Displaying publications 461 - 480 of 10433 in total

Abstract:
Sort:
  1. Fulltext Nitrogen dynamics in flooded soil systems: an overview on concepts and performance of models
    Nurulhuda K, Gaydon DS, Jing Q, Zakaria MP, Struik PC, Keesman KJ
    J Sci Food Agric, 2018 Feb;98(3):865-871.
    PMID: 28940491 DOI: 10.1002/jsfa.8683
    Extensive modelling studies on nitrogen (N) dynamics in flooded soil systems have been published. Consequently, many N dynamics models are available for users to select from. With the current research trend, inclined towards multidisciplinary research, and with substantial progress in understanding of N dynamics in flooded soil systems, the objective of this paper is to provide an overview of the modelling concepts and performance of 14 models developed to simulate N dynamics in flooded soil systems. This overview provides breadth of knowledge on the models, and, therefore, is valuable as a first step in the selection of an appropriate model for a specific application. © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
    Matched MeSH terms: Nitrogen/chemistry*; Soil/chemistry*; Water Pollutants, Chemical/chemistry
  2. Recent Advances in Antibacterial, Antiprotozoal and Antifungal Trends of Eurycoma longifolia: A Review of Therapeutic Implications and Future Prospects
    Thu HE, Hussain Z, Mohamed IN, Shuid AN
    Curr Drug Targets, 2018;19(14):1657-1671.
    PMID: 29468964 DOI: 10.2174/1389450119666180219123815
    BACKGROUND: Eurycoma longifolia (E. longifolia) has gained widespread recognition due to its versatile pharmacological activities including aphrodisiac, anticancer, antimicrobial, antioxidant, anti-inflammatory, anxiolytic, anti-diabetic, ergogenic, insecticidal, anti-rheumatism, bone protection, and anti-ulcer effects.

    OBJECTIVE: This review was aimed to critically overview the literature and summarizes the antibacterial, antiprotozoal, and antifungal trends of E. longifolia and its medicinally active components.

    RESULTS: Besides its well-documented safety, efficacy, and tolerability, a plethora of in vitro, in vivo, and human clinical studies has evidenced the antimicrobial efficacy of E. longifolia and its bioactive constituents. Phytochemical screening of various types of extracts (methanolic, ethyl acetate, and nbutanolic) from different parts (roots, stem, and leaves) of E. longifolia displayed a dose-dependent antibacterial, antiprotozoal, and antifungal responses. Comparative analysis revealed that the root extract of E. longifolia exhibited the highest antimicrobial efficacy compared to other parts of the plant. Bioactivity-guided fractionation identified that among all of the medicinal compounds isolated/ extracted from different parts of E. longifolia, eurycomanone displayed the strongest antibacterial, antiprotozoal and antifungal activities.

    CONCLUSION: Based on the critical analysis of the literature, we identified that E. longifolia exhibits promising antibacterial, antiprotozoal, and antifungal efficacies against various pathogenic microbes and thus can be considered as a potential complementary and alternative antimicrobial therapy.

    Matched MeSH terms: Anti-Bacterial Agents/chemistry; Antifungal Agents/chemistry; Antiprotozoal Agents/chemistry; Plant Leaves/chemistry; Plant Roots/chemistry; Plant Stems/chemistry; Eurycoma/chemistry*; Phytochemicals/chemistry*
  3. Synthesis and functionalization of chitosan built hydrogel with induced hydrophilicity for extended release of sparingly soluble drugs
    Ullah F, Javed F, Othman MBH, Khan A, Gul R, Ahmad Z, et al.
    J Biomater Sci Polym Ed, 2018 03;29(4):376-396.
    PMID: 29285989 DOI: 10.1080/09205063.2017.1421347
    Addressing the functional biomaterials as next-generation therapeutics, chitosan and alginic acid were copolymerized in the form of chemically crosslinked interpenetrating networks (IPNs). The native hydrogel was functionalized via carbodiimide (EDC), catalyzed coupling of soft ligand (1,2-Ethylenediamine) and hard ligand (4-aminophenol) to replace -OH groups in alginic acid units for extended hydrogel- interfaces with the aqueous and sparingly soluble drug solutions. The chemical structure, Lower solution critical temperature (LCST ≈ 37.88 °C), particle size (Zh,app ≈ 150-200 nm), grain size (160-360 nm), surface roughness (85-250 nm), conductivity (37-74 mv) and zeta potential (16-32 mv) of native and functionalized hydrogel were investigated by using FT-IR, solid state-13C-NMR, TGA, DSC, FESEM, AFM and dynamic light scattering (DLS) measurements. The effective swelling, drug loading (47-78%) and drug release (53-86%) profiles were adjusted based on selective functionalization of hydrophobic IPNs due to electrostatic complexation and extended interactions of hydrophilic ligands with the aqueous and drug solutions. Drug release from the hydrogel matrices with diffusion coefficient n ≈ 0.7 was established by Non- Fickian diffusion mechanism. In vitro degradation trials of the hydrogel with a 20% loss of wet mass in simulated gastric fluid (SGF) and 38% loss of wet mass in simulated intestinal fluid (SIF), were investigated for 400 h through bulk erosion. Consequently, a slower rate of drug loading and release was observed for native hydrogel, due to stronger H-bonding, interlocking and entanglement within the IPNs, which was finely tuned and extended by the induced hydrophilic and functional ligands. In the light of induced hydrophilicity, such functional hydrogel could be highly attractive for extended release of sparingly soluble drugs.
    Matched MeSH terms: Aminophenols/chemistry; Biocompatible Materials/chemistry; Cross-Linking Reagents/chemistry; Drug Carriers/chemistry*; Ethylenediamines/chemistry; Imides/chemistry; Hydrogels/chemistry*; Chitosan/chemistry*
  4. Fulltext Antioxidant and Antidiabetic Effects of Flavonoids: A Structure-Activity Relationship Based Study
    Sarian MN, Ahmed QU, Mat So'ad SZ, Alhassan AM, Murugesu S, Perumal V, et al.
    Biomed Res Int, 2017;2017:8386065.
    PMID: 29318154 DOI: 10.1155/2017/8386065
    The best described pharmacological property of flavonoids is their capacity to act as potent antioxidant that has been reported to play an important role in the alleviation of diabetes mellitus. Flavonoids biochemical properties are structure dependent; however, they are yet to be thoroughly understood. Hence, the main aim of this work was to investigate the antioxidant and antidiabetic properties of some structurally related flavonoids to identify key positions responsible, their correlation, and the effect of methylation and acetylation on the same properties. Antioxidant potential was evaluated through dot blot, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ABTS+ radical scavenging, ferric reducing antioxidant power (FRAP), and xanthine oxidase inhibitory (XOI) assays. Antidiabetic effect was investigated through α-glucosidase and dipeptidyl peptidase-4 (DPP-4) assays. Results showed that the total number and the configuration of hydroxyl groups played an important role in regulating antioxidant and antidiabetic properties in scavenging DPPH radical, ABTS+ radical, and FRAP assays and improved both α-glucosidase and DPP-4 activities. Presence of C-2-C-3 double bond and C-4 ketonic group are two essential structural features in the bioactivity of flavonoids especially for antidiabetic property. Methylation and acetylation of hydroxyl groups were found to diminish the in vitro antioxidant and antidiabetic properties of the flavonoids.
    Matched MeSH terms: Flavonoids/chemistry*; Hypoglycemic Agents/chemistry*; Free Radical Scavengers/chemistry*
  5. Decoration of polylactic acid on graphene oxide for efficient adsorption of methylene blue and tetracycline
    Nouri A, Ang WL, Mahmoudi E, Chua SF, Mohammad AW, Benamor A, et al.
    Chemosphere, 2023 May;322:138219.
    PMID: 36828108 DOI: 10.1016/j.chemosphere.2023.138219
    Decorating nanomaterials on graphene oxide (GO) can enhance its adsorption capacity and removal efficiency of water pollutants. In this study, for the first time, nano-sized polylactic acid (PLA) has been successfully decorated on the surface of GO through a facile synthesis approach. The adsorptive efficiency of GO-PLA for removing methylene blue (MB) and tetracycline (TC) from an aqueous solution was examined. The characterization confirmed the successful decoration of PLA on GO nanosheets with the nano size of PLA. It was hypothesized that the PLA was decorated on the surface of GO through covalent bonding between oxygen-containing functional groups and lactide molecules. The optimum adsorption parameters determined were at the adsorbent dose of 0.5 g L-1, pH 4, contact time of 120 min, and temperature of 318 K. The pseudo-second-order kinetic model described the contaminants' adsorption behaviour, and the intraparticle diffusion model revealed that both surface adsorption and intraparticle diffusion controlled the adsorption process. Langmuir isotherm model best described the adsorption behaviour of the pollutants on GO-PLA and demonstrated the maximum monolayer uptake capacities of MB (332.5 mg g-1) and TC (223.7 mg g-1). The adsorption results indicated that the uptake capacities of GO-PLA in comparison to GO have increased by approximately 70% and 110% for MB and TC, respectively. These observations reflect the remarkable role of nano-sized PLA that enhanced the adsorption capacity due to its additional functional group and larger surface area.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry; Methylene Blue/chemistry; Tetracycline/chemistry
  6. Alginate-based matrix tablets for drug delivery
    Veronica N, Heng PWS, Liew CV
    Expert Opin Drug Deliv, 2023 Jan;20(1):115-130.
    PMID: 36503355 DOI: 10.1080/17425247.2023.2158183
    INTRODUCTION: As a nature-derived polymer with swelling and gelling properties, alginate has found wide biopharma-relevant applications. However, there is comparatively limited attention on alginate in tablet formulations. Therefore, this review aimed to provide an overview of the applications of alginate in solid dosage form formulations.

    AREAS COVERED: This review outlines the role of alginate for oral sustained release formulations. For better insights into its application in drug delivery, the mechanisms of drug release from alginate matrices are discussed alongside the alginate inherent properties and drug properties. Specifically, the influence of alginate properties and formulation components on the resultant alginate gel and subsequent drug release is reviewed. Modifications of the alginate to improve its properties in modulating drug release are also discussed.

    EXPERT OPINION: Alginate-based matrix tablets is useful for sustaining drug release. As a nature-derived polymer, batch consistency and stability raise some concerns about employing alginate in formulations. Furthermore, the alginate gel properties can be affected by formulation components, pH of the dissolution environment and the tablet matrix micro-environment pH. Conscientious efforts are pivotal to addressing these formulation challenges to increase the utilization of alginate in oral solid dosage forms.

    Matched MeSH terms: Hexuronic Acids/chemistry; Tablets/chemistry; Glucuronic Acid/chemistry
  7. Titanium dioxide-based sonophotocatalytic mineralization of bisphenol A and its intermediates
    Sunasee S, Wong KT, Lee G, Pichiah S, Ibrahim S, Park C, et al.
    Environ Sci Pollut Res Int, 2017 Jun;24(18):15488-15499.
    PMID: 28512708 DOI: 10.1007/s11356-017-9124-0
    In this study, bisphenol A (BPA) removal by sonophotocatalysis coupled with commercially available titanium dioxide (TiO2, P25) was assessed in batch tests using energy-based advanced oxidation combining ultrasound (US) and ultraviolet (UV). The kinetics of BPA removal were systematically evaluated by changing operational parameters, such as US frequency and power, mechanical stirring speed, and temperature, but also comparison of single and coupled systems under the optimum US conditions (35 kHz, 50 W, 300 rpm stirring speed, and 20 °C). The combination of US/UV/P25 exhibited the highest BPA removal rate (28.0 × 10-3 min-1). In terms of the synergy index, the synergistic effect of sonophotocatalysis was found to be 2.2. This indicated that sonophotocatalysis has a considerably higher removal efficiency than sonocatalysis or photocatalysis. The removal of BPA was further investigated to identify BPA byproducts and intermediates using high-performance liquid chromatography-mass spectrometry. Five main intermediates were formed during sonophotocatalytic degradation, and complete removal of BPA and its intermediates was obtained after 3 h of operation. The degradation pathway of BPA by sonophotocatalysis was also elucidated.
    Matched MeSH terms: Benzhydryl Compounds/chemistry*; Environmental Pollutants/chemistry*; Phenols/chemistry*
  8. Catalytic microwave pyrolysis of oil palm fiber (OPF) for the biochar production
    Hossain MA, Ganesan PB, Sandaran SC, Rozali SB, Krishnasamy S
    Environ Sci Pollut Res Int, 2017 Dec;24(34):26521-26533.
    PMID: 28948458 DOI: 10.1007/s11356-017-0241-6
    Microwave pyrolysis of oil palm fiber (OPF) with three types of Na-based catalysts was experimentally investigated to produce biochar. Sodium hydroxide (NaOH), sodium chloride (NaCl), and sodium carbonate (Na2CO3) with purity 99.9% were selected for this investigation. Microwave muffle reactor (Model: HAMiab-C1500) with a microwave power controller including a microwave generator was used to perform the microwave pyrolysis. OPF particles were used after removing foreign materials, impurities, and dust. Microwave power ranges from 400 to 900 W, temperature ranges from 450 to 700 °C, and N2 flow rates ranges from 200 to -1200 cm3/min were used along with all three Na-based catalysts for this investigation. Lower microwave power, temperature, and N2 flow rate have been found favorable for higher yield of biochar. NaOH is to be found as the more suitable catalyst than NaCl and Na2CO3 to produce biochar. A maximum biochar yield (51.42 wt%) has been found by using the catalysts NaOH at N2 flow rate of 200 cm3/min. One sample of the biochar (maximum yield without catalysts) was selected for further characterization via thermo gravimetric analysis (TGA), scanning electron microscopy (SEM), BET surface area, Fourier transform infrared spectroscopy (FTIR), and ultimate and proximate analysis. SEM and BET surface area analysis showed the presence of some pores in the biochar. High percentage of carbon (60.24 wt%) was also recorded in the sample biochar. The pores and high percentage of carbon of biochar have significant impact on soil fertilization by increasing the carbon sequestration in the soil. It assists to slow down the decomposition rate of nutrients from soil and therefore enhances the soil quality.
    Matched MeSH terms: Charcoal/chemistry*; Soil/chemistry*; Arecaceae/chemistry*
  9. Biochar efficiency in pesticides sorption as a function of production variables--a review
    Yavari S, Malakahmad A, Sapari NB
    Environ Sci Pollut Res Int, 2015 Sep;22(18):13824-41.
    PMID: 26250816 DOI: 10.1007/s11356-015-5114-2
    Biochar is a stabilized, carbon-rich by-product derived from pyrolysis of biomass. Recently, biochar has received extensive attentions because of its multi-functionality for agricultural and environmental applications. Biochar can contribute to sequestration of atmosphere carbon, improvement of soils quality, and mitigation of environmental contaminations. The capability of biochar for specific application is determined by its properties which are predominantly controlled by source material and pyrolysis route variables. The biochar sorption potential is a function of its surface area, pores volume, ash contents, and functional groups. The impacts of each production factors on these characteristics of biochar need to be well-understood to design efficient biochars for pesticides removal. The effects of biomass type on biochar sorptive properties are determined by relative amounts of its lingo-cellulosic compounds, minerals content, particles size, and structure. The highest treatment temperature is the most effective pyrolysis factor in the determination of biochar sorption behavior. The expansion of micro-porosity and surface area and also increase of biochar organic carbon content and hydrophobicity mostly happen by pyrolysis peak temperature rise. These changes make biochar suitable for immobilization of organic contaminants. Heating rate, gas pressure, and reaction retention time after the pyrolysis temperatures are sequentially important pyrolysis variables effective on biochar sorptive properties. This review compiles the available knowledge about the impacts of production variables on biochars sorptive properties and discusses the aging process as the main factor in post-pyrolysis alterations of biochars sorption capacity. The drawbacks of biochar application in the environment are summarized as well in the last section.
    Matched MeSH terms: Charcoal/chemistry*; Environmental Pollutants/chemistry*; Pesticides/chemistry*
  10. Simultaneous removal of potent cyanotoxins from water using magnetophoretic nanoparticle of polypyrrole: adsorption kinetic and isotherm study
    Hena S, Rozi R, Tabassum S, Huda A
    Environ Sci Pollut Res Int, 2016 Aug;23(15):14868-80.
    PMID: 27072032 DOI: 10.1007/s11356-016-6540-5
    Cyanotoxins, microcystins and cylindrospermopsin, are potent toxins produced by cyanobacteria in potable water supplies. This study investigated the removal of cyanotoxins from aqueous media by magnetophoretic nanoparticle of polypyrrole adsorbent. The adsorption process was pH dependent with maximum adsorption occurring at pH 7 for microcystin-LA, LR, and YR and at pH 9 for microcystin-RR and cylindrospermopsin (CYN). Kinetic studies and adsorption isotherms reflected better fit for pseudo-second-order rate and Langmuir isotherm model, respectively. Thermodynamic calculations showed that the cyanotoxin adsorption process is endothermic and spontaneous in nature. The regenerated adsorbent can be successfully reused without appreciable loss of its original capacity.
    Matched MeSH terms: Polymers/chemistry*; Pyrroles/chemistry*; Magnetite Nanoparticles/chemistry*
  11. Electrochemical oxidation of azo dyes degradation by RuO2-IrO2-TiO2 electrode with biodegradation Aeromonas hydrophila AR1 and its degradation pathway: An integrated approach
    Abilaji S, Narenkumar J, Das B, S S, Rajakrishnan R, Sathishkumar K, et al.
    Chemosphere, 2023 Dec;345:140516.
    PMID: 37879370 DOI: 10.1016/j.chemosphere.2023.140516
    Azo dyes are the most varied class of synthetic chemicals with non-degradable characteristics. They are complex compounds made up of many different parts. It was primarily utilized for various application procedures in the dyeing industry. Therefore, it's crucial to develop an economical and environmentally friendly approach to treating azo dyes. Our present investigation is an integrated approach to the electrooxidation (EO) process of azo dyes using RuO2-IrO2-TiO2 (anode) and titanium mesh (cathode) electrodes, followed by the biodegradation process (BD) of the treated EO dyes. Chemical oxygen demand (COD) removal efficiency as follows MB (55%) ≥ MR (45%) ≥ TB (38%) ≥ CR (37%) correspondingly. The fragment generated during the degradation process which was identified with high-resolution mass spectrometry (HRMS) and its degradation mechanism pathway was proposed as demethylation reaction and N-N and C-N/C-S cleavage reaction occurs during EO. In biodegradation studies by Aeromonas hydrophila AR1, the EO treated dyes were completely mineralized aerobically which was evident by the COD removal efficiency as MB (98%) ≥ MR (92.9%) ≥ TB (88%) ≥ CR (87%) respectively. The EO process of dyes produced intermediate components with lower molecular weights, which was effectively utilized by the Aeromonas hydrophila AR1 and resulted in higher degradation efficiency 98%. We reported the significance of the enhanced approach of electrochemical oxidation with biodegradation studies in the effective removal of the pollutants in dye industrial effluent contaminated water environment.
    Matched MeSH terms: Azo Compounds/chemistry; Coloring Agents/chemistry; Titanium/chemistry
  12. Promises of Molecular Pharmaceutics in the Development of Novel Drug Delivery Formulations
    Kumar P, Chaudhary B, Jain V, Baboota S, Shivanandy P, Alharbi KS, et al.
    Curr Drug Deliv, 2023;20(9):1262-1274.
    PMID: 36380413 DOI: 10.2174/1567201820666221114113637
    Molecular pharmaceutics play a critical role in the drug delivery system, representing the direct interconnection of drug bioavailability with its molecular form. There is a diversity in the molecular structures by which it affects its properties, such as amorphous form, crystalline form, partialamorphous molecular dispersion, and disordered state. The active pharmaceutical ingredient (API) and the excipients utilized in the formulation process contain various divergent modes used in the formulation process. They include better formulations of any type to obtain good quality pharmaceutical products. This review reveals how the molecular states affect the API and are important in maintaining the quality of dosage forms. Furthermore, the physio-chemical properties of the components and various pharmaceutical approaches employed in the formulation of dosage forms are studied from the point of view of molecular pharmaceutics.
    Matched MeSH terms: Chemistry, Pharmaceutical*; Excipients/chemistry
  13. Pectin-interactions and the digestive stability of anthocyanins in thermal and non-thermal processed strawberry pulp
    Xing Y, Wang K, Zhang M, Law CL, Lei H, Wang J, et al.
    Food Chem, 2023 Oct 30;424:136456.
    PMID: 37267648 DOI: 10.1016/j.foodchem.2023.136456
    This study investigated the digestive stability of anthocyanins (ACNs) and their interaction with three pectin fractions-water-soluble pectin (WSP), cyclohexanetrans-1,2-diamine tetra-acetic acid-soluble pectin (CSP), and sodium carbonate-soluble pectin (NSP)-in strawberry pulp processed by pasteurization (PS), ultrasound (US), electron beam (EB) irradiation, and high pressure (HP). Compared with the control group, the ACNs content increased to the highest level (312.89 mg/mL), but the retention rate of ACNs in the simulated intestine decreased significantly after US treatment. The monosaccharide compositions indicated that the WSP and CSP possessed more homogalacturonan (HG) domains than the NSP, which contains more rhamngalacturonan-I (RG-I) domains. The microstructure of US-treated pectin was damaged and fragmented. Comprehensive analysis showed that the retention rate of ACNs was closely related to the pectin structure, primarily reflected by the degree of linearity and the integrity of structure. These results revealed the structure-activity relationship between ACNs and pectin during pulp processing.
    Matched MeSH terms: Anthocyanins/chemistry; Pectins/chemistry; Water/chemistry
  14. Fulltext From Green Remediation to Polymer Hybrid Fabrication with Improved Optical Band Gaps
    Brza MA, Aziz SB, Anuar H, Al Hazza MHF
    Int J Mol Sci, 2019 Aug 11;20(16).
    PMID: 31405255 DOI: 10.3390/ijms20163910
    The present work proposed a novel approach for transferring high-risk heavy metals tometal complexes via green chemistry remediation. The method of remediation of heavy metals developed in the present work is a great challenge for global environmental sciences and engineering because it is a totally environmentally friendly procedure in which black tea extract solution is used. The FTIR study indicates that black tea contains enough functional groups (OH and NH), polyphenols and conjugated double bonds. The synthesis of copper complex was confirmed by the UV-vis, XRD and FTIR spectroscopic studies. The XRD and FTIR analysis reveals the formation of complexation between Cu metal complexes and Poly (Vinyl Alcohol) (PVA) host matrix. The study of optical parameters indicates that PVA-based hybrids exhibit a small optical band gap, which is close to inorganic-based materials. It was noted that the absorption edge shifted to lower photon energy. When Cu metal complexes were added to PVA polymer, the refractive index was significantly tuned. The band gap shifts from 6.2 eV to 1.4 eV for PVA incorporated with 45 mL of Cu metal complexes. The nature of the electronic transition in hybrid materials was examined based on the Taucs model, while a close inspection of the optical dielectric loss was also performed in order to estimate the optical band gap. The obtained band gaps of the present work reveal that polymer hybrids with sufficient film-forming capability could be useful to overcome the drawbacks associated with conjugated polymers. Based on the XRD results and band gap values, the structure-property relationships were discussed in detail.
    Matched MeSH terms: Copper/chemistry*; Plant Extracts/chemistry; Polyvinyl Alcohol/chemistry*; Tea/chemistry*; Green Chemistry Technology/methods; Coordination Complexes/chemistry*; Polyphenols/chemistry*
  15. Structural Basis for the Effects of Phenylalanine on Tuning the Reduction Potential of Type 1 Copper in Azurin
    Liu Y, Marshall NM, Yu SS, Kim W, Gao YG, Robinson H, et al.
    Inorg Chem, 2023 Jul 24;62(29):11618-11625.
    PMID: 37424080 DOI: 10.1021/acs.inorgchem.3c01365
    In order to investigate the effects of the secondary coordination sphere in fine-tuning redox potentials (E°') of type 1 blue copper (T1Cu) in cupredoxins, we have introduced M13F, M44F, and G116F mutations both individually and in combination in the secondary coordination sphere of the T1Cu center of azurin (Az) from Pseudomonas aeruginosa. These variants were found to differentially influence the E°' of T1Cu, with M13F Az decreasing E°', M44F Az increasing E°', and G116F Az showing a negligible effect. In addition, combining the M13F and M44F mutations increases E°' by 26 mV relative to WT-Az, which is very close to the combined effect of E°' by each mutation. Furthermore, combining G116F with either M13F or M44F mutation resulted in negative and positive cooperative effects, respectively. Crystal structures of M13F/M44F-Az, M13F/G116F-Az, and M44F/G116F-Az combined with that of G116F-Az reveal these changes arise from steric effects and fine-tuning of hydrogen bond networks around the copper-binding His117 residue. The insights gained from this study would provide another step toward the development of redox-active proteins with tunable redox properties for many biological and biotechnological applications.
    Matched MeSH terms: Copper/chemistry; Phenylalanine/chemistry; Pseudomonas aeruginosa/chemistry
  16. Fulltext A Review on Plants and Microorganisms Mediated Synthesis of Silver Nanoparticles, Role of Plants Metabolites and Applications
    Mustapha T, Misni N, Ithnin NR, Daskum AM, Unyah NZ
    Int J Environ Res Public Health, 2022 Jan 07;19(2).
    PMID: 35055505 DOI: 10.3390/ijerph19020674
    Silver nanoparticles are one of the most extensively studied nanomaterials due to their high stability and low chemical reactivity in comparison to other metals. They are commonly synthesized using toxic chemical reducing agents which reduce metal ions into uncharged nanoparticles. However, in the last few decades, several efforts were made to develop green synthesis methods to avoid the use of hazardous materials. The natural biomolecules found in plants such as proteins/enzymes, amino acids, polysaccharides, alkaloids, alcoholic compounds, and vitamins are responsible for the formation of silver nanoparticles. The green synthesis of silver nanoparticles is an eco-friendly approach, which should be further explored for the potential of different plants to synthesize nanoparticles. In the present review we describe the green synthesis of nanoparticles using plants, bacteria, and fungi and the role of plant metabolites in the synthesis process. Moreover, the present review also describes some applications of silver nanoparticles in different aspects such as antimicrobial, biomedicine, mosquito control, environment and wastewater treatment, agricultural, food safety, and food packaging.
    Matched MeSH terms: Plant Extracts/chemistry; Green Chemistry Technology/methods
  17. Biomimetic oxidative dimerization of anodically generated stilbene radical cations: effect of aromatic substitution on product distribution and reaction pathways
    Hong FJ, Low YY, Chong KW, Thomas NF, Kam TS
    J Org Chem, 2014 May 16;79(10):4528-43.
    PMID: 24754525 DOI: 10.1021/jo500559r
    A systematic study of the electrochemical oxidation of 1,2-diarylalkenes was carried out with the focus on detailed product studies and variation of product type as a function of aromatic substitution. A reinvestigation of the electrochemical oxidation of 4,4'-dimethoxystilbene under various conditions was first carried out, and all products formed were fully characterized and quantitated. This was followed by a systematic investigation of the effect of aromatic substitution on the nature and distribution of the products. The aromatic substituents were found to fall into three main categories, viz., substrates in which the nature and position of the aromatic substituents gave rise to essentially the same products as 4,4'-dimethoxystilbene, for example, tetraaryltetrahydrofurans, dehydrotetralins, and aldehydes (p-MeO or p-NMe2 on one ring and X on the other ring, where X = o-MeO or p-alkyl, or m- or p-EWG; e.g., 4-methoxy-4'-trifluoromethylstilbene); those that gave rise to a mixture of indanyl (or tetralinyl) acetamides and dehydrotetralins (or pallidols) (both or one ring substituted by alkyl groups, e.g., 4,4'-dimethylstilbene); and those where strategic placement of donor groups, such as OMe and OH, led to the formation of ampelopsin F and pallidol-type carbon skeletons (e.g., 4,3',4'-trimethoxystilbene). Reaction pathways to rationalize the formation of the different products are presented.
    Matched MeSH terms: Cations/chemistry*; Electrochemistry; Flavonoids/chemistry; Stilbenes/chemistry*
  18. Antibacterial and antibiotic potentiating capabilities of extracts isolated from Burkillanthus malaccensis, Diospyros hasseltii and Cleisthanthus bracteosus against human pathogenic bacteria
    Kathirvalu G, Chandramathi S, S A A, Atiya N, Begum S, Christophe W, et al.
    Trop Biomed, 2023 Jun 01;40(2):152-159.
    PMID: 37650400 DOI: 10.47665/tb.40.2.004
    Antibiotics which once a boon in medicine and saved millions of lives are now facing an ever-growing menace of antibacterial resistance, which desperately needs new antibacterial drugs which are innovative in chemistry and mode of action. For many years, the world has turned to natural plants with antibacterial properties to combat antibiotic resistance. On that basis, we aimed to identify plants with antibacterial and antibiotic potentiating properties. Seventeen different extracts of 3 plants namely Burkillanthus malaccensis, Diospyros hasseltii and Cleisthanthus bracteosus were tested against multi-drug resistant Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Methicillinresistant Staphylococcus aureus (MRSA) and methicillin-susceptible Staphylococcus aureus (MSSA). Antibacterial activity of hexane, methanol and chloroform extracts of bark, seed, fruit, flesh and leaves from these plants were tested using, disk diffusion assay, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. Antibiotic potentiating capabilities were tested using time-kill assay. B. malaccensis fruit chloroform extract showed the biggest zone of inhibition against MRSA (13.00±0.0 mm) but C. bracteosus bark methanol extract showed the biggest inhibition zone against MSSA (15.33±0.6 mm). Interestingly, bark methanol extract of C. bracteosus was active against MRSA (8.7±0.6 mm), MSSA (7.7±0.6 mm) (Gram-positive) and A. baumannii (7.7±0.6 mm) (Gram-negative). Overall, the leaf methanol and bark methanol extract of C. bracteosus warrants further investigation such as compound isolation and mechanism of action for validating its therapeutic use as antibiotic potentiator importantly against MRSA and A. baumannii.
    Matched MeSH terms: Rutaceae/chemistry; Diospyros/chemistry; Phyllanthus/chemistry
  19. A review on natural based deep eutectic solvents (NADESs): fundamentals and potential applications in removing heavy metals from soil
    Lai ZY, Yiin CL, Lock SSM, Chin BLF, Zauzi NSA, Sar-Ee S
    Environ Sci Pollut Res Int, 2023 Nov;30(55):116878-116905.
    PMID: 36917382 DOI: 10.1007/s11356-023-26288-8
    Natural based deep eutectic solvent (NADES) is a promising green solvent to replace the conventional soil washing solvent due to the environmental benign properties such as low toxicity, high biodegradability, high polarity or hydrophilicity, and low cost of fabrication process. The application of NADES is intensively studied in the extraction of organic compounds or natural products from vegetations or organic matters. Conversely, the use of the solvent in removing heavy metals from soil is severely lacking. This review focuses on the potential application of NADES as a soil washing agent to remove heavy metal contaminants. Hydrophilicity is an important feature of a NADES to be used as a soil washing solvent. In this context, choline chloride is often used as hydrogen bond acceptor (HBA) whereby choline chloride based NADESs showed excellent performance in the extraction of various solutes in the past studies. The nature of NADES along with its chemistry, preparation and designing methods as well as potential applications were comprehensively reviewed. Subsequently, related studies on choline chloride-based NADES in heavy metal polluted soil remediation were also reviewed. Potential applications in removing other soil contaminants as well as the limitations of NADES were discussed based on the current advancements of soil washing and future research directions were also proposed.
    Matched MeSH terms: Choline/chemistry; Plant Extracts/chemistry; Solvents/chemistry
  20. Fulltext The impact of aqueous and N-hexane extracts of three Fabaceae species on seed germination and seedling growth of some broadleaved weed species
    Safdar ME, Wang X, Abbas M, Ozaslan C, Asif M, Adnan M, et al.
    PLoS One, 2021;16(11):e0258920.
    PMID: 34739485 DOI: 10.1371/journal.pone.0258920
    Weed infestation is a persistent problem for centuries and continues to be major yield reducing issue in modern agriculture. Chemical weed control through herbicides results in numerous ecological, environmental, and health-related issues. Moreover, numerous herbicides have evolved resistance against available herbicides. Plant extracts are regarded as an alternative to herbicides and a good weed management option. The use of plant extracts is environmentally safe and could solve the problem of herbicide resistance. Therefore, laboratory and wire house experiments were conducted to evaluate the phytotoxic potential of three Fabaceae species, i.e., Cassia occidentalis L. (Coffee senna), Sesbania sesban (L.) Merr. (Common sesban) and Melilotus alba Medik. (White sweetclover) against seed germination and seedling growth of some broadleaved weed species. Firstly, N-hexane and aqueous extracts of these species were assessed for their phytotoxic effect against lettuce (Lactuca sativa L.). The extracts found more potent were further tested against germination and seedling growth of four broadleaved weed species, i.e., Parthenium hysterophorus L. (Santa-Maria), Trianthema portulacastrum L. (Pigweed), Melilotus indica L (Indian sweetclover). and Rumex dentatus L. (Toothed dock) in Petri dish and pot experiments. Aqueous extracts of all species were more toxic than their N-hexane forms for seed germination and seedling growth of lettuce; therefore, aqueous extracts were assessed for their phytotoxic potential against four broadleaved weed species. Aqueous extracts of all species proved phytotoxic against T. portulacastrum, P. hysterophorus, M. indica and R. dentatus and retarder their germination by 57, 90, 100 and 58%, respectively. Nevertheless, foliar spray of C. occidentalis extract was the most effective against T. portulacastrum as it reduced its dry biomass by 72%, while M. alba was effective against P. hysterophorus, R. dentatus and M. indica and reduced their dry biomass by 55, 68 and 81%, respectively. It is concluded that aqueous extracts of M. alba, S. sesban and C. occidentalis could be used to retard seed germination of T. portulacastrum, P. hysterophorus, M. indica and R. dentatus. Similarly, aqueous extracts of C. occidentalis can be used to suppress dry biomass of T. portulacastrum, and those of M. alba against P. hysterophorus, R. dentatus. However, use of these extracts needs their thorough testing under field conditions.
    Matched MeSH terms: Herbicides/chemistry; Hexanes/chemistry; Fabaceae/chemistry*; Plant Extracts/chemistry*; Water/chemistry; Lettuce/chemistry; Melilotus/chemistry; Rumex/chemistry
Related Terms
Filters
Contact Us

Please provide feedback to Administrator ([email protected])

External Links