Green synthesis, characterization, and antibacterial activity of silver nanoparticles using stem extract of Zanthoxylum armatum.

In this study, we report the green synthesis of silver nanoparticles (AgNPs) using Zanthoxylum armatum stem extract. The characteristic absorption at 385 nm suggested synthesis of AgNPs which was further confirmed by SEM, with a size in the range of 46.66 nm to 60.12 nm and a spherical shape, having an FCC structure, analyzed by XRD. FTIR analysis revealed the presence of phenol and secondary alcohol groups over the AgNPS. The elemental composition was further investigated by FESEM-EDX analysis which revealed the presence of silver in the synthesis nanoparticles. The synthesized silver nanoparticles exhibited antimicrobial activity against tested microorganisms with a zone of inhibition of 21 mm for Staphylococcus aureus, 17 mm for Pseudomonas aeruginosa, 18 mm for Salmonella enteric, and 18 mm for Escherichia coli. Overall, the results showed that the green silver nanoparticles could be safe, as they are capable of potential antimicrobial activity against S. aureus.

Green synthesis, characterization, antibacterial activity of metal nanoparticles and composite oxides using leaves extract of Ocimum basilicum L.

Nanoparticles plays a key role in the development of novel antibacterial substances against various pathogenic microorganisms. These nanoparticles due to their smaller size could be very effective as they can improve the antibacterial activity through lysis of bacterial cell wall. In the present research work, ZnO, MgO, NiO, AlO nanoparticles, and MgNiO, and AlZnO composite oxides were synthesized by green method from Ocimum basilicum leaves extract. The nanoparticles formed were evaluated using FTIR, XRD, EDX, and SEM to confirm the formation of NPs and to determine the morphology, elemental composition, shape and size, composition, and nature of bonds present in the NPs. Further, the NPs were tested for their antibacterial activity. In particular, ZnO NPs showed a good inhibitory effect against Pseudomonas aeruginosa with 20 mm zone of inhibition. Hence, the process reported herein could be optimized for large-scale preparation of NPs. RESEARCH HIGHLIGHTS: Green synthesis of ZnO, MgO, NiO, AlO nanoparticles, and MgNiO, and AlZnO composite oxides using Ocimum basilicum leaves extract NPs were characterized by various established characterization techniques like FTIR, XRD, EDX, and SEM. NPs showed antibacterial activity which was investigated by agar well diffusion method against Bacillus cereus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus. The method proved to be very simple, cost-efficient, and convenient.

Phytochemical screening, green synthesis of gold nanoparticles, and antibacterial activity using seeds extract of Ricinus communis L.

In the current research study, the phytochemical tests of the Ricinus communis L methanolic extract detected the presence of coumarin, reducing sugar, emodines, terpenoids, flavonoids, and steroids while water extract showed the presence of alkaloids, terpenoids, steroids, and soluble starch. The methanolic extract was further subjected to synthesize Au nanoparticles. The synthesized nanoparticles were confirmed by UV-Vis through the appearance of a peak at 550 nm which correspond to the existence of Au nanoparticles. The size and morphology of synthesized nanoparticle were further studied by the dynamic light scattering technique which shows that nanoparticles were in the range of 100 nm which were further confirmed by transmission electron microscopy. The synthesized nanoparticles and extracts were tested against different bacterial strains. The results revealed that methanolic extract showed maximum inhibition of 19.5 mm against Klebsiella pneumoniae and 20.33 mm against Bacillus cereus while water extract showed maximum inhibition of 18.16 mm against Pseudomonas aeruginosa and 19.33 mm against B. cereus. On the other hand, Au nanoparticles showed maximum inhibition of 18.5 mm against Escherichia coli.

The Effect of AlI3 Nanoadditive on the Thermal Behavior of PMMA Subjected to Thermoanalytical Py-GC-MS Technique.

Thermal degradation of polymethylmethacrylate (PMMA) was studied by using inorganic salt of aluminum triiodide (AlI3). The composites of PMMA were prepared with AlI3 by changing the concentration of the AlI3 additive from 2% to 10% (w/w). The PMMA composites with AlI3 were characterized by TGA, DTG, SEM, FTIR, HBT, and Py-GC-MS techniques. The FTIR peaks of PMMA composite at 1316, 786, and 693 cm-1 justify the chemical association between PMMA and AlI3. TGA study shows that the stability of PMMA is enhanced by the addition of the AlI3 additive. SEM analysis represented that there is a relationship between polymer and additive when they are mixed at the molecular level. The horizontal burning test (HBT) also confirmed that the AlI3 additive produced the flame retarding properties in PMMA polymer. The burning rate of composite with 10% of AlI3 additive decreases five times as much as compared to pure PMMA polymer. Py-GC-MS analysis deduced that PMMA composite produced less toxic and environment-friendly substances (CO2) by the influence of AlI3 additive as compared to neat PMMA.

Density functional theory, molecular docking and bioassay studies on (S)-2-hydroxy-N-(2S,3S,4R,E)-1,3,4 trihydroxyicos-16-en-2-yl)tricosanamide.

A novel indigoferamide-A, earlier isolated from the seeds of Indigofera heterantha Wall was characterized using density functional theory, molecular docking and bioassays studies. Density functional theory calculations were performed at B3LYP/6-31G(d,p) to gain geometric insight of the compound. Conformational analyses have been performed around three important dihedral angles to explore the lowest energy structure and conformer. The simulated vibrational spectrum of the compound at B3LYP/6-31G(d,p) was scaled with two scaling factors, and the scaled harmonic vibrations shows nice correlation with the experimental values. 1H and 13C NMR chemical shifts were calculated using Cramer's re-parameterized function W04 at 6- 31G(d,p) basis set. Several conformers lying within 2 kcal mol-1 of the minimum energy conformer were considered; however, the chemical shifts were not significantly different among these conformers. The Gaussian averaged theoretical 1H and 13C chemical shifts correlate nicely with the experimental data. Electronic properties such as band gap, ionization potential and electron affinities were also simulated for the first time, however, no comparison could be made with the experiment. The compound was also screened for urease, antiglycation activities and the theoretical explanation of the results is provided based on molecular docking simulations.

Spectroscopic and density functional theory studies of 7-hydroxy-3'-methoxyisoflavone: A new isoflavone from the seeds of Indigofera heterantha (Wall).

A new isoflavone 7-hydroxy 3'-methoxyisoflavone (1) is isolated from the seeds of Indigofera heterantha. The structure of this new compound was established using spectroscopic techniques such as ID, 2D NMR, and mass spectrometry. Density functional theory calculations are carried out for the first time for geometric, electronic and spectroscopic properties of 1 (isoflavone). DFT calculations have been performed at B3LYP/6-311G(d,p) level of theory for obtaining geometric and spectroscopic properties of compound 1. The simulated vibrational spectrum of compound 1 at B3LYP/6-311G(d,p) shows nice correlation with the experimental IR spectrum after a scaling factor of 0.973. (1)H and (13)C NMR chemical shifts were calculated using Cramer's re-parameterized function WP04 at 6-311G(d,p) basis set, and show nice correlation with the experimental data. Four conformers were considered for NMR chemical shift calculations. Electronic properties such as band gap, Ionization potential and electron affinities were also simulated for the first time; however, no comparison could be made with the experiment.

Isolation, spectroscopic and density functional theory studies of 7-(4-methoxyphenyl)-9H-furo[2,3-f]chromen-9-one: a new flavonoid from the bark of Millettia ovalifolia.

The phytochemical examination of chloroform soluble fraction (FX2) of methanolic extract of bark of Millettia ovalifolia yielded a new flavonoid; 7-(4-methoxyphenyl)-9H-furo [2,3-f]chromen-9-one (1). Compound 1 is characterized by spectroscopic analytical techniques such as UV, IR, 1D, 2D NMR spectroscopy, and mass spectrometry. A theoretical model is also developed for obtaining geometric, electronic and spectroscopic properties of 1. The geometry optimization and harmonic vibration simulations have been carried out at B3LYP/6-31G(d,p). The vibrational spectrum of compound 1 shows nice correlation with the experimental IR spectrum, through a scaling factor of 0.9613. (1)H and (13)C NMR chemical shifts are simulated using Cramer's re-parameterized function WP04 at 6-31G(d,p) basis set, and correlate nicely with the experimental chemical shifts.