Gallic Acid Complex Research Articles

Computational and biological investigation of the soybean lecithin-gallic acid complex for ameliorating alcoholic liver disease in mice with iron overload.

Alcoholic liver disease (ALD) is associated with significant morbidity and mortality globally. In this study, the soybean lecithin-gallic acid complex was synthesized, and its physicochemical properties were evaluated, which confirmed the complex formation. Compared with the free state of the drug, gallic acid exhibited significantly different physicochemical properties after it was complexed with soybean lecithin. To clarify the binding mode between two monomers, computational investigation was performed. From the computational data, we deduced the structure of the compound and predicted that it has a high affinity for human phosphatidylcholine transfer protein and exhibits strong pharmacological activities in vivo. The complex not only effectively ameliorated liver fibrosis, lipid peroxidation, and oxidative stress, but also reduced liver iron overload in a mouse ALD model induced by alcohol (p < 0.05). Additionally, it regulated iron metabolism by inhibiting TfR1 expression (p < 0.05) and promoting hepcidin expression (p < 0.05). These results suggest that the soybean lecithin-gallic acid complex ameliorates hepatic damage and iron overload induced by alcohol and exert hepatoprotective effects.

Ab Initio Studies of Complexation of Gallic Acid in Aqueous Solutions

By an ab initio Hartree-Fock method at the (6-311+G*) level of theory the structural and energy characteristics of gallic acid (GA) complexes are calculated with and without taking into account the first hydration shell: GA–GA, GA–H2O, GA–H2O–GA and GA–H2O–GA (+6 water molecules), GA–GA (+8 water molecules). The calculations are carried out in the vacuum and aqueous solutions by the selfconsistent reaction field method (SCRF calculations). The solvent effect is studied using the Onsager model. The effect of the medium on the geometry, dipole moment, and stability of the considered complexes is estimated. The most stable structures of the complexes, their geometric parameters and atomic charges are determined and the vibrational spectra are calculated. In the aqueous medium, the GA–GA complex (ΔEint =–12.9758 kcal/mol) is found to be the most stable as compared to GA–H2O and GA–H2O–GA. It is shown that the involvement of solvent molecules as the first hydration shell significantly affects the structure and stability of GA complexes.

Development and characterization of a flexible electrochromic device based on polyaniline and enzymatically synthesized poly (gallic acid)

An effective polyaniline-based electrochromic device was successfully achieved using the enzyme-mediated poly (gallic acid) as a polyaniline polymerization template. Poly (gallic acid) proved non-toxic upon the conducted cytotoxicity assays. Thermogravimetric analysis of the novel polyaniline-poly (gallic acid) complex displayed a remarkable increase in thermal stability compared to polyaniline-HCl doped, polyaniline-poly (styrene sulfonate), polyaniline-poly (isobutylene-alt-maleic anhydride) complexes. Polyaniline-poly (gallic acid) water dispersion was readily processed by spray-coating on indium tin oxide-poly (ethylene terephthalate) sheet. These novel electrode was employed as an electroactive layer in flexible electrochromic device with propylene carbonate-poly (methyl methacrylate)-LiClO4 polymer electrolyte. The transmittance of the electrochromic device at 650nm in a wide voltage range varied from 59% (−0.87V) to 37.1% (+0.33V) giving an optical contrast of 22% and a life up to 700 cycles.

Synthesis, Characterization, and Anticancer Activities of Pyrogallol‐Based Arylspiroborates

Arylspiroborate salts derived from pyrogallol, gallic acid, and propyl gallate have been prepared and characterized fully, including an X‐ray diffraction study for the tetrabutylammonium gallic acid complex 4. The tetrabutylammonium salts were examined for their potential anticancer activities against renal cell carcinoma (RCC) cell lines, using NBu4[Bcat2] (cat = catecholato) as a control.

Selecting the nature of imprinted molecular organosilica sieves with gallic acid via thermal analyses

The stability of the organosilica–gallic acid (GA) complex, and thus the strength of initial interactions which influences directly the sorption parameters of imprinted materials, is mostly given by the nature of co-monomers. Therefore, combining tetraethoxysilane, tetrametoxysilane, vinyl triethoxysilane and vinyl benzyl triethoxysilane as functional monomers, six formulations were obtained in order to optimise the nature of imprinted sieves. Vinyl benzyl trimethylammonium chloride and tertamethyl ammonium hydroxide directed the mesophase formation. Morphology and thermal properties of imprinted organosilica sieves were evaluated and compared to those of blank polymers synthesised in the same conditions as the imprinted ones but without GA. Thermal analysis results corroborated with the morphology of imprinted sieves were confirmed by specific GA sorption tests.

Determination of Trace Antimony by Square-Wave Adsorptive Cathodic Stripping Voltammetry at an Ex Situ Prepared Bismuth Film Electrode

A square-wave adsorptive cathodic stripping voltammetric protocol to determine trace antimony(III) in the presence of gallic acid (GA) at an ex situ prepared bismuth film electrode (BiFE) has been investigated. A well-defined and sensitive stripping peak of the Sb(III)-gallic acid complex was observed at −0.53 V (vs. SCE) in a 0.1M acetate buffer solution (pH 4.8) at a deposition potential of −0.38 V (120 s). The experimental variables as well as potential interferences were studied. Compared with the ex situ mercury film electrode (MFE), the ex situ prepared BiFE displayed a better electroanalytical performance for the determination of antimony(III). Under the optimized conditions, the linear range was obtained between 2–25 μg/L, the limit of detection for antimony(III) was 60 ng/L and the relative standard deviation was 3.37% at the 10 μg/L level (n = 10). This method was applied to determine trace amounts of antimony in several environmental samples with the satisfactory results.

Micellar effect on the sensitivity of spectrophotometric Mo(VI) determination based on the formation of gallic acid complex providing evidence for the polyoxoanion structure of molybdate ions

In this study effects of anionic (sodium dodecyl sulfate, SDS), cationic (cetyltrimethylammonium bromide, CTAB) and nonionic (Triton X-100, TX100) micelles on the sensitivity of spectrophotometric molybdenum(VI) (Mo) determination based on the formation of a binary complex with gallic acid (GA) were investigated. Micellar CTAB was found to enhance the formation of Mo–GA complex. SDS micelles exerted an inhibitory effect while TX100 micelles had no effect on the complex formation. By the optimization of experimental conditions, the determination limit of the method suggested in the literature was lowered from 5.2 × 10 −5 to 4.6 × 10 −6 and to 5.7 × 10 −7 M, in the absence and presence of CTAB, respectively. The mechanism of the effect of CTAB was investigated by spectrophotometric titrations and it was concluded that CTAB did not form a ternary complex with Mo and GA. The stoichiometry of the complex, deduced from the results of spectrophotometric titrations, provided evidence for the formation of para-Mo 7O 4 6− polyanions at pH 4.5, indicating to the formation of a charge transfer complex between these ions and GA in micellar medium.

Ferric Complexes as Catalysts for “Fenton” Degradation of 2,4‐D and Metolachlor in Soil

AbstractFenton‐type reactions of hydrogen peroxide with Fe compounds generate hydroxyl radical (OH‐) or other reactive species and are potentially useful for degrading organic contaminants in soil. The use of simple Fe salts is limited, however. This study investigated certain pH 6‐soluble Fe(III) complexes (Fe‐L, where L is an organic ligand) as catalysts for degradation of herbicides 2,4‐dichlorophenoxyacetic acid (2,4‐D) and metolachor (2‐chloro‐N‐[2‐ethyl‐6‐methylphenyl]‐N‐[2‐methoxy‐1‐methylethyl]acetamide). Reactions were carried out in 1:1 aqueous suspensions of a topsoil (15.7 g kg−1 organic C) at the natural pH of 5.7 with herbicides at concentrations representative of a spill (2–3 g kg−1, about 0.01 mol kg−1). The two herbicides had contrasting sorption behavior in that 2,4‐D was mostly in solution, whereas metolachlor was mostly sorbed. The best results were obtained using Fe‐nitrilotriacetate (NTA) or Fehydroxyethyleniminodiacetate (HEIDA) at 0.01 mol kg−1 and [H2O2] ≥ 0.5 mol kg−1. The gallic acid complex was less effective. In 3 h, 14C‐labeled 2,4‐D was quantitatively dechlorinated and partially (15–30%) converted to 14CO2: metolachlor was 93% transformed and 29% dechlorinated. Controls using free ligand plus peroxide or peroxide alone gave little or no reaction. Fe‐L + H2O2 was superior to the Fenton reagent itself (Fe2+ + H2O2). The results of this study demonstrate that relatively mild chemical oxidation can be effective for remediation of certain contaminants in soil.

Constituents of Syzygium cordatum

Friedelin, epi-friedelinol, β-sitosterol, arjunolic acid, gallic acid, ellagic acid (hexahydroxydiphenic acid), glucose and a gallic acid-ellagic acid complex were isolated from wood and bark of Syzygium cordatum. Leucodelphinidin and leucocyanidin were detected in bark and leaf.