scholarly journals Photophysical and antibacterial activity of light-activated quaternary eosin Y

2019 ◽  
Vol 17 (1) ◽  
pp. 1244-1251 ◽  
Author(s):  
Desislava Staneva ◽  
Stanislava Yordanova ◽  
Evgenia Vasileva-Tonkova ◽  
Stanimir Stoyanov ◽  
Ivo Grabchev

AbstractThe functional characteristics of a new eosin dye with biocidal quaternary ammonium group (E) were studied in aqueous solution and in organic solvents of different polarity. The spectral properties depend on the nature and polarity of the respective solvents. The antimicrobial activity of compound E has been tested in vitro against Gram-negative bacteria (Escherichia coli, Acinetobacter johnsoni and Pseudomonas aeruginosa), Gram-positive bacteria (Sarcina lutea and Bacillus cereus) and the antifungal activity was tested against the yeasts Candida lipolytica in solution and after treated on cotton fabric. Broth dilution test has been used for quantitative evaluation of the antimicrobial activity of compound E against the model strains. The ability of compound E to inhibit the growth of model Gram-negative P. aeruginosa strain was assessed after 16 h of incubation in presence and absence of light. These experiments were conducted in planktonic format in solution and on cotton fabric. The results suggest that the new compound is effective in treating the relevant pathogens with better results being obtained by irradiation with light. In this case the quaternary ammonium group promotes the binding of eosin Y moiety to the bacterial cell wall thus accelerating bacterial photo inactivation.

2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Hassanain AT ◽  
Alyaa AK ◽  
Karim AJ

Introduction: Honey has potent bactericidal activity against many pathogenic organisms, including various Gram-negative and Gram-positive bacteria. This study aimed to determine the antimicrobial effect of Malaysian honey against different species of human pathogens using optimized honey broth media. Materials and Methods: The antimicrobial activity of honey against standard strains of Gram-negative and Grampositive bacteria and yeast was tested in vitro by the broth dilution method using 10%-100% w/v concentrations prepared in tryptic soy broth. Results: Streptococcus pyogenes was the most sensitive pathogen, it was completely inhibited by 30% honey broth medium. The most resistant were E. faecalis, S. aureus and MRSA, but they were all completely inhibited by 80% honey broth medium. Conclusion: Honey is shown to possess antimicrobial activity against human Gram-positive and negative medically important bacteria.


Soft Matter ◽  
2018 ◽  
Vol 14 (3) ◽  
pp. 387-395 ◽  
Author(s):  
Mintai P. Hwang ◽  
Xiaochu Ding ◽  
Jin Gao ◽  
Abhinav P. Acharya ◽  
Steven R. Little ◽  
...  

Betaine, a naturally occurring amino acid, is conjugated onto a polyester backbone, in which the quaternary ammonium group imparts additional functionality to the resulting polycation (B-PED). B-PED demonstrates excellentin vitroandin vivobiocompatibility and is also assessed for its effect on angiogenesis, anti-bacterial activity, and complex coacervation.


2021 ◽  
Vol 10 (4) ◽  
pp. 427-434 ◽  
Author(s):  
Turdibek Toshmurodov ◽  
Abdukhakim Ziyaev ◽  
Sobirdjan Sasmakov ◽  
Jaloliddin Abdurakhmanov ◽  
Mavluda Ziyaeva ◽  
...  

Amidoalkylation of secondary heterocyclic amines by N-[5-(alkylsulfanyl)-1,3,4-thiadiazol-2-yl]-2'-chloroacetamide resulted the new compounds 5-10 that contain 1,3,4-thiadiazole-5-thione moiety alongside pyperidine, morpholine, and cytisine fragments. In vitro screening of antimicrobial activity of synthesized compounds showed that N-[5-(amylsulfanyl)-1,3,4-thiadiazol-2-yl]-2'-morpholinacetamide exhibited an appreciable antibacterial activity against gram-negative bacteria of Escherichia coli (inhibition zone diameter of 16 mm) and gram-positive bacteria of Staphylococcus aureus and Bacillus subtilis (10-13 mm).


2020 ◽  
Vol 7 (7) ◽  
pp. 200290 ◽  
Author(s):  
Ricardo Corona-Sánchez ◽  
Alma Sánchez-Eleuterio ◽  
Claudia Negrón-Lomas ◽  
Yarisel Ruiz Almazan ◽  
Leticia Lomas-Romero ◽  
...  

A series of carbohydrate-linked 1,2,3-triazole derivatives were synthesized in good yields from glucofuranose and allofuranose diacetonides using as key step a three-component 1,3-dipolar azide–alkyne cycloaddition catalysed by a Cu–Al mixed oxide. In this multi-component reaction, Cu–Al mixed oxide/sodium ascorbate system serves as a highly reactive, recyclable and efficient heterogeneous catalyst for the regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles. The reported protocol has significant advantages over classical CuI/ N , N -diisopropylethylamine (DIPEA) or CuSO 4 /sodium ascorbate conditions in terms of efficiency and reduced synthetic complexity. In addition, the selective deprotection of synthesized di- O -isopropylidene derivatives was also carried out leading to the corresponding mono- O -isopropylidene products in moderate yields. Some of the synthesized triazole glycoconjugates were tested for their in vitro antimicrobial activity using the disc diffusion method against Gram-positive bacteria ( Staphylococcus aureus and Bacillus subtilis ), Gram-negative bacteria ( Escherichia coli and Pseudomonas aeruginosa ), as well as fungus ( Aspergillus niger ) and yeast ( Candida utilis ). The results revealed that these compounds exhibit moderate to good antimicrobial activity mainly against Gram-negative bacteria.


2012 ◽  
Vol 7 (7) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Rajesh K. Joshi ◽  
Vijaylaxmi Badakar

The essential oil of the flowers of Tridax procumbens L. was obtained by hydro-distillation and analyzed by gas chromatography equipped with a flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC/MS). Twenty-six compounds were identified, which comprised 90.6% of the total constituents. The most abundant compound was ( Z)-falcarinol (25.9%), followed by α-selinene (15.3%), limonene (8.3%) and zerumbone (4.3%). Antimicrobial activity was tested against six Gram-positive and eight Gram-negative bacteria, and three fungi. The oil was active against the tested Gram-positive bacteria at a concentration range of 0.14 ± 0.03 - 0.57±0.05 mg/mL, while 0.67 ± 0.12 - 4.58 ± 0.41 mg/mL was effective against the studied Gram-negative bacteria. Remarkable antifungal activity was found against the tested fungi at a concentration range of 0.06 ± 0.008 - 0.10 ± 0.01 mg/mL.


2021 ◽  
Vol 47 ◽  
pp. e645
Author(s):  
Jaqueline da Rosa COELHO ◽  
Karolina Victória ROSA ◽  
Jamilly Sousa ROCHA ◽  
Norha Constanza Bolívar RAMÍREZ ◽  
Marcelo MARASCHIN ◽  
...  

This study aimed to evaluate the in vitro effect of carvacrol on different microorganisms of importance in shrimp farming, as well as its in vivo effect on zootechnical, immunological and microbiological performance, as well as resistance, of Litopenaeus vannamei challenged with Vibrio parahaemolyticus. In particular, the antimicrobial activity of carvacrol was evaluated in vitro by analysis of the minimum inhibitory concentration (MIC) and by agar diffusion disc with Gram-negative and Gram-positive bacteria. The in vivo experiment was conducted using different concentrations of carvacrol (1, 3, 4 and 6 mg mL-1) added to shrimp feed, together with a control diet without carvacrol. After four weeks, zootechnical, immunological and microbiological parameters, as well as resistance, of animals challenged with V. parahaemolyticus were evaluated. The MIC of Vibrio alginolyticus and Vibrio harveyi was 0.078 mg mL-1, while for the other bacteria, it was 0.156 mg mL-1 of carvacrol. The greatest halos of inhibition were observed in V. parahaemolyticus and Vibrio harveyi with significant differences demonstrated for the other microorganisms, except Escherichia coli. The in vivo results showed no significant differences among treatments. In conclusion, the antimicrobial activity of carvacrol was confirmed with Gram-negative and Gram-positive bacteria, and it is suggested that its antimicrobial potential is more effective against Vibrio spp. However, the concentrations of carvacrol used in vivo did not affect the parameters evaluated.


Author(s):  
Halah A. Sahib ◽  
Mohammed H. Mohammed

A A new series of bases of Schiff (H2-H4) derived from phthalic anhydrideweresynthesized. These Schiff bases were prepared by the reaction of different amines (tyrosine methyl ester, phenylalanine methyl ester, and isoniazid) with the phthalimide derived aldehyde with the aid of glacial acetic acid or triethylamine ascatalysts. All the synthesized compounds were characterized by (FT-IR and 1HNMR) analyses and were in vitro evaluated for their antimicrobial activity against six various kinds of microorganisms. All the synthesized compounds had been screened for their antimicrobial activity against two Gram-positive bacteria “Staph. Aureus, and Bacillus subtilis”, two Gram-negative bacteria “Escherichia coli, and Klebsiella pneumoniae”, and two fungi species “Candida tropicalis and Candida albicans” using concentrations of 62.5, 125 and 250 µg\mLof derivative in dimethyl sulfoxide(DMSO). All the synthesized compounds showed no activity at all against Gram-positive bacteria, for Gram-negative bacteria and fungi they showed moderate or no activity except compound H1revealedhigh antifungal activityagainstCandida tropicalisat concentrations 125 and 250 µg\ mL. Keywords: Schiff base, phthalic anhydride, antimicrobial.  


2021 ◽  
Vol 7 (11) ◽  
pp. 104581-104591
Author(s):  
Samara Felicia Da Silva ◽  
Francine Maery Dias Ferreira-Romanichen ◽  
Tânia Mara Antonelli-Ushirobira

Os metabólitos secundários possuem diversas funções nas plantas, entre elas a de defesa contra microrganismos e, diante do aumento exponencial da resistência bacteriana, é necessário encontrar novos compostos para tratar essas infeções. A Punica granatum é rica em polifenólicos, conhecidos por apresentar atividade antimicrobiana. Para verificar a presença desses compostos foram realizadas as seguintes reações: gelatina, sais de ferro, acetato neutro de chumbo e vanilina clorídrica para observar os taninos, reação de Stiasny para separar os taninos condensados dos hidrolisáveis, pesquisa de açúcares liberados após hidrólise ácida para observar flavonoides e índice de espuma para saponinas. A fim de testar a atividade dessa planta foi realizado os testes de triagem do efeito, concentração inibitória mínima e concentração bactericida mínima. Os extratos da casca do caule, casca do fruto e folhas apresentaram flavonoides, saponinas e taninos, enquanto a polpa concentrada apresentou taninos e flavonoides, os extratos derivados dessa polpa apenas flavonoides. A maioria dos extratos apresentou atividade antibacteriana, porém em uma concentração consideravelmente alta. Esse resultado pode ser em função de uma diminuição na concentração dos metabólitos devido a fatores intrínsecos e extrínsecos da planta, sendo necessário a realização de mais análises a fim de se obter um extrato com maior atividade.


2005 ◽  
Vol 49 (8) ◽  
pp. 3501-3512 ◽  
Author(s):  
Helio S. Sader ◽  
Thomas R. Fritsche ◽  
Koné Kaniga ◽  
Yigong Ge ◽  
Ronald N. Jones

ABSTRACT PPI-0903M is a novel N-phosphono-type cephalosporin active against oxacillin-resistant staphylococci and many other gram-positive organisms. This study evaluated the in vitro activity and spectrum of PPI-0903M against 1,478 recent clinical isolates collected from 80 medical centers (22 countries). PPI-0903M demonstrated broader in vitro activity against gram-positive bacteria, particularly against multidrug-resistant staphylococci and streptococci of current clinical concern, than currently available extended-spectrum cephalosporins while maintaining similar activity against gram-negative pathogens.


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