Thermal characterization and compatibility studies of itraconazole and excipients for development of solid lipid nanoparticles

The current study was performed to investigate possible interactions between triazole antifungal drug itraconazole (ITR) with selected excipients commonly used for development of solid lipid nanoparticles. The excipients included common lipids (glyceryl behenate (Compritol 888 ATO?), glyceryl monostearate, stearic acid, and cetyl palmitate), charge inducers (dicetyl phosphate and stearlyamine), and surfactants (sodium cholate and sodium deoxycholate). Differential scanning calorimetry, isothermal stress testing, Fourier transform infrared spectral analysis, optical microcopy, and X-ray powder diffraction analysis were performed for assessing the compatibility between the drug and the excipients. Results of the study suggest that the stearic acid exhibited drug–excipient interactions, whereas all other excipients used in the study were found to be compatible with ITR.     

One‐Pot Three‐Component Domino Reaction for the Synthesis of Novel Spiro Indolinyl Isoxazolo[2,3‐c][1,3,5]Thiadiazepinones Catalyzed by PTSA

The synthesis of novel spiro indolinyl isoxazolo[2,3‐c] [1,3,5]thiadiazepinones has been achieved by using one‐pot three‐component domino reaction from 3‐amino‐5‐methylisoxazole, substituted isatins, and mercapto acetic acid by employing p‐toluene sulfonic acid as Lewis acid catalyst. The salient features of the present method are mild reaction conditions, cost effective, environmentally benign, high yields of products and operational simplicity.     

Effect on selective adsorption of ethane and ethylene of the polyoxometalates impregnation in the metal-organic framework MIL-101

Impregnation of ionic nanostructured units in the pores of metal-organic frameworks (MOFs) is one approach to modify their host–guest interactions. Although, the effect of this approach is well investigated in catalysis, drug delivery, and bio imaging, still little is known about its impact on the selective adsorption properties of MOFs. Here we report the impregnation of two different polyoxometalate (POM) nanoclusters (PW₁₁ and SiW₁₁) into chromium terephthalate-based MOF, MIL-101(Cr), to investigate the post-impregnation changes in selective adsorption behavior, which are observed in terms of an important paraffin–olefin separation, using ethane and ethylene, at high pressure. The PW₁₁ and SiW₁₁ POMs bring π-accepting tendency and highly electronegative oxygen atoms on their surface to MIL-101 structure that selectively increases the affinity of material for ethylene, which is confirmed from isosteric heats of adsorption and selectivity calculation. Impregnated samples retain about 74–81 % of working adsorption capacity, after regeneration by decreasing the pressure. This study shows that anionic metal-oxide nanoclusters (POMs) may be used to change the selectivity of MOFs for olefin molecules.     

Curing Studies of New Polyimide Model Compounds with Molecular Weights of About 1000 g/MOL

Abstract

Two new polyimide model compounds with molecular weights of ～1000 g/mol have been synthesized. While the amino terminated compound, 4,4′-bis-N-[N′-(4-aminophenoxy-4′-phenyl)-pyromellitimido]diphenylether,O(PO)₂, undergoes a branching or crosslinking side reaction, the corresponding anhydride terminated oligomer N,N′-bis[4(N-(3′,4′-bishydroxycarbonyl)phthal-imido)phenoxy-4′-phenyl]pyromellitimide dianhydride, P(OP)2, loses its anhydride functionality completely upon thermal treatment. In the case of O(PO)₂, the formed C=N species can be detected with Raman spectroscopy rather than FT-IR spectroscopy because of its low molecular absorptivity in the infrared region. The formation of imine bonds caused by the attack of terminal amino groups on the imide carbonyl group is evident by the appearance of peaks at about 1665 cm-¹ in the Raman spectra. The same behavior can be observed in bulky polyimides blended with an increasing amount of O(PO)2 upon curing.     

Evaluation of a Renewable Resource-based Carbon-Iron Oxide Nanocomposite for Removal of Arsenic from Contaminated Water

High arsenic concentration in groundwater is found in many countries, including Bangladesh, India, Vietnam, Thailand and United States. In these countries, the arsenic concentrations have reached dangerous levels for human consumption, especially where the main source of drinking water is from groundwater. Many techniques have been developed for arsenic removal, one being the use of iron oxide or magnetite nanoparticles for heavy metal removal. In this study, a novel tannin-based carbon-iron oxide composite has been developed by us for arsenic removal and results show that a concentration of 100 ppb As in water could be brought down to <10 ppb with the maximum capacity of the arsenic removal calculated to be 1.5 mg As/g Fe in the nanocomposite. The characterization of the nanocomposite and the advantages of using this renewable resource-based nanocomposite are also discussed.     

A simple and efficient route for the synthesis of novel isoxazolyl-2-azaspiro[4.5]deca-1,6,9-trien-8-ones

A new, simple and efficient method for the synthesis of novel isoxazolyl-2-azaspiro[4.5]deca-1,6,9-trien-8-ones is described by the intramolecular ipso-cyclization of 5-[(E)-2-(4-methoxyphenyl)-1-ethenyl]-3-methyl-4-nitroisoxazole with nitriles. In presence of 5-[(E)-2-(4-methoxyphenyl)-1-ethenyl]-3-methyl-4-nitroisoxazole, a variety of nitriles underwent the intramolecular ipso-cyclization smoothly, affording title compounds in moderate to good yields.     

Hydrazone comprising compounds as promising anti-infective agents: chemistry and structure-property relationship

Despite the adverse effects of microbial hazards on public health, major pharmaceutical firms have left the field of anti-infective development and a dramatic reduction in the number of researcher's intricated in the quest for new specific anti-infective leads. In the non-existence of an efficient forum for antibiotics development and over usage in human beings and animals, bacteria have demoralized this potential by gradually establishing the resistance toward most of the antibiotics used. Thus, the production of novel and successful anti-infective drugs is urgently required to combat this resistance. Hydrazones and hydrazides have mounted as a key-skeleton for the development of active drugs, due to their important biological and pharmacological profiles. Hydrazones are being manufactured as medicines by various investigators to fight against the ailments with maximal effects and minimal toxicity. This paper focuses on the outline of the literature results of recent years, incorporating the work on the anti-infective profile of hydrazone analogues. This review may also act as an excellent basis for the development of new derivatives of hydrazone as potential anti-infective mediators.     

Nanomotors Sense Local Physicochemical Heterogeneities in Tumor Microenvironments**

The invasion of cancer is brought about by continuous interaction of malignant cells with their surrounding tissue microenvironment. Investigating the remodeling of local extracellular matrix (ECM) by invading cells can thus provide fundamental insights into the dynamics of cancer progression. In this paper, we use an active untethered nanomechanical tool, realized as magnetically driven nanomotors, to locally probe a 3D tissue culture environment. We observed that nanomotors preferentially adhere to the cancer-proximal ECM and magnitude of the adhesive force increased with cell lines of higher metastatic ability. We experimentally confirmed that sialic acid linkage specific to cancer-secreted ECM makes it differently charged, which causes this adhesion. In an assay consisting of both cancerous and non-cancerous epithelia, that mimics the in vivo histopathological milieu of a malignant breast tumor, we find that nanomotors preferentially decorate the region around the cancer cells.     

Electronic structure of a superconducting Bi2212 crystal by angle resolved ultra violet photoemission

The electronic structure of a high quality superconducting Bi₂Sr₂CaCu₂O_8+δ (Bi2212) single crystal is studied by angle resolved ultra violet photoemission (ARUPS) using He I (21.2 eV). Our results appear to show two bands crossing the Fermi level in ΓX direction of the Brillouin zone as reported by Takahashiet al. The bands at higher binding energy do not show any appreciable dispersion. The nature of the states near the Fermi level is discussed and the observed band structure is compared with the band structure calculations.     

Composition and antimicrobial activity of the essential oil of Heracleum thomsonii (Clarke) from the cold desert of the western Himalayas

Volatile oil composition of hydro-distilled (HD) and supercritical carbon dioxide (SC-CO(2)) essential oil of freshly collected aerial parts of Heracleum thomsonii (Umbeliferae) from the western Himalayas was studied by GC-FID and GC-MS. Results revealed qualitative and quantitative dissimilarity in the composition of hydro-distilled and SC-CO(2) extracted oils. Nineteen constituents, which accounted for 89.32% of total constituents in HD oil, represented by limonene (4.31%), (Z)-β-ocimene (3.69%), terpinolene (22.24%), neryl acetate (36.19%), nerol (9.51%) and p-cymene-8-ol (2.61%) were identified. In SC-CO(2) extracted oil, 24 constituents representing 89.95% of total constituents were identified. Terpinolene (5.08%), germacrene D (2.17%), neryl acetate (51.62%), nerol (9.78%), geranyl acetate (2.06%), α-bisabolol (2.48%) and 1-nonadecanol (4.96%) were the dominating constituents. In?vitro antimicrobial activity of hydro-distilled oil was conducted against microrobial strains including two Gram-positive (Staphylococcus aureus and Bacillus subtilis) and five Gram-negative (Burkholderia cepacia, Escherichia coli, Enterobacter cloacae, Klebseilla pneumoniae and Pseudomonas aeruginosa) bacteria as well as seven fungi (Candida albicans, Issatchenkia orientalis, Aspergillus flavus, Aspergillus niger, Aspergillus parasiticus, Aspergillus sydowii and Trichophyton rubrum) using broth microdilution method. The results of bioassay showed that the oil exhibited moderate to high antimicrobial activity against fungi C. albicans (MIC 625 μg?ml(-1)), A. parasiticus (MIC 312.5 μg?ml(-1)), A. sydowii (MIC 312.5 μg?ml(-1)), T. rubrum (MIC 625 μg?ml(-1)), Gram-positive bacteria B. subtilis (MIC 625?μg?ml(-1)) and Gram-negative bacteria P. aeruginosa (MIC 312.5 μg?ml(-1)).