scholarly journals Synthesis, Antimicrobial, Moisture Absorption and Retention Activities of Kojic Acid-Grafted Konjac Glucomannan Oligosaccharides

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1979
Author(s):  
Lin Song ◽  
Wancui Xie ◽  
Yukun Zhao ◽  
Xinyao Lv ◽  
Huanbin Yang ◽  
...  

Kojic acid (KA) with antibacterial activities produced by fermentation was grafted onto konjac glucomannan oligosaccharide (KGO) composed of glucose and mannose linked by β-1,4 glycosidic bonds. A novel KGO derivative, konjac glucomannan oligosaccharide kojic acid (KGOK) possessing both moisture retention and antibacterial activities was synthesized. The structure of KGOK was characterized and analyzed by thermogravimetric analysis (TG), XRD, UV–vis absorption, FTIR, and 1H NMR. The analysis results suggest that KA was linked to the KGO molecular chain through a covalent bond, and the reaction site of KA was the methylol group. The studies demonstrate that KGOK maintained the excellent moisture absorption and retention properties of KGO and the good antibacterial activities of KA. The minimum inhibitory concentration (MIC) of KGOK is 2 mg/mL for Staphylococcus aureus, Staphylococcus epidermidis, Shewanella putrefaciens, and Salmonella enterica, while its MIC is 3 mg/mL for Escherichia coli. The multi-functionality of the KGOK synthesized from natural sources provides a theoretical foundation for their potential applications in the preservation of food, beverage, aquatic, and cosmetic products.

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Carolynne Zie Wei Sie ◽  
Zainab Ngaini ◽  
Nurashikin Suhaili ◽  
Eswaran Madiahlagan

The search for lead product with beneficial pharmacological properties has become a great challenge and costly. Extraction and synthetic modification of bioactive compounds from natural resources has gained great attention and is cost effective. In this study, kojic acid was produced from fungal fermentation, using sago waste as substrate, and chemically incorporated with chalcones and azobenzene to form a series of kojic ester derivatives and evaluated for antibacterial activities. Kojic ester bearing halogenated chalcone demonstrated active inhibition against Staphylococcus aureus compared to that of standard ampicillin. The inhibition increased as the electronegativity of halogens decreased, while incorporation of azobenzene derivatives on kojic acid backbone demonstrated fair antibacterial activity against Escherichia coli with minimum inhibitory concentration (MIC) of 190–330 ppm. The presence of C=C and N=N reactive moieties in both chalcone and azo molecules contributed to the potential biological activities of the kojic acid ester.


Author(s):  
Olufunmiso O. Olajuyigbe ◽  
Morenike O. Adeoye-Isijola ◽  
Otunola Adedayo

Background: Black soap is a medicinal product that could be harnessed for economic purpose if properly packaged, and misconception about its traditional use by herbalists is thrown overboard.Aims: To promote the relevance of these soaps for economic development, this study compared the antibacterial activity of black soaps with medicated soaps widely used against bacterial infections.Methods: The antibacterial activities of these soap samples were determined by agar diffusion and macrobroth dilution methods.Results: In this study, the statistical analysis of the inhibition zones showed that black soaps were significantly (p < 0.05) more active than medicated soaps used against the test bacterial isolates. The black soaps inhibited and killed the isolates better than the medicated soaps at the different concentrations used. The minimum inhibitory concentration for Klebsiella pneumoniae and Enterococcus faecalis ranged between 0.125 mg/mL and 2 mg/mL, Staphylococcus aureus (0.25–4) mg/mL, Escherichia coli (0.125–4) mg/mL and Pseudomonas aeruginosa (1–4) mg/mL. The result showed that K. pneumoniae and E. faecalis were the most susceptible, followed by E. faecalis > E. coli > S. aureus > P. aeruginosa.Conclusion: As a valuable medicinal output derivable from organic waste product that could be converted to wealth, African black soap production, utilisation and commercialisation have tremendous economic potentials. These soaps showed significant antibacterial activity greater than those of the medicated soaps. Hence, their use could be a better option in place of commercially available medicated and antiseptic soaps because of the degree of antibacterial activities they exhibited.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Irma Zarwinda ◽  
Fauziah Fauziah ◽  
Shara Shevalinda ◽  
Dwi Putri Rejeki

Startfruit (Averrhoa bilimbi L.) is one the kind of plant that is widely used as a traditional herbal medicineto overcome various diseases i.e. diabetes mellitus, cough, rheumatism, thrush, diabetes, toothache, acne, etc. The secondary metabolites of the starfruit leaves contain flavonoids and tannins, whereby these activecompounds can be used as an antibacterial. This study aimed to determine the inhibiting power of starfruit leaf ethanol extract against Staphylococcus epidermidis at concentrations of 25%, 50%, 75%, and 100%. The research was conducted at the  AKAFARMA Laboratory and the Chemistry Laboratory , Faculty of Teacher Training and Education, Syiah Kuala University from June to July 2020. The research method was laboratory experimental using the disk diffusion method. The population of starfruit leaves was obtained from Lhokseumawe  using a purposive sampling technique. Ethanol extract of starfruit leaves with concentrations of 25%, 50%, 75%, and 100%. The diameter of the inhibition zone of the ethanol extract  from the starfruit leaves at  concentrations of 100%, 75%, 50%, and 25% were 15 mm, 12 mm, 11 mm and 10 mm, respectively. It can be concluded that  ethanol extract of starfruit leaves can inhibit the growth  of  Staphylococcus  epidermidis  with  a  maximum inhibitory concentration  of  100%,  which is classified  as a strong category.


Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2653 ◽  
Author(s):  
José Cheel ◽  
Jan Hájek ◽  
Marek Kuzma ◽  
Kumar Saurav ◽  
Iva Smýkalová ◽  
...  

Muscotoxins are cyanobacterial cyclic lipopeptides with potential applications in biomedicine and biotechnology. In this study, Desmonostoc muscorum CCALA125 strain extracts were enriched by polymeric resin treatment, and subjected to HPCCC affording three cyclic lipopeptides (1–3), which were further repurified by semi-preparative HPLC, affording 1, 2, and 3, with a purity of 86%, 92%, and 90%, respectively. The chemical identities of 2–3 were determined as muscotoxins A and B, respectively, by comparison with previously reported ESI-HRMS/MS data, whereas 1 was determined as a novel muscotoxin variant (muscotoxin C) using NMR and ESI-HRMS/MS data. Owing to the high yield (50 mg), compound 2 was broadly screened for its antimicrobial potential exhibiting a strong antifungal activity against Alternaria alternata, Monographella cucumerina, and Aspergillus fumigatus, with minimum inhibitory concentration (MIC) values of 0.58, 2.34, and 2.34 µg/mL; respectively, and weak antibacterial activity against Bacillus subtilis with a MIC value of 37.5 µg/mL. Compounds 1 and 3 were tested only against the plant pathogenic fungus Sclerotinia sclerotiorum due to their low yield, displaying a moderate antifungal activity. The developed chromatographic method proved to be an efficient tool for obtaining muscotoxins with potent antifungal properties.


Author(s):  
Surachai Techaoei ◽  
Pattaranut Eakwaropas ◽  
Khemjira Jarmkom ◽  
Warachate Khobjai

Objective: The objective of this study was to investigate the antimicrobial activity of Phellinus linteus against skin infectious pathogens, Staphylococcus epidermidis ATCC12228 and Propionibacterium acnes DMST 14916.Methods: Fungal fruiting bodies were extracted with 95% ethanol and ethyl acetate, and then, vaporized. The antimicrobial activities were determined by the disc diffusion method against Propionibacterium acnes DMST 14916 and Staphylococcus epidermidis ATCC12228 skin infectious pathogens. A minimum inhibitory concentration (MIC) and a minimum bactericidal concentration (MBC) for those crude extracts were determined. Finally, the chemical profile of crude extract was determined by using thin layer chromatography and GC-MS.Results: The result demonstrated that the ethanolic extraction had more active fractions with an MIC of 0.5 mg/ml against the growth of Propionibacterium acnes DMST 14916 and Staphylococcus epidermidis ATCC12228 and also showed a minimum inhibitory concentration (MBC) at a concentration of 1.0 mg/ml, while ethyl acetate-based solvents failed to develop on TLC according to Retention factor (Rf) values of 0.71-0.76. The GC-MS was applied to investigate the chemical profile of crude extract of Phellinus linteus, revealing a component of hexadecanoic acid and 9, 12-octadecadienoic acid.Conclusion: Phellinus linteus fruiting body extracts have great potential as antimicrobial compounds against Propionibacterium acnes DMST 14916 and Staphylococcus epidermidis ATCC12228. Thus, they can be used in the treatment of infectious diseases caused by bacterial pathogens. 


2018 ◽  
Author(s):  
Eva Le Run ◽  
Michel Arthur ◽  
Jean-Luc Mainardi

Mycobacterium abscessus has emerged as a significant pathogen responsible for chronic pulmonary infections in cystic fibrosis (CF) patients, which are difficult to treat due to resistance to a broad range of antibiotics. The initial phase of the recommended treatment in CF patients includes imipenem used without any β-lactamase inhibitor in spite of the production of the β-lactamase BlaMab. Here, we determine whether the addition of tedizolid, a once-daily oxazolidinone, improves the activity of imipenem alone or in combination with a β-lactamase inhibitor, avibactam, and rifabutin.The activity of the drugs was evaluated against M. abscessus CIP104536 by determining in vitro and intracellular antibacterial activities. The impact of BlaMab inhibition by avibactam on antibiotic activity was assessed by comparing CIP104536 and its β-lactamase-deficient derivative (ΔblaMab).The minimal inhibitory concentrations (MICs) of tedizolid against M. abscessus CIP104536 and ΔblaMab were 4 μg/mL. Tedizolid combined with imipenem showed a moderate synergistic effect with fractional inhibitory concentration (FIC) indexes of 0.41 and 0.38 for CIP104536 and ΔblaMab, respectively. For both strains, the addition of tedizolid at 2 μg/mL, corresponding to the peak serum concentration, increased the intracellular efficacy of imipenem at 8 and 32 μg/mL. Addition of avibactam and rifabutin improved the activity of the imipenem-tedizolid combination against CIP104536S.The imipenem-tedizolid combination should be further considered for the treatment of M. abscessus pulmonary infections in CF patients. The efficacy of the treatment might benefit from the use of a β-lactamase inhibitor, such as avibactam, and the addition of rifabutin.


2021 ◽  
Vol 12 ◽  
Author(s):  
Anke Chen ◽  
Dan Wang ◽  
Rui Ji ◽  
Jixi Li ◽  
Shaohua Gu ◽  
...  

Beta-glucosidase is an enzyme that catalyzes the hydrolysis of the glycosidic bonds of cellobiose, resulting in the production of glucose, which is an important step for the effective utilization of cellulose. In the present study, a thermostable β-glucosidase was isolated and purified from the Thermoprotei Thermofilum sp. ex4484_79 and subjected to enzymatic and structural characterization. The purified β-glucosidase (TsBGL) exhibited maximum activity at 90°C and pH 5.0 and displayed maximum specific activity of 139.2μmol/min/mgzne against p-nitrophenyl β-D-glucopyranoside (pNPGlc) and 24.3μmol/min/mgzen against cellobiose. Furthermore, TsBGL exhibited a relatively high thermostability, retaining 84 and 47% of its activity after incubation at 85°C for 1.5h and 90°C for 1.5h, respectively. The crystal structure of TsBGL was resolved at a resolution of 2.14Å, which revealed a classical (α/β)8-barrel catalytic domain. A structural comparison of TsBGL with other homologous proteins revealed that its catalytic sites included Glu210 and Glu414. We provide the molecular structure of TsBGL and the possibility of improving its characteristics for potential applications in industries.


2011 ◽  
Vol 11 ◽  
pp. 2237-2242 ◽  
Author(s):  
S. C. Sati ◽  
Savita Joshi

The antibacterial activity of methanol, ethanol, chloroform, and hexane extracts of the leaves of Himalayan gymnospermous plantGinkgo bilobaL. was assessed against five animal and plant pathogenic strains (Agrobacterium tumefaciens, Bacillus subtilis, Escherichia coli, Erwinia chrysanthemi, and Xanthomonas phaseoli) employing disc-diffusion and broth-dilution assays. The methanol extract showed the highest activity (zone of inhibition of 15–21 mm) followed by ethanol (14–19 mm), chloroform (15–20 mm), and hexane (14–19 mm) extracts at 250 μg/mL. A minimum inhibitory concentration (MIC) of 7.8 μg/mL was found for the methanol extract against most of the pathogens tested.


Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1403 ◽  
Author(s):  
Jie Li ◽  
Bing Xie ◽  
Kai Xia ◽  
Yingchun Li ◽  
Jing Han ◽  
...  

Nano titanium dioxide (TiO2) with photocatalytic activity was firstly modified by diethanolamine, and it was then doped with broad spectrum antibacterial silver (Ag) by in situ method. Further, both Ag doped TiO2-chitosan (STC) and TiO2-chitosan (TC) composites were prepared by the inverse emulsion cross-linking reaction. The antibacterial activities of STC composites were studied and their antibacterial mechanisms under visible light were investigated. The results show that in situ doping and inverse emulsion method led to good dispersion of Ag and TiO2 nanoparticles on the cross-linked chitosan microsphere. The STC with regular particle size of 1–10 μm exhibited excellent antibacterial activity against E. coli, P. aeruginosa and S. aureus under visible light. It is believed that STC with particle size of 1–10 μm has large specific surface area to contact with bacterial cell wall. The increased antibacterial activity was attributed to the enhancement of both electron-hole separations at the surface of nano-TiO2 by the silver ions under the visible light, and the synergetic and sustained release of strong oxidizing hydroxyl radicals of nano-TiO2, together with silver ions against bacteria. Thus, STC composites have great potential applications as antibacterial agents in the water treatment field.


2017 ◽  
Vol 1 (2) ◽  
Author(s):  
Kanchana Wijesekera

A clerodane type diterpene, nasimalun A was isolated from a dichloromethane extract of the leaves of Croton oblongifolius Roxb. Nasimalun A showed moderate cytotoxicity toward MOLT- 3 cell line with IC50 value of 26.44 µg/mL. Furthermore, nasimalun A showed minimum inhibitory concentration (MIC) of 50, 12.5, and100 μg/mL for Bacillus cereus and both Staphylococcus aureus, and Staphylococcus epidermidis respectively.


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