scholarly journals Phytochemical Profiles, Antioxidant and Antibacterial Activities of Grape (Vitis vinifera L.) Seeds and Skin from Organic and Conventional Vineyards

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1470 ◽  
Author(s):  
Cristiana Radulescu ◽  
Lavinia Claudia Buruleanu ◽  
Cristina Mihaela Nicolescu ◽  
Radu Lucian Olteanu ◽  
Marius Bumbac ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activities ◽  
Diffusion Method ◽  
Total Phenolic ◽  
Vitis Vinifera L ◽  
Bacterial Strains ◽  
Disk Diffusion Method ◽  
Therapeutic Benefits ◽  
Inhibition Concentration ◽  
Red Grape

The therapeutic benefits of extracts obtained from different red grape fractions were thoroughly studied, however, data regarding the comparison of phytochemical extracts prepared from the same varieties coming from organic versus conventional management systems are rather lacking. The present study aimed at comparing some of the phytochemical characteristics and antimicrobial activity of hydroalcoholic (50% v/v) extracts obtained from four varieties of red grapes cultivated respectively in organic and conventional vineyards. Total flavonoid content, total phenolic compounds, and antioxidant activity were determined by molecular absorption spectroscopy. Antimicrobial activity of the studied extracts was evaluated against common bacterial strains isolated from different habitats according to specific lab procedures. The analyses were performed in solid broths by applying the disk diffusion method, which allowed for the simultaneous determination of the spectrum of the sensitivity of the tested bacteria as well as the values of the minimum inhibition concentration (MIC). It was found that favorable antagonistic activities against the tested bacteria strains were exhibited by the hydroalcoholic extracts from the seeds of the organic varieties, respectively the skin of the conventional varieties.

Antifungal and Antibacterial Activities of Pentanema divaricatum and Its Active Constituent

2008 ◽  
Vol 63 (9-10) ◽  
pp. 649-652 ◽  
Author(s):  
Nastaran Momen-Roknabadi ◽  
Ahamd R. Gohari ◽  
Hamid R. Monsef-Esfehani ◽  
Farideh Attar ◽  
Reza Hajiaghaee ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Aspergillus Niger ◽  
Preparative Thin Layer Chromatography ◽  
Antibacterial Activities ◽  
Diffusion Method ◽  
Active Constituent ◽  
Disk Diffusion Method ◽  
Bioassay Guided Fractionation ◽  
Layer Chromatography ◽  
And Staphylococcus Aureus

The antimicrobial activity of ethanol and chloroform extracts of Pentanema divaricatum Cass. was studied using the conventional disk diffusion method. The extracts’ highest antimicrobial activity was observed against Aspergillus niger. Bioassay-guided fractionation of the crude extract by preparative thin layer chromatography (PTLC) showed one antimicrobial fraction which was especially effective against Aspergillus niger. By conventional spectroscopy the active fraction was identified as 4α,5α-epoxy-10α,14H-1-epi-inuviscolide. This compound represented the most potent antimicrobial candidate, with MIC values of < 25 μg/disk against A. niger strains and 200 μg/disk against Bacillus cereus and Staphylococcus aureus.

scholarly journals ANTIMICROBIAL ACTIVITY OF METHANOLIC EXTRACT OF LUDWIGIA PARVIFLORA L. AGAINST STANDARD BACTERIAL STRAINS AND COMPARISON OF ITS ACTIVITY WITH THAT OF STANDARD ANTIBIOTICS

2019 ◽  
pp. 430-432
Author(s):  
SHIBU GEORGE ◽  
MEVLIN JOY
Keyword(s):  
Antimicrobial Activity ◽  
Bacterial Infections ◽  
Methanolic Extract ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Whole Plant ◽  
The Common ◽  
Susceptibility Tests

Objective: The objective of this study was to evaluate the antimicrobial activity of methanolic extract of Ludwigia parviflora L. using standard bacterial strains and compare its activity with that of standard antibiotics. Methods: The antibacterial activity and antibiotic susceptibility tests were done by disk diffusion method using MTCC bacterial strains. Results: The study revealed that the methanolic extract of the whole plant of L. parviflora L. was effective to inhibit the growth of Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli. Among the tested strains, S. aureus, P. aeruginosa, K. pneumoniae, and E. coli were more susceptible to the methanolic extract of L. parviflora than the commonly using antibiotic tetracycline 30 mcg. The activity of methanolic extract was also higher than the activity of gentamicin 10 mcg against the P. aeruginosa. Conclusion: The study concluded that the crude methanolic extract of the whole plant of L. parviflora L. is a good source for antibacterial agent against S. aureus, P. aeruginosa, K. pneumoniae, and E. coli. Hence, this plant can be used as a natural alternative to the common antibiotics such as gentamicin and tetracycline against common bacterial infections after validating its pharmacological and toxicological activities.

scholarly journals Synthesis, Characterization, and Antibacterial Activities of 1H-Imidazo [5, 6-f] [1,10] Phenanthroline-2(3H)-Thione and Its Ni(II) and Cu(II) Complexes

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Radiet Anbessie Tirkeso ◽  
Tilahun Wubalem Tsega ◽  
Gebru G/Tsadik Amdemichael
Keyword(s):  
Biological Activities ◽  
Free Ligand ◽  
Conductivity Measurement ◽  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Molar Conductivity ◽  
Diffusion Method ◽  
Distorted Octahedral Geometry ◽  
Bacterial Strains ◽  
Disk Diffusion Method

As multidrug resistant pathogens are emerging, the search for novel potent drug candidates is ever going. Heterocycles are known by their broad spectrum of biological activities, so a search for a new drug from heterocycles can elevate the chance of success. The aim of this study was to obtain novel potent antimicrobial compounds. In line with this, 1H-imidazo [5, 6-f] [1,10] phenanthroline-2(3H)-thione and its complexes (Ni(II) and Cu(II)) were synthesized, characterized, and evaluated against bacterial strains. The compounds were characterized by elemental analyses (C, H, N, and S), FT-IR, 1H-NMR, 13C-NMR, AAS, UV-Vis spectra, and molar conductivity measurement. The results showed that the ligand is bidentate, and the molar conductivity measurement indicates that complexes are electrolytic. Electronic spectral study showed octahedral and distorted octahedral geometry for the Ni(II) and Cu(II) complex, respectively. The ligand and its complexes were screened against four bacterial strains using disk diffusion method. The result revealed that the Ni(II) complex showed more bioactivity than gentamicin against Staphylococcus aureus and Escherichia coli, while the Cu(II) complex is more active than the Ni(II) complex against Bacillus subtilis. Both Cu(II) and Ni(II) complexes exhibit higher antibacterial activities than the free ligand.

Xanthine Oxidase Inhibition, In Vitro Antioxidant Activity and Antibacterial Effect of the Aerial Part Extracts of Thymus pallidus Coss

2020 ◽  
Vol 16 (4) ◽  
pp. 607-615
Author(s):  
Abderrahim Benslama ◽  
Sabah Boumerfeg ◽  
Sana Aouachria ◽  
Thoraya Guemmaz ◽  
Lekhmici Arrar ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antioxidant Activity ◽  
Linoleic Acid ◽  
Aerial Part ◽  
Antibacterial Effect ◽  
Pharmaceutical Preparation ◽  
Antibacterial Activities ◽  
Diffusion Method ◽  
Total Phenolic

Background: The Algerian medicinal plant Thymus pallidus Coss. is traditionally known to be used as an anti-infective, expectorant, healer of wounds and against inflammatory and gastrointestinal diseases. Objective: The aim of the present study is to investigate the antioxidants and the antibacterial activities of the aerial part extracts of this plant. Methods: Polyphenols extraction was performed with methanol 85%, followed by preliminary fractionation based on the polarity of the solvent. The extraction and fractionation process gave the crude extract (CrE), chloroform extract (ChE), ethyl acetate extract (EtAE) and aqueous extract (AqE). The antioxidant activity of extracts was evaluated using in vitro assays. While the antimicrobial activity was determined using disk diffusion method. Results: Quantitative analysis of polyphenol and flavonoids showed that EtAE includes the highest amount (P≤0.001) with 495.12±1.91 μg GAE/mg of extract and 97.25±2.84 μg QE/mg of extract, for both polyphenols and flavonoids respectively. The results of the antioxidant activity of extracts showed that the EtAE exhibited the highest inhibition activity on XO (IC50 =51.6±0.2 μg/ml) compared to other extracts (P≤0.001). Moreover, the EtAE was the most effective fraction in free radical scavenging assay against ABTS radical and hydrogen peroxide (EC50= 3.21±0.03 μg/ml and EC50 =12.12±0.05 μg/ml, respectively) compared to other extracts (P≤0.01). Using β-carotene/ linoleic acid bleaching assay, the AqE and ChE recorded a considerable inhibition effect on linoleic acid oxidation with a ratio of 81.81% and 80.86%, respectively. In the antimicrobial activity evaluation, the extracts exhibited moderate antibacterial activity against bacterial strain, with inhibition zone ranging from 07 to 14 mm. In addition, the EtAE showed a good action spectrum against six bacterial strains. In conclusion, the EtAE of Thymus pallidus showed good antioxidant activity and antibacterial effect. Conclusion: The obtained results revealed the presence of a strong correlation between the antioxidant and antibacterial activities of the extract and its total phenolic content. Furthermore, they reported that the EtAE has a considerable antioxidant capacity. This can be considered as an alternative natural source of antioxidants used generally as additives in food and pharmaceutical preparation.

scholarly journals Chemical composition and antimicrobial activity of Myrtus communis essential oils from Algeria

2021 ◽  
Vol 22 (2) ◽  
Author(s):  
YACINE MOHAMADI ◽  
TAKIA LOGRADA ◽  
Messaoud Ramdani ◽  
GILLES FIGUEREDO ◽  
PIERRE CHALARD
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Composition ◽  
Essential Oils ◽  
Bacterial Species ◽  
Antibacterial Activities ◽  
Geranyl Acetate ◽  
Diffusion Method ◽  
Klebsiella Pneumonia ◽  
Myrtus Communis ◽  
Disk Diffusion Method

Abstract. Mohamadi Y, Lograda T, Ramdani M, Figueredo G, Chalard P. 2021. Chemical composition and antimicrobial activity of Myrtus communis essential oils from Algeria. Biodiversitas 22: 933-946.  The objectives of this study were to determine the chemical composition and the antibacterial activities of Myrtus communis essential oils. The aerial parts of the myrtle were collected from nineteen localities of the Algerian coast, and subjected to hydrodistillation. The chemical composition of essential oils was analyzed using gas chromatography coupled with mass spectrometry (GC/MS). The antibacterial activity was evaluated by the disk diffusion method against ten bacterial species. Essential oils of M. communis was pale yellow oils, very fragrant, with an average yield of 0.68 ± 0.6%. Forty-six compounds were identified, representing an average of 99.17 ± 0.6% of total oils. The α-pinene was the most abundant component in the essential oils of all populations studied, with a mean of 50.1 ± 10.3%, followed by 1,8-cineole (22.27 ± 4.32%), limonene (5.16 ± 2.67%), linalool (3.79 ± 2.97%), α-terpineol (2.75 ± 1.12%), geranyl acetate (1.95 ± 0.7%) and methyl eugenol (1.40 ± 0.98%). Myrtenyl acetate was only observed in four populations with significant levels (from 10.66 to 20.94%). Six chemotypes have been identified in these oils. The α-pinene – 1,8-cineole - limonene chemotype was found in the majority of populations. The chemotype of α-pinene - 1,8-cineole - α-terphenyl acetate characterizes the Oued El-Aneb population. The α-pinene - neryl formate - limonene chemotype is observed in the Honaïn population. The remaining populations are characterized by myrtenyl acetate. The essential oils of M. communis were effective against Staphylococcus aureus ATCC 25923, Salmonella enterica ATCC35659, Proteus mirabilis, and Escherichia coli ATCC 25922; however, no significant effect was observed on Klebsiella pneumonia ATCC 700603 and Serratia liquefaciens.

scholarly journals Antimicrobial activity of four Valeriana L. (Caprifoliaceae) crude extracts, endemic species of the Venezuelan Andes

2018 ◽  
Vol 66 (3) ◽  
pp. 1282 ◽  
Author(s):  
Maria Eugenia Rondon ◽  
Judith Josefina Velasco ◽  
Janne Del Carmen Rojas ◽  
Luis Enrique Gamez ◽  
Antonio Morales
Keyword(s):  
Antimicrobial Activity ◽  
Diffusion Method ◽  
Moderate Activity ◽  
Bacterial Strains ◽  
Minimal Inhibition Concentration ◽  
Methanolic Extracts ◽  
Aerial Parts ◽  
Inhibition Concentration ◽  
Analytical Response ◽  
Hexane Extracts

Valeriana L. genus is represented in Venezuela by 16 species, 9 of these are endemic of Venezuelan Andes growing in high mountains at 2800 masl. In this investigation, four species were analyzed in order to determine the main secondary metabolites and antimicrobial activity of extracts obtained from aerial parts of Valeriana parviflora, V. rosaliana, V. triplinervis and V. phylicoides. Alkaloids, flavonoids, tannins, sterols, triterpenoids and saponins were qualitatively observed in all methanolic extracts tested. The color intensity or a precipitate formation was used as analytical response to these tests. Antimicrobial activity was evaluated against Gram positive, Gram negative bacterial strains and yeast, using disc diffusion method. N-hexane extracts of V. triplinervis and V. rosaliana showed the highest efficiency against Staphylococcus aureus, exhibiting inhibition zones of 16 mm and 15 mm; MIC (Minimal Inhibition Concentration) values were observed at 116 mg/mL and 150 mg/mL, respectively. Dichloromethane and methanolic extracts of V. triplinervis and methanolic extract of V. rosaliana showed a rather moderate activity (MIC between 200 to 316 mg/ml) but a very weak antibacterial activity was observed in V. phylicoides and V. parviflora extracts (MIC > 420 mg/mL). None of the extracts assayed in this investigation showed any activity against Candida albicans and Candida krusei. Statistical analysis showed no significant differences on the different polarity extracts assayed with respect to antimicrobial activity against S. aureus (P > 0.10), however it was observed significant differences between the Valeriana species analyzed (P < 0.10) in relation to the minimal inhibitory concentration (MIC). 

SEARCH FOR ANTIMICROBIAL AGENTS: QUINOXALINE AS A PROMISING TARGET

INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (07) ◽  
pp. 5-9
Author(s):  
R. G Ingle ◽  
◽  
S. J. Wadher
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Agents ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Disk Diffusion Method ◽  
Gram Negative ◽  
E Coli ◽  
Promising Target ◽  
Quinoxaline Derivatives

A set of ten new 2,3-diphenyl-6-sulfonamido quinoxaline derivatives was synthesized and screened for antimicrobial activity by disk diffusion method. Test derivatives R3, R5, R’’1 and R’’2 show promising results against bacterial strains S. aureus gram positive and E. coli gram negative organism with the concentration 1000 μg/mL in disk diffusion method. Rest of the derivatives show sensitivity against the same organisms. All the synthesized derivatives were confirmed by their spectral data.

scholarly journals Effects of Development and Ripening Stage on Phytochemical Compositions, Antioxidant and Antibacterial Activities of Date Palm Fruits

2019 ◽  
Vol 32 (2) ◽  
pp. 415-419
Author(s):  
F.Z. Bentebba ◽  
Z. Ghiaba ◽  
M. Saidi ◽  
C. Bensasi
Keyword(s):  
Antioxidant Activity ◽  
Reducing Power ◽  
Antibacterial Activities ◽  
Diffusion Method ◽  
Total Phenolic ◽  
Disk Diffusion Method ◽  
Maturation Stages ◽  
Palm Fruits ◽  
Edible Parts

Edible parts of two dates cultivars (Deguel ahmar and Tanslit) at four maturation stages khellal, besser, rutab and tamr were analyzed for their phytochemical composition (total phenolic, total flavonoid and condensed tannins contents) as well as antioxidant and antibacterial activities. The antioxidant activity evaluated in vitro using scavenging assays of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2′-azino-bis(3- ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical and ferric reducing power. Antibacterial activity of extracts were evaluated in vitro by the agar disk diffusion method against five pathogenic bacterias trains: Bacillus subtilis ATCC 6633, Enterococcus ATCC 3315, Staphylococcus aureus ATCC 43300, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 7320. Results suggested that the content of these phytochemicals are very important at khellal stage and then decreased during maturation followed by a decrease in the antioxidant activity.

scholarly journals Antimicrobial Activity of Mononuclear and Bionuclear Nitrite Complexes of Platinum (II) and Platinum (IV)

2020 ◽  
Vol 50 (2) ◽  
pp. 329-342
Author(s):  
Olesya Salishcheva ◽  
Alyeksandr Prosyekov ◽  
V. Dolganuk
Keyword(s):  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Aspergillus Niger ◽  
Antimicrobial Agents ◽  
Platinum Complexes ◽  
Diffusion Method ◽  
Complexing Agent ◽  
Bacterial Strains ◽  
Antimicrobial Drugs ◽  
Disk Diffusion Method

Introduction. Pathogens keep evolving and develop resistance to antimicrobial drugs. As a result, science is constantly searching for new antimicrobial agents. Their complex forms based on organic and inorganic ligands exhibit a stronger synergistic antimicrobial effect, if compared to free ligands. The Scopus database contains 73 thousand scientific articles about antimicrobial activity descriptors published during the last five years. This selection includes ten thousand reviews and three thousand publications that feature the antimicrobial activity of platinum complexes. The research objective was to screen the antimicrobial properties of platinum nitrite complexes. The present paper highlights some of the current domestic and foreign trends in this field of research: the biochemical synthesis of peptides as metabolites of bacteria; the development of anti-biofilm agents that act on the protective systems of pathogens; the creation of antimicrobial nanosystems; the synthesis of antimicrobial surfactants; the synthesis and study of the antimicrobial activity of platinum complexes, etc. The authors also give a brief description of the mechanisms of antibacterial action. Study objects and methods. Five previously synthesized complexes of platinum (II) and platinum (IV), both mononuclear and bionuclear, were tested for antimicrobial activity. The platinum complexes contained terminal and bridged nitrite ligands. The test cultures included Bacillus subtilis and Aspergillus niger. The experiment involved the disk-diffusion method and the macro method of serial dilutions. Results and discussion. All the complexes inhibited the metabolic growth of microorganisms to various degrees. The results depended on the composition and structure of the complex, the number and charge of the coordination centers, the degree of platinum oxidation, and the thermodynamic stability and lability of ligand bonds with the complexing agent. The response to Aspergillus niger proved more pronounced. The Pt+2 nonelectrolyte complex containing both terminal and bridged nitrite ligands was less active than the Pt+2 cationic complex, which contained only bridged NO2– ligands. The highest antibacterial activity belonged to the bionuclear complex of PtIV-PtII [(NH3)2 (NO2)2PtIV(µ-NO2)2PtII(NH3)2](NO3)2 in relation to Bacillus subtilis B4647 and Aspergillus niger. The minimum inhibitory concentration (MIC) was > 125 μmol. Conclusion. The complexing resulted in a synergistic effect between the ligand and the complexing substance. The poly-core complexes contain two or more linked platinum centers that can covalently bind to DNA. They form a completely different type of DNA adducts compared to mononuclear complexes, as well as cross-links between DNA chains with fixation on different parts. The octahedral platinum complexes are kinetic and thermodynamically inert. Unlike similar squamous complexes, they proved to be able to act as prodrugs, recovering inside or outside the bacterial cell. The antimicrobial activity of the mixed-valence PtIV-PtII bionuclear complex [(NH3)2 (NO2)2PtIV(µ-NO2)2PtII(NH3)2](NO3)2 produced inhibitory effect comparable to the existing antimicrobial drugs. A further research will focus on composite mixtures of platinum complexes with other existing antimicrobial agents, as well as on other bacterial strains.

scholarly journals Quality testing of industrially produced essential oil of white pine (Pinus sylvestris L.) from the Republic of Srpska

2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Vesna Gojković Cvjetković ◽  
Željka Marjanović-Balabań ◽  
Marijana Kapović-Solomuń ◽  
Ljiljaná́ Stanojevic ◽  
Jelená́ Stanojevic ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Composition ◽  
Essential Oil ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
White Pine ◽  
Disk Diffusion Method ◽  
Sesquiterpene Hydrocarbons ◽  
Zones Of Inhibition ◽  
The Republic

The quality of the essential oil obtained from white pine wood greenery from the territory of the Republic of Srpska was analyzed by examining the chemical composi- tion and antimicrobial activity of samples produced by the hydro-distillation process in industrial production conditions. The chemical composition of the essential oil was analyzed by GC/MS and GC/FID analysis. The antimicrobial activity of the ob- tained white pine oil was investigated for its possible use as an antimicrobial agent. The obtained results prove the presence of 37 components in the analyzed sam- ple, which represents 98.5% of the total components present. The most common are monoterpene hydrocarbons, followed by sesquiterpene hydrocarbons, much less represented are monoterpenes containing oxygen and aromatic compounds, while aliphatic esters are found only in traces. Antimicrobial activity was examined using the disk diffusion method. The results showed large zones of inhibition, both for the tested oil sample and for all eight analyzed bacterial strains (from 12.00 ± 0.00 to 17.33 ± 1.15mm), as well as for the fungal strain. The chemical composition and antimicrobial action of essential white pine oiled from plant material originating from the territory of the Republic of Srpska indicates its significant phytomedical potential.

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