Optimization of microwave-assisted enzymatic extraction of polyphenols from waste peanut shells and evaluation of its antioxidant and antibacterial activities in vitro

2013 ◽  
Vol 91 (2) ◽  
pp. 158-168 ◽  
Author(s):  
Guowen Zhang ◽  
Mingming Hu ◽  
Li He ◽  
Peng Fu ◽  
Lin Wang ◽  
...  
Keyword(s):  
Antibacterial Activities ◽  
Enzymatic Extraction ◽  
Microwave Assisted ◽  
Peanut Shells

scholarly journals Green Chemistry Approach for Efficient Synthesis of Schiff Bases of Isatin Derivatives and Evaluation of Their Antibacterial Activities

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Jnyanaranjan Panda ◽  
V. Jagannath Patro ◽  
Biswa Mohan Sahoo ◽  
Jitendriya Mishra
Keyword(s):  
Green Chemistry ◽  
Schiff Bases ◽  
Reaction Times ◽  
Antibacterial Activities ◽  
Primary Amines ◽  
Microwave Assisted Synthesis ◽  
Azomethine Group ◽  
Microwave Assisted ◽  
Isatin Derivatives

Microwave-assisted organic synthesis, a green chemistry approach, is nowadays widely used in the drug synthesis. Microwave-assisted synthesis improves both throughput and turnaround time for medicinal chemists by offering the benefits of drastically reduced reaction times, increased yields, and pure products. Schiff bases are the important class of organic compounds due to their flexibility, and structural diversities due to the presence of azomethine group which is helpful for elucidating the mechanism of transformation and rasemination reaction in biological system. This novel compound could also act as valuable ligands for the development of new chemical entities. In the present work, some Schiff bases of Isatin derivatives was synthesized using microwave heating method. Schiff base of Isatin were synthesized by condensation of the keto group of Isatin with different aromatic primary amines. They were characterized by means of spectral data and subsequently subjected to the in vitro antibacterial activities against gram positive and gram negative strains of microbes. It was observed that the compound with electron withdrawing substituents exhibited good antibacterial activities against almost all the micro organisms.

scholarly journals Ultrasound-microwave assisted extraction of flavonoid compounds from Eucommia ulmoides leaves and an evaluation of their antioxidant and antibacterial activities

2020 ◽  
Vol 72 (2) ◽  
pp. 211-221
Author(s):  
Xiang Wang ◽  
Mi-Jun Peng ◽  
Zhi-Hong Wang ◽  
Qiu-Ling Yang ◽  
Sheng Peng
Keyword(s):  
Antibacterial Activities ◽  
Eucommia Ulmoides ◽  
Microwave Assisted Extraction ◽  
Ultrasound Extraction ◽  
Microwave Assisted ◽  
Flavonoid Compounds ◽  
Assisted Extraction ◽  
Ic50 Values ◽  
Burman Design

Ultrasound/microwave assisted extraction (UMAE) of flavonoid compounds from Eucommia ulmoides leaves was studied and the extraction conditions were optimized by the Plackett-Burman design (PBD) method combined with the Box-Behnken design (BBD). The antioxidant and antibacterial activities of the flavonoid extract were investigated. The results show that the optimal conditions were an ethanol concentration of 41%, microwave power of 178 W and an ultrasound extraction time of 26 min. Under these conditions, the yield of the flavonoid compounds was 2.454%?0.230%, which was higher than that after direct solvent extraction, ultrasound extraction and microwave extraction. The results of in vitro antioxidant assays showed that the flavonoid extract had scavenging capacity for DPPH, ABTS and hydroxyl radicals, with corresponding IC50 values of 30.76 mg/L, 21.09 mg/L, 248.4 mg/L, respectively. In addition, this extract exhibited strong antibacterial activity on Escherichia coli, Staphylococcus aureus and Salmonella typhimurium.

scholarly journals Microwave-Assisted Synthesis of Schiff Bases of Isoniazid and Evaluation of Their Anti-Proliferative and Antibacterial Activities

Molbank ◽  
10.3390/m1189 ◽  
2021 ◽  
Vol 2021 (1) ◽  
pp. M1189
Author(s):  
Bayan Ahed Al-Hiyari ◽  
Ashok K. Shakya ◽  
Rajashri R. Naik ◽  
Sanaa Bardaweel
Keyword(s):  
Antibacterial Activity ◽  
Schiff Bases ◽  
Aromatic Aldehydes ◽  
Antibacterial Activities ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Ic50 Values ◽  
In Vitro Inhibition ◽  
Mcf 7

Three new Schiff bases of isoniazid were synthesized using microwave-assisted synthesis and conventional condensation with aromatic aldehydes. Synthesized compounds were characterized using elemental analysis, IR, NMR, and Mass spectroscopy. Synthesized compounds were evaluated for antiproliferative activity against MCF-7 cell line. The IC50 values were from 125 to 276 µM. The compounds were also evaluated for antibacterial activity against Staphylococcus aureus and Escherichia coli. Results showed that the synthesized compounds produce significant antibacterial activity in vitro. Inhibition of compounds ranged from 13 to 18 mm.

scholarly journals Zinc Complexes Derived from 5-Bromo-2-(((2-isopropylamino)ethyl)imino)methyl)phenol: Microwave-Assisted Synthesis, Characterization, Crystal Structures and Antibacterial Activities

2021 ◽  
Vol 68 (4) ◽  
pp. 921-929
Author(s):  
Wei-Guang Zhang ◽  
Ji-Hong Liang
Keyword(s):  
Antibacterial Activities ◽  
Molar Conductivity ◽  
Zinc Complexes ◽  
Microwave Assisted Synthesis ◽  
Tetrahedral Coordination ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Assisted ◽  
Elemental Analyses

Three new zinc complexes [Zn3L2(μ2-η1:η1-CH3COO)2(μ2-η2:η0-CH3COO)2] (1), [ZnCl2(HL)] (2) and [ZnBr2(HL)] (3), where L = 5-bromo-2-(((2-isopropylamino)ethyl)imino)methyl)phenolate, HL = 5-bromo-2-(((2-isopropylammonio) ethyl)imino)methyl)phenolate, have been synthesized under microwave irradiation. The complexes were characterized by elemental analyses, IR, UV-Vis spectra, molar conductivity, and single crystal X-ray diffraction. X-ray analysis revealed that the Zn atoms in complex 1 are in square pyramidal and octahedral coordination, and those in complexes 2 and 3 are in tetrahedral coordination. The molecules of the complexes are linked through hydrogen bonds and π···π interactions. In order to evaluate the biological activity of the complexes, in vitro antibacterial against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa was assayed.

Microwave assisted synthesis of novel Pyrazole derivatives and their biological evaluation as anti-bacterial agents

2020 ◽  
Vol 23 ◽  
Author(s):  
Hadis Khodadad ◽  
Farhad Hatamjafari ◽  
Khalil Pourshamsian ◽  
Babak Sadeghi
Keyword(s):  
Antibacterial Activity ◽  
Aromatic Aldehydes ◽  
Catalytic Amount ◽  
Antibacterial Activities ◽  
Structural Features ◽  
Biological Evaluation ◽  
Aureus Strain ◽  
Microwave Assisted Synthesis ◽  
Pyrazole Derivatives ◽  
Microwave Assisted

Aim and Objective: Microwave-assisted condensation of acetophenone 1 and aromatic aldehydes 2 gave chalcone analogs 3, which were cyclized to pyrazole derivatives 6a-f via the reaction with hydrazine hydrate and oxalic acid in the presence of the catalytic amount of acetic acid in ethanol. Materials and Methods: The structural features of the synthesized compounds were characterized by melting point, FT-IR, 1H, 13C NMR and elemental analysis. Results: The antibacterial activities of the synthesized pyrazoles was evaluated against three gram-positive bacteria such as Enterococcus durans, Staphylococcus aureus, Bacillus subtilis and two gram-negative bacteria such as Escherichia coli and Salmonella typhimurium. Conclusion: All the synthesized pyrazoles showed relatively high antibacterial activity against S. aureus strain and none of them demonstrated antibacterial activity against E. coli.

scholarly journals In Vitro Characterization of the Antibacterial Spectrum of Novel Bacterial Type II Topoisomerase Inhibitors of the Aminobenzimidazole Class

2006 ◽  
Vol 50 (4) ◽  
pp. 1228-1237 ◽  
Author(s):  
Nagraj Mani ◽  
Christian H. Gross ◽  
Jonathan D. Parsons ◽  
Brian Hanzelka ◽  
Ute Müh ◽  
...  
Keyword(s):  
Bacterial Resistance ◽  
Wide Spectrum ◽  
Dna Gyrase ◽  
Antibacterial Activities ◽  
Mechanisms Of Action ◽  
Fluoroquinolone Resistance ◽  
Topoisomerase Iv ◽  
Low Frequencies

ABSTRACT Antibiotics with novel mechanisms of action are becoming increasingly important in the battle against bacterial resistance to all currently used classes of antibiotics. Bacterial DNA gyrase and topoisomerase IV (topoIV) are the familiar targets of fluoroquinolone and coumarin antibiotics. Here we present the characterization of two members of a new class of synthetic bacterial topoII ATPase inhibitors: VRT-125853 and VRT-752586. These aminobenzimidazole compounds were potent inhibitors of both DNA gyrase and topoIV and had excellent antibacterial activities against a wide spectrum of problematic pathogens responsible for both nosocomial and community-acquired infections, including staphylococci, streptococci, enterococci, and mycobacteria. Consistent with the novelty of their structures and mechanisms of action, antibacterial potency was unaffected by commonly encountered resistance phenotypes, including fluoroquinolone resistance. In time-kill assays, VRT-125853 and VRT-752586 were bactericidal against Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecalis, and Haemophilus influenzae, causing 3-log reductions in viable cells within 24 h. Finally, similar to the fluoroquinolones, relatively low frequencies of spontaneous resistance to VRT-125853 and VRT-752586 were found, a property consistent with their in vitro dual-targeting activities.

scholarly journals Flavone-Rich Fractions and Extracts from Oroxylum indicum and Their Antibacterial Activities against Clinically Isolated Zoonotic Bacteria and Free Radical Scavenging Effects

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1773
Author(s):  
Patchima Sithisarn ◽  
Piyanuch Rojsanga ◽  
Pongtip Sithisarn
Keyword(s):  
Antibacterial Activities ◽  
Inhibitory Effect ◽  
Total Flavonoid ◽  
Total Phenolic ◽  
Antibacterial Effects ◽  
E Coli ◽  
Young Fruit ◽  
Oroxylum Indicum ◽  
Zoonotic Bacteria

Oroxylum indicum extracts from the seeds collected from Lampang and Pattani provinces in Thailand, and young fruits and flowers exhibited in vitro display antioxidant and antibacterial activities against clinically isolated zoonotic bacteria including Staphylococcus intermedius, Streptococcus suis, Pseudomonas aeruginosa, β-hemolytic Escherichia coli and Staphylococcus aureus. The orange crystals and yellow precipitates were obtained from the preparation processes of the seed extracts. The orange-red crystals from the seeds collected from Lampang province exhibited strong in vitro 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging effects (EC50 value = 25.99 ± 3.30 μg/mL) and antibacterial effects on S. intermedius and β-hemolytic E. coli while the yellow precipitate from the same source exhibited only antioxidant activity. Quantitative analysis of phytochemicals in O. indicum samples by spectrophotometric and HPLC techniques showed that they contained different amounts of total phenolic, total flavonoid and three major flavones; baicalin, baicalein and chrysin contents. Young fruit extract, which contained low amounts of flavone contents, still promoted antibacterial effects against the tested bacteria with IC50 values lower than 1 mg/mL and MIC values between 4 to 10 mg/mL in S. intermedius, S. aureus and S suis while higher IC50 and MIC values against P. aeruginosa and β-hemolytic E. coli were found. From scanning electron microscopy, the extract of the young fruit of O. indicum promoted morphological changes in the bacterial cells by disrupting the bacterial cell walls, inducing leakage of the cellular content, and generating the abnormal accumulation of cells. The mechanism of action of the extract for this antibacterial effect may be the disruption of the cell membrane and abnormal cell aggregations. Regression analysis of the results suggests the correlation between total phenolic and total flavonoid contents and antioxidant and antibacterial effects. Baicalin was found to have a high correlation with an inhibitory effect against β-hemolytic E. coli while three unidentified peaks, which could be flavones, showed high correlations with an inhibitory effect against S. intermedius, S. suis, P. aeruginosa and S. aureus.

scholarly journals In Vitro Anti-Biofilm and Antibacterial Properties of Streptococcus downii sp. nov.

2021 ◽  
Vol 9 (2) ◽  
pp. 450
Author(s):  
Maigualida Cuenca ◽  
María Carmen Sánchez ◽  
Pedro Diz ◽  
Lucía Martínez-Lamas ◽  
Maximiliano Álvarez ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Quantitative Polymerase Chain Reaction ◽  
Bacterial Load ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Oral Bacteria ◽  
Periodontal Pathogens ◽  
Biofilm Model ◽  
Biofilm Development

The aim of this study was to evaluate the potential anti-biofilm and antibacterial activities of Streptococcus downii sp. nov. To test anti-biofilm properties, Streptococcus mutans, Actinomyces naeslundii, Veillonella parvula, Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans were grown in a biofilm model in the presence or not of S. downii sp. nov. for up to 120 h. For the potential antibacterial activity, 24 h-biofilms were exposed to S. downii sp. nov for 24 and 48 h. Biofilms structures and bacterial viability were studied by microscopy, and the effect in bacterial load by quantitative polymerase chain reaction. A generalized linear model was constructed, and results were considered as statistically significant at p < 0.05. The presence of S. downii sp. nov. during biofilm development did not affect the structure of the community, but an anti-biofilm effect against S. mutans was observed (p < 0.001, after 96 and 120 h). For antibacterial activity, after 24 h of exposure to S. downii sp. nov., counts of S. mutans (p = 0.019) and A. actinomycetemcomitans (p = 0.020) were significantly reduced in well-structured biofilms. Although moderate, anti-biofilm and antibacterial activities of S. downii sp. nov. against oral bacteria, including some periodontal pathogens, were demonstrated in an in vitro biofilm model.

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