IN VITRO ASSESSSMENT OF ANTIOXIDANT AND ANTIMICROBIAL ACTIVITIES OF DIFFERENT SOLVENT EXTRACTS FROM LICHEN RAMALINA NERVULOSA

Objective: The purpose of the existent study is to assess the in vitro antioxidant and antimicrobial activity of different solvent extracts of Ramalina nervulosa. Methods: Folin ciocalteu's and Aluminium chloride method were used for total phenolic and flavonoid content estimation respectively. The antioxidant activity was evaluated through free radical scavenging activity by DPPH (2, 2-diphenyl-1-picrylhydrazyl), FRAP (ferric ions reducing antioxidant potential), cupric ion chelation ability. Agar diffusion method was used to assess the antimicrobial capacity. GC-MS analysis was carried out to identify the presence of compounds in the extracts.Results: Ethanol extracts exhibited that the highest zone of inhibition with Bacillus subtilis, Proteus vulgaris, Pseudomonas aeruginosa, Klebsiella pneumoniae and with two fungal strains such as Fusarium oxyparum and Penicillium notatum. The extract also has high inhibition capacity of 64.29% and 62.49% towards DPPH and Cu2+ion respectively. But the aqueous extract showed higher amount of phenolic and flavonoid content of about 211.40 mg GAE/g dw and 50.72 mg QE/g dw respectively and Fe2+ ion reducing capacity of about 144.41 mol ascorbic acid equivalent/g db. Further analysis of GC-MS showed the presence of various bioactive molecules present in the lichen Ramalina nervulosa.Conclusion: The results of FRAP assay were positively correlated with the total phenolic and flavonoid content. Ethanol extracts of R. nervulosa showed promising antibacterial, antifungal and antioxidant activities which can be considered as the potent source of antioxidant product and offer protection from oxidative stress under many pathophysiological conditions.Â

Perspective Chapter: Podological Deformities and Its Management

The ankle and foot complex plays on important role in gait and weight bearing of the body weight. The deformity of the ankle and foot affects and alters the biomechanics of the body and normal gait pattern, and this consequently affects the other parts and joints of the lower limb and also trunk

Ion mobility action spectroscopy of flavin dianions reveals deprotomer-dependent photochemistry

The intrinsic optical properties and photochemistry of flavin adenine dinucleotide (FAD) dianions are investigated using a combination of tandem ion mobility spectrometry and action spectroscopy. Two principal isomers are observed, the more stable form being deprotonated on the isoalloxazine group and a phosphate (N-3,PO4 deprotomer), and the other on the two phosphates (PO4,PO4 deprotomer). Ion mobility data and electronic action spectra suggest that photo-induced proton transfer occurs from the isoalloxazine group to a phosphate group, converting the PO4,PO4 deprotomer to the N-3,PO4 deprotomer. Comparisons of the isomer selective action spectra of FAD dianions and flavin monoanions with solution spectra and gas-phase photodissociation action spectra suggests that solvation shifts the electronic absorption of the deprotonated isoalloxazine group to higher energy. This is interpreted as evidence for significant charge transfer in the lowest optical transition of deprotonated isoalloxazine. Overall, this work demonstrates that the site of deprotonation of flavin anions strongly affects their electronic absorptions and photochemistry

Dimerisation induced formation of the active site and the identification of three metal sites in EAL-phosphodiesterases

The bacterial second messenger cyclic di-3′,5′-guanosine monophosphate (c-di-GMP) is a key regulator of bacterial motility and virulence. As high levels of c-di-GMP are associated with the biofilm lifestyle, c-di-GMP hydrolysing phosphodiesterases (PDEs) have been identified as key targets to aid development of novel strategies to treat chronic infection by exploiting biofilm dispersal. We have studied the EAL signature motif-containing phosphodiesterase domains from the Pseudomonas aeruginosa proteins PA3825 (PA3825EAL) and PA1727 (MucREAL). Different dimerisation interfaces allow us to identify interface independent principles of enzyme regulation. Unlike previously characterised two-metal binding EAL-phosphodiesterases, PA3825EAL in complex with pGpG provides a model for a third metal site. The third metal is positioned to stabilise the negative charge of the 5′-phosphate, and thus three metals could be required for catalysis in analogy to other nucleases. This newly uncovered variation in metal coordination may provide a further level of bacterial PDE regulation

Insights into the dynamics of conical breakdown modes in coaxial swirling flow field

The main idea of this paper is to understand the fundamental vortex breakdown mechanisms in the coaxial swirling flow field. In particular, the interaction dynamics of the flow field is meticulously addressed with the help of high fidelity laser diagnostic tools. Time-resolved particle image velocimetry (PIV) (similar to 1500 frames s(-1)) is employed in y-r and multiple r-theta planes to precisely delineate the flow dynamics. Experiments are carried out for three sets of co-annular flow Reynolds number Re-a = 4896, 10 545, 17 546. Furthermore, for each Re-a condition, the swirl number `SG' is varied independently from 0 <= S-G <= 3. The global evolution of flow field across various swirl numbers is presented using the time-averaged PIV data. Three distinct forms of vortex breakdown namely, pre-vortex breakdown (PVB), central toroidal recirculation zone (CTRZ; axisymmetric toroidal bubble type breakdown) and sudden conical breakdown are witnessed. Among these, the conical form of vortex breakdown is less explored in the literature. In this paper, much attention is therefore focused on exploring the governing mechanism of conical breakdown. It is should be interesting to note that, unlike other vortex breakdown modes, conical breakdown persists only for a very short band of S-G. For any small increase/decrease in S-G beyond a certain threshold, the flow spontaneously reverts back to the CTRZ state. Energy ranked and frequency-resolved/ranked robust structure identification methods - proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD) respectively - are implemented over instantaneous time-resolved PIV data sets to extract the dynamics of the coherent structures associated with each vortex breakdown mode. The dominant structures obtained from POD analysis suggest the dominance of the Kelvin-Helmholtz (KH) instability (axial + azimuthal; accounts for similar to 80 % of total turbulent kinetic energy, TKE) for both PVB and CTRZ while the remaining energy is contributed by shedding modes. On the other hand, shedding modes contribute the majority of the TKE in conical breakdown. The frequency signatures quantified from POD temporal modes and DMD analysis reveal the occurrence of multiple dominant frequencies in the range of similar to 10-400 Hz with conical breakdown. This phenomenon may be a manifestation of high energy contribution by shedding eddies in the shear layer. Contrarily, with PVB and CTRZ, the dominant frequencies are observed in the range of similar to 20-40 Hz only. We have provided a detailed exposition of the mechanism through which conical breakdown occurs. In addition, the current work explores the hysteresis (path dependence) phenomena of conical breakdown as functions of the Reynolds and Rossby numbers. It has been observed that the conical mode is not reversible and highly dependent on the initial conditions