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1.
RSC Adv ; 14(21): 14992-15007, 2024 May 02.
Article in English | MEDLINE | ID: mdl-38720988

ABSTRACT

This work explores one centrosymmetric binuclear Cu(ii)-Salen complex synthesis, characterization, photosensitive Schottky barrier diode (PSBD) function, and DFT spectrum. The crystal growth involves H2LSAL and Cu(NO3)2·3H2O in CH3OH + ACN (acetonitrile) solvent medium. Herein, structural characterization employs elemental, IR/Raman, NMR, UV-VIS, DRS, SEM-EDX, PXRD, SCXRD, and XPS analyses. The complex crystal size is 0.2 × 0.2 × 0.2, showing monoclinic space group C2/c. The dimeric unit contains two Cu(ii) centres with distorted square pyramidal (SQP) geometries. The crystal packing consists of weak C-H⋯O interactions. DFT and Hirshfeld surface (HS) further substantiated the packing interactions, providing valuable insights into the underlying mechanisms. The 2-D fingerprint plots showed the presence of N⋯H (3%) and O⋯H (8.2%) contacts in the molecular arrangement. NBO, QTAIM, ELF-LOL, and energy frameworks are utilized to investigate the bonding features of the complex. We extensively studied electrical conductivity and PSBD for H2LSAL and the complex based on band gap (3.09 and 3.07 eV). Like an SBD, the complex has better electrical conductivity, evidencing potentiality in optoelectronic device applications. Optical response enhances conductivity, according to I-V characteristics. Complex Schottky diode has lower barrier height, resistance, and higher conductivity under light. The complex transports charge carriers through space and is rationalized by the 'hopping process' and 'structure-activity-relationship' (SAR). The charge transport mechanism was analysed by estimating complex mobility (µeff), lifetime (τ), and diffusion length (LD). The experimental and theoretical DOS/PDOS plots provide evidence for the Schottky diode function of the complex.

2.
Int J Biol Macromol ; 168: 743-749, 2021 Jan 31.
Article in English | MEDLINE | ID: mdl-33232703

ABSTRACT

A new water soluble galactoglucan with apparent molecular weight ~1.61 × 105 Da, was isolated from the edible mushroom Pleurotus djamor by hot water extraction followed by purification through dialysis tubing cellulose membrane and sepharose 6B column chromatography. The sugar analysis showed the presence of glucose and galactose in a molar ratio of nearly 3:1 respectively. The structure of the repeating unit in the polysaccharide was determined through chemical and NMR experiments as: In vitro antioxidant studies showed that the PDPS exhibited hydroxyl radical scavenging activity (EC50 = 1.681 ± 0.034 mg/mL), DPPH radical scavenging activity (EC50 = 3.83 ± 0.427 mg/mL), reducing power (EC50 = 4.258 ± 0.095 mg/mL), and ABTS radical quenching activity (EC50 = 0.816 ± 0.077 mg/mL). So, PDPS should be explored as a natural antioxidant.


Subject(s)
Antioxidants/pharmacology , Galactans/pharmacology , Glucans/pharmacology , Pleurotus/chemistry , Polysaccharides, Bacterial/pharmacology , Antioxidants/chemistry , Biphenyl Compounds/chemistry , Carbohydrate Sequence , Chromatography , Galactans/chemistry , Galactose/chemistry , Glucans/chemistry , Glucose/chemistry , Molecular Weight , Picrates/chemistry , Polysaccharides, Bacterial/chemistry
3.
Int J Biol Macromol ; 162: 1025-1034, 2020 Nov 01.
Article in English | MEDLINE | ID: mdl-32599238

ABSTRACT

A green synthesis of silver nanoparticles was synthesized by AgNO3 with arabinoxylan, isolated from green stem of Andrographis paniculata (Kalmegh). The synthesized Ag NPs-arabinoxylan conjugates were characterized by UV-vis spectroscopy, FE-SEM, TEM, XRD, TGA, EDX, and Zeta potential experiments. The Ag NPs formation was established by the surface plasmon resonance band ~410.25 nm. SEM image showed mostly spherical morphology of Ag NPs. The fcc crystalline nature was identified by XRD, SAED and the size were 24.5 and 25 nm from TEM and XRD analysis respectively. The prepared Ag NPs showed dose-dependent antimicrobial activity against Streptococcus pneumonia, Candida albicans and E. coli. The nanoparciles damage 4% hemolysis to human RBCs at 12.5 µg/mL. MTT assay of Ag NPs showed that half of the cell killed at 10 µg/mL and wound healing assay observed effective inhibition cell proliferation.


Subject(s)
Acanthaceae/chemistry , Anti-Infective Agents , Candida albicans/growth & development , Escherichia coli/growth & development , Metal Nanoparticles/chemistry , Streptococcus pneumoniae/growth & development , Xylans/chemistry , Anti-Infective Agents/chemistry , Anti-Infective Agents/pharmacology , Green Chemistry Technology , Silver/chemistry , Silver/pharmacology , Xylans/isolation & purification
4.
Langmuir ; 35(47): 15306-15314, 2019 11 26.
Article in English | MEDLINE | ID: mdl-31689362

ABSTRACT

The interfacial and micellization behavior of three dicarboxylic amino acid-based anionic surfactants, abbreviated as AAS (N-dodecyl derivative of -aminomalonate, -aspartate, and -glutamate) in combination with hexadecyltrimethylammonium bromide (HTAB) were investigated by surface tension, conductance, UV-vis absorption/emission spectroscopy, dynamic light scattering (DLS), and viscosity studies. Critical micelle concentration (CMC) values of the surfactant mixtures are significantly lower than the predicted values, indicating associative interaction between the components. Surface excess, limiting molecular area, surface pressure at the CMC, and Gibbs free energy indicate spontaneity of the micellization processes compared to the pure components. CMC values were also determined from the sigmoidal variation in the plot of micellar polarity and pyrene UV-vis absorption/emission intensities with surfactant concentration. The aggregation number, determined by static fluorescence quenching method, increases with decreasing mole fraction of the AAS (αAAS), where the micelles are mainly dominated by the HTAB molecules. The size of the micelle increases with decreasing αAAS, leading to the formation of larger and complex aggregates, as also supported by the viscosity studies. Micelles comprising 20-40 mol % AAS are highly viscous, in consonance with their sizes. Some of the mixed surfactant systems show unusual viscosity (shear thickening and increased viscosity with increasing temperature). Such mixed surfactant systems are considered to have potential in gel-based drug delivery and nanoparticle synthesis.

5.
Carbohydr Polym ; 222: 114990, 2019 Oct 15.
Article in English | MEDLINE | ID: mdl-31320072

ABSTRACT

A water insoluble ß-glucan (PS), with molecular mass ∼9.16 × 104 Da was isolated from the 4% alkaline extract of an edible mushroom, Pleurotus djamor and found to consist of (1→3)-ß-d-glucopyranosyl moiety. The structure of the PS was elucidated on the basis of total hydrolysis, methylation analysis, periodate oxidation, and NMR experiments (1H, 13C, DQF-COSY, DEPT-135, and HSQC). The structure of the repeating unit of the polysaccharide was established as: →3)-ß-d-Glcp-(1→. The water insoluble ß-glucan showed cytotoxic effect against PA1 cells, where˜50% population was destroyed at 100 µg/mL concentration, and almost all cells at 250 µg/mL concentration. The wound healing assay showed significant anticarcinogenic effect against ovarian carcinoma PA1 cells after 48 h of treatment.


Subject(s)
Antineoplastic Agents/pharmacology , Ovarian Neoplasms/drug therapy , Pleurotus/metabolism , beta-Glucans , Carbohydrate Sequence , Female , Humans , Solubility , Tumor Cells, Cultured , beta-Glucans/chemistry , beta-Glucans/pharmacology
6.
Carbohydr Polym ; 212: 297-303, 2019 May 15.
Article in English | MEDLINE | ID: mdl-30832860

ABSTRACT

A water soluble arabinoxylan (APPS), with a molecular weight ∼1.49 × 105 Da was isolated from the green stem of Andrographis paniculata. The APPS contained D-xylose, 2-methoxy D-xylose and L- arabinose in molar ratio of 3:1:1. The structure of the repeating unit in the polysaccharide was determined through several chemical (acid hydrolysis, Methylation analysis and periodate oxidation) and spectroscopic analysis (1D/2D NMR experiments) as: In vitro antioxidant assay, APPS was found to possess ferrous ion chelating activity (EC50 = 283 µg/ml), superoxide radical scavenging activity (EC50 = 470 µg/ml), and hydroxide radical scavenging activity (EC50 = 193 µg/ml). Thus, APPS could be used as a natural antioxidant agent for food and pharmaceutical industries.


Subject(s)
Andrographis , Antioxidants/chemistry , Plant Extracts/chemistry , Plant Stems , Xylans/chemistry , Antioxidants/isolation & purification , Free Radical Scavengers/chemistry , Free Radical Scavengers/isolation & purification , Plant Extracts/isolation & purification , Structure-Activity Relationship , Xylans/isolation & purification
7.
J Fluoresc ; 24(4): 1245-51, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24908400

ABSTRACT

The recognition ability of N-Furfurylsalicylaldimine (HL) toward various cations (Pb(2+), Hg(2+), Ba(2+), Cd(2+), Ag(+), Zn(2+), Cu(2+), Ni(2+), Co(2+), K(+), Sr(2+), and Na(+)) has been studied by UV-Vis and fluorescence spectroscopy. The compound showed highly selective fluorescence signaling behaviour for Zn(2+) ions in methanol-water medium based on CHEF process and is capable of distinguishing Zn(2+) from Cd(2+) ion. From single crystal X-ray analysis it is revealed that a Zn(2+) ion binds two ligand molecules through imine nitrogen and phenolate oxygen atom.

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