scholarly journals The antimicrobial activity of polyfloral honey and its awareness among urban consumers in Slovakia

10.5219/1621 ◽  
2021 ◽  
Vol 15 ◽  
pp. 467-474
Author(s):  
Peter Šedí­k ◽  
Kristína Predanócyová ◽  
Elena Horská ◽  
Miroslava Kačániová

The current interdisciplinary research studies the antimicrobial activity of selected polyfloral kinds of honey (n = 30) against three microorganisms (gram-positive bacteria Enterococcus faecalis, gram-negative bacteria Salmonella enterica, and one yeast Candida krusei) as well as investigates consumer behavior and awareness towards honey healing properties. Consumer research involved 617 honey consumers living in urban areas. T-test for Equality of means, non-parametric tests, and descriptive statistics were applied. Results showed that antimicrobial activity was found in all honey samples with a concentration of 50%. Nevertheless, better activity was obtained in honey samples from urban beekeepers compared to samples from retail stores. Results of consumer research showed that honey is mostly used as food (sweetener in beverages, ingredient in the recipe, or direct consumption) and as medicine mainly during the winter period. The consumer awareness towards honey healing effects was very high (97%), however, 1/3 of respondents were not able to list any specific examples, and only 11 % mentioned antibacterial activity. Furthermore, more than 70% of respondents did not know to explain the term “medical honey” and more than 50% of respondents are not aware of the maximum temperature used for heating honey without decreasing its biologically active compounds.

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Mashooq Ahmad Bhat ◽  
Mohamed A. Al-Omar ◽  
Ahmed M. Naglah ◽  
Abdul Arif Khan

A series of pyrazoles derived from the substituted enaminones were synthesized and were evaluated for antimicrobial activity. All the compounds were characterized by the spectral data and elemental analysis. The synthesized compounds were initially screened for their antimicrobial activity against ATCC 6538, NCTC 10400, NCTC 10418, and ATCC 27853. During initial screening, compounds (P1, P6, and P11) presented significant antimicrobial activity through disc diffusion assay. These compounds were further evaluated for antimicrobial activity at different time points against Gram-positive and Gram-negative bacteria and presented significant activity for 6 hours. The activity was found to be greater against Gram-positive bacteria. In contrast at 24 hours, the activity was found only against Gram-positive bacteria except compound (P11), showing activity against both types of bacteria. Compound (P11) was found to have highest activity against both Gram-positive and Gram-negative bacteria.


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.


2019 ◽  
Vol 21 (2) ◽  
pp. 125
Author(s):  
U.B. Issayeva ◽  
G.S. Akhmetova ◽  
U.M. Datkhayev ◽  
M.T. Omyrzakov ◽  
K.D. Praliyev ◽  
...  

With the aim to introduce fragment of cyclopropane and fragments of p-, m-, o-fluorophenyls into the structures of N-ethoxyethylpiperidines, acylation of oxime and phenylacetylenic alcohol of 1-(2-ethoxyethyl)-4-ketopiperidine by cyclopropanecarbonylchloride was carried out; on the basis of 1-(2-ethoxyethyl)-4-ethynyl-4-hydroxypiperidine (cascaine alcohol), acylation by 4-fluoro-, 3-fluoro-, 2-fluorobenzoylchlorides was carried out with formation of the corresponding piperidine containing hydrochlorides of cyclopropanecarboxylic acid esters and para-, meta-, ortho-fluorobenzoic esters. Acylation reaction on the hydroxyl group of compounds is carried out in absolute dioxane, the acylating agents are cyclopropanecarbonylchloride, p-, m-, o-fluorobenzoyl chlorides taken in excess. The obtained esters of cyclopropanecarboxylic and para-, meta-, ortho-fluorobenzoic acids are crystalline substances with a clear melting point, well soluble in water, ethanol, acetone. P-fluorobenzoates are obtained with better yields, m-fluorobenzoates occupy an intermediate position, and o-fluorobenzoates are formed with the lowest yields. The best yields of fluorobenzoates are obtained using dioxane as a solvent. Para-, meta-, ortho-fluorobenzoic esters of 1-(2-ethoxyethyl)-4-ethynyl-4-hydroxypiperidine coded A-4 – A-6 were studied for the presence of antimicrobial activity, the actions of these preparations were evaluated in vitro in relation to strains of gram-positive bacteria Staphylococcus aureus, Bacillus subtilis, gram-negative strains of Escheriсhia coli, Pseudomonas aeruginosa and to yeast fungus Сandida albicans by the diffusion method into agar (holes). Introduction of fluorine atom into the structure of cascaine lead to manifestation of antimicrobial activity.


2021 ◽  
Vol 12 (4) ◽  
pp. 2383-2388
Author(s):  
Suguna Selvakumaran ◽  
Kayathri Marimuthu ◽  
Thiruvany Poopalan ◽  
Kalaiyarasi Tamil Selvan ◽  
Nozieana Khairuddin

Silver nanoparticles have attracted high attention worldwide for their various applications. The physiochemical parameters such as temperature, media, mixing ratio affect the rate of synthesis of silver nanoparticles and their yield. Thus, optimization of these physiochemical parameters is needed to enhance the production of silver nanoparticles. In this study, silver nanoparticles were synthesized using Aspergillus niger culture supernatant. The produced silver nanoparticles were characterized using UV-visible Spectrophotometer at 200 nm to 700 nm, which had a peak at 450 nm, indicates the formation of silver nanoparticles. It was found that Sabouraud Dextrose Broth (SDB) as optimum media, 40 ml of supernatant and 10 ml of silver nitrate as optimum mixing ratio and 65°C as optimum temperature to produce silver nanoparticles. The optimized silver nanoparticles were subjected to antimicrobial activity, and it was found that it is highly effective towards gram-negative bacteria than gram-positive bacteria where the zone of inhibition for Escherichia coli was  7 ± 2.7 mm and 5.3 ± 2.1 mm for Staphylococcus aureus.


2016 ◽  
Vol 78 (3-2) ◽  
Author(s):  
Nor Syafawani Sarah Md Saad ◽  
Nik Ahmad Nizam Nik Malek ◽  
Chun Shiong Chong

The aim of this research was to determine the antimicrobial activity of kaolinite modified with antimicrobial compounds against Gram positive and Gram negative bacteria. Copper kaolinite (Cu-kaolinite) was prepared by loading raw kaolinite with copper nitrate trihydrate (CuNO3) while surfactant modified Cu-kaolinite (SM-Cu-kaolinite) was prepared by adding cationic surfactants hexadecyltrimethyl ammonium (HDTMA) on Cu-Kaolinite. Samples was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analyzer. The antimicrobial activity of the samples was tested against Gram negative bacteria (Escherichia coli ATCC 11229 and Pseudomonas aeruginosa ATCC 15442), and Gram positive bacteria (Staphylococcus aureus ATCC 6538 and Enterococcus faecalis ATCC 29212) through disc diffusion technique (DDT) and minimum inhibition concentration (MIC). The results showed that the antimicrobial activity of Cu-kaolinite increased after modified with HDTMA due to the synergistic effects of Cu ions and HDTMA molecules on the kaolinite. The antimicrobial activity for surfactant modified Cu-kaolinite was greater for Gram positive bacteria compared to Gram negative bacteria. In conclusion, the attachment of HDTMA on Cu-kaolinite contributed to the enhanced antimicrobial activity against wide spectrum of bacteria (Gram positive and Gram negative bacteria).


Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3577
Author(s):  
Yuri E. Sabutski ◽  
Ekaterina S. Menchinskaya ◽  
Ludmila S. Shevchenko ◽  
Ekaterina A. Chingizova ◽  
Artur R. Chingizov ◽  
...  

A series of new tetracyclic oxathiine-fused quinone-thioglycoside conjugates based on biologically active 1,4-naphthoquinones and 1-mercapto derivatives of per-O-acetyl d-glucose, d-galactose, d-xylose, and l-arabinose have been synthesized, characterized, and evaluated for their cytotoxic and antimicrobial activities. Six tetracyclic conjugates bearing a hydroxyl group in naphthoquinone core showed high cytotoxic activity with EC50 values in the range of 0.3 to 0.9 μM for various types of cancer and normal cells and no hemolytic activity up to 25 μM. The antimicrobial activity of conjugates was screened against Gram-positive bacteria (Staphylococcus aureus, Bacillus cereus), Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli), and fungus Candida albicans by the agar diffusion method. The most effective juglone conjugates with d-xylose or l-arabinose moiety and hydroxyl group at C-7 position of naphthoquinone core at concentration 10 µg/well showed antimicrobial activity comparable with antibiotics vancomicin and gentamicin against Gram-positive bacteria strains. In liquid media, juglone-arabinosidic tetracycles showed highest activity with MIC 6.25 µM. Thus, a positive effect of heterocyclization with mercaptosugars on cytotoxic and antimicrobial activity for group of 1,4-naphthoquinones was shown.


Antibiotics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 238 ◽  
Author(s):  
Yamil Liscano ◽  
Constain H. Salamanca ◽  
Lina Vargas ◽  
Stefania Cantor ◽  
Valentina Laverde-Rojas ◽  
...  

Recently, resistance of pathogens towards conventional antibiotics has increased, representing a threat to public health globally. As part of the fight against this, studies on alternative antibiotics such as antimicrobial peptides have been performed, and it has been shown that their sequence and structure are closely related to their antimicrobial activity. Against this background, we here evaluated the antibacterial activity of two peptides developed by solid-phase synthesis, Alyteserin 1c (WT) and its mutant derivative (ΔM), which shows increased net charge and reduced hydrophobicity. These structural characteristics were modified as a result of amino acid substitutions on the polar face of the WT helix. The minimum inhibitory concentration (MIC) of both peptides was obtained in Gram-positive and Gram-negative bacteria. The results showed that the rational substitutions of the amino acids increased the activity in Gram-positive bacteria, especially against Staphylococcus aureus, for which the MIC was one-third of that for the WT analog. In contrast to the case for Gram-positive bacteria, these substitutions decreased activity against Gram-negative bacteria, especially in Escherichia coli, for which the MIC was eight-fold higher than that exhibited by the WT peptide. To understand this, models of the peptide behavior upon interacting with membranes of E. coli and S. aureus created using molecular dynamics were studied and it was determined that the helical stability of the peptide is indispensable for antimicrobial activity. The hydrogen bonds between the His20 of the peptides and the phospholipids of the membranes should modulate the selectivity associated with structural stability at the carboxy-terminal region of the peptides.


2004 ◽  
Vol 59 (9-10) ◽  
pp. 657-662 ◽  
Author(s):  
Juliana B. Pretto ◽  
Valdir Cechinel-Filho ◽  
Vânia F. Noldin ◽  
Mara R. K. Sartori ◽  
Daniela E. B Isaias ◽  
...  

Abstract Calophyllum brasiliense (Clusiaceae/Guttiferae) is a native Brazilian medicinal plant traditionally used against several diseases, including infectious pathologies. Crude methanolic extracts (CME) and two fractions, denoted non-polar (soluble in chloroform) and polar (nonsoluble in chloroform), were prepared from different parts of the plant (roots, stems, leaves, flowers and fruits) and studied. The following compounds were isolated and tested against pathogenic bacteria and yeasts by determination of the minimal inhibitory concentration (MIC): brasiliensic acid (1), gallic acid (2), epicatechin (3), protocatechuic acid (4), friedelin (5) and 1,5-dihydroxyxanthone (6). The results indicated that all the parts of the plant exhibited antimicrobial activity against Gram-positive bacteria, which are selectively inhibited by components of C. brasiliense. No activity was observed against Gram-negative bacteria and yeasts tested. Regarding the isolated compounds, substance 4 showed antimicrobial activity against all the tested microorganisms, whereas compound 6 exhibited antimicrobial activity only against Gram-positive bacteria. The results from the current study confirm and justify the popular use of this plant to treat infectious processes.


2017 ◽  
Vol 46 (25) ◽  
pp. 8110-8124 ◽  
Author(s):  
Veysel T. Yilmaz ◽  
Ceyda Icsel ◽  
Jenaidullah Batur ◽  
Seyma Aydinlik ◽  
Murat Cengiz ◽  
...  

New silver(i) 5,5-diethylbarbiturate complexes exhibit very high antimicrobial activity against Gram-positive bacteria and kill MCF-7 cells, damaging mitochondria and DNA.


1999 ◽  
Vol 54 (7-8) ◽  
pp. 605-609 ◽  
Author(s):  
J. Garcia Rowe ◽  
M. D. Garcia Gimenez ◽  
M. T. Saenz Rodriguez

Abstract Antimicrobial activity in some lichens from south Spain has been studied. Some lichenical substances are also identified. The structures of all compounds were elucidated by physical, spectral and chemical methods. A very high activity against Gram-positive bacteria has been observed in lichens containing usnic acid.


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