PHYTOCHEMICAL EVALUATION AND IN VITRO ANTIMICROBIAL AND ANTIOXIDANT STUDIES OF LEAF AND STEM BARK EXTRACTS OF POLYALTHIA FRAGRANS (DALZ.) BEDD.–AN ENDEMIC SPECIES OF WESTERN GHATS

Objective: Phytochemical constituents of various solvent extracts of leaf and stem bark of Polyalthia fragrans (Dalz.) Bedd were screened. Antimicrobial and antioxidant activities of the extracts were evaluated.Methods: Crude extracts of methanol, ethyl acetate, chloroform and aqueous of leaf and stem bark were evaluated for antimicrobial activity by disc diffusion method and antioxidant activity by DPPH (diphenyl-2-picrylhydrazyl) radical scavenging and reducing power assay. Quantitative analysis of total phenolics was done by the Folin-Ciocalteau method and total flavonoids by aluminum chloride method.Results: The study revealed the presence of several physiologically active phytochemicals such as alkaloids, phenols, flavonoids and tannins. The highest antibacterial activity of methanol extract of the leaf was observed against Bacillus subtilis with 14.33±0.57 mm inhibition zone and water extract of stem bark against Proteus vulgaris with 17.67±1.52 mm inhibition zone among other extracts. The lowest activity of leaf methanol and leaf water extract was observed against Bacillus subtilis. The IC50 values of 58.18±2.04 µg/ml, 116.58±2.43 µg/ml, 134.78±3.64 µg/ml and 387.28±2.9 µg/ml for DPPH activity were observed in methanol stem bark, ethyl acetate stem bark, methanol leaf and ethyl acetate leaf extracts respectively. The reducing power of extracts was very potent which increased with increasing concentrations of the sample.Conclusion: The results indicate that phytochemicals like alkaloids, phenols, flavonoids and tannins may be responsible for the antimicrobial and antioxidant properties. The results suggest that P. fragrans can be further researched to be used as a natural source of a potent drug by mankind

In vitro pharmacological potential of Epiprinus mallotiformis – An endemic species of Western Ghats

Epiprinus mallotiformis is an endemic species of Western Ghats, traditionally known to cure dysentery, digestive problems, ulcers, gonorrhoea and also as a good antimicrobial and diuretic agent. The present investigation was done to evaluate the in vitro pharmacological activities and preliminary screening for phytochemicals in leaf, stem and bark extracts. The study revealed an optimum antioxidant, anti-inflammatory and antimicrobial activities and the presence of phenolics, flavonoids and saponins in the plant extracts. The ethyl acetate fraction of leaf samples exhibited a very significant antibacterial activity against S. aureus with a minimum bactericidal concentration of 8 mg/mL which might be due to the presence of high saponin content (9 %) in the leaves. The investigation also suggests the possible use of E. mallotiformis as an antioxidant, anti-inflammatory and antibacterial agent

ANTIOXIDANT AND ANTIMICROBIAL ACTIVITIES OF TABERNAEMONTANA HEYNEANA WALL. AN ENDEMIC PLANT OF WESTERN GHATS

Objective: The aim of this study was to investigate the antioxidant and antimicrobial properties of different crude extracts of leaves of T. heyneanaMethods: Crude extracts of methanol, chloroform, dichloromethane and dichloroethane of leaf were evaluated for antimicrobial activity by disc diffusion method and antioxidant activity by DPPH (diphenyl-2-picrylhydrazyl) and reducing power assay. Quantitative analysis of total phenolics was done by Folin-Ciocalteau method and total flavonoids by aluminium chloride method.Results: Methanolic extract of T. heyneana exhibited the presence of all the phytochemicals tested except triterpenoids and saponins. The highest phenolic content of 14.0±0.45 mg GAE/g and flavonoid content of 81.62±0.47 mg QE/g were found in methanol extract. The highest DPPH scavenging activity (IC50 20.3±0.56 µg/ml) and reducing power was exhibited by methanolic extract. The methanolic extract showed maximum antibacterial activity of 12.66±0.57 mm zone of inhibition against Staphylococcus aureus and least of 9.23±0.25 mm against Proteus vulgaris.Conclusion: These findings provide scientific evidence to support the traditional use of Tabernaemontana heyneana Wall. and also indicate that the leaves of this species are a promising potential for the development of antioxidant and antimicrobial agents

PHYTOCHEMICAL EVALUATION, ANTIOXIDANT AND ANTIBACTERIAL ACTIVITY OF HOPEA PONGA (DENNST) MABBERLY EXTRACTS

Objective: The present study was aimed at evaluating the in vitro antioxidant and antibacterial activities of methanol and aqueous extracts of Hopea ponga. Methods: Hopea ponga leaf and stem sample were powdered and extracted with methanol and water. The extracts were screened for various phytochemical by HPLC and TLC studies. The total phenolic and flavonoid contents were assessed by spectrophotometric method and the antioxidant activity was estimated using 2,2 diphenyl-1-picrylhydrazyl (DPPH) free radical scavening activity and inhibition of lipid peroxidation assay. Antibacterial activity was evaluated by disc diffusion method & MIC by Broth dilution method. Results: The methanol extracts exhibited significant (p <0.05) higher antioxidant activity with an IC50 value of 108µg/ml and 122 µg/ml in leaf and stem extracts respectively in the DPPH radical scavenging method, 147.2 µg/ml 136 µg/ml in the hydroxyl radical scavenging assay compared to aqueous extracts. The amount of total phenolics in methanol leaf and stem was around 286mg and 213mg gallic acid equivalent (GAE) respectively. The total flavonoid contents of methanol extracts of stem and leaf were around 108.3 mg and 86 mg catechin equivalents per gram respectively. Methanol leaf and stem extracts were found to possess maximum antibacterial activity with MIC ranging around167-648ug/ml against tested strains. High Performance Liquid Chromatography (HPLC) analysis indicated the presence of phenolic compounds such as quercetin, gallic acid, para hyroxybenzoic acid. Conclusion: The results indicate that the extracts had significant free radical scavenging and antibacterial activity. The results suggest that Hopea ponga, may be a good source of natural antioxidants and antibacterial source

Isolation of Endophytic Colletotrichum gloeosporioides Penz. from Salacia chinensis and its Antifungal Sensitivity

Salacia chinensis L (Celestraceae), an endangered medicinal plant is well known for its antidiabetic activity. An attempt of in – vitro culturing to micropropagate the plant led to the discovery of an endophytic association of Colletotrichum gloeosporioides Penz. with both stem and leaf of the plants. The fungus did not respond to the lower concentrations of Amphotericin B and Nystatin (upto 60 µg/ml) in the culture medium. However, it was sensitive at a higher concentration of 100µg/ml

Bell-inequality in path-entangled single photon and purity test

Different degrees of freedom of single photons have been entangled and used as a resource for various quantum technology applications. We present a scheme to perform Bell's test and show the violation of CHSH inequality in a path-entangled single photon state using non-interferometric approach in beam splitter setting. We demonstrate this experimentally by generating and controlling path-entangled state using single photons from spontaneous parametric down-conversion and performing non-interferometric measurements using two detector module. The transition from violation of CHSH inequality to validity is demonstrated when the purity of single photons state decrease below 70\% visibility, $\mathcal{P} < 0.7$. Our procedure allows a purity test on any single photon source and to study quantum correlations on systems driven by dynamics where single particle entanglement with position space is prominent.Comment: 10 pages, 10 figures revised version with extended theoretical description and experimental resul

Flexible and miniaturized design of microstrip patch antenna with improved cross-polarized radiation

A simple and miniaturized design of rectangular microstrip patch antenna (RMPA) is presented with improved cross-polarization (XP) purity. This design approach is much more flexible to tune the resonance frequency of the antenna for its optimum performance. A complete design guideline based on theoretical analysis has been provided to estimate the antenna resonance frequency and corresponding resonant mode. The higher-order spurious mode, orthogonal to the co-polarized fields, has been identified as the source of XP radiation. The physical insight into the XP suppression has been thoroughly discussed and successfully applied for an optimum design. An improved antenna configuration has been realized without any perturbation in the radiating patch or the ground plane. Size, gain, and impedance matching of the proposed antenna have also been considered along with the suppression of XP value. This may be applicable to any conventional working RMPA by introducing very small possible changes. As much as 16 dB suppression of XP radiation is realized in the H-plane without affecting the co-polarized peak-gain value of 5.27 dBi. The proposed concept has been experimentally validated using a set of antenna prototypes. Measured results are closely corroborated with the simulated predictions. (C) 2020 Elsevier GmbH. All rights reserved