Rizwana Sarwar

Evaluation of Antioxidant, Free Radical Scavenging, and Antimicrobial Activity of Quercus incana Roxb.

Considering the indigenous utilization of Quercus incana Roxb., the present study deals with the investigation of antioxidant, free radical scavenging activity, total phenolic content, and antimicrobial activity of Q. incana Roxb. In vitro antioxidant activity of the plant fractions were determined by 1,1-diphenyl-2-picrylhydrazyl and nitric oxide scavenging method. Total phenolic contents were determined by gallic acid equivalent and antimicrobial activities were determined by agar well diffusion method. It was observed that Q. incana Roxb. showed significant antibacterial activity against Gram-positive and Gram-negative bacteria. n-Butanol fraction showed maximum activity against Micrococcus leuteus with 19 mm zone of inhibition. n-Butanol fraction of Q. incana Roxb. showed immense antifungal activity against Aspergillus niger (32 mm ± 0.55) and A. flavus (28 mm ± 0.45). Similarly n-butanol fraction showed relatively good antioxidant activity with IC50 value of 55.4 ± 0.21 μg/mL. The NO scavenging activity of ethyl acetate fraction (IC50 = 23.21 ± 0.31 μg/mL) was fairly good compared to other fractions. The current study of Q. incana Roxb. suggests the presences of synergetic action of some biological active compounds that may be present in the leaves of medicinal plant. Further studies are needed to better characterize the important active constituents responsible for the antimicrobial, antioxidant and free radical scavenging activity.

A new rosane-type diterpenoid from Stachys parviflora and its density functional theory studies

A new rosane-type diterpenoid (1) has been isolated from the chloroform fraction of Stachys parviflora. Structure of 1 was proposed based on 1D and 2D NMR techniques including correlation spectroscopy, heteronuclear multiple quantum coherence, heteronuclear multiple bond correlation and nuclear Overhauser effect spectroscopy. A theoretical model for the electronic and spectroscopic properties of compound 1 is also developed. The geometries and electronic properties were modelled at B3LYP/6-31G* and the theoretical scaled spectroscopic data correlate nicely with the experimental data.

Preparation, characterization and application of Cu–Ni/TiO2 in Orange II photodegradation under visible light: effect of different reaction parameters and optimization

Bimetallic Cu–Ni/TiO2 photocatalysts were prepared using a wet impregnation method. The physicochemical and morphological properties of the photocatalysts were studied using different characterization techniques. FTIR analysis showed the nitrate peaks are still present but did not show an effect on the catalytic performance of the photocatalysts. Photocatalysts were of nanosize and their morphologies are spherical and slightly agglomerated. From DR-UV-visible analysis, it was proved that incorporation of Cu and Ni onto TiO2 has successfully shifted the optical absorption to the visible region with reduced bandgap energies. Furthermore, by increasing the calcination temperature the bandgap energy was reduced. The lowest band gap energy (2.74 eV) was reported for 9Cu:1Ni-300. Photocatalytic degradation of Orange II was studied under visible light. The photocatalyst performance of bimetallic Cu–Ni/TiO2 for Orange II decoloration and mineralization is promising compared to bare TiO2 and the monometallic photocatalysts. Compared to other Cu:Ni mass compositions, results for photodegradation studies showed that a 9Cu:1Ni mass composition was observed with 100% Orange II decoloration and 89.8% and 100% TOC removal in 1 h and 1.5 h of irradiation duration, respectively. The optimum pH value was 6.8. The main identified intermediates and by-products of Orange II photodegradation under visible light irradiation during reaction as a function of time were oxalic acid, formic acid, formaldehyde, benzyl alcohol and benzaldehyde as measured by HPLC analysis.

Isolation and Structure Determination of Three New Sesquiterpenoids from Achillea millefolium

Phytochemical investigation of the whole plant of Achillea millefolium led to the isolation of three new sesquiterpenes which were trivially named as sesquiterpene lactone-esters A and B (1 and 2), and sesquiterpene lactone-diol (3). The structures of these compounds were determined with the help of one- and two-dimensional (1D and 2D) NMR techniques including 1H NMR, 13C NMR, HMQC, HMBC, COSY, and NOESY experiments. Graphical Abstract Isolation and Structure Determination of Three New Sesquiterpenoids from Achillea millefolium

Identification of new benzamide inhibitor against α-subunit of tryptophan synthase from Mycobacterium tuberculosis through structure-based virtual screening, anti-tuberculosis activity and molecular dynamics simulations

Multi-drug-resistant tuberculosis and extensively drug-resistant tuberculosis has emerged as global health threat, causing millions of deaths worldwide. Identification of new drug candidates for tuberculosis (TB) by targeting novel and less explored protein targets will be invaluable for antituberculosis drug discovery. We performed structure-based virtual screening of eMolecules database against a homology model of relatively unexplored protein target: the α-subunit of tryptophan synthase (α-TRPS) from Mycobacterium tuberculosis essential for bacterial survival. Based on physiochemical properties analysis and molecular docking, the seven candidate compounds were selected and evaluated through whole cell-based activity against the H37Rv strain of M. tuberculosis. A new Benzamide inhibitor against α-subunit of tryptophan synthase (α-TRPS) from M. tuberculosis has been identified causing 100% growth inhibition at 25 μg/ml and visible bactericidal activity at 6 μg/ml. This benzamide inhibitor displayed a good predicted binding score (−48.24 kcal/mol) with the α-TRPS binding pocket and has logP value (2.95) comparable to Rifampicin. Further refinement of docking results and evaluation of inhibitor-protein complex stability were investigated through Molecular dynamic (MD) simulations studies. Following MD simulations, Root mean square deviation, Root mean square fluctuation and secondary structure analysis confirmed that protein did not unfold and ligand stayed inside the active pocket of protein during the explored time scale. This identified benzamide inhibitor against the α-subunit of TRPS from M. tuberculosis could be considered as candidate for drug discovery against TB and will be further evaluated for enzyme-based inhibition in future studies.

Antidepressent Effect of Two New Benzyl Derivatives from Wild Strawberry Fragaria vesca var. nubicola Lindl. ex Hook.f.

Two new benzyl derivatives were isolated from ethyl acetate fraction of wild strawberry, Fragaria vesca var. nubicola Lindl. ex Hook.f. The structures of these compounds were elucidated to be 5-(4-hydroxy-3-methoxyphenethyl)-7-methoxy-2H-chromen-3-ol (1) and 5-(4-hydroxy-3-methoxyphenethyl)-4,7-dimethoxy-2H-chromen-3-ol (2) based on spectroscopic data through IR, UV, 1H-NMR, 13C-NMR along with two dimensional (2D) techniques HMBC, HMQC, and COSY. Both compounds 1 and 2 were studied in tail suspension and forced swim tests for antidepressant like effects. A significant dose dependent antidepressant like effect was observed by causing spontaneous anti-immobility at various test doses upon intraperitoneal administration.

The Potential Use of Vetiveria zizanioides for the Phytoremediation of Antimony, Arsenic and Their Co-Contamination

Antimony (Sb) and arsenic (As) contaminations are the well reported and alarming issues of various contaminated smelting and mining sites all over the world, especially in China. The present hydroponic study was to assess the capacity of Vetiveria zizanioides for Sb, As and their interactive accumulations. The novelty of the present research is this that the potential of V. zizanioides for Sb and As alone and their interactive accumulation are unaddressed. This is the first report about the interactive co-accumulation of Sb and As in V. zizanioides. Highest applied Sb and As contaminations significantly inhibited the plant growth. Applied Sb and As alone significantly increased their concentrations in the roots/shoot of V. zizanioides. While co-contamination of Sb and As steadily increased their concentrations, in the plant. The co-contamination of Sb and As revealed a positive correlation between the two, as they supplemented the uptake and accumulation of each other. The overall translocation (TF) and bioaccumulation factors (BF) of Sb in V. zizanioides, were 0.75 and 4. While the TF and BF of As in V. zizanioides, were 0.86 and 10. V. zizanioides proved as an effective choice for the phytoremediation and ecosystem restoration of Sb and As contaminated areas.

Phytoextraction of HG by parsley (Petroselinum crispum) and its growth responses.

ABSTRACT The effect of mercury (Hg) on the growth and survival of parsley (Petroselinum crispum) was explored at various treatments. The plants were grown in pots having Hoaglands solution to which various Hg treatments were applied and placed under greenhouse conditions. The treatments were: no metal applied (control) and six doses of Hg as mercuric chloride for 15 days. Linear trend of Hg accumulation was noted in roots, stems, and leaves with increasing Hg treatments. The maximum Hg concentration in root, stem and leaf was 8.92, 8.27, and 7.88 at Hg treatments of 25 mg l–1, respectively. On the whole, Hg accumulation in different plant parts was in the following order: leaves > stem > roots. Linear trend was also observed for Bioaccumulation Factor (BF) and Translocation Factor (TF) with increasing Hg concentrations in the growth medium. The highest respective BFHg and TFHg values were 9.32 and 2.02 for the Hg treatments of 25 and 50 mg l–1. In spite of the reduced growth in the presence of Hg, the plant has phytoremediation potential. It is recommended that parsley should not be cultivated in Hg contaminated sites in order to avoid dietary toxicity.

Combined in Vitro and in Silico Studies for the Anticholinesterase Activity and Pharmacokinetics of Coumarinyl Thiazoles and Oxadiazoles

In a continuation of our previous work for the exploration of novel enzyme inhibitors, two new coumarin-thiazole 6(a–o) and coumarin-oxadiazole 11(a–h) hybrids have been designed and synthesized. All the compounds were characterized by 1H- and 13C-NMR spectroscopy and elemental analysis. New hybrid analogs were evaluated against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in order to know their potential for the prevention of Alzheimers disease (AD). In coumarinyl thiazole series, compound 6b was found as the most active member against AChE having IC50 value of 0.87 ± 0.09 μM, while the compound 6j revealed the same efficacy against BuChE with an IC50 value of 11.01 ± 3.37 μM. In case of coumarinyl oxadiazole series, 11a was turned out to be the lead candidate against AChE with an IC50 value of 6.07 ± 0.23 μM, whereas compound 11e was found significantly active against BuChE with an IC50 value of 0.15 ± 0.09 μM. To realize the binding interaction of these compounds with AChE and BuChE, the molecular docking studies were performed. Compounds from coumarinyl thiazole series with potent AChE activity (6b, 6h, 6i, and 6k) were found to interact with AChE in the active site with MOE score of −10.19, −9.97, −9.68, and −11.03 Kcal.mol−1, respectively. The major interactions include hydrogen bonding, π-π stacking with aromatic residues, and interaction through water bridging. The docking studies of coumarinyl oxadiazole derivatives 11(a–h) suggested that the compounds with high anti-butyrylcholinesterase activity (11e, 11a, and 11b) provided MOE score of −9.9, −7.4, and −8.2 Kcal.mol−1, respectively, with the active site of BuChE building π-π stacking with Trp82 and water bridged interaction.

Isolation and Characterization of Two New Secondary Metabolites From Quercus incana and Their Antidepressant- and Anxiolytic-Like Potential

The ethyl acetate fraction of Quercus incana yielded two new compounds [1 and 2]. The characterization and structure elucidation of these compounds were carried out through various spectroscopic techniques such as mass spectrometry along with one- and two-dimensional NMR techniques. The structural formula was deduced to be 2-(4-hydroxybutan-2-yl)-5-methoxyphenol [1] and 4-hydroxy-3-(hydroxymethyl) pentanoic acid [2]. The elevated plus maze (EPM) and light–dark box (LDB) tests (classical mouse models) were performed in order to reveal the anxiolytic potential of both compounds [1 and 2]. Both compounds displayed dose-dependent increases in open-arm entries and time spent in open arms in EPM (∗P < 0.05, ∗∗P < 0.01), and increased the time spent in the lit compartment and increased transitions between the two compartments in LDB test (∗P < 0.05, ∗∗P < 0.01). Co-administration of selective benzodiazepine (BZP) receptor antagonist, flumazenil (2.5 mg/kg) with compounds [1 and 2] decreased the anxiolytic-like activity of both compounds in the EPM indicating BZP-binding site of GABA-A receptors are involved in the anxiolytic-like effect. Similarly, both compounds at the dose level of 10 and 30 mg/kg, i.p. exerted pronounced antidepressant-like effect in both forced swimming as well as tail suspension tests (∗P < 0.05, ∗∗P < 0.01; ANOVA followed by Dunnett’s post hoc test). The effect at 30 mg/kg was comparable to the reference drug imipramine (60 mg/kg).