmed to depend upon their molecular sizes and chemical properties. For other lipophilic compounds, the translocation and diffusion behaviors conform to our donut model of PAHs in previous work, while for hydrophilic contaminants, the translocation and diffusion are more complicated owing to the second uptake pathways by roots. Further, the gingko tree exhibits selective absorption to heavy metals, such as Cu, Cd, Zn, Cr, Pb, Ni, Fe, and Mn. The relative accumulation degrees of these heavy metals are estimated by comparing to Fe in the soil and the gingko tree, and the result suggests that the gingko accumulates Cr, Cd and Pb from the soil. However, the metals in annual rings might not reflect historical environment changes for their diffusive nature in water-sapwood.     

Regioselective addition of thiophenol to α,β-unsaturated N-acylbenzotriazoles

Regioselective addition of thiophenol to α,β-unsaturated N-acylbenzotriazoles has been achieved by controlling the conditions. Thus, three types of products, namely α,β-unsaturated thioesters, β-thiophenoxy substituted N-acylbenzotriazoles, and β-thiophenoxy substituted thioesters were selectively obtained in good to excellent yields.     

Supramolecular Architectures with Open Frameworks Constructed by Transitional Metal Ions,Linear Dicarboxylic Acid,and 2,2′‐Bipyridine

Four new transitional metal supramolecular architectures, [Zn(cca)(2,2′‐bpy)]_n · n(2,2′‐bpy) ( 1 ), [Cu(cca)(2,2′‐bpy)]_n ( 2 ), [Zn(bpdc)(2,2′‐bpy)(H₂O)]_n · 0.5nDMF · 1.5nH₂O ( 3 ), and [Co(bpdc)(2,2′‐bpy)(H₂O)]_n · nH₂O ( 4 ) (H₂cca = p‐carboxycinnamic acid; H₂bpdc = 4,4′‐biphenyldicarboxylic acid; 2,2′‐bpy = 2,2′‐bipyridine) were synthesized by hydrothermal reactions and characterized by single crystal X‐ray diffraction, elemental analyses, and IR spectroscopy. Although the metal ions in these four compounds are bridged by linear dicarboxylic acid into 1D infinite chains, there are different π–π stacking interactions between the chains, which results in the formation of different 3D supramolecular networks. Compound 1 is of a 3D open‐framework with free 2,2′‐bpy molecules in the channels, whereas compound 2 is of a complicated 3D supramolecular network. Compounds 3 and 4 are isostructural. Both compounds have open‐frameworks.     

Solvothermal synthesis, crystal structure, and properties of lanthanide-organic frameworks based on thiophene-2,5-dicarboxylic acid

A series of lanthanide-organic framework coordination polymers, {[La(2)(TDC)(2)(NO(3))(H(2)O)(4)](OH)·5H(2)O}(n) (1) and [Ln(TDC)(NO(3))(H(2)O)](n) (TDC = thiophene- 2, 5- dicarboxylic acid; Ln = Nd(2), Sm(3), Eu(4), Gd(5), Tb(6), Dy(7), Ho(8), Er(9), Yb(10)) have been synthesized by solvothermal reaction and characterized by elemental analysis, FT-IR, TG analysis, single-crystal X-ray diffraction and power X-ray diffraction. The single-crystal X-ray diffraction analysis results show that 1 displays a 3-D porous framework with (3,7)-connected {4(10).6(11)}{4(3)} topology. The compounds 2-10 crystallized in the same P2(1)/c space group and exhibits a (3,6)-connected {4.6(2)}(2){4(2).6(10).8(3)} topology, Right-handed and left-handed helical chains coexist in the 2-D layer structure. The luminescence properties of 2-10 and the magnetic properties of 5,7,8,9 were investigated.     

A short synthesis of bisabolane sesquiterpenes

A facile total synthesis of three members of the bisabolane sesquiterpene family, namely (±)-curcumene, (±)-xanthorrhizol and (±)-curcuhydroquinone had been achieved in high overall yield. The synthesis used bromobenzene derivatives as starting materials. The halogen-lithium exchange followed by addition of isoprenylacetone and reduction of the obtained carbinols are the key steps of the synthetic pathway. This synthetic approach provides a new route to the bisabolane sesquiterpenes.     

多孔Ce_(1-x)Nd_xO_(2-y)的微波引诱燃烧合成及其光催化性能研究

采用硝酸铈、硝酸钕、尿素为原料,使用微波引诱燃烧法合成了多孔Ce1-xNdxO2-y固溶体。利用X射线衍射仪、Raman光谱仪、红外光谱仪、扫描电镜、N2吸附-脱附技术、紫外-可见吸收光谱仪等测试手段对产物进行了表征。XRD分析表明,Ce1-xNdxO2-y固溶体的粒径范围在40~60 nm之内,且所有产物为萤石结构。Raman测试表明,在Ce1-xNdxO2-y中,由于Nd3+的掺杂而产生氧空位,且空位浓度随Nd3+掺杂量的提高而增加。红外结果证明,Ce-O键的吸收峰在1400 cm-1左右处,由于Nd3+的掺杂而使得在2346 cm-1的吸收峰消失。从SEM和孔径分布结果可看出,产物为多孔结构。紫外-可见光吸收和可见光催化降解实验表明,随着Nd3+掺杂量的增加,Ce1-xNdxO2-y的紫外吸收增强;由于多孔结构和氧缺位的产生,产物在可见光范围内有较明显的吸收。     

Synthesis,crystal structures,and magnetic properties of two manganese(II) coordination polymers bearing 1,1′-biphenyl-3,3′-dicarboxylate ligands

Two Mn(II) coordination polymers, namely [Mn(bpda)] _n (1) and [Mn(bpda)(bpy)_0.5] _n (2) (H₂bpda = 1,1′-biphenyl-3,3′-dicarboxylic acid and bpy = 4,4′-bipyridine), have been synthesized from H₂bpdc, bpy, and MnSO₄·2H₂O under hydrothermal conditions. The complexes were characterized by physicochemical and spectroscopic methods, as well as by X-ray crystallography. Compound 1 possesses a 3D structure consisting of carboxylate-bridged edge-sharing Mn–O–Mn double chains. Compound 2 features a 3D open structure with a dinuclear Mn(II) secondary building unit. Magnetic susceptibility measurements of compounds 1 and 2 exhibit antiferromagnetic interactions between the nearest Mn(II), with J = –11.3 cm⁻¹ and g = 2.12 for 1, and J = –13.5 cm⁻¹ and g = 2.12 for 2.     

3-脱氢莽草酸甲酯、乙酯的合成与表征

以莽草酸为起始原料,在酰化试剂二氯亚砜作用下,分别与甲醇和乙醇发生酯化反应得到莽草酸甲酯及乙酯,然后以四氢呋喃为溶剂,在氧化剂2-碘酰基苯甲酸(IBX)作用下,制备得到3-脱氢莽草酸甲酯和3-脱氢莽草酸乙酯.本方法采用可再生原料莽草酸为起始物,以性能温和、选择性好、绿色环保的IBX为氧化剂,具有操作简便、收率高等优点....