scholarly journals Synthesis of Novel Chitin Derivatives Bearing Amino Groups and Evaluation of Their Antifungal Activity

Marine Drugs ◽  
2018 ◽  
Vol 16 (10) ◽  
pp. 380
Author(s):  
Jingjing Zhang ◽  
Fang Luan ◽  
Qing Li ◽  
Guodong Gu ◽  
Fang Dong ◽  
...  

Chemical modification is one of the most effective methods to improve the biological activity of chitin. In the current study, we modified C3-OH and C6-OH of chitin (CT) and successfully synthesized 6-amino-chitin (NCT) and 3,6-diamino-chitin (DNCT) through a series of chemical reactions. The structure of NCT and DNCT were characterized by elemental analyses, FT-IR, 13C NMR, XRD, and SEM. The inhibitory effects of CT, NCT, and DNCT against six kinds of phytopathogen (F. oxysporum f. sp. cucumerium, B. cinerea, C. lagenarium, P. asparagi, F. oxysporum f. niveum, and G. zeae) were evaluated using disk diffusion method in vitro. Meanwhile, carbendazim and amphotericin B were used as positive controls. Results revealed that 6-amino-chitin (NCT) and 3,6-diamino-chitin (DNCT) showed improved antifungal properties compared with pristine chitin. Moreover, DNCT exhibited the better antifungal property than NCT. Especially, while the inhibition zone diameters of NCT are ranged from 11.2 to 16.3 mm, DNCT are about 11.4–20.4 mm. These data demonstrated that the introduction of amino group into chitin derivatives could be key to increasing the antifungal activity of such compounds, and the greater the number of amino groups in the chitin derivatives, the better their antifungal activity was.

2014 ◽  
pp. 99-116 ◽  
Author(s):  
Jelena Vulic ◽  
Aleksandra Velicanski ◽  
Dragana Cetojevic-Simin ◽  
Vesna Tumbas-Saponjac ◽  
Sonja Djilas ◽  
...  

The main chemical composition, i.e. the total content of bioactive compounds (phenolics 2209.86 ? 70.32 mg GAE/100g FDR, flavonoids 831.87 ? 12.61 mg R/100g FDR and anthocyanins 144.55 ? 0.39 mg CGE/100g FDR), in freeze-dried raspberry (FDR) was evaluated spectrophotometrically. Vitamin C content was determined by HPLC analysis (88.81 ? 4.38 mg vit C/100g FDR). Antioxidant activities of FDR extract were evaluated spectrophotometrically on stable 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals and by electron spin resonance spectroscopy (ESR) method on hydroxyl radicals (?OH). EC50 values were evaluated. EC50 DPPH? was 0.127 ? 0.013 mg/ml, while EC50 ?OH was 1.366 ? 0.026 mg/ml. Antiproliferative activity of the FDR extract was evaluated in vitro in three human cell lines by colorimetric sulphorhodamine B (SRB) assay. The most pronounced effects were obtained in the breast adenocarcinoma cell line (MCF7). EC50 value was 395.07 ? 96.38 ?g/ml. Antimicrobial activity was determined by disk diffusion method. The FDR extract produced a clear inhibition zone (without visible colonies) only toward Staphylococcus aureus. The minimal inhibitory (MIC) and minimal bactericidal (MBC) concentrations of FDR extract were evaluated. The values MIC were in the range of 4.7 - 100 mg/ml, and of MBC in the range of 6.3 - > 100 mg/ml.


2019 ◽  
Vol 70 (4) ◽  
pp. 1496-1499
Author(s):  
Ioana Maria Carmen Ienascu ◽  
Diana Obistioiu ◽  
Iuliana Maria Popescu ◽  
Mariana Nela Stefanut ◽  
Osser Gyongyi ◽  
...  

In the dental office, disinfection and sterilization are a matter of utmost importance for both the physician, the medical staff and the patient. Twelve N-(2-bromo-phenyl)-2-hydroxy-benzamide and N-(4-bromo-phenyl)-2-hydroxy-benzamide derivatives were synthesized and tested for antimicrobial activity against 6 bacterial and 2 fungal strains using the Disk diffusion method for susceptibility testing. The obtained results indicated that the N-(2-bromo-phenyl)-2-hydroxy-benzamide derivatives were more active against the tested microbes, inhibition zones of 6-12 mm being obtained, although the most effective compound against S. pyogenes proved to be N-(4-bromo-phenyl)-2-hydroxy-benzamide (14 mm inhibition zone). The tested compounds presented no effect against S. aureus, S. flexneri, S. typhimurium and C. parapsilopsis at the tested concentration.


2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Nyoman Mastra

ABSTRACTBackground Staphylococcus aureus is a pathogenic bacteria that can cause infection. Biduri leaf has antibacterial compound such as tannin, flavonoid, saponin, and polyphenol.Objective This study aimed to know the difference of growth inhibition zone of Staphylococcus aureus at the various concentration of ethanol extract of biduri leaf and to determine an effective concentration.Methods This study was the true experiment with posttest only control design, used Kirby-Bauer disk diffusion method with five concentrations (20%, 40%, 60%, 80%,100%), positive control (chloramphenicol 30 µg) and negative control (ethanol 96%).Result The result of this study showed the average of inhibition zone diameter of each concentration consecutively 26,2 mm, 28,3 mm, 29,7 mm, 31 mm and 31,5 mm. One Way Anova statistic analysis showed that the value of p is 0.000 so there is the difference of growth inhibition zone of Staphylococcus aureus at various concentrations of ethanol extract of a biduri leaf.Conclusion The conclusion of this study is there are differences in growth inhibition zone of Staphylococcus aureus at various concentrations of ethanol extract of biduri leaf and an effective concentration that can inhibit of Staphylococcus aureus is concentration 20% with mean inhibition zone is 26,2 mm. Keywords: ethanol extract of biduri leaf; Staphylococcus aureus; inhibition zone


2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Nyoman Mastra

AbstractBackground Staphylococcus aureus is one of causes infection and this bacteria have been resistence for many antibiotic. Bay leaf have antibacterials substance, which stew leaves can be treat infection caused Staphylococcus aureus. The purpose of this study was to determine differences in growth inhibition zone of Staphylococcus aureus at various concentrations of water stew of bay leaf.Method The method of this study is true experiment with posstest only control design, and used Kirby Bauer disk diffusion method with various concentrations of water stewed of bay leaf (20%, 40%, 60%, 80%,100%), positive control (chloramfenicol 30 μg) and negative control (sterile distilled water). Result The result showed that the average diameter of inhibition zone in concentration 20%, 40%, 60%, 80%, and 100% is 7 mm, 8,4 mm, 9,6 mm, 10,5 mm and 11,5 mm. Based on statistical analysis using oneway ANOVA available the value of p (0,000) α (0,05), so the inhibition zone is significant difference of growth inhibition zone of Staphylococcus aureus at various concentrations of stewed water bay leaf. Conclusion Water stew of bay leaf can inhibit the growth of Staphylococcus aureus, and there are differences in growth inhibition zone of Staphylococcus aureus at various concentrations of water stew of bay leaf. Keywords: stew of bay leaf; Staphylococcus aureus; inhibition zone 


2018 ◽  
Vol 9 (3) ◽  
pp. 336
Author(s):  
Ni Luh Budi Artaningsih ◽  
Nur Habibah ◽  
Mastra Nyoman

<p><em>Streptococcus mutans</em> is a positive gram bacteria which cause dental caries. From the several previous studies, Gamal leaf has been predicted as the antibacterial agent because of their active substance such as tannins, alkaloids, saponins, and flavonoids. The objective of the study was to know the antibacterial activity of ethanol extract of Gamal leaf (<em>Gliricidia sepium</em>) for <em>Streptococcus mutans</em> in various concentrations. This study was a true experimental with post-test only control design. The determination of antibacterial activity in this study was conducted by using Kirby Bauer disk diffusion method with the various concentrations, there were 40, 50, 60, 70 and 80%. The positive and negative controls in this study were 30 µg disk diffusion of chloramphenicol and the 96% of ethanol. The average inhibition of zone diameter in the concentrations of 40, 50, 60, 70 and 80% were 11.3, 12.3, 13.4, 15.3 and 19.2 mm, respectively. One Way ANOVA statistical analysis showed that the value of p was 0.000, so there was a difference of growth inhibition zone of <em>Streptococcus mutans</em> in various concentrations of ethanol extract of Gamal leaf (<em>Gliricidia sepium</em>). Based on the result, it can be concluded that the ethanol extract of Gamal leaf (<em>Gliricidia sepium</em>) have strong antibacterial activity, especially to <em>Streptococcus mutans</em> bacteria.</p>


Author(s):  
Maral Gharaghani ◽  
Marzieh Halvaeezadeh ◽  
Ali Zarei Mahmoudabadi

Background: Biosurfactants are amphiphilic surface active compounds that produced by several microorganisms, including, bacteria and fungi. Biodegradability, low toxicity, applications diversity and functionality under extreme conditions are characterized them from chemically biosurfactants. It is found that, Rhodotorula species, read yeasts, have high potency for biosurfactant producing. Recently, antimicrobial activities of biosurfactants have been subjected for new antibiotic therapy. The aim of the present study was to evaluate biosurfactant production by the different strains of Rhodotorula species in laboratory conditions. In addition, antifungal activity of produced biosurfactant was assessed against several saprophytic fungi. In the present study 54 strains of Rhodotorula including, R. glutinis (48 strains), R. minuta (2 strains), R. mucilaginosa (2 strains) and Rhodotorula species (2 strains) were screened for biosurfactant production. The biosurfactant was produced using the Sabouraud dextrose broth medium and confirmed by specific tests. Antifungal assay was also evaluated by disk diffusion method and the serial dilutions of biosurfactant. In the present study, although all tested strains were capable to produce biosurfactant in vitro, the degree of biosurfactant production was varied among stains. 7.4% strains had the highest (+5) biosurfactant activity followed by 16.7%, 29.5%, 25.8% and 20.4% had +4, +3, +2 and +1, respectively. In the present study, all tested fungi were inhibited at 40 &micro;l of biosurfactant. Rhodotorula species are appropriate organisms for the production of biosurfactants and R. glutinis strains have the greatest ability to producing biosurfactant than another species. Furthermore, our results were demonstrated that the produced biosurfactant by R. glutinis presented a valuable potential for biopharmaceutical applications.


Author(s):  
R. Gaglio ◽  
L. Botta ◽  
G. Garofalo ◽  
G. Guida ◽  
L. Settanni ◽  
...  

Background: Active packaging represents a defining strategy to improve food quality and safety of the packaged foods. This study aimed to evaluate the in vitro ability of commercial biopolymeric foams, namely Mater-Bi (MB), activated with 20% of carvacrol, to develop a completely biodegradable and compostable packaging to inhibit the growth of spoilage and pathogenic yeasts. Methods: MB foams, with and without carvacrol, were produced by melt mixing and the foaming process was performed in a laboratory press. The antifungal activity of foams containing carvacrol was tested applying the disk diffusion method. Statistical analysis was done using XLStat software version 7.5.2 for Excel. Results: Statistically significant differences (p<0.05) were observed between sensitivity of the tested yeasts. Candida zeylanoides 4G362 and Rhodotorula mucilaginosa ICE29 were found to be the most sensitive strains with a clear zone of 28.9±0.1 and 29.0±0.1 mm, respectively. However, Aureobasidium pullulans was the least sensitive yeast strain, showing clear zone of 20.4±0.3 mm. Conclusion: This study provided, for the first time, an in vitro analysis of the antifungal activity of MB foams activated with carvacrol against yeasts that commonly contaminate raw materials and processed foods. In conclusion, this biopolymer was highly effective against all the yeasts used as indicators strains.


2017 ◽  
Vol 43 (1) ◽  
pp. 9-13 ◽  
Author(s):  
Mustafa Nadhim Owaid ◽  
Sajid Salahuddin Saleem Al-Saeedi ◽  
Idham Ali Abed Al-Assaffii

ABSTRACT This study evaluated the antifungal activity of four fruiting bodies of oyster mushroom harvested from three agro-substrates in vitro. At three concentrations (2, 4 and 8 mg/disc), extracts discs of Pleurotus ostreatus (grey), P. ostreatus var. florida, P. cornucopiae var. citrinopileatus and P. salmoneostramineus were tested against three fungal pathogens: Trichoderma harzianum (after 2 days), Verticillium sp. and Pythium sp. (after 5 days) via the Disc Diffusion Method. The highest overall activity was by the extract disc Y2 (P. cornucopiae grown on M2 substrate; 70% wheat straw, 20% hardwood sawdust and 10% date palm fibers) and the lowest by Y1 (P. cornucopiae grown on wheat straw). The best inhibition zone was 16 mm toward T. harzianum by extract disc W2 (2 mg/disc) (P. ostreatus var. florida grown on M2 substrate), compared with 23 mm with Nystatin disc (100 U), followed 7 and 5 mm by P3 (P. salmoneostramineus grown on M3 substrate; 50% wheat straw, 30% hardwood sawdust and 20% date palm fibers) extract disc (8 mg/disc) against Pythium sp., and (4 mg/disc) against Verticillium sp., respectively.


2009 ◽  
Vol 79 (2) ◽  
pp. 331-337 ◽  
Author(s):  
Kayo Saito ◽  
Tohru Hayakawa ◽  
Rihito Kawabata ◽  
Daijiro Meguro ◽  
Kazutaka Kasai

Abstract Objective: To assess the antibacterial activity and cytotoxicity of an orthodontic bonding material containing an antibacterial agent. Materials and Methods: Superbond C&B (4-methacryloxyethyl trimellitate anhydride/methyl methacrylate-tri-n-butyl borane [4-META/MMA-TBB]) resin was mixed with benzalkonium chloride (BAC) to obtain final BAC concentrations of 0.25%, 0.75%, 1.25%, 1.75%, 2.5%, and 5.0% (wt/ wt). Antibacterial activity against Streptococcus mutans and Streptococcus sobrinus was evaluated by soaking the BAC-resin in distilled water at 37°C for periods of 30, 90, and 180 days. Antibacterial activity of the BAC-resin was measured by the disk diffusion method, and the inhibition zone around each sample was measured and recorded. For evaluation of cytotoxicity, BAC-resin samples were put into cell culture inserts placed above human gingival cells and were incubated at 37°C for 1, 3, and 6 days. Cytotoxicity was assessed with a tetrazolium bromide reduction assay. Results: The antibacterial activity of BAC-incorporated resin samples decreased significantly after immersion in water for 180 days, regardless of BAC concentration. The antibacterial activity of nonimmersed resin containing 0.25% or 1.75% BAC was comparable with that of 5.0% BAC-resin immersed for 180 days. In cytotoxicity tests, most cells died when exposed to resins containing 1.75%, 2.5%, and 5% BAC. No difference was observed between resins containing 0.25% and 0.75% BAC at 1, 3, and 6 days of culture. Conclusions: The addition of BAC to 4-META/MMA-TBB resin confers an antibacterial effect even after immersion in water, and 4-META/MMA-TBB resin containing 0.25% to 0.75% BAC has no significant cytotoxic effect.


2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S104-S104
Author(s):  
Visanu Thamlikitkul ◽  
Surapee Tiengrim

Abstract Background Most of Neisseria gonorrhoeae strains isolated from Thai patients are resistant to ciprofloxacin and ciprofloxacin is no longer recommended for therapy of gonococcal infection in Thailand. Sitafloxacin is a new generation of fluoroquinolones that contains in vitro activities against many bacteria that are resistant to ciprofloxacin. Sitafloxacin has a high concentration in urine. The objective of the study was to determine in vitro activity of sitafloxacin against ciprofloxacin-resistant N.gonorrheae. Methods Antimicrobial susceptibility tests for 52 strains of Neisseria gonorrhoeae isolated from patients attended Bangrak Hospital in Bangkok were performed. The tested antibiotics were ceftriaxone, cefixime, ciprofloxacin, and sitafloxacin. The minimum inhibitory concentrations (MICs) and inhibition zone diameters were determined by standard agar dilution and disk diffusion method, respectively, according to the Clinical and Laboratory Standards Institute (CLSI) 2013. Results All 52 N.gonorrheae isolates were susceptible to ceftriaxone (MIC &lt; 0.025 mg/l, zone diameter &gt; 35mm) and cefixime (MIC &lt; 0.025 mg/l, zone diameter &gt; 31mm). All N. gonorrheae isolates were resistant to ciprofloxacin (MIC &gt; 1 mg/l, zone diameter &lt; 27 mm). The inhibition zone diameters of sitafloxacin (5 microgram disk) against 52 isolates of N. gonorrhoeae were &gt; 41 mm in 35 isolates (67%) and between 28 and 40 mm in 17 isolates (33%). If the cut-off value of inhibition zone diameter of resistance to ciprofloxacin (&lt;27 mm) is applied, no isolates of N. gonorrheae is considered to be resistant to sitafloxacin. Conclusion Sitafloxacin seems to be active against ciprofloxacin-resistant N. gonorrheae. A clinical study on therapy of gonococcal urethritis due to ciprofloxacin-resistant N. gonorrheae should be considered. Disclosures All authors: No reported disclosures.


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