Papers by Keyword: Gallic Acid

Abstract: At the present time, the electrodeposition of chromium metal coatings of sufficient thickness and quality is possible only from chromium plating electrolytes containing chromic acid. The authors investigated the effect of the composition of chromium plating electrolyte on the quality of the resulting metal coating. It has been demonstrated that the introduction of organic additives, of gallic acid in particular, leads to significant changes in the surface of the metal deposit and to a decrease in its hardness. Assumptions have been made about the influence of organic additives on the metal deposition process. The experimental data on the content of gases in the chromium deposits obtained from electrolytes with gallic acid additive and without it have been presented.

Abstract: Madhuca longifolia (J.Koenig ex L.) Macbr. belongs to the Sapotaceae family. This research work focused on the determination of gallic acid and quercetin in an aqueous leaf extract of M. longilolia. The development and validation of the analytical method using HPLC-DAD have been performed. The validated method was applied to determine both compounds in the leaves of M. longifolia. Optimized HPLC conditions were developed and validated for specificity, linearity, sensitivity, precision and accuracy. The linearity ranges and linear regression value were 3.125 to 100 μg/mL with r²=1 for gallic acid and 0.78 to 50 μg/mL with r²=0.9999 for quercetin, respectively. The LOD and LOQ were 0.24 and 0.73 μg/mL for gallic acid and 0.21 and 0.63 μg/mL for quercetin. Intra and inter-day precision were in the range of 0.18 to 1.76. The recovery percentage were 103.86% to 104.98% for gallic acid and 100.10% to 102.97% for quercetin. The concentration ranges of gallic acid and quercetin in the extracts were 207.95 to 405.79 mg/100 g and 7.31 to 20.56 mg/100 g, respectively. The developed HPLC method was considered to be accurate, precise and reliable for the determination of gallic acid and quercetin in M. longifolia aqueous leaf extract. This may be the first-time report for HPLC-DAD method development for the determination of bioactive phenolic compounds in Madhuca longifolia from Myanmar.

Abstract: Graphene quantum dots (GQDs), with stable photoluminescence (PL) and electrocatalytic activity, have potential application in sensor field. Herein, a facile novel electrochemiluminescence (ECL) sensor based on GQDs and glassy carbon electrode (GCE) was developed to detect Butyl hydroxy anisd (BHA) and Gallic acid. The optimization of ECL detection conditions were investigated. Hence, the sensor exhibited relatively strong luminescence intensity even without the modification of the GCE, which make this sensor system easy to implement. The developed sensor exhibited a linear response ranging from 5 to 160 μM under the optimum conditions. The method displayed the advantages of high sensitivity, good selectivity, wide linear range, low detection limit and fine reproducibility. Moreover, the practicability of the ECL sensing platform in real water samples had shown the satisfactory results, which holds a great potential in the field of pharmaceutical analysis.

Abstract: Blending of two polymers can result in a number of new composite materials with enhanced properties and applications in several fields. Biopolymers need to be crosslinked in order to modulate their general properties. Chemical crosslinking is a highly versatile method and is generally carried out using aldehydic compounds. Although these are very good cross-linkers, they are not preferred owning to their physiological toxicity. Therefore, the search for natural crosslinking agents is of great interest. Possible candidates are polyphenols, which are widely distributed as minor but functionally important constituents of plant tissues. Thus, this work investigated the use of polyphenols as natural cross-linking agents to produce new materials, namely methylcellulose-chitosan (MC-CS) biocomposites. Two plant–derived polyphenols, i.e. gallic acid (GA) and ferulic acid (FA), were studied as cross-linking agents. FT-IR, DSC, and SEM techniques were used to investigate the formation of the biocomposites. The results showed that only FA can interact with methylcellulose and chitosan as it formed turbid appearance when the clear solutions of MC and plant–derived polyphenols were mixed. The particle size of MC-FA was in the range of 500-600 nm when using 0.5% of polymer and polyphenol compounds. The CS-FA composite possessed relatively large size (6-8 µm) compared to that of the MC one. SEM analysis showed the differences in surface morphology between the cross-linked MC-CS biocomposites and the polymers. The FT-IR and DSC results also indicated that new compounds were formed.

Abstract: In this paper, using capillary zone electrophoresis method determined gallic acid content in terminalia. Under the condition of buffer solution containing 20 mmol/L Na₂B₄O₇, effective separation of components to be tested was realized. Measured content of gallic acid in terminalia was 25.36 mg/g (RSD=6.8%) (n=6), the average recovery was 87.6%. This method is simple and fast.

Abstract: In this paper, using capillary zone electrophoresis method determined gallic acid content in Paeonia lactiflora Pall. Under the condition of buffer solution containing 20 mmol/L Na₂B₄O₇, effective separation of components to be tested was realized. Measured content of gallic acid in Paeonia lactiflora Pall was 1.15 mg/g (RSD=4.28%) (n=6), the average recovery was 88.48% (n=5). This method is simple and fast.

Abstract: A new sorbent (PAMAM4.0GASG) with gallic acid as functional group has been prepared based on G4.0 polyamidoamine dendrimer modified silica gel (PAMAM4.0SG) and characterized with FTIR. It was employed for selective separation, preconcentration and determination of lead in different samples by flame atomic absorption spectrometry (FAAS). Experimental conditions for effective separation and preconcentration of lead were optimized. The preconcentration factor reaches 200 for lead. The relative standard deviation (R.S.D.) under optimum conditions was 2.1% for 5.0 μg ml¹ of Pb (II).The relative standard deviation (R.S.D.) was 2.1% for 5.0 μg ml¹ of Pb (II). The limit of detection (LOD) of 0.081μg ml¹ was achieved with a sample loading flow rate of 4.2 ml min¹ and a 10 ml sample volume in the proposed method. The proposed column enrichment method was applied for the preconcentration/separation and determination of Pb (II) in tap water and river water samples successfully.

Abstract: Laccase from Rhus vernicifera was applied to catalyze the polymerization of gallic acid (GA) as a way of “in situ” dyeing and finishing for wool, silk, nylon, cotton and viscose fabrics. The laccase-catalyzed polymerization of GA was confirmed by the results of UV-vis spectroscopy and differential thermal analysis. The adsorption of the GA oxidation product on the fibers contributed to the color effect and functional performance of treated fabrics. The dyed fabrics exhibited gray colors with pale to medium shades, depending on fiber categories. All the dyed fabrics showed significantly enhanced UV protection performance and antioxidant activity, and the dyed wool and silk had obviously improved deodorizing ability. These improved functional properties were related to the increased quantity of aromatic rings, phenolic hydroxyl groups and carboxyl groups in the GA oxidation product adsorbed by fibers.

Abstract: In order to obtain a gallic acid platinum complex, the title compound was synthesed from cis-[Pt(Cyclohexylamine)]2I2 by the reaction with NH3, silver nitrate and gallic acid respectively. The complex structure and component were characterized by elemental analysis, ESI-MS, 1H-NMR and IR and the anticancer activity was measured by MTT method. The result showed that its structure was consistent with the title compound and had inhibiting effect on the growth of tumor cell lines in vitro.

Abstract: Abstract. In order to obtain a gallic acid platinum complex, the title compound was synthesed from potassium tetrachloroplatinate by the reaction potassium iodide, (1R,2R)-1,2-cyclohexanediamine, silver nitrate and gallic acid respectively. The complex structure and component were characterized by elemental analysis, ESI-MS, 1H-NMR and IR and the anticancer activity was measured by MTT method. The result showed that its structure was consistent with the title compound and had inhibiting effect on the growth of tumor cell lines in vitro.