Curcumin-sulfobutyl-ether beta cyclodextrin inclusion complex: preparation, spectral characterization, molecular modeling, and antimicrobial activity.

Urinary tract infections (UTIs) caused by Gram-negative bacteria E. coli is responsible for 80-90% of uncomplicated cases in women. The increased prevalence of antibiotic resistance has made the management of UTIs more challenging. Plant-derived compounds have long been used to treat various diseases, and constitute an alternative to antibiotic resistance. Curcumin (CUR), a naturally occurring polyphenolic phytoconstituent obtained from Curcuma longa is endowed with diverse medicinal properties. The present study aims to form a complex of CUR with Sulfobutyl ether-ß-cyclodextrin (SBEßCD) to overcome the poor solubility and bioavailability of CUR and to evaluate the antimicrobial activity of CUR-SBEßCD. Phase solubility studies and spectral characterization showed the entrapment of CUR in the SBEßCD cavity. In silico docking studies performed to investigate the complexation process of CUR with SBEßCD, revealed that the methoxy group and OH group of CUR interacted with SBEßCD. The cytotoxicity and HET-CAM assays confirmed that CUR-SBEßCD was non-irritant. The prepared complex investigated with the disc diffusion method showed antimicrobial activity with a zone of inhibition (ZOI) of 13 mm against Escherichia coli (E. coli) and 11.5 mm against Staphylococcus aureus (S. aureus) whereas CUR alone did not show any ZOI. It can be concluded that prepared CUR-SBEßCD demonstrated superior antimicrobial activity and therefore can be a promising alternative for the treatment of UTIs.Communicated by Ramaswamy H. Sarma.

Structural characterization and in vitro biomedical activities of sulfated chitosan from Sepia pharaonis.

A low molecular weight sulfated chitosan (SP-LMWSC) was isolated from the cuttlebone of Sepia pharaonis. Elemental analysis established the presence of C, H and N. The sulfation of SP-LMWSC was confirmed by the presence of characteristic peaks in FT-IR and FT-Raman spectra. The thermal properties of SP-LMWSC were studied by thermogravimetric analysis and differential scanning calorimetry. Electrolytic conductivity of SP-LMWSC was measured by cyclic voltammetry and the molecular weight was determined by MALDI-TOF/MS. The molecular structure and sulfation sites of SP-LMWSC were unambiguously confirmed using (1)H, (13)C, 2D COSY and 2D HSQC NMR spectroscopy. SP-LMWSC exhibited increased anticoagulant activity in avian blood by delaying coagulation parameters and displayed cytostatic activity by inhibiting the migration of avian leucocytes. SP-LMWSC demonstrated avian antiviral activity by binding to Newcastle disease virus receptors at a low titer value of 1/64. These findings suggested that SP-LMWSC isolated from an industrial discard holds immense potentials as carbohydrate based pharmaceuticals in future.

Reversible Mechanical Interlocking of D-Shaped Molecular Karabiners bearing Coordination-Bond Loaded Gates: Route to Self-Assembled [2]Catenanes.

Complexation of 1,4-phenylenebis(methylene) diisonicotinate, L1, with cis-protected Pd(II) components, [Pd(L')(NO3 )2 ], in an equimolar ratio yielded binuclear complexes, 1 a-d of [Pd2 (L')2 (L1)2 ](NO3 )4 formulation where L' stands for ethylenediamine (en), tetramethylethylenediamine (tmeda), 2,2'-bipyridine (bpy), and phenanthroline (phen). The combination of 4,4'-bipyridine, L2, with the cis-protected Pd(II) units is known to yield molecular squares, 2 a-d. However, 2 b-d coexist with the corresponding molecular triangles, 3 b-d. Combination of an equivalent each of the ligands L1 and L2 with two equivalents of cis-protected Pd(II) components in DMSO resulted in the D-shaped heteroligated complexes [Pd2 (L')2 (L1)(L2)](NO3 )4 , 4 a-d. Two units of the D-shaped complexes interlock, in a concentration dependent fashion, to form the corresponding [2]catenanes [Pd2 (L')2 (L1)(L2)]2 (NO3 )8 , 5 a-d under aqueous conditions. Crystal structures of the macrocycle [Pd2 (tmeda)2 (L1)(L2)](PF6 )4 , 4 b'', and the catenane [Pd2 (bpy)2 (L1)(L2)]2 (NO3 )8 , 5 c, provide unequivocal support for the proposed molecular architectures.

High resolution 1H NMR structural studies of sucrose octaacetate in supercritical carbon dioxide.

High pressure (HP), high resolution (HR), proton nuclear magnetic resonance (1H NMR) spectroscopy has been utilized for the first time to investigate the solution structure of a carbohydrate based system, sucrose octaacetate (SOA), in supercritical CO2. The studies indicate that the average solution state conformation of the alpha-D-Glucopyranosyl ring of SOA in scCO2 medium is consistent with the 4C1 chair form, while the beta-D-fructofuranosyl ring adopts an envelope conformation. The investigations also suggest that scCO2 is a promising medium to study the solution structure and conformation of acetylated sugar systems. Spectral manifestations of a specific interaction between the acetate methyl protons and CO2 molecules are also presented.

Application of continuous-wave EPR spectral-spatial image reconstruction techniques for in vivo oxymetry: comparison of projection reconstruction and constant-time modalities.

In this study we report the application of continuous-wave (CW) electron paramagnetic resonance (EPR) constant-time spectral spatial imaging (CTSSI) for in vivo oxymetry. 2D and 3D SSI studies of a phantom and live mice were carried out using projection reconstruction (PR) and constant-time (CT) modalities using a CW-EPR spectrometer/imager operating at 300 MHz frequency. Distortion of line shape, which is inherent in the PR method, was minimized by the CTSSI modality. It was also found that CTSSI offers improved noise reduction, restores a smoother line shape, and gives high convergence of estimated values. Spatial resolution was also improved by CTSSI, although fundamental spectral line-width broadening was observed. Although additional corrections are required for accurate estimations of spectral line width, CTSSI was able to demonstrate distinct differences in oxygen tension between a tumor and the normal legs of a C3H mouse. The PR method, on the other hand, was unable to make such a distinction unequivocally with the triarylmethyl spin probes. CTSSI promises to be a more suitable method for quantitative in vivo oxymetric studies using radiofrequency EPR imaging (EPRI).