scholarly journals Synthesis and Biological Studies on (KLAKLAK)2-NH2 Analog Containing Unnatural Amino Acid β-Ala and Conjugates with Second Pharmacophore

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7321
Author(s):  
Sirine Jaber ◽  
Veronica Nemska ◽  
Ivan Iliev ◽  
Elena Ivanova ◽  
Tsvetelina Foteva ◽  
...  

(1) Background: Peptides are good candidates for anticancer drugs due to their natural existence in the body and lack of secondary effects. (KLAKLAK)2 is an antimicrobial peptide that also shows good anticancer properties. (2) Methods: The Solid Phase Peptide Synthesis (Fmoc-strategy) was used for the synthesis of target molecules, analogs of (KLAKLAK)2-NH2. The purity of all compounds was monitored by HPLC, and their structures were proven using mass spectrometry. Cytotoxicity and antiproliferative effects were studied using 3T3 NRU and MTT tests, respectively. For determination of antimicrobial activity, the disc-diffusion method was used. Hydrolytic stability at three pH values, which mimic the physiological pH in the body, was investigated by means of the HPLC technique. (3) Results: A good selective index against MCF-7 tumor cell lines, combined with good cytotoxicity and antiproliferative properties, was revealed for conjugates NphtG-(KLAKLAK)2-NH2 and Caf-(KLAKLAK)2-NH2. The same compounds showed very good antifungal properties and complete hydrolytic stability for 72 h. The compound Caf-(KLβ-AKLβ-AK)2-NH2 containing β-Ala in its structures exhibited good antimicrobial activity against Escherichia coli K12 407 and Bacillus subtilis 3562, in combination with very good antiproliferative and cytotoxic properties, as well as hydrolytic stability. (4) Conclusions: The obtained results reveal that all synthesized conjugates could be useful for medical practice as anticancer or antimicrobial agents.

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4383
Author(s):  
Barbara Lapinska ◽  
Aleksandra Szram ◽  
Beata Zarzycka ◽  
Janina Grzegorczyk ◽  
Louis Hardan ◽  
...  

Modifying the composition of dental restorative materials with antimicrobial agents might induce their antibacterial potential against cariogenic bacteria, e.g., S.mutans and L.acidophilus, as well as antifungal effect on C.albicans that are major oral pathogens. Essential oils (EOs) are widely known for antimicrobial activity and are successfully used in dental industry. The study aimed at evaluating antibacterial and antifungal activity of EOs and composite resin material (CR) modified with EO against oral pathogens. Ten EOs (i.e., anise, cinnamon, citronella, clove, geranium, lavender, limette, mint, rosemary thyme) were tested using agar diffusion method. Cinnamon and thyme EOs showed significantly highest antibacterial activity against S.mutans and L.acidophilus among all tested EOs. Anise and limette EOs showed no antibacterial activity against S.mutans. All tested EOs exhibited antifungal activity against C.albicans, whereas cinnamon EO showed significantly highest and limette EO significantly lowest activity. Next, 1, 2 or 5 µL of cinnamon EO was introduced into 2 g of CR and microbiologically tested. The modified CR showed higher antimicrobial activity in comparison to unmodified one. CR containing 2 µL of EO showed the best antimicrobial properties against S.mutans and C.albicans, while CR modified with 1 µL of EO showed the best antimicrobial properties against L.acidophilus.


1970 ◽  
Vol 46 (4) ◽  
pp. 513-518 ◽  
Author(s):  
V Subhadradevi ◽  
K Asokkumar ◽  
M Umamaheswari ◽  
AT Sivashanmugam ◽  
JR Ushanandhini ◽  
...  

Since ancient times plant as sources of medicinal compounds have continued to play a dominant role in the maintenance of human health. To treat chronic and infectious diseases plants used in traditional medicine contain a wide range of ingredients. In this regard, Cassia auriculata L. (Caesalpiniaceae) is widely used in Ayurvedic medicine as a tonic, astringent and as a remedy for diabetes, conjunctivitis, ulcers, leprosy, skin and liver diseases. The aim of present study was to evaluate the antimicrobial activity of ethanolic extract of Cassia auriculata leaves and flowers (CALE & CAFE). CALE and CAFE exhibited broad spectrum antimicrobial activity against standard strains of Staphylococcus aureus, Escherichia coli and Bacillus subtilis and exhibited no antifungal activity against standard strains of Candida albicans and Aspergillus niger. Minimum inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) was carried out for CALE and CAFE. The results obtained in the present study indicate that the CALE and CAFE can be a potential source of natural antimicrobial agents. Key words: Cassia auriculata; Antimicrobial activity; Agar well diffusion method. DOI: http://dx.doi.org/10.3329/bjsir.v46i4.9600 BJSIR 2011; 46(4): 513-518


Author(s):  
Aseel Alsarahni ◽  
Zuhair Muhi Eldeen ◽  
Elham Al-kaissi ◽  
Ibrahim Al- Adham ◽  
Najah Al-muhtaseb

<p><strong>Objective: </strong>To design and synthesize amino acetylenic and thiocarbonate of 2-mercapto-1,3-benthiazoles as potential antimicrobial agents.</p><p><strong>Methods: </strong>A new series of 2-{[4-(t-amino-1-yl) but-2-yn-1-yl] sulfanyl}-1,3-benzothiazole derivatives (AZ1-AZ6), and S-1,3-benzothiazol-2-yl-O-alkyl carbonothioate derivatives were synthesised, with the aim that the target compounds show new and potential antimicrobial activity. The elemental analysis was indicated by the EuroEA elemental analyzer, and biological characterization was via IR, <sup>1</sup>H-NMR, [13]C-NMR, DSC were determined with the aid of Bruker FT-IR and Varian 300 MHz spectrometer using DMSO-d<sub>6</sub> as a solvent.<em> </em><em>In vitro </em>antimicrobial activity, evaluation was done for the synthesised compounds, by agar diffusion method and broth dilution test. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined. <em></em></p><p><strong>Results: </strong>The IR, <sup>1</sup>H-NMR, <sup>13</sup>C-NMR, DSC and elemental analysis were consistent with the assigned structures. Compound of 2-{[4-(4-methylpiperazin-1-yl)but-2-yn-1-yl] sulfanyl}-1,3-benzothiazole (AZ1), 2-{[4-(2-methylpiperidin-1-yl)but-2-yn-1-yl]sulfanyl}-1,3-benzothiazole (AZ2), 2-{[4-(piperidin-1-yl) but-2-yn-1-yl]sulfanyl}-1, 3-benzothiazole (AZ6), S-1,3-benzothiazol-2-yl-O-ethyl carbonothioate (AZ7), and S-1,3-benzothiazol-2-yl-O-(2-methylpropyl) carbonothioate (AZ9) showed the highest antimicrobial activity against <em>Pseudomonas aeruginosa </em>(<em>P. aeruginosa</em>), AZ-9 demonstrated the highest antifungal activity against <em>Candida albicans </em>(<em>C. albicans</em>), with MIC of 31.25 µg/ml.</p><p><strong>Conclusion: </strong>These promising results promoted our interest to investigate other structural analogues for their antimicrobial activity further.</p>


Author(s):  
Pratibha ◽  
Nesari Tanuja ◽  
Ghildiyal Shivani ◽  
Vandhana

The emergence of antibiotic resistance and the evolution of new strains of disease causing agents, are of highly concern to the global health community. Plants are potential source of antimicrobial agents. They have been used traditionally for prevention of infections caused by micro-organisms. Description of Krimighana herbs enumerated in Ayurveda classics is suggestive towards the importance of this group of medicine. Jambu (Syzygium cumini (L.) Skeels) is a member of Myrtaceae family. In Raja Nighantu it is mentioned that plant Jambu is having Kriminashaka property. It has been widely used medicine in the prevention of various ailments like cough, Dysentary, Diabetes, inflammation and ringworm. It is well established fact that geographical variations effects the potential and activity of medicinal herbs. Hence, the present study was undertaken to investigate Syzygium cumini procured from different geographical locations including Delhi, Rajasthan and Maharashtra for their potential activity against human infections caused by pathogens. Method The aqueous extract of Syzygium cumini of all the three areas was prepared. The activity of the plant extract was evaluated against nine bacterial pathogens and one fungal strain, which include Staphyllococcus aureus, Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Klebsiella pneumonia and Candida albicans. The activity was carried out using Disk diffusion method. Result and Conclusion: All samples of Syzygium cumini showed potential antimicrobial activity against four pathogens including Staphyllococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa and Candida albicans. MIC was also evaluated against the tested pathogenic strains. The sample from Maharashtra showed MIC i.e. 80µg, 40µg, 80µg against Staphyllococcus aureus, Streptococcus pyogenes and Candida albicans respectively which is less as compare to sample from Rajasthan and Delhi. Region wise sample from Maharashtra showed good ZOI and MIC.


2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Ahmed M. Amer

The discovery of novel and more efficient antimicrobial agents from natural sources like plants is one of the most important ways through which the growing threat of antibiotic-resistant pathogens can be overcome. Herein, we report the potential antimicrobial activity ofCichorium endiviaL.subsp.pumilum. Different concentrations of various solvent extracts prepared from several parts of chicory were tested for their antimicrobial effect against a panel of microorganisms. The antimicrobial activity was analyzed using the well diffusion method, where zones of inhibition were used as indicators of antimicrobial activity. The results indicated the superiority of seed extracts over both leaf and root extracts. Methanol extracts showed higher activity compared with chloroform and water extracts. Increased solvent extract concentration was accompanied by a parallel increase in the diameter of the inhibition zone. Gram-positive bacteria were found to be more sensitive than Gram-negative bacteria and fungi. On a whole, the highest observed inhibition zones (21.3 ± 0.6 and 20.1 ± 0.4 mm) were recorded with the methanolic extract of chicory seeds againstS. aureusandB. cereus, respectively.These results offer insights into the antimicrobial potency of this Egyptian local plant and provide a basis for further phytochemical and pharmacological research.


2012 ◽  
Vol 56 (6) ◽  
pp. 3004-3010 ◽  
Author(s):  
E. N. Lorenzón ◽  
G. F. Cespedes ◽  
E. F. Vicente ◽  
L. G. Nogueira ◽  
T. M. Bauab ◽  
...  

ABSTRACTIt is well known that cationic antimicrobial peptides (cAMPs) are potential microbicidal agents for the increasing problem of antimicrobial resistance. However, the physicochemical properties of each peptide need to be optimized for clinical use. To evaluate the effects of dimerization on the structure and biological activity of the antimicrobial peptide Ctx-Ha, we have synthesized the monomeric and three dimeric (Lys-branched) forms of the Ctx-Ha peptide by solid-phase peptide synthesis using a combination of 9-fluorenylmethyloxycarbonyl (Fmoc) andt-butoxycarbonyl (Boc) chemical approaches. The antimicrobial activity assay showed that dimerization decreases the ability of the peptide to inhibit growth of bacteria or fungi; however, the dimeric analogs displayed a higher level of bactericidal activity. In addition, a dramatic increase (50 times) in hemolytic activity was achieved with these analogs. Permeabilization studies showed that the rate of carboxyfluorescein release was higher for the dimeric peptides than for the monomeric peptide, especially in vesicles that contained sphingomyelin. Despite different biological activities, the secondary structure and pore diameter were not significantly altered by dimerization. In contrast to the case for other dimeric cAMPs, we have shown that dimerization selectively decreases the antimicrobial activity of this peptide and increases the hemolytic activity. The results also show that the interaction between dimeric peptides and the cell wall could be responsible for the decrease of the antimicrobial activity of these peptides.


2009 ◽  
Vol 37 (05) ◽  
pp. 855-865 ◽  
Author(s):  
Supawadee Umthong ◽  
Songchan Puthong ◽  
Chanpen Chanchao

Propolis is one of the natural bee products which has long been used as a crude preventative and prophylactic medicine, and has been reported to possess antibacterial, antiviral, anti-inflammatory, antioxidative and anticancer properties. Propolis of the stingless bee, Trigona laeviceps, was extracted by water or methanol at 35% (w/v) yielding a crude water or a methanolic extract at 60 and 80 mg/ml, respectively, which is 17.1 and 22.9% (w/w) of the total propolis, respectively. The antimicrobial activity of both crude extracts was assayed on four selected pathogenic microbes by using the agar well diffusion method. The results suggested that both water and methanolic crude extracts have some antimicrobial activities, water extract has greater antimicrobial activity than methanolic extract. The relative order of sensitivity of the four microbes were, however, the same between the two extracts from the most to least sensitive, S. aureus > E. coli ≫ C. albicans ⋙ A. niger, with indeed no observed growth inhibition of A. niger at all. Antiproliferative and cytotoxic affects were tested on the colon carcinoma cell line, SW620, using the three parameters: (1) MTT assay; (2) cell morphology; and (3) the fragmentation of genomic DNA. The water extract of propolis showed a higher antiproliferative activity than that of methanolic extract to SW620 cells, additionally both appeared to cause cell death by necrosis.


2018 ◽  
Vol 16 (1-2) ◽  
Author(s):  
Ljiljana P. Stanojević ◽  
Milorad D. Cakić ◽  
Jelena S. Stanojević ◽  
Dragan J. Cvetković ◽  
Bojana R. Danilović

Wild cyclamen tubers (Cyclamen purpurascens Mill.) (mountain Kukavica, Southeast Serbia) were used as material for extraction in this study. Aqueous extract was obtained by reflux extraction on boiling temperature with hydromodulus 1:20 m/v during 180 minutes. The total phenolic content was determined spectrophotometrically by the method of Folin-Ciocalteu, and the total flavonoids content by method with AlCl3. The antioxidant activity of extract was investigated spectrophotometrically by DPPH and ABTS test. Disc-diffusion method was used for antimicrobial activity investigation on the following pathogenic microorganisms: Staphylococcus aureus, Bacillus cereus, Enterococcus faecalis, Pseudomonas aeruginosa and Klebsiella pneumoniae. The content of total phenols was 8.27 mg GAE/g dry extract while the total flavonoid content was 11.51 mg RE/g dry extract. The extract concentrations required to neutralize 50% of the initial concentration of DPPH radicals (EC50) after 20 minutes incubation and immediately after adding DPPH radical solution were 0.413 and 2.0 mg/ml, respectively, while concentrations of extract required to neutralize 50% of the initial ABTS radicals concentration is 0.743 mg/ml. The extract showed the highest antimicrobial activity on bacteria Staphylococcus aureus. The presented results indicate that cyclamen tubers extract is a potential source of natural antioxidants and antimicrobial agents.


2020 ◽  
Vol 16 ◽  
Author(s):  
V. Vanitha ◽  
S. Vijayakumar ◽  
S. Rajalakshmi

Aim: To investigate the antimicrobial efficacy of various solvents leaf extracts of Aegle marmelos, Plumbago zeylanica and Rhinacanthus nasutus against human pathogenic organisms such as Acinetobacter baumannii, Salmonella enteriditis, Bacillus cereus, Streptococcus pneumonia, Mycobacterium tuberculosis and Aspergillus fumigatous by agar well diffusion method. Background: Also, this is the first time report on MIC and MBC/MFC activities and identify the phytochemicals and functional groups using HPLC, GC-MS and FT-IR analysis. Objective: Minimum inhibitory concentration (MIC), minimum bactericidal (MBC/MFC) values were also carried out by the micro dilution method. Methods: Ethyl acetate extract of P. zeylanica showed better antimicrobial activity against the tested pathogens, especially for S. pneumoniae (40 mm) followed by ethyl acetate extract of R. nasutus (36 mm) against S. pneumoniae. While least inhibition was observed for aqueous extract of P.zeylanica against S. enteritis (10 mm). Results: The MIC ranged from 3.75 µg/ml to 60µg/ml and MBC/MFC 7.5 µg/ml to 60 µg/ml. Phytochemical analysis exhibited the presence of alkaloids, steroids, saponins, flavonoids, tannins, terpenes, phenolics and cardiac glycoside in all samples of selected plant extracts. Tannins, phenolics and glycoside were found only in the ethyl acetate extract of P.zeylanica. HPLC and GC-MS analysis of ethyl acetate leaf extract of P. zeylanica exposed ten major peaks and eleven compounds respectively. Chemical nature of the leaf extract was analysed by FT-IR spectrum. Conclusion: Ethyl acetate leaf extract of P. zeylanica showed better antimicrobial activity than other extracts as well as standard drugs. Therefore, this plant could be studied in detail for the identification of active biomolecules for antimicrobial agents.


Author(s):  
H. Tkachenko ◽  
L. Buyun ◽  
Z. Osadovskyy ◽  
M. Truhan ◽  
Ye. Sosnowski ◽  
...  

In the current investigation, screening of ethanolic extract obtained from Ficus lyrata leaves against pathogenic bacteria has been done in order to assess the antimicrobial activity aimed at detecting new sources of antimicrobial agents. The antimicrobial activity of the extract was determined using agar disc diffusion method. The antibacterial activity of leaf extract of F. lyrata was tested against human pathogenic bacteria — both Gram-positive (Staphylococcus aureus, methicillin-resistant S. aureus and Streptococcus pneumoniae) and Gram-negative strains (Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli). The results of this study provide evidence that the ethanolic extract of F. lyrata leaves has a mild antimicrobial activities, apparently, attributed to the presence of various secondary metabolites, which confirm the traditional use of this plant for the treatment of diseases caused by pathogens. These data allow us to suggest that the extracts of F. lyrata can be used to discover antibacterial substances for developing new pharmaceuticals to control clinically important pathogens responsible for severe disorders.


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