Total Synthesis and Antibacterial Screening of (±)-6,8-Dihydroxy-3- undecyl-3,4-dihydroisochromen-1-one: A Structural Analogue of Metabolites from Ononis natrix

2019 ◽  
Vol 16 (3) ◽  
pp. 245-248
Author(s):  
Hummera Rafique ◽  
Aamer Saeed ◽  
Ehsan Ullah Mughal ◽  
Muhammad Naveed Zafar ◽  
Amara Mumtaz ◽  
...  

Background: (±)-6,8-Dihydroxy-3-undecyl-3,4-dihydroisochromen-1-one is one of the structural analog of several substituted undecylisocoumarins isolated from Ononis natrix (Fabaceae), has been successfully synthesized by direct condensation of homopthalic acid (1) with undecanoyl chloride yields isochromen-1-one (2). Methods: Alkaline hydrolysis of (2) gave the corresponding keto-acid (3), which is then reduced to hydroxy acid (4) then its cyclodehydration was carried out with acetic anhydride to afford 3,4- dihydroisochromen-1-one (5). Followed by demethylation step, the synthesis of target 6,8- dihydroxy-7-methyl-3-undecyl-3,4-dihydroisocoumarin (6) was achieved. Results: In vitro antibacterial screening of all the synthesized compounds were carried out against ten bacterial strains by agar well diffusion method. Conclusion: Newly synthesized molecules exhibited moderate antibacterial activity and maximum inhibition was observed against Bacillus subtilus and Salmonella paratyphi.

2020 ◽  
Vol 11 ◽  
pp. 37-43
Author(s):  
Prof. Teodora P. Popova ◽  
Toshka Petrova ◽  
Ignat Ignatov ◽  
Stoil Karadzhov

The antimicrobial action of the dietary supplement Oxidal® was tested using the classic Bauer and Kirby agar-gel diffusion method. Clinical and reference strains of Staphylococcus aureus and Escherichia coli were used in the studies. The tested dietary supplement showed a well-pronounced inhibitory effect against the microbial strains commensurable with that of the broad-spectrum chemotherapeutic agent Enrofloxacin and showed even higher activity than the broad spectrum antibiotic Thiamphenicol. The proven inhibitory effect of the tested dietary supplement against the examined pathogenic bacteria is in accordance with the established clinical effectiveness standards for antimicrobial agents.


2020 ◽  
Vol 88 (4) ◽  
pp. 57
Author(s):  
Oussama Moussaoui ◽  
Rajendra Bhadane ◽  
Riham Sghyar ◽  
El Mestafa El Hadrami ◽  
Soukaina El Amrani ◽  
...  

A new series of amino acid derivatives of quinolines was synthesized through the hydrolysis of amino acid methyl esters of quinoline carboxamides with alkali hydroxide. The compounds were purified on silica gel by column chromatography and further characterized by TLC, NMR and ESI-TOF mass spectrometry. All compounds were screened for in vitro antimicrobial activity against different bacterial strains using the microdilution method. Most of the synthesized amino acid-quinolines show more potent or equipotent inhibitory action against the tested bacteria than their correspond esters. In addition, many of them exhibit fluorescent properties and could possibly be utilized as fluorophores. Molecular docking and simulation studies of the compounds at putative bacterial target enzymes suggest that the antimicrobial potency of these synthesized analogues could be due to enzyme inhibition via their favorable binding at the fluoroquinolone binding site at the GyrA subunit of DNA gyrase and/or the ParC subunit of topoisomerase-IV.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Agata Cieślik-Bielecka ◽  
Tadeusz Bold ◽  
Grzegorz Ziółkowski ◽  
Marcin Pierchała ◽  
Aleksandra Królikowska ◽  
...  

The aim of the study was to investigate the leukocyte- and platelet-rich plasma (L-PRP) antimicrobial activity. The studied sample comprised 20 healthy males. The L-PRP gel, liquid L-PRP, and thrombin samples were testedin vitrofor their antibacterial properties against selected bacterial strains using the Kirby-Bauer disc diffusion method. Two types of thrombin were used (autologous and bovine). Zones of inhibition produced by L-PRP ranged between 6 and 18 mm in diameter. L-PRP inhibited the growth ofStaphylococcus aureus(MRSA and MSSA strains) and was also active againstEnterococcus faecalisandPseudomonas aeruginosa. There was no activity againstEscherichia coliandKlebsiella pneumoniae. The statistically significant increase of L-PRP antimicrobial effect was noted with the use of major volume of thrombin as an activator. Additionally, in groups where a bovine thrombin mixture was added to L-PRP the zones of inhibition concerning MRSA,Enterococcus faecalis, andPseudomonas aeruginosawere larger than in the groups with autologous thrombin. Based on the conducted studies, it can be determined that L-PRP can evokein vitroantimicrobial effects and might be used to treat selected infections in the clinical field. The major volume of thrombin as an activator increases the strength of the L-PRP antimicrobial effect.


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 2 (1) ◽  
pp. 19
Author(s):  
Murni Halim

A study was carried out to screen for phytochemical constituents and assess the antioxidant and antimicrobial activities of Senna alata and Senna tora leaf extracts. The leaves were first dried at room temperature and 50°C in an oven prior to solvent extraction using ethanol and methanol. The in-vitro qualitative assays showed that both S. alata and S. tora leaf extracts contained bioactive and secondary metabolites components such as tannins, steroids, saponin, terpenoids, glycosides, flavonoids and phenols. The antioxidant activity and capacity test were carried out by conducting free radical of 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and Ferric reduction antioxidant plasma (FRAP) assays. Both assays showed S. tora leaf extract has higher antioxidant capacity than S. alata leaf extract. The efficacy of these leaf extracts were tested against skin pathogens through agar well diffusion method. S. alata extract showed an inhibition zone (1.15 – 1.59 mm) against Pseudomonas aeruginosa while S. tora extracts exhibited a strong antimicrobial activity against S. epidermidis (inhibition zone of 12 – 16.94 mm) followed by P. aeruginosa (inhibition zone of 1 – 1.59 mm). Nonetheless, no inhibition zone was observed for S. aureus by both leaf extracts. The phytochemicals and antioxidant constituents as well as inhibitory potential on skin pathogens possessed by S. alata and S. tora leave highlighted their potential utilization in the development of natural drugs or cosmetics to treat skin related diseases or infections.


Author(s):  
Bilgin Taşkın

Kefir; is a fermented milk product which is produced by granules containing a wide variety of microorganisms such as lactic acid bacteria, acetic acid bacteria and yeasts. It is traditionally consumed in many countries. It has been shown in many studies that the polysaccharide structure surrounding the granules which is composed mainly of kefiran molecule has antimicrobial effect against various pathogens as well as many health promoting effects. In this study, 24 h fermented kefir was used with two types of kefir granules for production of kefiran extract. One of them is being sold commercially and the other was collected from private households in a different region of Turkey. Kefiran extraction was carried out from matured kefir granules using three different temperatures, 80°C, 90°C and 100°C. Also, the protein contents of the extracted solutions were determined by Bradford method. Protein content of the extract solutions obtained were measured as 0.001 g/ml. The antibacterial effect of 0.05, 0.1, 1 and 2 mg of this extract against several plant pathogenic bacterial strains belonging to genus Pseudomonas, Xanthomonas, Erwinia ve Clavibacter was investigated in vitro for the first time. For this purpose, two methods, disc diffusion method and spreading method were used. The AN and SD kefir supernatants used as the positive controls in the experiments showed an average of 13-17 mm and 10-14 mm inhibition zones on the isolates, respectively, but the antibacterial effect of kefiran extracts was not observed.


2016 ◽  
Vol 11 (6) ◽  
pp. 1934578X1601100 ◽  
Author(s):  
Giovanna Pesavento ◽  
Valentina Maggini ◽  
Isabel Maida ◽  
Antonella Lo Nostro ◽  
Carmela Calonico ◽  
...  

Essential oils (EOs) are known to inhibit the growth of a wide range of microorganisms. Particularly interesting is the possible use of EOs to treat multidrug-resistant cystic fibrosis (CF) pathogens. We tested the essential oil (EO) from Origanum vulgare for in vitro antimicrobial activity, against three of the major human opportunistic pathogens responsible for respiratory infections in CF patients; these are methicillin-resistant Staphylococcus aureus, Stenotrophomonas maltophilia and Achromobacter xylosoxidans. Antibiotic susceptibility of each strain was previously tested by the standard disk diffusion method. Most strains were resistant to multiple antibiotics and could be defined as multi-drug-resistant (MDR). The antibacterial activity of O. vulgare EO (OEO) against a panel of 59 bacterial strains was evaluated, with MIC and MBC determined at 24, 48 and 72 hours by a microdilution method. The OEO was effective against all tested strains, although to a different extent. The MBC and MIC of OEO for S. aureus strains were either lower or equal to 0.50%, v/v, for A. xylosoxidans strains were lower or equal to 1% and 0.50%, v/v, respectively; and for S. maltophilia strains were lower or equal to 0.25%, v/v. The results from this study suggest that OEO might exert a role as an antimicrobial in the treatment of CF infections.


Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 544 ◽  
Author(s):  
Eman Assirey ◽  
Azhaar Alsaggaf ◽  
Arshi Naqvi ◽  
Ziad Moussa ◽  
Rawda M. Okasha ◽  
...  

Novel flavanones that incorporate chromene motifs are synthesized via a one-step multicomponent reaction. The structures of the new chromenes are elucidated by using IR, 1H-NMR, 13C-NMR, 1H-1H COSY, HSQC, HMBC, and elemental analysis. The new compounds are screened for their in vitro antimicrobial and cytotoxic activities. The antimicrobial properties are investigated and established against seven human pathogens, employing the agar well diffusion method and the minimum inhibitory concentrations. A majority of the assessed derivatives are found to exhibit significant antimicrobial activities against most bacterial strains, in comparison to standard reference drugs. Moreover, their cytotoxicity is appraised against four different human carcinoma cell lines: human colon carcinoma (HCT-116), human hepatocellular carcinoma (HepG-2), human breast adenocarcinoma (MCF-7), and adenocarcinoma human alveolar basal epithelial cell (A-549). All the desired compounds are subjected to in-silico studies, forecasting their drug likeness, bioactivity, and the absorption, distribution, metabolism, and excretion (ADME) properties prior to their synthetic assembly. The in-silico molecular docking evaluation of all the targeted derivatives is undertaken on gyrase B and the cyclin-dependent kinase. The in-silico predicted outcomes were endorsed by the in vitro studies.


2011 ◽  
Vol 6 (2) ◽  
pp. 1934578X1100600
Author(s):  
Andrés F. Peralta-Bohórquez ◽  
Clara Quijano-Célis ◽  
Mauricio Gaviria ◽  
Consuelo Vanegas-López ◽  
Jorge A. Pino

The chemical composition of the volatile compounds from the leaves of Lantana canescens Kunth (Verbenaceae) and L. lopez-palacii Moldenke grown in Colombia were analyzed by GC and GC/MS. One hundred and thirty-nine volatile compounds were identified in L. canescens, of which the major ones were β-caryophyllene (13.5%), germacrene D (10.3%) and 1-octen-3-ol (8.4%). In the oil obtained from L. lopez-palacii, eighty-three compounds were identified, of which the most prominent were 1-octen-3-ol (24.4%) and β-caryophyllene (15.2%). The in vitro antibacterial activity of the L. lopez-palacii essential oil was studied against three bacterial strains using the disc diffusion method. No antimicrobial activity was found against Escherichia coli, Enterobacter sakazakii and Listeria monocytogenes.


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