7-取代-8-羟基喹啉的合成

由2-氯辛烷与8-羟基喹啉钠反应制得7-(1′-甲基庚基)-8-羟基喹啉.用长碳链脂肪醛在碱性介质中与8-羟基喹啉反应,合成了一系列7-烯基-8-羟基喹啉(1);对不同结构长碳链脂肪醛合成作了研究.     

钒氧配合物[VOL(C9H6NO)]·CH2Cl2的合成与晶体结构

A oxovanadium(Ⅴ) complex of [VOL(C₉H₆NO)]·CH₂Cl₂[H₂L=2-hydroxy-1-naphthaldehyde 4-methoxy-benzoylhydrazone, C₉H₆NO^-=8-hydroxyquinoline anion] has been synthesized and characterized by elemental analyses, IR and single crystal X-ray diffraction. The crystal crystallizes in triclinic system, the space group is P1, with the crystal cell parameters a=1.087 0(2) nm, b=1.107 1(2) nm, c=1.269 3(3) nm, α=67.84(3)°, β=79.26(3)°, γ=73.85(3)° and V=1.353 1(6) nm³ , M_r=614.34, R=0.0503, wR=0.1409. The V(Ⅴ) atom is six-coordinated by one O atom of oxo group, two O atoms and one N atom of the tridentate hydrazone ligand, as well as one N atom and one O atom of 8-hydroxyquinoline ligand, thus defining a distorted octahedral VO(ONO)(NO) geometry. A two-dimensional supramolecular layer structure is formed through π-π stacking interactions. CCDC: 268672.     

8-Hydroxyquinoline-substituted boron-dipyrromethene compounds: synthesis, structure, and OFF-ON-OFF type of pH-sensing properties

A series of four novel 8-hydroxyquinoline-substituted boron-dipyrromethene derivatives, namely 4,4-difluoro-8-(5-(8-hydroxyquinoline))-3,5-dimethyl-4-bora-3a,4a-diaza-s-indacene (1), 4,4-difluoro-8-(5-(8-hydroxyquinoline))-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene (2), 4,4-difluoro-8-(5-azastyryl-(8-hydroxyquinoline))-3,5-dimethyl-4-bora-3a,4a-diaza-s-indacene (3), and 4,4-difluoro-8-(5-azastyryl-(8-hydroxyquinoline))-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene (4), have been synthesized and characterized by a series of spectroscopic methods. The molecular structures of 1 and 2 have been determined by single-crystal X-ray diffraction analyses. The two methyl substituents attached at C-1 and C-7 positions of boron-dipyrromethene (Bodipy) in compound 2 was revealed to prevent the free rotation of the 8-hydroxyquinoline (8-HQ) moiety, resulting in an almost vertical 8-HQ-Bodipy configuration of this compound. This is obviously different from those for 1 with the dihedral angle between 8-hydroxyquinoline and Bodipy moieties of 65.44 and 66.79° due to the lack of methyl substituents in the latter compound. The intense fluorescence from the Bodipy subunit of these compounds was revealed to gradually get diminished along with either decreasing or increasing the pH value under acidic and basic conditions, respectively, in particular for 1, 2, and 4 because of the photoinduced intramolecular electron transfer from excited Bodipy moiety to 8-HQ unit and just an opposite process. This renders these compounds the first OFF-ON-OFF type of pH-dependent fluorescent sensors. Nevertheless, both the intrinsic fluorescence of these compounds and their fluorescent quenching properties along with the change in the pH value have been found to depend on the steric configuration as well as the linking group between 8-hydroxyquinoline and Bodipy moieties, revealing the effect of molecular structure on their fluorescence properties.     

Preparation of glycyrrhetic acid glycosides having various beta(1----2)-linked disaccharides and their cytoprotective effects on carbon tetrachloride-induced hepatic injury.

Glycyrrhetic acid glycosides (1-7) having beta(1----2)-linked disaccharides such as 2-O-beta-D-glucopyranosyl-beta-D-galactopyranose, 2-O-beta-D-galactopyranosyl-beta-D-galactopyranose, 2-O-beta-D-glucuronopyranosyl-beta-D-galactopyranose, 2-O-beta-D-glucopyranosyl-beta-D-glucuronopyranose, 2-O-beta-D-galactopyranosyl-beta-D-glucuronopyranose, 2-O-beta-D-galactopyranosyl-beta-D-glucopyranose, 2-O-beta-D-glucuronopyranosyl-beta-D-glucopyranose, respectively, were synthesized by stepwise construction; from glycyrrhetic acid monoglycosides to the diglycosides. The cytoprotective activities of the glycosides 1-7 and 2-O-(beta-D-glucopyranosyl)-beta-D-glucopyranosyl-11-oxoolean-12-e n-30-oate (8) were compared with natural occurring glycyrrhizin (9). Among these glycosides 1-8, glycosides 3 and 7 having beta-D-glucuronopyranose (glcUA) as the only terminal sugar component were more effective materials against hepatic injury than glycyrrhizin 9.     

Oplopanphesides A-C, three new phenolic glycosides from the root barks of Oplopanax horridus

Three new phenolic glycosides, named oplopanphesides A-C (1-3), have been isolated from the root barks of Oplopanax horridus. Their structures were elucidated by a combination of spectroscopic analyses, including 1D- and 2D-NMR techniques. These phenolic glycosides possess a novel feature in their sugar moieties that a 3-hydroxy-3-methylglutaryl moiety was connected with C-6 of the β-D-glucopyranosyl group. Those compounds showed no cytotoxic effects against human cancer cell lines (MDA-231 and MCF-7) by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method.     

Synthesis and Binding of Mannose-Specific Synthetic Carbohydrate Receptors

Synthetic carbohydrate receptors (SCRs) that selectively recognize cell-surface glycans could be used for detection, drug delivery, or as therapeutics. Here we report the synthesis of seven new C_2h symmetric tetrapodal SCRs. The structures of these SCRs possess a conserved biaryl core, and they vary in the four heterocyclic binding groups that are linked to the biaryl core via secondary amines. Supramolecular association between these SCRs and five biologically relevant C¹-O-octyloxy glycans, α/β-glucoside ( α/β-Glc ), α/β-mannoside ( α/β-Man ), and β-galactoside ( β-Gal ), was studied by mass spectrometry, ¹H NMR titrations, and molecular modeling. These studies revealed that selectivity can be achieved in these tetrapodal SCRs by varying the heterocyclic binding group. We found that SCR017 (3-pyrrole), SCR021 (3-pyridine), and SCR022 (2-phenol) bind only to β-Glc. SCR019 (3-indole) binds only to β-Man. SCR020 (2-pyridine) binds β-Man and α-Man with a preference to the latter. SCR018 (2-indole) binds α-Man and β-Gal with a preference to the former. The glycan guests bound within their SCR hosts in one of three supramolecular geometries: center-parallel, center-perpendicular, and off-center. Many host–guest combinations formed higher stoichiometry complexes, 2:1 glycan⋅SCR or 1:2 glycan⋅SCR , where the former are driven by positive allosteric cooperativity induced by glycan–glycan contacts.     

Structure of cucumariosides H5, H6, H7 and H8, triterpene glycosides from the sea cucumber Eupentacta fraudatrix and unprecedented aglycone with 16,22-epoxy-group

Four new triterpene glycosides cucumariosides H5 (1), H6 (2), H7 (3) and H8 (4) along with the known cucumarioside H (5) have been isolated from the Far Eastern sea cucumber Eupentacta fraudatrix. The structures of glycosides 1-4 were elucidated on the basis of spectral data (2D NMR and MS). Glycosides 1-4 belong to the group o f cucumariosides H having branched rare pentasaccharidecarbohydrate moieties with one sulfate group and 3-O-methyl-D-xylose as a terminal monosaccharide unit. Glycosides 1-3 and 5 differ from each other in structures of side chains of the aglycones, while cucumarioside H8 (4) has a novel aglycone with unprecedented 16(22)-epoxy-group, never found in the sea cucumbers glycosides. Glycosides 1-3, and 5 were cytotoxic against mouse lymphocytes and hemolytic against mouse erythrocytes. Glycoside 2 was less active in comparison with others.     

Synthesis of 3-amido-3-deoxy-β-d-talopyranosides: all-cis-substituted pyranosides as lectin inhibitors

3-Deoxy-3-amino-β-d-talopyranosides have been synthesized for the first time. The amines were obtained from galactopyranosides through 2,3-anhydrogulosides that were opened to idosides followed by an oxidation/reductive amination sequence. From the amines, 11 corresponding 3-deoxy-3-arylamido-β-talopyranosides have been synthesized and evaluated as inhibitors against galectin-1, -2, -3, -4C, -4N, -7, -8N and -9N. The synthesized talosamides showed selectivity for Galectin-4C with three of the monosaccharides having dissociation constants at around 100 μM against the lectin, which is more than two orders of magnitude better than methyl β-galactoside and significantly better than the previous best galectin-4C monosaccharide inhibitor.     

SYNTHESIS AND BIOLOGICAL ACTIVITY OF SOME NEW 8-HYDROXYQUINOLINE SULPHONAMIDE DERIVATIVES

Abstract

Some new derivatives containing both 8-hydroxyquinoline and sulphonylamino β-lactams and thiazolidinones have been prepared. These compounds were synthesized from the corresponding 8-hydroxyquinoline sulphonylhydrazide (1) by converting it to hydrazones (2). The latter hydrazones (2) were easily transformed to β-lactams (3) and thiazolidinones (4) by cyclocondensation reaction with chloroacetyl chloride and/or mercaptoacetic acid. Some metal chelates with Fe³⁺. Co²⁺+, Ni²⁺, Cu²⁺ and Cd²⁺ have been prepared for some of the compounds and screened in vitro for their biological activity.     

Triterpene glycosides from the sea cucumber Eupentacta fraudatrix. Structure and cytotoxic action of cucumariosides A2, A7, A9, A10, an, A13 and A14, seven new minor non-sulfated tetraosides and an aglycone with an uncommon 18-hydroxy group

Seven new minor triterpene glycosides, cucumariosides A2 (1), A7 (2), A9 (3), A10 (4), A11 (5), A13 (6) and A14 (7) have been isolated from the Far Eastern sea cucumber Eupentacta fraudatrix. Structures of the glycosides were elucidated by 2D NMR spectroscopy and MS. Glycosides 1-7 belong to the group of cucumariosides A, having linear tetrasaccharide carbohydrate moieties without any sulfate group and possessing 3-O-methyl-D-xylose as a terminal monosaccharide unit. Glycosides 1, 2, 5-7 differ from each other in side chain structures in aglycone moieties, while cucumarioside A10 (4) has a 23,24,25,26,27-pentanorlanostane aglycone with 18(16)-lactone. Cucumarioside A9 (3), having an uncommon 18-hydroxy group, is the second representative of the unique metabolically active glycosides that are regarded as intermediates of glycoside biosynthesis in sea cucumbers. Cytotoxic activities of glycosides 1-7 and cucumarioside A8 (8) against mouse spleen lymphocytes and the cells of the ascite form of mouse Ehrlich carcinoma, along with hemolytic activity against mouse erythrocytes and antifungal activity were studied. Cucumariosides A2 (1), A8 (8) and A13 (6) demonstrated high hemolytic activities. Glycosides 1, 4 and 6 showed moderate cytotoxic activity. Only cucumarioside A8 (8), having an 18-oxymethylene group and a 24(25)-double bond, was very active in all the tests.     

Structural basis for the β-adrenergic receptor subtype selectivity of the representative agonists and antagonists

The β(3)-adrenegic receptor (β(3)-AR) selectivity over β(1)- and β(2)-ARs has been the most important aspect for successful therapeutic agents for obesity and type-II diabetes, as the concomitant activation of β(1)- and β(2)-ARs would lead to undesirable side effects, such as increased heart rate. In order to explore the structural basis for the β-AR subtype selectivity of agonists and anatagonists, a three-dimensional structure of until date unresolved β(3)-AR has been modeled, compared with the resolved X-ray structures of β(1)- and β(2)-ARs, and used to study its stereoselective binding with until-date known diverse classes of representative agonists and antagonist. The obtained binding structures and calculated prime molecular mechanics-generalized Born surface area (MM-GBSA) binding free energies consistently reveal that while the subtype selectivity is strongly governed by the residues present in the extracellular ends of TM3, TM5, TM6, TM7 helices and of the ECL2 domain, the binding affinity is governed by the conserved residues present in the deep pocket limiting the degree of conformational and rotational freedoms to the bound ligand. The study demonstrates that the key structural requirements for the β(3)-selectivity are: (i) a negatively ionizable group (NIG) for direct interaction with β(3)-specific residue R315(6.58), (ii) a linker (9-10 ? length) between the protonated amine and NIG, and (iii) a substituted aryl ring directly attached to the β-hydroxyl carbon. The new computational insights acquired in this study are expected to be valuable in structure-based rational design of high-affinity agonists and antagonists with pronounced β(3)-selectivity for successful therapeutic agents for type-II diabetes and obesity.     

Binding properties of a polyclonal antibody directed towards lead complexes

A previously described conjugate of 8-hydroxyquinoline and bovine serum albumin was complexed with lead(II), (8-hydroxyquinoline to metal ion ratio 2:1) and used as an immunogen to produce polyclonal antibodies against lead in chickens. Antibodies obtained from a first blood sample during a standard immunisation procedure showed very promising features (dynamic range of the assay was 1 to 1000 ng l(-1)). Nevertheless, proceeding with the immunisation caused a complete loss of the recognition of the complex. A modified brief immunisation procedure was carried out and, in this case, the immunogen proved to be sufficiently stable in vivo to produce antibodies that selectively bound to the lead(II) complex (in the same 2:1 ratio used as an immunogen). Since the antiserum obtained cannot reach the same performance levels as the first one, standard curves were obtained by adding the free 8-hydroxyquinoline to the solution, which enables 2:1 complexes to be more easily formed. Cross-reactivity and dependence from buffer were investigated, showing at least 10-fold lower binding to non-target divalent metal ions compared to lead(II). MES buffer (pH = 6.0) gave more sensitive but very imprecise curves, whereas Tris (pH = 8.5) allows higher precision but lower sensitivity to be observed.     

2-乙烯基硝基苯-8-羟基喹啉锌配合物的合成及紫外、荧光性质研究

设计合成了3种8-羟基喹啉衍生物配体:(E)-2-[2-(2-硝基苯基)乙烯基]-8-羟基喹啉(4a),(E)-2-[2-(3-硝基苯基)乙烯基]-8-羟基喹啉(4b),(E)-2-[2-(4-硝基苯基)乙烯基]-8-羟基喹啉(4c)及其相应的锌配合物5a～5c,产物经1H NMR,IR,MS和元素分析技术进行了结构表征.通过紫外滴定模拟了金属锌与配体的配位过程,分别测定了它们固态和溶液状态下的荧光性质:光谱显示化合物5a～5c固体荧光光谱的λmax分别是596,625,592 nm,在DMF溶液中的λmax分别是562,536,618 nm.荧光光谱显示硝基位置的改变可以调控8-羟基喹啉锌配合物的发光性质.     

Theoretical Study of Haloacetonitrile Anions: CH2XCN- (X=F,Cl)

Haloacetonitrile anions CH2XCN- (X=F, Cl) were studied by HF-SCF, Becke3-LYP, and MP2 methods together with the Dunning's basis set aug-cc-PVTZ. The vertical electron attachments to the neutral are endothermic. The geometrically optimized CH2FCN- is mainly a valence-bounded anion and CH2FCN-→CH2CN+F- is a nonadiabatic dissociation. This theoretical study in good agreement with the experimental results shows that the Becke3-LYP method is reasonable in describing the electronic structures of anions and dissociative attachment dynamics, while significant differences between MP2 and Becke3-LYP results are shown for the dissociation potential curves of CH2ClCN-→CH2CN+Cl-.2,70-(Ethylene)-bis-8-hydroxyquinoline was optimized with DFT/B3LYP and ab initio HF methods, so ionization potential and electron affinity could be determined. Absorption spectrum was calculated by ZINDO and TD-DFT. CIS method was used to calculate the S1 excited states of the compound and afterwards the emission spectrum was computed. When the solvent effect was taken into account, the computed results show encouraging agreement with known experimental data. The results of analyzing the relationship between the energies and absorption spectra indicate that the ability to transporting electrons is strengthened compared with 8-hydroxyquinoline and that absorption and emission spectra are red-shifted. The intramolecular reorganization energy of tris(2,70-(ethylene)-bis-8-hydroxyquinoline)-aluminum implies its electron transporting property is worse than tris(8-hydroxyquinoline)-aluminum. The predicted maximum emission wavelength is red-shifted compared with tris(8-hydroxyquinoline)-aluminum.     

l-Idoseptanosides: substrates of d-glucosidases?

Based on the reported glycosidase inhibitory activities of 1,6-dideoxy-1,6-imino-l-iditol, the corresponding aryl glycosides 4-nitrophenyl α- and β-l-idoseptanoside 7 and 8 were synthesised as possible glycosidase substrates. Despite their inherently larger size, these septanosides were indeed shown to be glycosidase substrates, albeit weak ones. In addition, these two substrate analogues 7 and 8 also demonstrated a remarkable degree of selectivity for β- and α-glucosidases, respectively.     

Structure and vibrational spectroscopy investigation of 2-(4-chlorophenyliminomethyl)-8-hydroxyquinoline

2-(4-Chlorophenyliminomethyl)-8-hydroxyquinoline was synthesized and crystal data was obtained in the orthorhombic space group P-1, with Z=4. Unit cell parameters a=4.744(7) ?, b=9.981(15) ?, c=27.27(4) ? and V=12915(3) ?(3). In this paper the structural properties and vibrational frequencies of 8-hydroxyquinoline derivative, 2CP8HQ, are studied with the B3LYP and HF methods. Two stable conformers are obtained. The calculated frequencies are in good agreement with the experiment results. It is indicated that both of theoretical calculations were suitable for molecular vibrational frequencies study and the scaled B3LYP method was superior to the scaled HF methods.     

High-Performance Liquid Chromatographic Determination of the Metabolites of the Potato Glycoalkaloids, α-Chaconine and α-Solanine,in Potato Tubers and Potato Products

Abstract

A high-performance liquid chromatographic method has been developed to separate and quantify the metabolites, γ-chaconine, β₁-and β₂-chaconine, γ-solanine and β₂-solanine, of the potato gly-coalkaloids α-chaconine and α-solanine in potatoes and potato products. A carbohydrate analysis column and a solvent system of tetrahydrofuran-water-acetonitrile (55:8:37) were employed for the separation. Flow rate was 1.1 ml/min and the compounds were monitored at 215 nm. β₂-chaconine (0.63 mg to 29.75 mg/100 g dried weight) was present in all samples whereas the other glycosides of α-chaconine were only detectable in the animal feed products. It appears that some of the animal feeds may contain trace amounts of γ-solanine and an unknown which maybe β₁-solanine. Limit of detection for all glycosides was 0.05 μg/μl. Elution time for all the lower glycosides of α-chaconine was 8 min versus 16 min for the α-solanine group. These metabolic compounds were confirmed using thin-layer chromatography.     

新型8-羟基喹啉席夫碱的合成与抑菌活性

以2-甲基-8-羟基喹啉为原料,经羟基保护、甲基氧化、水解后得到2-甲酰基-8-羟基喹啉(L)。L分别与苯胺衍生物缩合得到三种新型喹啉衍生物。经元素分析、红外光谱、紫外光谱、核磁共振谱表征,确定了席夫碱的组成。产物分别与大肠杆菌、产气杆菌、枯草杆菌、变形杆菌、金黄色葡萄球菌进行抑菌活性实验,配体与席夫碱均有较好的抑菌活性。     

EFFICIENT SYNTHESIS OF POLYLACTOSAMINE STRUCTURES THROUGH REGIOSELECTIVE GLYCOSYLATIONS[1]

Di-, tri- and tetramers of β-(1→3)-linked N-acetyllactosamine residues have been synthesised as their methyl glycosides, to be used in ITC binding studies to various galectins. The synthetic strategy involves two types of regioselective glycosylations: couplings of a galactosyl donor to 3,4-diol N-tetrachlorophthalimido glucose acceptors to give the lactosamine monomer building blocks, and subsequent formation of the oligomers through consecutive couplings of lactosamine donors to 2′,3′,4′-lactosamine acceptors, with high selectivity for the desired products.     

新型含噻吩基8-羟基喹啉锌配合物的合成及光电性能简

设计合成了含噻吩基的新型配体(E)-2-[2-(3-噻吩基)乙烯基]-8-羟基喹啉(4)及相应的锌配合物5,产物结构经核磁共振、红外光谱和元素分析进行表征. 利用X射线单晶衍射仪测定了中间体(E)-2-[2-(3-噻吩基)乙烯基]-8-乙酰氧基喹啉(3)和配体4的单晶结构,结果表明中间体3晶体分子间并无明显的氢键作用,分子间呈交错堆叠;配体4分子之间由硫氢氧键弱作用相互排列形成网状结构. 通过核磁滴定及紫外和荧光滴定模拟了配体4在溶液中与金属锌的配位过程. 固体荧光寿命研究结果表明,配合物5的荧光寿命为18.8 ms. 通过电致发光器件研究发现,配合物5作为发光层具有良好的电致发光性能,同时具有较好的电子传输能力.