Formulation and characterization of a biocompatible microemulsion composed of mixed surfactants: lecithin and Triton X-100

We report on the formation and characterization of a biocompatible microemulsion (ME) system composed of lecithin (L), Triton X-100 (T) as the surfactant(s), butyl lactate (BL) as the cosurfactant, and isopropyl myristate (IPM) as the oil phase and water. Detailed phase construction reveals that mixing of surfactants (L and T) produces larger single-phase ME region compared to L. In the mixed surfactant systems, a three-phase body appears which is otherwise not obtained in the single surfactant counterparts signifying the synergistic solubilization behaviour upon mixing. The maximum solubilization capacity decreases as the content of T increases in the mixture. Viscosity, conductance and adiabatic compressibility measurements of the single-phase ME systems at a constant amphiphile concentration (80 % w/w) show a linear trend with increasing water content revealing a droplet-type structure of all the studied formulations. FTIR studies in the water-in-oil (w/o) region identify the presence of three distinct types of water molecules in these systems and their relative content changes with the interfacial composition as well as the total water content in the system. Our study offers a biocompatible mixed ME system in which the physical properties do not differ much from those of the lecithin-based systems with the additional advantage of having higher solubilization capacity, low pH dependency and low viscosity, which renders its potential to be used for specific pharmaceutical applications.     

Structural and magnetic properties of a syn-anti carboxylate bridged one-dimensional copper(II) complex with ferromagnetic exchange interaction

The compound [Cu(phen)(O₂CCF₃)₂]_n (phen = 1,10-phenanthroline) has been synthesized and its crystal structure determined. It crystallizes in monoclinic space group C2/c, with a = 19.229(7), b = 11.281(5), c = 7.621(2) Å, = 104.305(12)°, and Z = 4. The crystal structure is polymeric, being built from infinite zigzag chains of trifluoroacetate bridged copper(II), with the phenanthroline ligands being stacked between the chains. The variable-temperature (13–300 K) magnetic susceptibility and ESR data are reported and a weak ferromagnetic exchange interaction is observed with the exchange parameter estimated as J = 2.9 cm^–1.     

One pot three-component synthesis of 5-substituted 1H-tetrazole from aldehyde

A versatile, robust and efficient strategy for the synthesis of vast range of highly functionalized 5-substituted 1H-tetrazole derivatives by using one pot three-component synthesis from various aldehydes, hydroxylamine hydrochloride and sodium azide in presence of a catalytic amount of ceric ammonium sulphate, a non toxic, easily available, inexpensive, unexplored and reusable catalyst is reported. This one-pot synthesis has several advantages such as mild reaction conditions, shorter reaction time, low catalyst loading, good to moderate yields and functional group tolerance making this methodology practically feasible. The synthesized compounds were characterized by ¹H NMR, ¹³C NMR and HRMS.     

Novel glitazones as PPARγ agonists: molecular design,synthesis, glucose uptake activity and 3D QSAR studies

Background

An alarming requirement for finding newer antidiabetic glitazones as agonists to PPARγ are on its utmost need from past few years as the side effects associated with the available drug therapy is dreadful. In this context, herein, we have made an attempt to develop some novel glitazones as PPARγ agonists, by rational and computer aided drug design approach by implementing the principles of bioisosterism. The designed glitazones are scored for similarity with the developed 3D pharmacophore model and subjected for docking studies against PPARγ proteins. Synthesized by adopting appropriate synthetic methodology and evaluated for in vitro cytotoxicity and glucose uptake assay. Illustrations about the molecular design of glitazones, synthesis, analysis, glucose uptake activity and SAR via 3D QSAR studies are reported.

Results

The computationally designed and synthesized ligands such as 2-(4-((substituted phenylimino)methyl)phenoxy)acetic acid derivatives were analysed by IR, ¹H-NMR, ¹³C-NMR and MS-spectral techniques. The synthesized compounds were evaluated for their in vitro cytotoxicity and glucose uptake assay on 3T3-L1 and L6 cells. Further the activity data was used to develop 3D QSAR model to establish structure activity relationships for glucose uptake activity via CoMSIA studies.

Conclusion

The results of pharmacophore, molecular docking study and in vitro evaluation of synthesized compounds were found to be in good correlation. Specifically, CPD03, 07, 08, 18, 19, 21 and 24 are the candidate glitazones exhibited significant glucose uptake activity. 3D-QSAR model revealed the scope for possible further modifications as part of optimisation to find potent anti-diabetic agents.

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Synthesis and structural characterization of a (N,N′-bis[2(S)-pyrrolidylmethyl]-propane-1,3-diamine) nickel (II) complex

The nickel(II) complex [Ni(C₄H₃NCH=N–(CH₂)₃–N=CHC₄H₃N)], (1) containing the symmetrical N₄ tetradentate Schiff base ligand, which is the 2:1 condensation product of pyrrole-2-carboxaldehyde and 1,3-diaminopropane respectively, was prepared. Structural investigation shows that it is monomeric, having space group P2₁/c, a = 7.989(7), b = 17.406(14), c = 9.193(5) Å, = 90, = 100.39(6), = 90, and Z = 4. The coordination geometry around the nickel atom is slightly distorted square planar and the conformation of the six-membered ring containing the metal,azomethine nitrogens and three carbon atoms of the connecting 1,3-diaminopropane is a symmetric boat.     

Crystal structure of tylophorine methiodide monohydrate,C25H30NO 4 + I−·H2O

The crystal structure of tylophorine (Chemical name 2,3,6,7 tetramethoxy phenanthro [9,10:6, 7] indolizidine. Contribution No. 0871.) methiodide monohydrate has been determined. C₂₅H₃₀NO ₄ ⁺ I^–·H₂0, triclinic, P,a=8.831(1)Å, b=10.842(2),c=13.902(2), =105.0(1)^o, =104.7(1), =97.3(1),V=1210.22ų, Z=2,D _x =1.428 g./cm^–3, (CuK)=1.54184Å, (CUK)=107.2 cm^–1, F(000)=544,T=295^oK,R=0.038,Rw=0.046, for 2331 observed reflections withI2(I). Apart from van der Waals forces, the structure is stabilized by two hydrogen bonds of the type Ow(H) ... O and Ow(H) ... I^– involving the water molecule as the donor and atom O4 of the methoxy group and I^– as acceptors.     

Physicochemical studies on the interaction of gelatin with cationic surfactants alkyltrimethylammonium Bromides (ATABs) with special focus on the behavior of the hexadecyl homologue

The interaction of a denatured interfacially active protein, gelatin (G) (at pH 9, above its isoelectric pH 4.84, and ionic strength mu=0.005), with a cationic amphiphile, hexadecyl (or cetyl) trimethylammonium bromide, CTAB, has been elaborately studied using a variety of techniques. Two types of protein-surfactant complexes at a concentration below the normal critical micellar concentration (cmc) were formed in solution. The first, G-CTAB (monomer) combined complex (GS(n)(I)) adsorbed at the air/solution interface, followed by its gradual transformation to the poor interfacially active second G-CTAB (aggregate) complex (GS(m)(B)) at a critical aggregation concentration (cac) of the interacting oppositely charged surfactant. In the higher concentration range, upon completion of GS(m)(B) formation, coacervation (association of GS(m)(B)) led to add turbidity. With increasing addition of CTAB, the coacervates became disintegrated and ultimately remained dissolved in the free micellar solution of CTAB. The above features were studied using the techniques of tensiometry, conductometry, turbidimetry, fluorimetry, and microcalorimetry. The interaction features were prominent at [G] >or= 0.05 g %, and several of these were either marginal or absent at [G]<0.05 g %. The denatured protein was found to form viscous as well as gel-forming consistencies at higher [G] and at lower temperature. A temperature variation study on the interaction of G with CTAB has revealed that enhanced interaction takes place at higher temperature. The effect of [G] on its interaction with cationic surfactants of varying chain length in the alkyltrimethylammonium bromide (ATAB) series has been also studied; a similar interactional profile as that of CTAB has been exhibited by octadecyltrimethylammonium bromide; however, the lower homologues (dodecyl- and tetradecyl-) of ATAB have offered different profiles. It has been found that the ATABs with higher alkyl chain lengths were more interactive with negatively charged G than their lower homologues. Quantification of the results in terms of different transition points, counterion binding of the protein-bound surfactant aggregates and free micelles, the enthalpy of binding interactions and energetics of ATAB micellization, and so forth have been studied. The results have been rationalized in terms of an interaction model.     

Halogen-containing tetrametallic aluminium alkoxides

New halogen-containing tetrametallic aluminium alkoxides of formula [Al{(mu-OEt)2AlMeCl}3] ( 2-cis; 2-trans), and [Al{(mu-OEt)2AlBr2}3] ( 4), have been synthesized by combining Al(OEt)3 and Me2AlCl (for 2) or EtAlBr2 (for 4). They were fully characterized by (1H, 27Al) NMR, IR, mp, elemental analysis, and single-crystal X-ray diffractometry. The chloride analogue of 4, [Al{(mu-OEt)2AlCl2}3] ( 3), prepared previously using a different route, was also prepared here by combining Al(OEt)3 and EtAlCl2.