Stable expression of foot-and-mouth disease virus protein VP1 fused with cholera toxin B subunit in the potato (Solanum tuberosum)

The expression vector, pBI121CTBVP1, containing the fusion of the foot and mouth disease virus (FMDV) VP1 gene and the cholera toxin B subunit (CTB) gene was constructed by fused PCR and transferred into potato (Solanum tuberosum L.) by Agrobacterium-mediated transformation. Transformed plants were obtained by selecting on kanamycin-resistant medium strictly and regenerated. The transgenic plantlets were identified by PCR, Southern-blot and the production of fused protein was confirmed and quantified by Western-blot and ELISA assays. The results showed that the fused genes were expressed stablely under the control of specific-tuber patatin promoter. The expressed fused proteins have a certain degree of immunogenicity.     

Synthesis of 2-(4-amino substituted benzylidene) indanone analogues from aromatic nucleophilic substitution (SNAr) reaction

A novel, efficient and convenient procedure has been developed for the synthesis of 2-(4-amino-substituted benzylidene)indanone derivatives. In the first step, the reaction of 4-fluorobenzaldehyde with 5, 6-dimethoxy-2, 3-dihydro-1H-inden-1-one in the presence of NaOH in EtOH was described. In the next step, a variety of aliphatic and aromatic amines were reacted with 2-(4-fluorobenzylidene)-5, 6-dimethoxy-2, 3-dihydro-1H-Inden-1-one via aromatic substitution (S_NAr) reaction to produce 2-(4-aminobenzylidene)-5, 6-dimethoxy-2, 3-dihydro-1H-Inden-1-one derivatives as a novel class of 1-indanones. These products have been successfully prepared in good to excellent yields. ^1?H and ^13?C NMR, FT-IR spectroscopy and CHN analysis supported the proposed structures of the products.     

Zn(AA)SO4·H2O(AA=Thr,Phe,Val,Met)在水和丙酮混合溶剂中的结晶动力学研究

Zincisanecessarylifeelementinhumanbody．L－α－aminoacidisthebasicunitofproteinrelatedwithlife．L－α－Thr（Threonine），L－α－Phe（Phenylalanine），L－α－Val（Valine）andL－α－Met（Methionine）arein－dispensabletolifewhichhavetobeabsorbedfromfoodbecausetheycannotbesynthesizedinhumanbody．Thecomplexesofzincsaltswithα－aminoacidasad－ditivehaveawideapplicationinmedicine，foodstuffandcosmetics犤１～３犦．Thesynthesismethodsofthecom－plexesofzincsaltswithα－aminoacidhavebeenre－viewed犤…     

Origin of enantioselectivity with heterobidentate sulfide-tertiary amine (sp) ligands in palladium-catalyzed allylic substitution

A series of new chiral heterobidentate sulfide-tertiary amine (sp³) ligands 3a-c, 6 were readily prepared from cheap and easily available (R)-cysteine and l-(+)-methionine. A Pd-catalyzed asymmetric allylic alkylation of 1,3-diphenyl-2-propenyl acetate with dimethyl malonate was used as a model reaction to examine the catalytic efficiencies of these aziridine sulfide ligands, and ligand 3b afforded the enantioselectivity of up to 91% ee. The origin of enantioselectivity for heterobidentate sulfide-tertiary amine (sp³) ligands was first rationalized based on X-ray crystallographic data, and NMR spectroscopic data for relevant intermediate palladium allylic complexes. Our results demonstrated that the sulfur atom was a better π-allyl acceptor than the nitrogen atom for heterobidentate sulfide-tertiary amine (sp³) ligands, and the steric as well electronic properties of the palladium allylic complexes were crucial for the enantioselectivity.     

Enantioselective copper-catalysed propargylic substitution: synthetic scope study and application in formal total syntheses of (+)-anisomycin and (-)-cytoxazone

A copper catalyst with a chiral pyridine-2,6-bisoxazoline (pybox) ligand was used to convert a variety of propargylic esters with different side chains (R=Ar, Bn, alkyl) into their amine counterparts in very high yields and with good enantioselectivities (up to 90% enantiomeric excess (ee)). Different amine nucleophiles were applied in the reactions and the highest enantioselectivities were obtained for aniline and its analogues. Interestingly, some carbon nucleophiles could also be used and with indoles excellent ee values were obtained (up to 98% ee). The versatility of the propargylic amines obtained was demonstrated by their further elaboration to formal total syntheses of the antibiotic (+)-anisomycin and the cytokine modulator (-)-cytoxazone.     

Crystal Structure of Praseodymium Complex with L－proline，Pr_2（L－Pro）_6（H_2O）_4·6ClO_4

ＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅｏｆＰｒａｓｅｏｄｙｍｉｕｍＣｏｍｐｌｅｘｗｉｔｈＬ－ｐｒｏｌｉｎｅ，Ｐｒ_２（Ｌ－Ｐｒｏ）_６（Ｈ_２Ｏ）_４·６ＣｌＯ_４￥ＷａｎｇＺｅｎｇ－Ｌｉｎ；ＨｕＮｉｎｇ－Ｈａｉ；ＮｉｕＣｈｕｎ－Ｊｉ；ＮｉＪｉａ－Ｚｕａｎ（Ｃ?..     

Nitropyrazoles. 11. Isomeric 1-methyl-3(5)-nitropyrazole-4-carbonitriles in nucleophilic substitution reactions. Comparative reactivity of the nitro group in positions 3 and 5 of the pyrazole ring

With reactions of isomeric 1-methyl-3-nitro- and 1-methyl-5-nitropyrazole-4-carbonitriles with anionic S-, O-, and N-nucleophiles (RSH, PhOH, and 3,5-dimethyl-4-nitropyrazole in the presence of K₂CO₃ or MeONa), it was shown that for N-substituted 3(5)-nitropyrazoles, the nitro group in position 5 is much more reactive than in position 3.     

Isocationic substitution of copper(II) complexes in anisotropic materials based on benzenetricarboxylate

A phase transfer isocationic substitution of lattice constituent macrocyclic complexes by copper(II) aqua complexes occurs upon the interaction of crystalline mono-and bis(macrocyclic) copper carboxylate complexes with acetonitrile solutions of copper(II) ammine complex. On the other hand, these materials do not react with cupric bis(ethylenediamine). __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 43, No. 2, pp. 124–129, March–April, 2007.     

Ligand substitution in HC(O)CCo3(CO)9 with 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd): Diphosphine ligand fluxionality, decarbonylation of the formyl moiety and competitive P-Ph bond cleavage reactivity

The reaction of the formyl-capped cluster HC(O)CCo₃(CO)₉ (1) with the diphosphine ligand 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) in the presence of added Me₃NO leads to the production of the disubstituted cluster HC(O)CCo₃(CO)₇(bpcd) (2). Thermolysis of 2 in toluene at 60 °C gives the methylidyne-capped cluster HCCo₃(CO)₇(bpcd) (4) and the phosphido-bridged cluster Co₃(CO)₇[μ₂,η²,η¹-P(Ph)CC(PPh₂)C(O)CH₂C(O)] (5). Cluster 4 has been independently prepared from HCCo₃(CO)₉ and bpcd and shown to serve as the precursor to 5. The new clusters 2, 4, and 5 have been isolated and characterized in solution by IR and NMR (¹H and ³¹P) spectroscopies and their solid-state structures have been established by X-ray diffraction analyses. Both clusters 2 and 4 contain 48e- and exhibit triangular Co₃ cores with a chelating and bridging bpcd ligand in the solid state, respectively. The structure of 5 provides unequivocal support for the loss of the methylidyne capping ligand and P-Ph bond cleavage attendant in the activation of 4 and confirms the presence of the face capping seven-electron μ₂,η²,η¹-P(Ph)CC(PPh₂)C(O)CH₂C(O) ligand in the final product. The fluxionality displayed by the bpcd ligand in clusters 2 and 4 and the decarbonylation behavior of the formyl moiety in the former cluster are discussed relative to related alkylidyne-capped Co₃ derivatives.     

LC-MS analysis of the formed peptides from N-(O,O-diiso-propyl)phosphoryl aspartic acid

LC-ESI-MS method was used to analyze the formed di-and tri-peptide hi the reaction system of N-(O,O-diisopropyl)phosphoryl aspartic acid and adenosine.Ouster ions of the peptides were given hi the ESI-MS.The structures of these small peptides were confirmed by LC-MS-MS analysis.Compared with the traditional HPLC-UV detection,this method showed good sensitivity and selectivity for peptide in the presence of compounds with strong UV absorption,such as nucle-oside and nucleotide.     

Nucleophilic substitution of nitro groups by [F]fluoride in methoxy-substituted ortho-nitrobenzaldehydes—A systematic study

As model reactions for the introduction of [¹⁸F]fluorine into aromatic amino acids, the replacement of NO₂ by [¹⁸F]fluoride ion in mono- to tetra-methoxy-substituted ortho-nitrobenzaldehydes was systematically investigated. Unexpectedly, the highly methoxylated precursors 2,3,4-trimethoxy-6-nitrobenzaldehyde and 2,3,4,5-tetramethoxy-6-nitrobenzaldehyde showed high maximum radiochemical yields (82% and 48% respectively). When the electrophilicity of the leaving group substituted carbon atom is expressed by its ¹³C NMR chemical shift a good correlation with the reaction rate at the beginning of the reaction (first min) was found (R² = 0.89), whereas the maximum radiochemical yields correlated much poorer with this electrophilicity parameter. This may be caused by side reactions becoming influencial in the further reaction course. As possible side reactions the demethylation of methoxy groups and intramolecular redox reactions could be detected by HPLC/MS.     

Screening of ligands in the asymmetric metallocenethiolatocopper(I)-catalyzed allylic substitution with Grignard reagents

Screening of metallocenethiolate ligands for copper(I)-catalyzed substitution of allylic acetates with Grignard reagents has been carried out. The previously used ligand, lithium (R,S_p)-2-(1-dimethylaminoethyl)ferrocenylthiolate (4a), possessing both central and planar chirality, was the starting point for the screening. It was found that the diastereomeric ligand lithium (R,R_p)-2-(1-dimethylaminoethyl)ferrocenylthiolate (4b) exhibiting reversed planar chirality gave increased enantioselectivity in the allylic substitution, at least when cinnamyl acetate was used as a substrate. The ruthenocene-based ligand lithium (R,S_p)-2-(1-dimethylaminoethyl)ruthenocenylthiolate (4c) gave an enhanced reaction rate, but lower chiral induction. The use of disulfide bis[(R,S_p)-2-(1-dimethylaminoethyl)ferrocenyl]disulfide (7a) as a ligand precursor worked well but resulted in lower enantioselectivity.     

The 2-(4-trifluoromethylphenylsulfonyl)ethoxycarbonyl (Tsc) amino-protecting group: use in the solid-phase synthesis of pyrrole-imidazole polyamides

The development of the 2-(4-trifluoromethylphenylsulfonyl)ethoxycarbonyl (Tsc) function, a novel base-sensitive amino-protecting group, and its application to the preparation of DNA-binding polyamides are described. Pyrrole-imidazole polyamides were synthesized by an efficient solid-phase method under conditions compatible with Fmoc chemistry using two Tsc-protected amino acids, Tsc-Py-OH 1a and Tsc-Im-OH 1b.     

Synthesis of 4-(2-hydroxyaryl)-3-nitro-4H-chromenes

A combinatorial library of 4-(2-hydroxyaryl)-3-nitro-4H-chromenes was synthesized in high yield by C4-SMe substitution in N-alkyl/phenyl 4-(methylthio)-3-nitro-4H-chromen-2-amines with a variety of phenols. The reaction always provided C2 substitution in the phenol ring, dictated by hydrogen bond interactions between the phenolic hydroxyl group and the nitro group in 3-nitro-4H-chromenes. Reduction of the nitro group with concomitant hydrolysis of the enamine in 4-(2-hydroxyaryl)-3-nitro-4H-chromenes with Zn, Ac₂O in AcOH furnished hybrid amino-acid lactone incorporating ortho-tyrosine and phenyl alanine moieties.     

The preparation and resolution of 2-(2-pyridyl)- and 2-(2-pyrazinyl)-Quinazolinap and their application in palladium-catalysed allylic substitution

The preparation and resolution of two new axially chiral quinazoline-containing phosphinamine ligands, 2-(2-pyridyl)-Quinazolinap and 2-(2-pyrazinyl)-Quinazolinap, is described. The ligands were synthesised in good yield over eight steps and included two Pd-catalysed reactions, a Suzuki coupling to form the biaryl linkage and the introduction of the diphenylphosphino group, as the key transformations. The racemic ligands were resolved via the fractional crystallisation of diastereomeric palladacycles derived from (+)-di-μ-chlorobis{(R)-dimethyl[1-(1-naphthyl)ethyl]aminato-C₂,N}dipalladium (II) X-ray crystal structures of the (S,R)-2-pyridyl- and (S,R)-2-pyrazinyl-palladacycles are included. Displacement of the resolving agent by reaction with 1,2-bis(diphenylphosphino)ethane gave enantiopure 2-(2-pyridyl)-Quinazolinap and 2-(2-pyrazinyl)-Quinazolinap, new atropisomeric phosphinamine ligands for asymmetric catalysis. These ligands were applied in the palladium-catalysed allylic substitution of 1,3-diphenylprop-2-enyl acetate resulting in moderate conversions and enantioselectivities of up to 81%.     

Synthesis，Crystal Structure and Infrared Spectrum of Lanthanum Dinuclear Coordination Compound with Alanine：〔La_2（ala）_4（H_2O）_8〕·（ClO_4）_6

Ｓｙｎｔｈｅｓｉｓ，ＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅａｎｄＩｎｆｒａｒｅｄＳｐｅｃｔｒｕｍｏｆＬａｎｔｈａｎｕｍＤｉｎｕｃｌｅａｒＣｏｏｒｄｉｎａｔｉｏｎＣｏｍｐｏｕｎｄｗｉｔｈＡｌａｎｉｎｅ：〔Ｌａ_２（ａｌａ）_４（Ｈ_２Ｏ）_８〕·（ＣｌＯ_４）_６...     

Ca-for-Sr substitution in the thermoelectric [(Sr,Ca)2(O,OH)2]q[CoO2] misfit-layered cobalt-oxide system

Calcium-for-strontium substituted samples of the misfit-layered cobalt-oxide system, [(Sr_1−xCa_x)₂(O,OH)₂]_q[CoO₂], were successfully synthesized up to x=0.2 with a sample-encapsulation technique originally developed for the x=0 end phase. While the x=0 sample has a commensurate match between the two layer blocks (i.e. q=0.5), isovalent Ca-for-Sr substitution induces lattice misfit (i.e. q>0.5). At the same time the Seebeck coefficient gets increased, but the increase in resistivity results in suppressing the thermoelectric power factor. The magnetic anomaly in the x=0 sample gets released upon the Ca substitution for the x=0.2 sample to exhibit an almost Curie-Weiss behavior. It is concluded that with increasing x in [(Sr_1−xCa_x)₂(O,OH)₂]_q[CoO₂] the properties smoothly evolve towards those previously reported for the x=1.0 end member, [Ca_1.7O_2.1H_2.4]_0.58[CoO₂].     

(N,N) vs. (N,S) chelation of palladium in asymmetric allylic substitution using bis(thiazoline) ligands: A theoretical and experimental study

New thiazoline-containing ligands including non-symmetric bis(thiazolines) and oxazoline-thiazolines were synthesized and then compared to C₂-symmetric bis(thiazolines) in the palladium-catalyzed allylic substitution. The experimental results obtained in this study support the hypothesis of a competition between the (N,N) and the (N,S) palladium chelation, when sterically hindered bis(thiazolines) are used as ligands. A quantum chemical study performed on the Pd-complexes derived from three selected ligands, two C₂-symmetric bis(thiazolines) and one oxazoline-thiazoline, also supports this hypothesis.     

ESI／MS of N-（O, O-Diisopropyl） Phosphoryl Aromatic Amino Acids and their Stability Investigation Using HPLC／UV／ESI／MS

The full scan ESI/MS and ESI/MS^2 of N-(O, O-diisopropyl) phosphoryl aromatic amino acids (DIPPAAAs), N-(O, O-diisopropyl) phosphoryl phenylalanine, N-(O, O-diisopropyl)phosphoryl tryptophan and N-(O, O-diisopropyl) phosphoryl tyrosine, were obtained. The specific ions for them were found. Their stability in the LC mobile phase was investigated using developed HPLC/UV/ESI/MS and the results demonstrated that the DIPPAAAs were stable in the mobile phase (5 mmol/L NH4Ac-MeCN (80:20,v/v, pH7.5) within 48 h.