Michael-Addition Reaction of Malononitrile with α,β-Unsaturated Cycloketones Catalyzed by KF／Al2O3

A series of KF/Al2O3 catalyzed Michael-addition reactions between malononitrile and α,β-unsaturated cycloketones in DMF solution were studied. At room temperature, 2-cyano-3-aryl-3-(1,2,3,4-tetrahydronaphthalen-1-one-2-yl) propionitrile derivatives were synthesized by the reaction between 2-arylmethylidene-1,2,3,4-tetra-hydronaphthalen-1-one and malononitrile. However, if the temperature was increased to 80℃, 2-amino-3-cyano-4-aryl-4H-benzo[h]chromene derivatives were obtained in high yields. When the α,β-unsaturated ketones were replaced by 2,6-biarylmethylidenecyclohexanone or 2,5-biarylmethylidenecyclopentanone, another series of 2-amino-3-cyano-4H-pyran derivatives was isolated successfully. The structures of the products were confirmed by X-ray diffraction analysis.     

新型四硫代富瓦烯衍生物的合成及其性质的研究

合成了3个新的含有卤素取代基的四硫代富瓦烯衍生物及6个新的相关化合物。利用溶液的电子吸收光谱对四硫代富瓦烯衍生物的性质进行了研究。研究结果表明, 四硫代富瓦烯衍生物的分子中π轨道之间的能级差较小, 因而分子具有较高的稳定性。     

Study on interaction between drug and membrane by using liposome coated zirconia-magnesia chromatography

The interactions between drug molecules and membrane were studied using the new chromatography stationary phase of liposome coated zirconia–magnesia. log K_s(ZrO₂–MgO) on this new chromatography for some drugs, compared with that on liposome coated silica chromatography and other reported data, fair correlations were observed between them when excluding effect of special adsorption. log K_s(ZrO₂–MgO) values for barbitalum, diazepam, benzene, benzocaine and toluene correlated well with corresponding values on liposome coated silica chromatography (R = 0.99778, P < 0.001; R = 0.98229, P < 0.003; R = 0.9985, P < 0.0001; R = 0.99925, P < 0.0001, pH value of mobile phase at pH 7.4, 7.0, 6.4 and 5.4, respectively). They also correlated well with the literature data on immobilized artificial membrane chromatography (R = 0.99999, P < 0.004 at pH 7.4) and liposome chromatography (R = 0.99994, P < 0.008) for procaine, lidocaine and bupivacaine. Liposome coated zirconia–magnesia chromatography can thus be used for studying drug–membrane interaction and prediction of drug absorption as another liposome chromatography method.     

Lycopodine‐Type Lycopodium Alkaloids from Huperzia serrata

Eleven Lycopodium alkaloids with a lycopodine‐type skeleton were isolated from the basic material of the whole plant of Huperzia serrata (Thunb .) Trev. (Huperziaceae). Among them, 12‐epilycodoline N‐oxide (=(12α,15R)‐12‐hydroxy‐15‐methyllycopodan‐5‐one N‐oxide; 1 ), 7‐hydroxylycopodine (=(15S)‐7‐hydroxy‐15‐methyllycopodan‐5‐one; 2 ), and 4,6α‐dihydroxylycopodine (=(6α,15R)‐4,6‐dihydroxy‐15‐methyllycopodan‐5‐one; 3 ) are new compounds. Their structures were identified spectroscopically, especially by means of 1D‐ and 2D‐NMR.     

Native and stearic acid modified ceria-zirconia supports in normal and reversed-phase HPLC

Porous ceria-zirconia composite with narrow particle size distribution and large specific surface area was synthesized by a sol-gel process. Chromatographic properties of the native supports was investigated in normal phase mode for the separation of test mixtures of basic, neutral and acidic compounds. The new packing material exhibited polar and basic properties, which are suitable for the separation of basic compounds. Lypophilic packing has been obtained by the modification of the ceria-zirconia with stearic acid, which exhibited strong hydrophobicity relative to the native packing. Therefore, the modified ceria-zirconia behaves as a reversed-phase packing material. Different selectivity towards basic compounds was observed on the new packing compared to the native ceria-zirconia and conventional ODS stationary phase.     

Determination of endocrine disruptors in environmental waters using poly(acrylamide-vinylpyridine) monolithic capillary for in-tube solid-phase microextraction coupled to high-performance liquid chromatography with fluorescence detection

A method for the determination of endocrine disruptors, bisphenol A and 17alpha-ethinylestradiol, in environmental water samples was developed using in-tube solid-phase microextraction followed by liquid chromatography and fluorescence detection. A poly(acrylamide-vinylpyridine) monolithic capillary column was applied as the extraction media in view of its greater phase ratio than open-tubular capillaries and thus higher extraction efficiency. After optimizing the extraction conditions, bisphenol A and 17alpha-ethinylestradiol were extracted directly from water samples in a wide dynamic linear range of 0.5-1000 ng mL(-1), with the detection limits obtained as 0.064 and 0.12 ng mL(-1), respectively. The precision of the method was satisfactory with the intraday and interday RSD values smaller than 7.2%. Environmental water samples of different sources were successfully analyzed with the presented method and the monolithic capillary was proved to be robust and reusable in analyzing real water samples.     

Pseudolarolides O and P,Two Novel Triterpene Dilactones from Pseudolarix kaempferi

Pseudolarolides O ( 1 ) and P ( 2 ), two novel triterpenoids with a cycloartane‐type framework, were isolated from the seeds of Pseudolarix kaempferi Gord. (Pinaceae). Their structures were elucidated as (16R,23S,25R)‐16,23‐epoxy‐3,4 : 9,10‐disecocycloartan‐1(10),9(11)‐diene‐3(4),26(23)‐diolide ( 1 ), and (9S,16R,23S,25R)‐1,9 : 16,23‐diepoxy‐8,9 : 9,10‐disecocycloartan‐1(29),5(6),10(19)‐triene‐3(4),26(23)‐diolide ( 2 ), respectively, on the basis of spectroscopic techniques and X‐ray‐diffraction studies.     

The binding ability of iron bonded to porphodimethene: structural, magnetic, and electronic relationship to iron porphyrin complexes

The availability of the parent compound, meso-hexaethylporphodimetheneiron(II), [(Et6N4)Fe] (2), of this report results from a novel synthetic methodology that makes [Et6N4Li2] (1) easily available. The major focus is on how the axial positions, which are the key reactive sites in metalloporphyrins, and the electronic configuration of the metal can be affected by the breakdown of the aromaticity of the porphyrin skeleton and by the nonplanar conformation of the ligand. DFT calculations indicate a 3B1(dz2)1(dyz)1 ground state for 2 versus the 3A2(dxz)1(dyz)1 ground state in the porphyrin analogue. The intermediate-spin state (S = 1) of 2 changed drastically upon addition of one or two axial ligands, as hexacoordination is preferred by iron(II). The hexacoordinate complexes [(Et6N4)Fe(L)(L')] (L = L' = THF, 3; L = L' = Py, 4; L = PhNO, L' = Py, 14) have been isolated and structurally characterized. Strong-field ligands lead to a low-spin diamagnetic state for iron(II), namely for complexes 4-7, 9, and 14, whereas 3 is a typical d6 high-spin complex, as is the pentacoordinate [(Et6N4)Fe(CN)]Bu4N (8). The structural analysis showed common features for 6, 7, 9, and 14: i) a small displacement of the metal from the N4 plane, and ii) an N4 cavity, larger than that in the corresponding porphyrins, affecting the Fe-N bond lengths. The 1H NMR spectrum is quite diagnostic of the two-fold symmetry in the diamagnetic hexacoordinate complexes, revealing either a D2h or a C2v symmetry. The CO stretching frequency (1951 cm(-1)) in complex 6 probes the good electron density at the metal. The one-electron oxidation of 2 led to pentacoordinate iron(III) derivatives [(Et6N4)Fe(Cl)] (10), [(Et6N4)2Fe2(mu-O)] (11), and [(Et6N4)2Fe2(mu-p-OC6H4-O)] (12). Complex 10 is a typical high-spin iron(III) (5.85muB at 298 K), while 11 and 12 behave as antiferromagnetic coupled iron(III) (J = -9.4cm(-1), 12, and J = -115cm(-1), 11). In complexes 10, 11, and 12 iron is sitting in a quite distorted square pyramidal geometry, in which the ligand displays a very distorted roof conformation with different degrees of ruffling. Distinctive structural and magnetic features have been found for the nitrosyl derivative [(Et6N4)Fe-NO], which has a low-spin state (S = 1/2) and the following structural parameters: Fe-N-O, 147.3(2) degrees; Fe-N, 1.708(2) A; N-O, 1.172(3) A. A comparative structural, magnetic, and theoretical analysis of the compounds listed above has been made with the analogous porphyrin derivatives. The detailed structural investigation has been mapped through the X-ray analysis of 2, 7, 8, 9, 11, 13, and 14.     

Synthesis and spectral characterization of some complexes of platinum(II) containing η-methyleugenol

Several complexes of the formula trans-[Pt(Meug)(Am)Cl₂], Meug: methyleugenol (4-allyl-1,2-dimethoxybenzene), a η²-coordinated olefin, and Am: ammine, methylamine, diethylamine, o-toluidine, m-toluidine, p-toluidine, o-anisidine, m-anisidine and p-anisidine have been prepared. UV, IR, Raman, ¹H NMR, ¹³C NMR and 2D NMR spectra of the complexes were recorded and analyzed.     

Synthesis of novel 1,4‐dihydropyrido[3′,2′:5,6]thiopyrano[4,3‐c]‐pyrazoles and 5H‐pyrido[3′,2′:5,6]thiopyrano[4,3‐d]pyrimidines as potential antiproliferative agents

The synthesis of new planar derivatives characterized by the presence of a pyridothiopyranopyrazole or pyridothiopyranopyrimidine nucleus, carrying a substituted aryl group, is reported. The novel 1,4‐dihydropyrido[3′,2′:5,6]thiopyrano[4,3‐c]pyrazole derivatives were obtained by condensation of 2,3‐dihydro‐3‐hydroxymethylenethiopyrano[2,3‐b]pyridin‐4(4H)‐ones with appropriate hydrazines. The preparation of 2‐substituted pyrido[3′,2′:5,6]thiopyrano[4,3‐d]pyrimidines was accomplished from the intermediate 2,3‐dihy‐dro‐3‐dimethylaminomethylenethiopyrano[2,3‐b]pyridin‐4(4H)‐ones by reaction with the appropriate binucleophile amidines. The antiproliferative activity of some new products was tested by an in vitro assay on human tumour cell lines (HL‐60 and HeLa), but none of them showed any significant effects in the tests performed. Accordingly, linear flow dichroism measurements indicated their inability to form a molecular complex with DNA.