Nucleic acid base grafted imino polyurethane

Preparation of two model polymers of polynucleotides with linear polyurethane backbone and 2-(thymin-1-yl)propionyl or 2-(uracil-1-yl)propionyl group as grafted pendant are described. 2-(Thymin-1-yl)propionic acid (TPA) and 2-(uracil-1-yl)propionic acid (UPA) were grafted into partial imino functionalized polyurethane, poly[(β,β′-diethylene)amine methylene bis(4-phenylcarbamate)]-75 (PU-NH-75), at the secondary amino group through amide bonds with 1-hydroxybenzotriazole (HOBT) using the active ester technique. Two novel polymer models of polynucleotides, poly[(N-(2-(thymin-1-yl)propionyl)-β,β′-diethylene)amine methylene bis(4-phenylcarbamate)]-75 (PU-NT-75) and poly[(N-(2-(uracil-1-yl)propionyl)-β,β′-diethylene)amine methylene bis(4-phenylcarbamate)]-75 (PU-NU-75) were obtained. The imino polyurethane PU-NH-75 was produced from the partially deprotected N-Cbz imino polyurethane, poly[N-(benzyloxycarbonyl-β,β′-diethylene)amine methylene bis(4-phenylcarbamate)] (PU-NCbz) which was prepared by the polyaddition of 4,4′-diphenylmethane diisocyanate (MDI) with diol monomer N-benzyloxycarbonyl-β,β′-dihydroxyethylamine (CbzHEA). Selective N-protection of N-benzyloxycarbonyloxy-5-norbornene-2,3-bicarboximide (CbzONB) with β,β′-dihydroxyethylamine (HEA) gave the N-Cbz protected diol monomer HEA. The related monomer model compounds were also prepared by the same methods.     

Two Zn(II) coordination polymers constructed by a new tricarboxylate and different N-containing ligands: synthesis,crystal structures,and selective luminescence sensing for Fe3+ in aqueous solution

Two Zn(II) coordination polymers, {[Zn₃(L)₂(bipy)₂(H₂O)₄}_n (1) and {[Zn(HL)(4,4′-bibp)}_n (2), were obtained from Zn(II) nitrate, a tricarboxylate ligand (H₃L) and different N-containing ligands with hydrothermal conditions, where H₃L = 4-((6-carboxynaphthalen-2-yl)oxy)phthalic acid, bipy = 4,4′-bipyridine, and 4,4′-bibp = 4,4′-di(1H-imidazol-1-yl)-1,1′-biphenyl. Single-crystal X-ray analysis reveals that 1 has a 2-D layer framework formed by L^3? and bipy and 2 has an infinite 1-D structure with Zn₂ units built by 4,4′-bibp ligands. The phase purity, IR spectra, thermal stabilities, and fluorescence properties in the solid state of 1 and 2 were investigated. Moreover, 1 and 2 were chosen as fluorescent probes to sense different metal ions, showing selective response to Fe³⁺ ion through luminescence quenching. The possible sensing mechanism to Fe³⁺ ion is also discussed.     

1-芳酰基-4-(1＇-N-β-D-吡喃型糖基)氨基硫脲类化合物的合成

通过2,3,4,6-四-O-乙酰基-β-D-吡喃型葡萄糖异硫氰酸酯和2,3,4-三-O-乙酰基-β-D-吡喃型木糖异硫氰酸酯与取代的芳基酰肼的亲核加成反应合成了10个1-芳酰基-4-(1＇-N-2＇,3＇,4＇,6＇-四-O-乙酰基-β-D-吡喃型葡萄糖基)氨基硫脲和7个1-芳酰基-4-(1＇-N-2＇,3＇,4＇-三-O-乙酰基-β-D-吡喃型木糖基)氨基硫脲,所得化合物的结构经元素分析,IR,1H NMR确证.     

Synthesis and bioactivity evaluation of some novel sulfonamide derivatives

A simple and convenient method for the synthesis of biologically active sulfonamide derivatives was achieved. All the title compounds were characterized by spectral and elemental analysis. They were further screened in vitro for their abilities towards antibacterial, antifungal and antioxidant activities. The compound N,N'-(3,3′-dimethoxybiphenyl-4,4′-diyl)bis(4-fluorobenzenesulfonamide) (5b) and N-(3-(9H-carbazol-4-yloxy)-2-hydroxypropyl)-4-fluoro-N-isopropylbenzenesulfonamide (5e) exhibited good activity when compared to the standard bactericide, Chloramphenicol and fungicide, Ketoconazole respectively. The compounds (2S)-N-((2S,4S)-5-(4-Chloro-phenylsulfonamido)-4-hydroxy-1, 6-diphenylhexan-2-yl)-3-methyl-2-(2-oxotetrahydropyrim-idin-1(2H)-yl)butan-amide (4f) and (2S)-N-((2S,4S)-5-(4-fluorophenylsulfonamido)-4-hydroxy-1,6-diphenyl-hexan-2-yl)-3-methyl-2-(2-oxotetrahydropyrimidin-1(2H)-yl)bu-tana-mide (5f) exhibited good antioxidant activity when compared with standard antioxidant, Ascorbic acid.     

Synthesis of Interglycosidically S‐Linked 1‐Thio‐Oligosaccharides Under Microwave Irradiation*

Microwave irradiation (MWI) has accelerated the synthesis of S‐(2,3,4,6‐tetra‐O‐acetyl‐β‐D‐glucopyranosyl)thiouronium bromide (2a), whose reaction with 2,3,4,6‐tetra‐O‐acetyl‐α‐D‐glucopyranosyl bromide (1a) in the presence of Et₃N afforded stereoselectively the acetylated β,β‐1‐thiotrehalose 4a. Similarly, the respective D‐galactopyranosyl 4b and 2‐acetylamino‐2‐deoxy‐D‐glucopyranosyl 4c analog as well as 4,4′‐di‐O‐(2,3,4,6‐tetra‐O‐acetyl‐β‐D‐galactopyranosyl) 4d and 4,4′‐di‐O‐(2,3,4,6‐tetra‐O‐acetyl‐α‐D‐glucopyranosyl) 4e derivatives of 2,2′,3,3′,6,6′‐hexa‐O‐acetyl β,β‐1‐thiotrehalose were prepared.     

Synthesis of the tetrasaccharide repeating unit of the o-specific polysaccharide from salmonella muenster and salmonella minneapolis

The tetrasaccharide β-D-Man-(1→4)-α-L-Rha-(1→3)-D-Gal-(4←1)-α-D-Glc the repeating unit of the O-specific polysaccharide chain of the lipopolysaccharides from Salmonella muenster and S, minneapolis was obtained by glycosylation of benzyl 2,6-di-O-benzyl-4-0(2,3,4-tri-O-benzyl-6-O-benzoyl-α-D-glucopyranosyl)-β-D-galactopyranoside with 3-O-acetyl-4-0-(2,3,4,6-tetra-O-acetyl-β-D-mannopyranosyl)- β-L-rhamnopyranose-1,2-(methylorthoacetate), followed by removal of protecting groups. The structure of the synthetic tetrasaccharide was confirmed by methylation analysis, CrO₃-AcOH oxidation and ¹³C-NMR.     

Chemical-Enzymatic Synthesis of A Branched Hexasaccharide Fragment of Type Ia Group B Streptococcus Capsular Polysaccharide

ABSTRACT

A branched hexasaccharide fragment of type Ia group B streptococcal polysaccharide, α-NeuAc(2→3)-β-D-Gal(1→4)-β-D-GlcNAc(1→3)-[β-D-Glc(1→4)]-β-D-Gal(1→4)-β-D-Glc-OMe (13), has been synthesized by chemical-enzymatic procedures. Chemical synthesis of a pentasaccharide, β-D-Gal(1→4)-β-D-GlcNAc(1→3)-[β-D-Glc(1→4)]-β-D-Gal(1→4)-β-D-Glc-OMe (12), was achieved from glycosyl donor, 4-O-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)-3,6-di-O-acetyl-2-deoxy-2-phthalimido-β-D-glucopyranosyl trichloroacetimidate (9), and acceptor, methyl O-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)-(1→4)-O-(2,6-di-O-benzyl-β-D-galactopyranosyl)-(1→4)-2,3,6-tri-O-benzyl-β-D-glucopyranoside (6), by block condensation in 41% yield. Following enzymatic sialylation of 12 at the 3-O-position of its terminal galactopyranosyl residue using recombinant α-(2→3)-sialyltransferase and CMP-NeuAc afforded 13 in 59% yield.     

Carotenoids of Rhizobia. IV. Isolation and structure elucidation of the carotenoids of a mutant of Rhizobium lupini

The structures of the main carotenoid pigments from the mutant 1-207 of Rhizobium lupini were elucidated by spectroscopic techniques (UV./VIS., CD., 270 MHz ¹H-NMR., and MS.). Ten carotenoids were identified, namely β,β-carotene ( 1 ), β,β-caroten-4-one (echinenone, 2 ), β,β-carotene-4,4′-dione (canthaxanthin, 3 ), (3S)-3-hydroxy-β,β-caroten-4-one ((3S)-3-hydroxyechinenone, 4 ), (2R, 3R)-β,β-carotene-2,3-diol ( 5 ), (3S)-3-hydroxy-β,β-carotene-4,4′-dione ((3S)-adonirubin, 6 ), (2R, 3S)-2,3-dihydroxy-β,β-caroten-4-one ( 7 ), (2R, 3S)-2,3-dihydroxy-β,β-caroten-4,4′-dione ( 8 ), (2R, 3S, 2′R, 3′R)-2,3,2′,3′-tetrahydroxy-β,β-caroten-4-one ( 9 ) and the corresponding (2R, 3S, 2′R, 3′S)-4,4′-dione ( 10 ). Structures 5, 7, 8 and 10 have not been reported before. From the observed carotenoid pattern it is concluded that in this mutant the oxidation to 4-oxo compounds is favoured compared to the hydroxylation at C(3) and C(2).     

Synthesis of Methyl 2-O-, 3-O-, 4-O-, 6-O-, 2,3-Di-O- and 4,6-Di-O-β-D-Galactopyranosyl-β-D-glucopyranoside

Abstract

Synthesis of methyl O-β-D-galactopyranosyl-(1→2)-β-D-glucopyranoside 1, methyl O-β-D-galactopyranosyl-(1→3)-β-D-glucopyranoside 2, methyl O-β-D-galactopyranosyl-(1→4)-β-D-glucopyranoside 3, methyl O-β-D-galactopyranosyl-(1→6)-β-D-glucopyranoside 4, methyl O-β-D-galactopyranosyl-(1→4)-[O-β-D-galactopyranosyl-(1→6)]-β-D-glucopyranoside 5, and methyl O-β-D-galactopyranosyl-(1→2)-[O-β-D-galactopyranosyl-(1→3)]-β-D-glucopyranoside 6, using 2,3,4,6 tetra-O-acetyl-α-D-galactopyranosyl trichloroacetimidate or 2,3,4,6 tetra-O-acetyl-α-D-galactopyranosyl bromide as a glycosyl donor and selectively protected derivatives of methyl O-β-D-glucopyranoside as glycosyl acceptors are described.     

β-D-葡萄糖基硫脲合成及生物活性研究

从1-溴-2,3,4,6-四乙酰化-β-D-吡喃葡萄糖I出发, 经异硫氰酸酯化反应, 合成了2,3,4,6-四乙酰化-β-D-吡喃糖基硫脲化合物IV, 再经脱乙酰化得到V. 将乙酰化糖基异硫氰酸酯的合成从文献的60%提高到80%. 所得化合物经元素分析, IR, MS, ¹H NMR和 ¹³C NMR谱学分析确定了结构, 并对产物进行了初步的除草活性测试.     

Combined Chemical and Enzymatic Synthesis of a Disialylated Tetrasaccharide Analogous to M and N Bloodgroup Determinants of Glycophorin a

Abstract

Reaction of 2,3,4,6-tetra-O-acetyl-α-D-galactopyraaosyl bromide (1) with phenyl 2-acetamido-2-deoxy-4,6-O-(4-methoxy-benzylidene)-α-D-galactopyranoside (3) mediated by mercuric salts, followed by removal of the 4-methoxybenzylidene group and O-deacylation afforded phenyl 2-acetamido-2-deoxy-3-O-p-D-galactopyranosyl-α-D-galactopyranoside (6). Compound 6 was used as a substrate for the selective introduction of two neuraminic acid residues with partially purified sialyltrans-ferase preparations. First, disaccharide 6 was treated with CMP-[¹⁴c]-NeuAc as donor substrate and CMP-NeuAc: Gal-p(l-3)-GalNac-a(2-3)sialyltransferase from human placenta to afford trisaccharide 7 (yield 85X), sialylated at C-3 of the galactose residue. Treatment of 7 with CMP-[³H]-NeuAc and a micro-somal fraction from regenerating rat liver, containing the CMP-NeuAc: NeuAc-a(2-3)-Gal-p(l-3)GalNAc-α(2-6) sialyltrans-ferase activity, gave the disialylated tetrasaccharide 8 in 10X yield.     

一种含载流子传输基的铱配合物:合成及深黄色电致磷光器件

合成了一种含有载流子传输基新的铱配合物(BPPBI)2Ir(ECTFBD)[HBPPBI:1-苯基-2-(4-联苯基)苯并咪唑,HECTFBD:1-(9-乙基-3-咔唑基)-4,4,4-三氟-1,3-丁二酮],其结构和组成经核磁共振氢谱和元素分析所证实。研究了这种铱配合物二氯甲烷溶液的光物理和电化学性质。制作了基于这种铱配合物的电致磷光器件。器件结构是ITO/MoO3(10 nm)/NPB(80 nm)/CBP:x%(BPPBI)2Ir(ECTFBD)(20 nm)/TPBi(45 nm)/LiF/Al[x%:质量百分比为4%和7%的掺杂浓度;NPB:N4,N4′-二(1-萘基)-N4,N4′-二苯基-4,4′-联苯二胺,CBP:4,4′-二(9-咔唑基)联苯,TPBi:1,3,5-三(2-(1-苯基)苯并咪唑基)苯]。这些器件显示出深黄色的发射。对于7%掺杂浓度器件,最大的电流效率和最大发光亮度分别是5.2 cd.A-1和8 690 cd.m-2。     

SYNTHESIS AND REACTVITY OF N-[N-PHOSPHORAMIDO-1H-BENZIMIDAZOL-2-YL] IMIDATES

N-(-1H-Benzimidazol-2-yl) imidates 1a–c react with chlorophosphoramide to give the N-[-1-N,N,N′,N′-tetramethylphosphoramidoyl-1H-benzimidazol-2-yl]-imidates 2a–c or with dichlorophosphoramide to yield the bis[(N-1-benzimidazol-2-yl)-imidate] phosphoramide derivatives 3a–b. The reaction of compounds 2a–c toward primary amines is studied. The obtained amidine derivatives 4a–b were unambiguously characterized by different spectroscopic techniques (IR, ¹H, ¹³C, and ³¹P NMR, and in some cases MS).     

Synthesis of diols containing nucleic acid bases and their polyesters

Preparation of four diols containing nucleic acid bases derived from 3-(thymin-1-yl)propanoic acid (3-TPA) and 3-(uracil-1-yl)propanoic acid (3-UPA), and the corresponding model polymers of polynucleotides with linear polyester backbone and nucleic acid base derivative as pendant side chains are described. N-(1′,3′-Dihydroxy-2′-methyl-2′-propyl)-3-(thymin-1-yl)propionamide ( VIa , 3-HMPTPA), N-(1′3′-dihydroxy-2′-methyl-2′-propyl)-3-(uracyl-1-yl)propionamide ( VIb , 3-HMPUPA) and their isomers, N(β,β-dihydroxyethyl)-3-(thymin-1-yl)propionamide ( VIIa , 3-HETPA), and N-(β,β-dihydroxyethyl)-3-(uracil-1-yl)propionamide ( VIIb , 3-HEUPA) were synthesized through the selective N-acylation of 2-methyl-2-amino-1,3-propanediol and diethanolamine with 3-TPA and 3-UPA, respectively, by the active ester-N-hydroxyl-1,4-epoxy-5-cyclohexene-2,3-dicarboximide (HOEC) method. The resulting diols were polycondensed with active diamide of benzotriazole (HBT) such as 1,1′-(isophthaloyl)bis-benzotriazole (IPBBT), giving polyesters containing thymine and uracil derivatives as the side group, by the selective O-acrylation of active amide-benzotriazole method.     

Studies on the Thioglycosides of N-Acetylneuraminic Acid 7: Synthesis of S-(α-Sialyl)-(2↠6)-β-D-Hexopyranosyl and -(2↠6)-β-D-Lactosyl Ceramides and their Biological Activity

ABSTRACT

The coupling of the sodium salt of methyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3, 5-dideoxy-2-thio-D-glycero-α-D-galacto-2-nonulopyranosonate (17) with 2-(trimethylsilyl)ethyl 2,3,4-tri-O-acetyl-6-bromo-6-deoxy-β-D-galactopyranoside (5), glucopyranoside (10), and 2-(trimethylsilyl)ethyl 2,3,6,2′,3′,4′-hexa-O-acetyl-6′-bromo-6′-deoxy-β-D-lactoside (16), gave the corresponding α-thioglycosides 18, 21, and 24 of the 2-thio-N-acetyl-neuraminic acid derivative in good yields, which were converted, via selective removal of the 2-(trimethylsilyl)ethyl group, trichloroacetimidation, and coupling with (2S,3R,4E)-2-azido-3-O-benzoyl-4-octadecene-1,3-diol (27), into the ß-glycosides 28, 32, and 36, respectively.

Compounds 28, 32, and 36 were transformed, via selective reduction of the azide group, coupling with octadecanoic acid, O-deacetylation, and de-esterification, into the title compounds 31, 35, and 39, which showed potent inhibitory effect for sialidases from influenza and other viruses.     

Syntheses and structures of three coordination polymers based on 4-methylbenzenethiolates of Zn(II) and Cd(II) and bipyridine

Using 4-methylbenzenethiolates of Zn or Cd as precursors and 4,4′-bipyridine (4,4′-bpy) as bridges, we have synthesized three new Zn(II)/Cd(II) coordination polymers, {[Cd(4,4′-bpy)₂(NCS)₂] · 2(SC₆H₄CH₃-4)₂} _n (1), {[Zn(4,4′-bpy)(SC₆H₄CH₃-4)₂] · DMF} _n (2) and {[Zn(4,4′-bpy)(SC₆H₄CH₃-4)₂] · H₂O · 0.5CH₃OH} _n (3). Compound 1 is a 2-D sheet-like square polymer in which four 4,4′-bpy ligands and two isothiocyanate ligands complete the octahedral Cd(II) coordination sphere. Compounds 2 and 3 have similar coordination around Zn(II), but have different polymer structures. In 2, Zn(II) centers are linked via a bidentate 4,4′-bipyridine to form 1-D twisted arched chains, which is a new structural type for Zn(II). Compound 3 has 1-D zigzag chains. The 2-D sheets in 1 and 1-D chains in 2 and 3 are assembled via intermolecular C–H ··· π and C–H ··· S interactions into 3-D supramolecular networks. C–H ··· S interactions are a vital factor in constructing the sulfur-containing coordination polymers. Different coordination modes and packing schemes in 1–3 show that the guest molecule has a critical influence on formation of polymers.     

SYNTHESIS OF NEW 8-METHOXY-4-METHYL-3-(N-[2′-AMINO-(1′,3′,4′)THIA/OXA-DIAZOL-5′-YL]-SUBSTITUTED METHYL)-AMINO THIOCOUMARINS

8-Methoxy-4-methyl-3-(N-[2′-amino-(1′, 3′,4′)thia/oxa-diazol-5′-yl] substituted methyl)-amino thiocoumarins 6(a–f) and 7(a–f), were synthesized by using the unreported 8-methoxy-4-methyl-3-[N-(2′-oxo-2′-methoxy-1′-substituted ethan-1′-yl) amino thiocoumarins as key intermediates.     

Isolation of a new carboline alkaloid from Trigonostemon lii

A new carboline alkaloid, 1-(7-methoxy-quinolinyl-4′-yl)-3,4-dihydro-β-carboline (1), was isolated from the leaves and twigs of Trigonostemon lii Y.T. Chang, together with three known ones, trigonostemonines C and D (2 and 3), and trigonoliimine A (4). Their structures were elucidated by spectroscopic analyses, including 2D-NMR techniques.     

Emissive mononuclear Eu(III) and Tb(III) complexes bearing deprotonated 2,2′-bipyridyl-1,2,4-triazole terdentate ligands

A series of new emissive mononuclear Ln(III) complexes with deprotonated 2,2?-bipyridyl-1,2,4-triazole terdentate ligands, [Ln(L)(DMF)₂(NO₃)₂]?n(solvent) (Ln = Eu (1 and 2), Tb (3 and 4), HL = 6-(5-trifluoromethyl-1,2,4-triazol-3-yl)-2,2′-bipyridine, 6-(5-trifluoromethyl-1,2,4-triazol-3-yl)-4,4′-dimethyl-2,2′-bipyridine), have been synthesized and characterized. As revealed by X-ray crystallography, each Ln(III) has a distorted tricapped trigonal prism generated by three nitrogens from one 2,2?-bipyridyl-1,2,4-triazolate chelate and six oxygens from two DMF molecules and two chelating nitrates, where 2,2?-bipyridyl-1,2,4-triazole serves as a mono-anionic tridentate chelate via deprotonation of the 1,2,4-triazolyl-NH. Complexes 1–4 are all emissive at room temperature in solution and solid states, and the introduction of two methyl groups into the 2,2?-bipyridyl ring is efficient in enhancing luminescence efficiencies of Ln(III) complexes.