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

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). 

2020 ◽  
Vol 7 (1) ◽  
pp. 71-85
Author(s):  
Kadri Farida ◽  
Boudjeniba Messaoud ◽  
Wathelet Bernard ◽  
Akkal Salah

AbstractCertain phenolics have been recognized to possessing antibacterial and antifungal activities and high levels of flavonoids and tannins have been reported in several varieties of Sorghum bicolor (L.) Moench. Antimicrobial activity and phenolics contents were investigated in five Algerian sorghum seeds. AS20 sorghum extract showed the highest levels of: total phenolics (3214.46±263.64 mg/100 g), flavonoids (32.03±1.64 mg/100 g) and tannins (615.35±6.10 mg/g) contents; however, comparable flavonoids content was recorded in I27 extract. FZ40 and AS12 flavonoids contents were comparable. Screening for antimicrobial activity, carried out by the disc’s diffusion method revealed an antimicrobial potential of sorghum crude extracts against Gram-positive and Gram-negative bacteria and candida albicans yeast. Minimal inhibition concentration determined by microdilution method varied between 0.2 and 2 mg/ml. the lowest value was recorded with F11 and FZ40 extract against Streptococcus pneumoniae and F11 against Escherichia coli. Bacillus subtilis, Staphylococcus aureus ATTCC6538 and MRSA strains showed sensitivity to all extracts. The results show these sorghums as a potential source of natural anti-streptococcal, anti-staphylococcal and anti-candida substances.


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1470 ◽  
Author(s):  
Cristiana Radulescu ◽  
Lavinia Claudia Buruleanu ◽  
Cristina Mihaela Nicolescu ◽  
Radu Lucian Olteanu ◽  
Marius Bumbac ◽  
...  

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.


Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 745
Author(s):  
Melaine González-García ◽  
Fidel Morales-Vicente ◽  
Erbio Díaz Pico ◽  
Hilda Garay ◽  
Daniel G. Rivera ◽  
...  

Cm-p5 is a snail-derived antimicrobial peptide, which demonstrated antifungal activity against the pathogenic strains of Candida albicans. Previously we synthetized a cyclic monomer as well as a parallel and an antiparallel dimer of Cm-p5 with improved antifungal activity. Considering the alarming increase of microbial resistance to conventional antibiotics, here we evaluated the antimicrobial activity of these derivatives against multiresistant and problematic bacteria and against important viral agents. The three peptides showed a moderate activity against Pseudomonas aeruginosa, Klebsiella pneumoniae Extended Spectrum β-Lactamase (ESBL), and Streptococcus agalactiae, with MIC values > 100 µg/mL. They exerted a considerable activity with MIC values between 25–50 µg/mL against Acinetobacter baumanii and Enterococcus faecium. In addition, the two dimers showed a moderate activity against Pseudomonas aeruginosa PA14. The three Cm-p5 derivatives inhibited a virulent extracellular strain of Mycobacterium tuberculosis, in a dose-dependent manner. Moreover, they inhibited Herpes Simplex Virus 2 (HSV-2) infection in a concentration-dependent manner, but had no effect on infection by the Zika Virus (ZIKV) or pseudoparticles of Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2). At concentrations of >100 µg/mL, the three new Cm-p5 derivatives showed toxicity on different eukaryotic cells tested. Considering a certain cell toxicity but a potential interesting activity against the multiresistant strains of bacteria and HSV-2, our compounds require future structural optimization.


2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Eti Nurwening Sholikhah ◽  
Maulina Diah ◽  
Mustofa ◽  
Masriani ◽  
Susi Iravati ◽  
...  

Pycnarrhena cauliflora (Miers.) Diels., local name sengkubak, is one of indigenous plants from West Kalimantan that has been used as natural flavor. Pycnorrhena cauliflora is one of species of Menispermaceae family which is rich in bisbenzylisoquinoline alkaloids. This alkaloids are known to have various biological activities including antiprotozoal, antiplasmodial, antifungal and antibacterial activities. This study aimed to investigate antimicrobial activity of  the P. cauliflora (Miers.) Diels. methanolic extracts against gram-positive and gram-negative bacteria. The methanolic extract of P. cauliflora (Miers.) Diels., root, leaf and stem were prepared by maceration. The disk-diffusion method was then used to determine the antimicrobial activity of the extracts against Streptococcus pyogenes, S. mutants, Staphylococcus aureus, S. epidermidis, Salmonella typhi, Shigella flexneri, Pseudomonas aeruginosa and Escherichia coli after 18-24 h incubation at 37 oC. Amoxicillin was used as positive control for gram-positive bacteria and ciprofloxacin was used as gram-negative bacteria. The inhibition zones were then measured in mm. Analysis were conducted in duplicates. The results showed in general the methanolic extracts of P. cauliflora (Miers.) Diels. root (inhibition zone diameter= 10-23 mm) were more active than that leaf (0-15 mm) and stem (0-17 mm) extracts against gram-positive bacteria. The zone inhibition diameter of amoxicillin as positive control was 8-42 mm. In addition, the methanolic extracts of P. cauliflora (Miers.) Diels. root (12-17 mm) were also more active than that leaf (0-12 mm) and stem (0-12 mm) extracts against gram-negative bacteria. The zone inhibition diameter of ciprofloxacin as positive control was 33-36 mm. In conclusion, the methanolic extract of P. caulifloria (Miers.) Diels. root is the most extract active against both gram-positive and gram-negative bacteria. Further study will be focused to isolate active compounds in the methanolic extract of the root.


2016 ◽  
Vol 11 (2) ◽  
pp. 248 ◽  
Author(s):  
Kathirvel Poonkodi ◽  
Subban Ravi

<p class="Abstract">The present study was aimed to evaluate the phytochemical screening and antimicrobial activity of the petroleum ether and methanol extracts from the mature leaves of <em>Richardia scabra</em> from India. Disc diffusion method was used to determine the zone inhibition of the tested samples for antibacterial and agar plug method was used to determine the antifungal activity, while the microtube-dilution technique was used to determine the minimum inhibitory concentration. Both extracts showed significant antibacterial and antifungal activities when tested against 10 bacterial and four fungal strains. The minimum inhibitory concentrations of the methanol extract of<em> R. scabra</em> ranged between 12.5–100 μg/mL for bacterial strains. Alkaloids, steroids, flavonoids, fatty acids, terpenoids and simple sugar were detected as phytoconstituents of extracts. To the best of our knowledge, this is the first report against antimicrobial activity of common weed species <em>R. scabra</em> found in India.</p><p> </p>


Author(s):  
M. Binigha ◽  
R. Gayatri Devi ◽  
J. Selavaraj ◽  
A. Jothi Priya

Tecoma stans is a flowering plant belonging to the family Bignoniaceae. It is the floral emblem of the Bahamas. Abutilon indicum belongs to the family Malvaceae. It is also called Indian Mallow. Tecoma stans and Abutilon indicumhave antimicrobial activity and can be used in producing antibiotics. There is an urgent need to produce new antibiotics as there is an increase in the development of pathogen resistant drugs. The aim of this study was to compare the antimicrobial activity of ethanolic extract of Tecoma stansand Abutilonindicum leaves. E.faecalis bacteria were maintained in nutrient agar slopes. The powder of the two herbs, were subjected to extraction by Soxhlet extractor and was concentrated to dry residue by Agar well diffusion method. The nutrient broth was inoculated with bacterial strains. The culture was adjusted to 0.5McFarland turbidity standard. Lawn culture was done in Muller-Hinton agar plate and then the plates were dried. A 6 mm diameter well is bored for different concentrations. The extracts were introduced into the well and allowed to stand for 24 hrs. The antibacterial activity was determined by measuring the zone of inhibition. The present finding on the antimicrobial potential of Abutilon indicum and Tecoma stands showed that the two plants have growth inhibitory activity against oral pathogen E. faecalis. Abutilon indicum has a zone of inhibition greater than Tecoma stans. Abutilon indicum exhibited better activity compared to Tecoma stans.


2019 ◽  
Vol 31 (5) ◽  
pp. 1077-1080
Author(s):  
Kottakki Naveen Kumar ◽  
Karteek Rao Amperayani ◽  
V. Ravi Sankar Ummdi ◽  
Uma Devi Parimi

A series 1,2,4-triazole piperine analogues (TP1-TP6) were designed and synthesized. The structures were confirmed using 1H NMR and 13C NMR. Antibacterial study was done using Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram-negative micro-organisms (E. coli and Pseudomonas aeruginosa) by disc diffusion method. Compound containing chloro substitution (TP6) showed the highest effect, while compound TP1, TP3, TP4, TP5 showed the moderate activity.


2020 ◽  
Vol 15 (3) ◽  
pp. 1934578X2091503 ◽  
Author(s):  
Gordana S. Stojanović ◽  
Jovana D. Ickovski ◽  
Aleksandra S. Đorđević ◽  
Goran M. Petrović ◽  
Katarina D. Stepić ◽  
...  

Volatiles of diethyl ether extract (DE), ethyl acetate extract (EE), and hexane extract (HE) of Artemisia scoparia Waldst. et Kit. were analyzed by gas chromatography with flame ionization detector and gas chromatography-mass spectrometry. In both DE and EE, the main compound was scoparone (24.0% and 86.1%, respectively) while in the HE, alkanes were dominant with nonacosane as the most represented (19.4%). Antimicrobial activity was tested against 4 bacterial strains and 1 fungal strain using disc-diffusion method. Tested samples were inactive against Gram-negative bacteria and they exhibited activity against Gram-positive bacteria and yeast Candida albicans. This is the first report on the chemical composition of volatile components and antimicrobial activity of DE, EE, and HE of A. scoparia Waldst. et Kit.


2007 ◽  
Vol 2 (5) ◽  
pp. 1934578X0700200
Author(s):  
Fadwa El Hanbali ◽  
Ahmed El Hakmaoui ◽  
Fouad Mellouki ◽  
Lahoussine El Rhaffari ◽  
Mohamed Akssira

The essential oil of the aerial parts of Anvillea radiata Coss. & Dur. was examined by GC-MS. Twenty-nine constituents were identified, representing 88.8% of the total. 6-Oxocyclonerolidol (66.6%) and 6-hydroxycyclonerolidol (11.4%) were found to be the major components. The disc diffusion method, used for antimicrobial activity testing, showed that the essential oil had a significant antibacterial activity against all tested microorganisms.


2009 ◽  
Vol 4 (1) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Branislava Lakušić ◽  
Violeta Slavkovska ◽  
Milica Pavlović ◽  
Marina Milenković ◽  
Jelena Antić Stanković ◽  
...  

The essential oils of the aerial parts and fruits of Chaerophyllum aureum L., collected from two mountains in Serbia, were analyzed by GC and GC/MS. Sabinene (18.5-31.6%), p-cymene (7.9-25.4%) and limonene (1.9-10.9%) were characterized as the main constituents. The oils were tested against six bacterial strains and one strain of yeast, Candida albicans. The highest antimicrobial activity was observed against the Gram-positive bacteria Staphylococcus aureus, S. epidermidis and Micrococcus luteus, while of the Gram-negative strains, Escherichia coli was the most sensitive.


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