ANTIOXIDANT, FREE RADICAL SCAVENGING ACTIVITY AND GC-MS STUDIES ON PEDILANTHUS TITHYMALOIDES (L.) POIT

Objective: To evaluate the methanolic extract of the leaves of Pedilanthus tithymaloides for total phenol, total flavonoid, total antioxidant and free radical scavenging ability and detect the phytoconstituents using GC-MS. Methods: The total phenols were quantified using Folin-Ciocalteu method. Aluminium chloride method and Phosphomolybdenum method were used to quantify total flavonoid and total antioxidant contentrespectively. In addition to the above, Ferric thiocyanate assay, the thiobarbituric acid assay,Ferric Reducing Antioxidant Power assay and ABTS assay were performed to know the antioxidant potency of the methanolic extract of leaves of Pedilanthus tithymaloides. The phytoconstituents was detected using GC-MS. Results: The leaves of Pedilanthus tithymaloides recorded a phenolic content of 10.98±0.08 mg TAE/g DW, flavonoid content of 11.49±0.15 µg QE/g DW and total antioxidant content of 6.64±0.05 mg TAE/g DW. The study also revealed significant free radical scavenging ability of the plant leaves as assessed by FTC, TBA, FRAP and ABTS assays. The structural elucidation by GC-MS analysis revealed five different compounds, includingthree esters, an amine and an alkaloid. Conclusion: The study proves the anticipative potential ability of Pedilanthus tithymaloides, suggesting its exploitation in pharmaceutical applications

4′-(2,4-Dichloro­phen­yl)-1,1′-dimethyl­piperidine-3-spiro-3′-pyrrolidine-2′-spiro-3′′-indoline-4,2′′-dione

In the title compound, C23H23Cl2N3O2, the pyrroline ring adopts an envelope conformation and the piperidinone ring assumes a slightly twisted chair form. In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds generate an R 2 8 graph-set motif and a short Cl⋯Cl contact of 3.478 (1) Å occurs

Antibacterial Effect of Green Synthesized Silver Nanoparticles using Cineraria maritima

Nanoparticles display entirely novel physicochemical characteristics for specific applications because of their exceptional size and shape. Owing to the present study, we reported biosynthesis, characterization and antibacterial properties of Cineraria maritima (Cm) assisted silver nanoparticles (Ag NPs). The surface plasmon vibration, crystalline structure, surface morphology, elemental composition, and possible functional molecules vibration of prepared Cm-Ag NPs were characterized by different instrumentation techniques. The spectrum of UV-Vis of Cm-Ag NPs showed maximum plasma intensity occurred around 425nm. XRD spectrum showed the face-centred cubic (FCC) nature of Cm-Ag NPs. The SEM image of the Cm-Ag NPs demonstrated a predominantly spherical shape with cluster formation of small particles to large particles with sizes ranging from 21.57 nm to 39.16 nm. EDS spectrum indicated the existence of Ag elements in Cm-Ag NPs. FTIR intense peaks of Cm-Ag NPs showed the different functional molecules such as phenol, alkene, aldehydes, and a carbonyl group. In addition, Cm-Ag NPs coated textile cotton fabric sample showed substantial anti-bacterial properties against a tested bacterial pathogen

High Performance Liquid Chromatographic Fluorescence Detection Method for the Quantification of Rivastigmine in Rat Plasma and Brain: Application to Preclinical Pharmacokinetic Studies in Rats

A highly sensitive and selective high performance liquid chromatographic fluorescence detection method has been developed and validated for the quantification of rivastigmine in rat plasma and brain. Protein precipitation and one-step liquid–liquid extraction techniques were utilized for the extraction of RSM from brain and plasma, respectively, along with an internal standard. The chromatographic separation was achieved with a column inertsil ODS-3V and a mobile phase consisting of ammonium acetate buffer (20 mM, pH 4.5) and acetonitrile (76:24, v/v) delivered at a flow rate of 1 ml/min. The lower limit of quantitation for the developed method was 10 ng/mL for both matrices. The method was found to be accurate and reproducible and was successfully used to quantify levels of RSM in plasma and brain following intravenous administration of RSM in rats

Rapid growth of new atmospheric particles by nitric acid and ammonia condensation

New-particle formation is a major contributor to urban smog$^{1,2}$, but how it occurs in cities is often puzzling$^{3}$. If the growth rates of urban particles are similar to those found in cleaner environments (1–10 nanometres per hour), then existing understanding suggests that new urban particles should be rapidly scavenged by the high concentration of pre-existing particles. Here we show, through experiments performed under atmospheric conditions in the CLOUD chamber at CERN, that below about +5 degrees Celsius, nitric acid and ammonia vapours can condense onto freshly nucleated particles as small as a few nanometres in diameter. Moreover, when it is cold enough (below −15 degrees Celsius), nitric acid and ammonia can nucleate directly through an acid–base stabilization mechanism to form ammonium nitrate particles. Given that these vapours are often one thousand times more abundant than sulfuric acid, the resulting particle growth rates can be extremely high, reaching well above 100 nanometres per hour. However, these high growth rates require the gas-particle ammonium nitrate system to be out of equilibrium in order to sustain gas-phase supersaturations. In view of the strong temperature dependence that we measure for the gas-phase supersaturations, we expect such transient conditions to occur in inhomogeneous urban settings, especially in wintertime, driven by vertical mixing and by strong local sources such as traffic. Even though rapid growth from nitric acid and ammonia condensation may last for only a few minutes, it is nonetheless fast enough to shepherd freshly nucleated particles through the smallest size range where they are most vulnerable to scavenging loss, thus greatly increasing their survival probability. We also expect nitric acid and ammonia nucleation and rapid growth to be important in the relatively clean and cold upper free troposphere, where ammonia can be convected from the continental boundary layer and nitric acid is abundant from electrical storms$^{4,5}$

Arctic warming by abundant fine sea salt aerosols from blowing snow

The Arctic warms nearly four times faster than the global average, and aerosols play an increasingly important role in Arctic climate change. In the Arctic, sea salt is a major aerosol component in terms of mass concentration during winter and spring. However, the mechanisms of sea salt aerosol production remain unclear. Sea salt aerosols are typically thought to be relatively large in size but low in number concentration, implying that their influence on cloud condensation nuclei population and cloud properties is generally minor. Here we present observational evidence of abundant sea salt aerosol production from blowing snow in the central Arctic. Blowing snow was observed more than 20% of the time from November to April. The sublimation of blowing snow generates high concentrations of fine-mode sea salt aerosol (diameter below 300 nm), enhancing cloud condensation nuclei concentrations up to tenfold above background levels. Using a global chemical transport model, we estimate that from November to April north of 70° N, sea salt aerosol produced from blowing snow accounts for about 27.6% of the total particle number, and the sea salt aerosol increases the longwave emissivity of clouds, leading to a calculated surface warming of +2.30 W m−2 under cloudy sky conditions

The gas-phase formation mechanism of iodic acid as an atmospheric aerosol source

Iodine is a reactive trace element in atmospheric chemistry that destroys ozone and nucleates particles. Iodine emissions have tripled since 1950 and are projected to keep increasing with rising O-3 surface concentrations. Although iodic acid (HIO3) is widespread and forms particles more efficiently than sulfuric acid, its gas-phase formation mechanism remains unresolved. Here, in CLOUD atmospheric simulation chamber experiments that generate iodine radicals at atmospherically relevant rates, we show that iodooxy hypoiodite, IOIO, is efficiently converted into HIO3 via reactions (R1) IOIO + O-3 -> IOIO4 and (R2) IOIO4 + H2O -> HIO3 + HOI + O-(1)(2). The laboratory-derived reaction rate coefficients are corroborated by theory and shown to explain field observations of daytime HIO3 in the remote lower free troposphere. The mechanism provides a missing link between iodine sources and particle formation. Because particulate iodate is readily reduced, recycling iodine back into the gas phase, our results suggest a catalytic role of iodine in aerosol formation.Peer reviewe

Synergistic HNO3_{3}–H2_{2}SO4_{4}–NH3_{3} upper tropospheric particle formation

New particle formation in the upper free troposphere is a major global source of cloud condensation nuclei (CCN)$^{1,2,3,4}$. However, the precursor vapours that drive the process are not well understood. With experiments performed under upper tropospheric conditions in the CERN CLOUD chamber, we show that nitric acid, sulfuric acid and ammonia form particles synergistically, at rates that are orders of magnitude faster than those from any two of the three components. The importance of this mechanism depends on the availability of ammonia, which was previously thought to be efficiently scavenged by cloud droplets during convection. However, surprisingly high concentrations of ammonia and ammonium nitrate have recently been observed in the upper troposphere over the Asian monsoon region5,6. Once particles have formed, co-condensation of ammonia and abundant nitric acid alone is sufficient to drive rapid growth to CCN sizes with only trace sulfate. Moreover, our measurements show that these CCN are also highly efficient ice nucleating particles—comparable to desert dust. Our model simulations confirm that ammonia is efficiently convected aloft during the Asian monsoon, driving rapid, multi-acid HNO$_{3}$–H$_{2}$SO$_{4}$–NH$_{3}$ nucleation in the upper troposphere and producing ice nucleating particles that spread across the mid-latitude Northern Hemisphere