Bifunctional chelators for copper radiopharmaceuticals: the synthesis of [Cu(ATSM)-amino acid] and [Cu(ATSM)-octreotide] conjugates

Two new bifunctional chelators that are derivatives of the bis(thiosemicarbazone) ATSMH(2) proligand have been prepared, one with two phenyl carboxylate substituents on the exocyclic nitrogens (L(1)H(2)) and one with a single phenyl carboxylate (L(2)H(2)). The new ligands have been characterised by NMR spectroscopy, mass spectrometry and in the case of L(1)H(2) by X-ray crystallography. The copper, nickel and zinc complexes of the new ligands have been synthesised and characterised. Electrochemical measurements show that the copper(II) complexes undergo a reversible reduction attributable to a Cu(II)/Cu(I) process. The new proligands have been tethered to the N-alpha-Boc-protected amino acids lysine and ornithine using solution and solid phase methods. The new amino acid conjugates form copper complexes and the complexes have been characterised by mass spectrometry and electronic spectroscopy. The bifunctional chelator L(2)H(2) has been conjugated to the tumour targeting peptide octreotide and the new ATSMH(2)-octreotide conjugate and its copper complex have been characterized by mass spectrometry. These new systems have the potential to be used for new targeted copper radiopharmaceuticals for imaging and therapy.     

A new three-stages six-step finite difference pair with optimal phase properties for second order initial and/or boundary value problems with periodical and/or oscillating solutions

A new symmetric six-step method with improved phase properties is introduced, for the first time in the literature, in this paper. The proposed method: (1) is a symmetric nonlinear six-step method, (2) is of three-stages, (3) is of twelfth algebraic order, (4) has vanished the phase-lag and (5) has vanished the derivatives of the phase-lag up to order five. For the new symmetric six-step method we present a detailed theoretical, numerical and computational analysis which consists of: (a) the development of the new three-stages symmetric six-step method, (b) the computation of the local truncation error of the new scheme, (c) the comparative error analysis of the new algorithm with other schemes of the same family: (i) the classical algorithm of the family (i.e. the method with constant coefficients), (ii) the recently proposed method of the same family with vanished phase-lag and its first derivative, (iii) the recently proposed method of the same family with vanished phase-lag and its first and second derivatives, (iv) the recently proposed method of the same family with vanished phase-lag and its first, second and third derivatives and finally (v) the recently proposed method of the same family with vanished phase-lag and its first, second, third and fourth derivatives, (d) the stability and the interval of periodicity analysis for the new developed method and finally (e) the study of the accuracy and computational effectiveness of the new proposed method for the solution of the Schrödinger equation. The theoretical, numerical and computational analysis of the new obtained three-stages symmetric six-step method show the efficiency of the new algorithm compared with other known or recently developed schemes of the literature.     

Improved CNDO/S calculation of electronic spectra of organic compounds. I. New CNDO/S calculation by using an improved method of one-center electron repulsion integral

The NM-gamma CNDO/S program previously developed by our group was modified by the introduction of a new one-center electron repulsion integral gamma(AA)(new) approximation, namely, the gamma(AA)(new)-CNDO/S method. The value of this gamma(AA)(new) was evaluated according to the product values of the coefficient C with the gamma(AA) value proposed in our previous paper. This method using a new gamma(AA) was also found to improve the two-center electron repulsion integral gamma(AB) value with respect to the chemical softness proposed by Nishimoto and co-workers, together with the difference between HOMO and LUMO orbital energies. The results calculated by the present improved gamma(AA)(new)-CNDO/S method demonstrated that not only the calculated absorption maxima wavelengths and ionization potentials, but also the order and the assignment of orbitals coincided very well with those based on the results of experiments investigating a variety of polyenes, cyanynes, and polycyclic aromatic hydrocarbons.     

Synthesis and reactivity of new Ni, Pd, and Pt 2,6-bis(di-tert-butylphosphinito)pyridine pincer complexes

Synthesis and characterization of new (PONOP) [2,6-bis(di-tert-butylphosphinito)pyridine] metal (Ni, Pd, Pt) complexes are reported. Surprisingly, these compounds [(PONOP)MCl]Cl in the presence of 1 equiv of superhydride (LiEt(3)BH) formed a new class of complexes (H-PONOP)MCl, in which the pyridine ring in the PONOP ligand lost its aromaticity as a result of hydride attack at the para position of the ring. The new Ni-H compound [(H-PONOP)NiH] was synthesized by reacting (H-PONOP)NiCl with 1 equiv of superhydride. Analogous Pd and Pt compounds were prepared. Reactivity of these new pincer complexes toward MeLi and PhLi also has been studied. These Ni complexes catalyzed the hydrosilylation of aldehyde. In some cases characterization of new (PONOP)M complexes was difficult because of high instability due to degradation of the P-O bond.     

Visualization of DNA sequences based on 3DD-Curves

In this paper we (1) introduce a new 3D graphical representation of DNA sequences; (2) visualize DNA sequences based on 3DD-Curves; (3) provide a new invariant of DNA sequences based on our 3DD-Curve. All this represents a new development of graphical representation and numerical characterization for DNA sequences.     

Straightforward synthesis and structure of a new starting material for niobium cluster phases: [Nb6Cl(i)12(CH3OH)a4Cla2].6CH3OH

A new, fast, and straightforward synthetic route for the new cluster compound [Nb(6)Cl(i)(12)(CH(3)OH)(a)(4)Cl(a)(2)].6CH(3)OH, taking advantage of the special solubility properties of tetracyanoborate salts has been established, and the single-crystal X-ray structure of this compound, which is a promising starting material for new cluster phases, has been determined.     

A new six-step algorithm with improved properties for the numerical solution of second order initial and/or boundary value problems

A new four-stages symmetric six-step finite difference pair with improved properties is developed in this paper and for the first time in the literature. The new finite difference pair: (1) is a symmetric non-linear six-step method, (2) is of four stages, (3) is of fourteenth algebraic order, (4) has eliminated the phase-lag, (5) has eliminated the first derivative of the phase-lag. A numerical analysis of the new developed finite difference pair is presented. The analysis of the scheme consists of: (1) the production of the new four-stages symmetric six-step finite difference pair, (2) the calculation of the local truncation error of the new finite difference pair, (3) the comparative error analysis of the new method with other scheme of the same family which is the classical finite difference pair of the family (i.e. the finite difference pair with constant coefficients). (4) The stability and an interval of periodicity analysis and (5) finally, the study of the numerical and computational efficiency of the new method for the solution of the Schrödinger equation. The theoretical and numerical achievements for the new obtained four-stages symmetric six-step finite difference pair show its efficiency compared with other known or recently obtained schemes of the literature.     

CoFe2O4 magnetic nanoparticles as a peroxidase mimic mediated chemiluminescence for hydrogen peroxide and glucose

This communication presents a new peroxidase mimic of CoFe(2)O(4) nanoparticles evaluated by the luminol-based chemiluminescent (CL) reaction. This offers a new method for evaluation and screening of the nanoparticles-based enzyme mimetics.     

2-酰肼基-5-(2,4-二氯苯基)-1,3,4-噁二唑的合成及环化反应研究

二唑衍生物具有抗菌、消炎和调节植物生长等活性［１～５］．二唑硫醚衍生物也具有一定抗菌活性［６］．为筛选具有生物活性的新化合物和研究亲核取代反应的规律,我们设计和合成了新的２－酰肼基－５－（２,４－二氯苯基）－１,３,４－二唑２,研究了２在Ｋ２Ｃ...     

Steroidal glycosides from Agave utahensis

Three new spirostanol glycosides (1-3) and a new furostanol glycoside (4), together with two known spirostanol glycosides (5 and 6) were isolated from the whole plants of Agave utahensis (Agavaceae). The structures of the new compounds were determined by spectroscopic analysis and the results of hydrolytic cleavage.     

Enantioselective formal total synthesis of the antitumor macrolide bryostatin 7

A new enantioselective synthesis of Masamune's AB fragment (1) for bryostatin 7 is described. Key steps in the new route include a Meerwein-Ponndorf-Verley reduction to set the O(7) stereocenter and an alkylative union between the dithiane 6 and iodide 5 to construct the C(9)-C(10) bond. Because we have previously published a synthesis of Masamune's C-ring phenyl sulfone 2, our new route to 1 constitutes a formal total synthesis of bryostatin 7; it also corrects the previously reported spectral data for 1 in CDCl3.     

Two new alkaloids and a new polyphenolic compound from <Emphasis Type="Italic">Cotula coronopifolia</Emphasis>

Two new alkaloid derivatives of the 3-benzazocine skeleton (cotuzine A and B) and a new polyphenolic substance (3-(1,3-dihydroxyprop-2-yl)-4-hydroxyanisol) (corimen) have been isolated from the aerial part (stems, leaves) of the plant Cotula coronopifolia (L.). These three new structures were established by spectroscopic procedures (¹H, ¹³C, one- and two-dimensional NMR). The stereochemistry of the new alkaloids was established based on different NOE effects revealed on the NOESY spectrum. Mass spectrometry and IR spectroscopy were used to confirm these structures.     

New Investigation of Potential Acting on an Electron in a Molecule to Draw Molecular Faces

A new approach to calculate the potential acting on an electron in a molecule(PAEM) has been established for drawing the molecular face(MF) of a macromolecule, according to the classic point charge model and the atom-bond electronegativity equalization method(ABEEMσπ) for one electron in a molecule. We introduced a dynamic charge distribution from the view of a local electron movement in a molecule based on the new approach, and as further direct evidence, we calculated some physical quantities using the original ab initio method and the new method to verify the accuracy of the method, such as the boundary distance(BD), molecular face surface area(MFSA) and molecular reactivities indicated by the MFs for a variety of organic molecules. All the results by the new method are in agreement with the results by ab initio method.     

Preparation of new spongy adsorbent for removal of EDTA-Cu(Ⅱ) and EDTA-Ni(Ⅱ) from water

A new spongy adsorbent (PU-DTC) was prepared with a polyurethane (PU) adsorbent for removal of EDTA-Cu(Ⅱ) and EDTA-Ni(Ⅱ) from water. This new spongy adsorbent was characterized by using SEM and 13C NMR and FT-IR spectroscopy. Adsorption kinetic curve indicated that this new spongy adsorbent could quickly remove EDTA-Cu(Ⅱ) and EDTA-Ni(Ⅱ) from water, and adsorption isotherm also indicated that PU-DTC had high equilibrium adsorption capacity for EDTA-Cu(Ⅱ) and EDTA-Ni(Ⅱ).     

Cholestane glycosides from the bulbs of Galtonia candicans and their cytotoxicity

Further search for cytotoxic compounds contained in the bulbs of Galtonia candicans (Liliaceae) led to the isolation of four potent cytotoxic cholestane glycosides (1-4) based upon 3beta,16beta,17alpha-trihydroxycholest-5-en-22-one, three of which (2-4) have not been reported previously. A new cholestane bisdesmoside (5) and a new rearranged cholestane glycoside (6) were also isolated. The structural assignment of the new constituents was carried out by spectroscopic analysis and a few chemical transformations.     

Characterization, synthesis and self-aggregation of (-)-alternarlactam: a new fungal cytotoxin with cyclopentenone and isoquinolinone scaffolds

(-)-Alternarlactam [(-)-1], a new promising cytotoxin against two human cancer cell lines, was isolated from an endophyte culture and synthesized (along with (+)-1) from readily available starting materials. The absolute configuration, chirality-activity relevance and self-aggregation of (-)-1 were assigned by a combination of synthetic, spectroscopic and computational approaches. The full characterization of the new fungal cytotoxin may provide valuable information in the discovery of new antitumor agents.     

Functionalization of Alkynes by a (Salen)ruthenium(VI) Nitrido Complex

Exploring new reactivity of metal nitrides is of great interest because it can give insights to N₂ fixation chemistry and provide new methods for nitrogenation of organic substrates. In this work, reaction of a (salen)ruthenium(VI) nitrido complex with various alkynes results in the formation of novel (salen)ruthenium(III) imine complexes. Kinetic and computational studies suggest that the reactions go through an initial ruthenium(IV) aziro intermediate, followed by addition of nucleophiles to give the (salen)ruthenium(III) imine complexes. These unprecedented reactions provide a new pathway for nitrogenation of alkynes based on a metal nitride.     

Detection, characterization and identification of phenolic acids in Danshen using high-performance liquid chromatography with diode array detection and electrospray ionization mass spectrometry

By using HPLC-diode array detection-electrospray ion trap tandem mass spectrometry (HPLC-DAD-ESI-MS(n)) in negative ion mode, we have analyzed the fragmentation pathways of 11 phenolic acids which were isolated from Danshen. Then the extract of Danshen was analyzed, and a total of 42 phenolic acids, including sixteen new minor constituents, were identified or tentatively identified for the first time. A new solid-phase extraction (SPE) method, new HPLC separation method, new liquid chromatography (LC)-MS and LC-MS(n) (n=3-5) data and proposed fragmentation pathways, LC retention time for phenolic acids are reported.     

Unexpected formation of (E)-4-alkene 1,3-diketones from the three-component reaction of lithium selenolates with 1-(1-alkynyl)cyclopropyl ketones and aldehydes

A novel three-component stereoselective synthesis of (E)-4-alkene 1,3-diketones from lithium selenolates, 1-(1-alkynyl)cyclopropyl ketones, and aldehydes is reported. This reaction afforded the products in moderate to good yields with the formation of a new C-Se single bond, a new C-C double bond, and a new C-O double bond.     

Abietane lactones and iridoids from Goldfussia yunnanensis

Two new abietane diterpene lactones (1--2), three new abietane diterpene lactone glycosides (3--5) and a new iridoid glycoside (6), together with five known compounds, were isolated from the aerial parts of Goldfussia yunnanensis. The new compounds were determined to be 18-hydroxyhelioscopinolide A (1), 18-oxohelioscopinolide A (2), 18-hydroxy-3-O-beta-D-glucopyranosylhelioscopinolide A (3), 3-O-beta-D-glucopyranosylhelioscopinolide A (4), 3-O-beta-D-galactopyranosylhelioscopinolide A (5), and 6-O-trans-cinnamoyl E-harpagoside (6) on the basis of spectral data and chemical evidence.