Studies on rhizosphere microbial diversity of some commercially important medicinal plants

A preliminary study was made on four medicinal plants viz., Ocimum sanctum L., Coleus forskholii Briq, Catharanthus roseus (L.) G. Don. and Aloe vera in order to identify and enumerate the rhizosphere, non-rhizosphere and diazotrophic microorganisms in soil. The diazotrophic bacterial population studied includes Azospirillum, Azotobacter and Pseudomonas. The rhizosphere bacterial populations were 23.33 x 10(6)g(-1) in O. sanctum followed by C. roseus (20.46 x 10(6)g(-1)), A. vera (18.44 x 10(6)g(-1)) and C. forskholii (16.64 x 10(6)g(-1)). The fungi populations were 19.44 x 10(4)g(-1) in C. roseus, 18.66 x 10(4)g(-1) in O. sanctum, 16.44 x 10(4)g(-1) in A. vera and 14.22 x 10(4)g(-1) in C. forskholii. The actinomycetes population was 12.22 x 10(5)g(-1) in O. sanctum, 10.44 x 10(5)g(-1) in C. roseus, 8.44 x 10(5)g(-1) in A. vera and 6.22 x 10(5)g(-1) in C. forskholii. The diazotrophic bacterial population of Azospirillum, Azotobacter and Pseudomonas is 8.2 x 10(4)g(-1), 12 x 10(4)g(-1), 6 x 10(4)g(-1) in the rhizosphere soil. In all the four medicinal plants the microbial population is more in the rhizosphere soil, when compared to non-rhizosphere soil. These results are helpful in developing a biofertilizer consortium for these commercially grown medicinal plants.     

Antioxidant potential and indole alkaloid profile variations with water deficits along different parts of two varieties of Catharanthus roseus

The variations in antioxidant potentials and indole alkaloid content were studied in the present investigation, in two varieties (rosea and alba) of Catharanthus roseus, an important herb used in traditional as well as modern medicine, exposed to water deficit stress. The antioxidant and alkaloid profiles were estimated from root, stem, leaf, flowers and pods. The antioxidant potentials were examined in terms of non-enzymatic antioxidant molecules and activities of antioxidant enzymes. The non-enzymatic antioxidant molecules studied were ascorbic acid (AA), -tocopherol (-toc) and reduced glutathione (GSH). The estimated antioxidant enzymes were superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), peroxidase (POX) and polyphenol oxidase (PPO). The antioxidant concentrations and activities of antioxidant enzymes were high under water deficit stress in all parts of the plants. Indole alkaloid content was high in the roots of rosea variety in response to stress when compared to alba variety.     

Liquid chromatography/mass spectrometry determination of endogenous plasma acetyl and palmitoyl carnitines as potential biomarkers of beta-oxidation in mice

A robust bioanalytical method capable of measuring acetyl and palmitoyl carnitines was developed and validated. Application of hydrophilic interaction chromatography (HILIC) enabled retention of these highly polar and difficult to analyze compounds on a silica HPLC column. The chromatography was conducted with a high percentage of an organic component in the mobile phase, allowing high sensitivity for the pre-existing positively charged quaternary ammonium ions by electrospray ionization mass spectrometry. Successful application of the method to reliably quantify naturally occurring acyl carnitines in mouse plasma depended on the use of corresponding deuterated analogues. The specificity of the method, achieved through the use of stable isotope labeled compounds in combination with a mass spectral multiple reaction monitoring technique, permitted a non-invasive assessment of the overall change in the levels of these acyl carnitines in the plasma of intact animals administered peroxisome proliferator activated receptor (PPAR) agents. These acyl carnitines, as carriers of the corresponding long-chain fatty acids for transport into mitochondria, can be employed as potential biomarkers for significant alteration in the beta-oxidation process in an intact animal.     

Thermophysical properties of 1-hexyl-3-methyl imidazolium based ionic liquids with tetrafluoroborate, hexafluorophosphate and bis(trifluoromethylsulfonyl)imide anions

The thermophysical properties of 1-hexyl-3-methyl imidazolium based hydrophobic room temperature ionic liquids (RTILs); with tetrafluoroborate (BF₄), hexafluorophosphate (PF₆), and bis(trifluoromethylsulfonyl)imide (Tf₂N) anions, namely density ρ (298.15 to 348.15) K, dynamic viscosity η (288.2 to 348.2) K, surface tension σ (298.15 to 338) K, and refractive index n_D (302.95 to 332.95) K have been measured. The coefficients of thermal expansion α_p values were calculated from the experimental density data using an empirical correlation. The thermal stability of all ILs is also investigated at two different heating rates (10 and 20) °C · min⁻¹) using thermogravimetric analyzer (TGA). The experimental results presented in this study reveal that the choice of anion type shows the most significant effect on the properties of ILs. The chloride and water contents of ILs (as impurities) are also investigated and reported in the present work.     

A small-angle X-ray scattering study of the structure of lysozyme-sodium dodecyl sulfate complexes

The structure of lysozyme-sodium dodecyl sulfate (SDS) complexes in solution is studied using small-angle X-ray scattering (SAXS). The SAXS data cannot be explained by the necklace and bead model for unfolded polypeptide chain interspersed with surfactant micelles. For the protein and surfactant concentrations used in the study, there is only marginal growth of SDS micelles as they complex with the protein. Being a small and rather rigid protein, lysozyme can penetrate the micellar core which is occupied by flexible and disordered paraffin chains and also the shell occupied by the hydrated head groups. A partially embedded swollen micellar model seems appropriate and describes well the scattering data. The SAXS intensity profiles are analyzed by considering the change in the electron scattering length density of the micellar core and shell due to complexation with protein and treating the intermicellar interaction using rescaled mean spherical approximation (RMSA) for charged spheres.     

An optical fiber biosensor for chlorpyrifos using a single sol-gel film containing acetylcholinesterase and bromothymol blue

An optical fiber biosensor consisting of acetylcholinesterase (AChE) and bromothymol blue (BTB) doped sol-gel film was employed to detect organophosphate pesticide chlorpyrifos. The main advantage of this optical biosensor is the use of a single sol-gel film with immobilized AChE and BTB. The compatibility of this mixture (AChE and BTB) with the sol-gel matrix has prevented leaching of the film. The immobilization of the enzyme and indicator was simple without chemical modification. The biosensing element on single sol-gel film has been placed inside the flow-cell for flow system. In the presence of a constant AChE, a color change of the BTB and the measured reflected signal at wavelength 622nm could be related to the pesticide concentration in the sample solutions. The performance of optical biosensor in the flow system has been optimized, including chemical and physical parameters. The response time of the biosensor is 8min. A linear calibration curve of chlorpyrifos against the percentage inhibition of AChE was obtained from 0.05 to 2.0mg/L of chlorpyrifos (18-80% inhibition, R(2)=0.9869, n=6). The detection limit for chlorpyrifos was 0.04mg/L. The results of the analysis of 0.5-1.5mg/L of chlorpyrifos using this optical biosensor agreed well with chromatographic method.     

GC Determination of Cisplatin in Serum and Urine of Cancer Patients after Chemotherapy as Platinum (II) Pyrrolidinedithiocarbamate Chelate

A gas chromatographic procedure has been developed for determination of cisplatin from pharmaceutical preparation, serum and urine after chemotherapy of cancer patients as platinum(II) pyrrolidinedithiocarbamate chelate. The elution was carried from the column DB-1701 (30 m × 0.32 mm i.d.) coupled with FID detection. Cu(II), Ni(II), Co(III), Mn(II), Fe(III), Zn(II) and VO(II) when present together with Pt(II) separated completely and did not affect the determination of platinum. The linear calibration curve for platinum (II) was within 1–30 μg mL^?1 with a detection limit of 300 ng mL^?1. The amount of cisplatin detected from serum and urine was 250–325 and 20–116 ng mL^?1 with relative standard deviations (RSD) of 0.8–1.2%, and 0.9–1.2%. The % recovery of Pt from serum and urine by standard addition was 98 and 98.2% with RSD 1.4 and 1.1%.     

Synthesis and evaluation of in vitro antibacterial activity of novel 2,5-disubstituted-1,3,4-thiadiazoles from fatty acids

A series of new 1-(alkenoyl/hydroxyalkenoyl)-4-benzoyl-thiosemicarbazides 2a-d and 2-benzamide-5-alkenyl/hydroxyalk-enyl-1,3,4-thiadiazoles 3a-d were synthesized from fatty acid hydrazides. Structure of all these compounds was confirmed by IR, 1H NMR, 13C NMR, mass spectra and elemental analysis. The bioassay results indicate that some compounds 2,c, 2d, 3c and 3d have good antibacterial activity.     

Effect of diluent and reaction parameter on selective oxidation of propane over MoVTeNb catalyst using nanoflow catalytic reactor

The selective oxidation of propane to acrylic acid over an MoVTeNb mixed oxide catalyst, dried and calcined before reaction has been studied using high-throughput instrumentation, which is called nanoflow catalytic reactor. The effects of catalyst dilution on the catalytic performance of the MoVTeNb mixed oxide catalyst in selective oxidation of propane to acrylic acid were also investigated. The effects of some reaction parameters, such as gas hourly space velocity （GHSV） and reaction temperature, for selective oxidation of propane to acrylic acid over diluted MoVTeNb catalyst have also been studied. The configuration of the nanoflow is shown to be suitable for screen catalytic performance, and its operating conditions were mimicked closely to conventional laboratory as well as to industrial conditions. The results obtained provided very good reproducibility and it showed that preparation methods as well as reaction parameters can play significant roles in catalytic performance of these catalysts.     

Stereoelectronic effects on molecular geometries and state-energy splittings of ligated monocopper dioxygen complexes

The relative energies of side-on versus end-on binding of molecular oxygen to a supported Cu(I) species, and the singlet versus triplet nature of the ground electronic state, are sensitive to the nature of the supporting ligands and, in particular, depend upon their geometric arrangement relative to the O2 binding site. Highly correlated ab initio and density functional theory electronic structure calculations demonstrate that optimal overlap (and oxidative charge transfer) occurs for the side-on geometry, and this is promoted by ligands that raise the energy, thereby enhancing resonance, of the filled Cu dxz orbital that hybridizes with the in-plane pi* orbital of O2. Conversely, ligands that raise the energy of the filled Cu dz2 orbital foster a preference for end-on binding as this is the only mode that permits good overlap with the in-plane O2 pi*. Because the overlap of Cu dz2 with O2 pi* is reduced as compared to the overlap of Cu dxz with the same O2 orbital, the resonance is also reduced, leading to generally more stable triplet states relative to singlets in the end-on geometry as compared to the side-on geometry, where singlet ground states become more easily accessible once ligands are stronger donors. Biradical Cu(II)-O2 superoxide character in the electronic structure of the supported complexes leads to significant challenges for accurate quantum chemical calculations that are best addressed by exploiting the spin-purified M06L local density functional, single-reference completely renormalized coupled-cluster theory, or multireference second-order perturbation theory, all of which provide predictions that are qualitatively and quantitatively consistent with one another.