scholarly journals Total Phenolic Content and Antimicrobial Activity of Different Lithuanian Propolis Solutions

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Kristina Ramanauskienė ◽  
Asta Marija Inkėnienė ◽  
Vilma Petrikaitė ◽  
Vitalis Briedis
Keyword(s):  
Antimicrobial Activity ◽  
Phenolic Compounds ◽  
Propylene Glycol ◽  
Reduction Reaction ◽  
Total Phenolic ◽  
Technological Parameters ◽  
Oxidation Reduction ◽  
Alkaline Conditions ◽  
Oxidation Reduction Reaction

The manufacture of ethanol-free propolis solutions offers a broader application. A few trials with Lithuanian propolis have been conducted. The aims of the study are to manufacture propolis water and water-free solutions and evaluate the quality and antimicrobial activity of these solutions. The studied solutions containing 2.5%, 5%, and 10% propolis are prepared. As solvents, purified water, 70% v/v ethanol, 96.3% v/v ethanol, propylene glycol, and their systems were used. Determination of total levels of phenolic compounds (FAE mg/g) is based on colour oxidation-reduction reaction using Folin-Ciocalteu reagent under alkaline conditions and performed at 765 nm wavelength using UV spectrophotometer. The highest content of phenolic compounds was determined in solutions containing 10% propolis extracts, and the lowest amounts in 2.5% propolis extracts. The water extracted the lowest amount of phenolic compounds from crude propolis, ethanol extracted the highest amount, and propylene glycol ranked the middle position. It is determined that technological parameters (stirring, temperature) contribute to content of phenolic compounds. During microbiological study, MICs were determined. The studies showed that water extracted propolis solutions and solvents mixture did not inhibit the growth of the studied microorganisms, and propolis solutions in propylene glycol were found to have antimicrobial activity.

scholarly journals Phytochemical screening and in vitro antibacterial, antifungal, antioxidant and antitumor activities of the red propolis Alagoas

2019 ◽  
Vol 79 (3) ◽  
pp. 452-459 ◽  
Author(s):  
F. R. G. Silva ◽  
T. M. S. Matias ◽  
L. I. O. Souza ◽  
T. J. Matos-Rocha ◽  
S. A. Fonseca ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Gallic Acid ◽  
Bioactive Metabolites ◽  
Diffusion Method ◽  
Total Phenolic ◽  
Phytochemical Screening ◽  
Dpph Method

Abstract The study aimed to evaluate the antimicrobial activity, antioxidant, toxicity and phytochemical screening of the Red Propolis Alagoas. Antimicrobial activity was evaluated by disk diffusion method. Determination of antioxidant activity was performed using the DPPH assay (1.1-diphenyl-2-picrylhydrazyl), FTC (ferric thiocyanate) and determination of phenolic compounds by Follin method. Toxicity was performed by the method of Artemia salina and cytotoxicity by MTT method. The phytochemical screening for the detection of allelochemicals was performed. The ethanol extract of propolis of Alagoas showed significant results for antimicrobial activity, and inhibitory activity for Staphylococcus aureus and Candida krusei. The antioxidant activity of the FTC method was 80% to 108.3% hydrogen peroxide kidnapping, the DPPH method showed an EC50 3.97 mg/mL, the content of total phenolic compounds was determined by calibration curve gallic acid, resulting from 0.0005 mg/100 g of gallic acid equivalent. The extract was non-toxic by A. salina method. The propolis extract showed high activity with a higher percentage than 75% inhibition of tumor cells OVCAR-8, SF-295 and HCT116. Chemical constituents were observed as flavonones, xanthones, flavonols, and Chalcones Auronas, Catechins and leucoanthocyanidins. It is concluded that the extract can be tested is considered a potential source of bioactive metabolites.

scholarly journals Exploiting a Simple Method for the Determination of Manganese in Polyethylene Lined Tubing for Petroleum and Natural Gas Industries

2018 ◽  
Vol 142 ◽  
pp. 01006
Author(s):  
Xiaodong Shao ◽  
Xin Shi
Keyword(s):  
Ammonium Persulfate ◽  
Reduction Reaction ◽  
Simple Method ◽  
Oxidation Reduction ◽  
Security Challenges ◽  
Relative Standard ◽  
Characteristic Wavelength ◽  
Oxidation Reduction Reaction ◽  
Optimum Reaction

The polyethylene lined tubing is the key to enabling the industry to meet some of the energy security challenges that nations face today. It is well known that manganese is an important element in polyethylene lined tubing. In this paper, a simple spectrophotometric method was described for the determination of manganese in polyethylene lined tubing. The method was based on the oxidation-reduction reaction between ammonium persulfate and manganese(II) producing manganese(VII) in the presence of silver nitrate as a catalyst. The characteristic wavelength of maximum absorption of manganese(VII) was obtained locating at 530 nm. Under the optimum reaction conditions the absorption value was proportional to the concentration of manganese in the range of 0.2%~1.9% (R2 = 0.9997), and the relative standard deviation was less than 3.0% (n=5). The proposed method was applied successfully to determine manganese in polyethylene lined tubing real samples.

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