1-Phenyl-6,7-disubstituted-aminopropyl)-1,2,3,4-tetrahydroisoquinolines as possible antituberculer agents

The Condensation of 3,4-disubstituted phenylethylamine and benzaldehyde furnished l-phenyl-6,7-disubstituted-1,2,3,4-tetrahydroisoquinolines l. which on reaction with 1,3-dibromopropane gave l-phenyl-6,7-disubstituted-2-(3-bromoprophyl)-1,2,3,4-tetrahydroisoquinolines 2. The reaction of 2 with different secondary amines resulted in the synthesis of 3. The compounds 3 were screened for their in vitro antituberculer activity against Mycobacterium smegmatis, and some of them have been found to be total inhibitors of M. Smegmatis     

NOVEL UNSYMMETRICAL N,N-BIS(METHYLENE)BISPHOSPHONIC ACIDS OF α,ω-DIAMINES. PREPARATION AND CHARACTERIZATION OF [[(2-AMINOETHYL)IMINO]BIS(METHYLENE)]BISPHOSPHONIC ACID AND [[(6-AMINOHEXYL)IMINO]BIS(METHYLENE)]BISPHOSPHONIC ACID

Abstract

Reaction of ethylenediamine with phosphorous acid and formaldehyde in molar ratio 1:2:2 gives [[(2-aminoethyl)imino]bis(methylene)]bisphosphonic acid (2a) as the major product. Similarly, reaction of hexamethylenediamine with phosphorous acid and formaldehyde in molar ratio 1:2:2 yields [[(6-aminohexyl)imino]bis(methylene)]bisphosphonic acid (2b) which is isolated either as [[(6-carbobenzoxyaminohexyl)imino]bis](methylene)]bisphosphonic acid (3b) or as [[6-(N-benzoylamino)hexyl)imino]bis(methylene)]bisphosphonic acid (4b). Removal of the carbobenzoxy group with HBr from 3b or the benzoyl group with HCl from 4b gives pure [[(6-aminohexyl)imino]bis(methylene)]bisphosphonic acid (2b). All compounds were characterized by ¹³C NMR, ³¹P NMR and elemental analysis.     

EPR Studies of Oxo-Molybdenum(V) Complexes with Sulfur Donor Ligands: Implications for the Molybdenum Center of Sulfite Oxidase

A series of six-coordinate compounds containing a chelating dithiolate coordinated to the [LMo(V)O](2+) unit (L = hydrotris(3,5-dimethyl-1-pyrazolyl)borate) have been characterized by EPR spectroscopy as models for the molybdenum centers of pterin-containing molybdenum enzymes. The structure of LMoO(bdt) (1) (bdt = 1,2-benzenedithiolate) has been determined by X-ray crystallography; the space group is P2(1)/n with a = 10.727(1) ?, b = 14.673(2) ?, c = 15.887(2) ?, beta = 100.317(4) degrees and Z = 4. Compound 1 exhibits distorted octahedral stereochemistry; the terminal oxo group and the sulfur atoms are mutually cis to one another. The Mo=O distance is 1.678(4) ?, and the average Mo-S distance is 2.373(2) ?. The EPR parameters for 1, determined from simulation of the frozen-solution spectrum, are g(1) = 2.004, g(2) = 1.972, g(3) = 1.934 and A(1)((95,97)Mo) = 50.0 x 10(-)(4), A(2) = 11.4 x 10(-)(4), A(3) = 49.7 x 10(-)(4) cm(-)(1). The EPR parameters for several LMo(V)O{S(CH(2))(x)()S} compounds (x = 2-4) with saturated chelate skeletons are similar to those of 1, indicating that it is the coordinated S atoms and not unsaturation of the chelate skeleton that gives rise to the large g values for 1. The presence of g components larger than the free-electron value is ascribed to low-energy charge transfer transitions from the filled sulfur pi orbitals to half-filled Mo d orbitals. The EPR spectrum of [LMo(V)O{S(2)P(OEt)(2)}](+) shows an unusually large isotropic (31)P hyperfine splitting of 66.1 x 10(-)(4) cm(-)(1) from the noncoordinated phosphorus atom. The frozen-solution EPR spectra of the low-pH and high-pH forms of sulfite oxidase have been reinvestigated in D(2)O and the anisotropic g and A((95,97)Mo) parameters determined by simulation of the spectrum arising from the naturally abundant Mo isotopes (75% I = 0, 25% I = (5)/(2)). The EPR parameters for the low-pH form are g(1) = 2.007, g(2) = 1.974, g(3) = 1.968 and A(1) = 56.7 x 10(-)(4), A(2) = 25.0 x 10(-)(4), A(3) = 16.7 x 10(-)(4) cm(-)(1). The EPR parameters for the high-pH form are g(1) = 1.990, g(2) = 1.966, g(3) = 1.954 and A(1) = 54.4 x 10(-)(4), A(2) = 21.0 x 10(-)(4), A(3) = 11.3 x 10(-)(4) cm(-)(1). These are the first determinations of the complete A((95,97)Mo) hyperfine components for an enzyme that possesses an [Mo(VI)O(2)](2+) core in its fully oxidized state.     

Phosphonomethylation of 2-aminoethanethiol and thiazolidine. An unexpected product

Phosphonomethylation of 2-aminoethanethiol and thiazolidine gives the unexpected dimethylene diphosphonic acid 6.     

Size dependent structural and magnetic behaviour of CaFe2O4

CaFe₂O₄ nanocrystalline powders were synthesized through sol–gel treatment in which the stoichiometric mixing of various nitrates involving calcium and iron in presence of citric acid was performed. Subsequently, the as prepared sample was annealed at various temperatures in order to obtain the fine distribution of size including the bulk counterpart. The samples were then characterized using powder X-ray diffraction followed by ⁵⁷Fe Mössbauer spectroscopy, SQUID as well as vibrating sample magnetometry. The results of spectroanalyses revealed that the samples were formed in single phase cubic spinel structure and exhibits room temperature superparamagnetism, except the bulk one, which crystallizes in characteristic orthorhombic structure of CaFe₂O₄ and displays trivial coercivity and remanent magnetization at room temperature.     

Theranostic Iron@Gold Core–Shell Nanoparticles for Simultaneous Hyperthermia‐Chemotherapy upon Photo‐Stimulation

The challenges of nanoparticles, such as size‐dependent toxicity, nonbiocompatibility, or inability to undergo functionalization for drug conjugation, limit their biomedical application in more than one domain. Oval‐shaped iron@gold core–shell (oFe@Au) magnetic nanoparticles are engineered and their applications in magnetic resonance imaging (MRI), optical coherence tomography (OCT), and controlled drug release, are explored via photo stimulation‐generated hyperthermia. The oFe@Au nanoparticles have a size of 42.57 ± 5.99 nm and consist of 10.76 and 89.24 atomic % of Fe and Au, respectively. Upon photo‐stimulation for 10 and 15 minutes, the levels of cancer cell death induced by methotrexate‐conjugated oFe@Au nanoparticles are sixfold and fourfold higher, respectively, than oFe@Au nanoparticles alone. MRI and OCT confirm the application of these nanoparticles as a contrast agent. Finally, results of in vivo experiments reveal that the temperature is elevated by 13.2 °C, when oFe@Au nanoparticles are irradiated with a 167 mW cm^?2 808 nm laser, which results in a significant reduction in tumor volume and scab formation after 7 days, followed by complete disappearance after 14 days. The ability of these nanoparticles to generate heat upon photo‐stimulation also opens new doors for studying hyperthermia‐mediated controlled drug release for cancer therapy. Applications include biomedical engineering, cancer therapy, and theranostics fields.     

A modified method for the determination of uranium in Nb/Ta minerals by LED fluorimetry

A modified LED fluorimetry determination of uranium in Nb/Ta minerals has been developed. The mineral is brought into solution by fusion with mixed phosphate flux (NaH₂PO₄, H₂O and Na₂HPO₄). Iron quenches uranium fluorescence when it is present above the ratio of (iron to uranium) 100. Uranium is separated in ethyl acetate by solvent extraction and then stripped back into pyrophosphate buffer (pH ~ 7) prior to its LED fluorimetry determination. This modified method has been applied for the determination of uranium in synthetic mixtures and Nb/Ta minerals including Certified Reference Materials (X1807) with high degree of accuracy and precision.

     

Equivalent Gaussian measure whose R-N derivative is the exponential of a diagonal form

A simple necessary and sufficient condition, on a trace-class kernel K, is given in order to demonstrate the existence of a measurable (relative to the completed product σ-algebra) Gaussian process with covariance K. Using this result, sufficient conditions are given on the means and the covariances (relative to two equivalent (~) Gaussian measures P and P_λ) of a process X so that the Radon-Nikodým (R-N) derivative $\text{dp}{}_{\mathrm{\lambda }}\text{dP}$ is the exponential of the diagonal form in X. Analogues of the last two results in the setup of Hilbert space are also proved.