Extraction Of Gallic Acid Research Articles

Selective extraction of gallic acid in pomegranate rind using surface imprinting polymers over magnetic carbon nanotubes.

A novel surface imprinting polymer based on magnetic carbon nanotubes was prepared using dendritic polyethyleneimine as functional monomer to amplify the number of imprinted cavities. The characteristics of resulting polymers were evaluated by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and vibrating sample magnetometer (VSM). Results suggest that magnetic nanoparticles are deposited onto the surface of multiwalled carbon nanotubes and the imprinted shell is coated on the surface of magnetic carbon nanotubes with a thickness of approximately 8 nm. Magnetic imprinted polymers are sensitive to magnetic fields and can be easily separated within 3 s using an external magnet. The adsorption results indicate that the obtained imprinted polymers have fast kinetics, an ultrahigh adsorption capacity of 479.9 mg g(-1), and satisfactory selectivity towards the template molecule. The prepared materials have excellent stability with no obvious deterioration after six adsorption-regeneration cycles. In addition, a method for determination of gallic acid (GA) in pomegranate rind was developed, using a combination of the prepared polymers used as solid-phase extraction (SPE) sorbents and high-performance liquid chromatography (HPLC) for rapid isolation and determination of GA. The limit of detection of the proposed method is 0.001 μg mL(-1), and the intra and inter-day relative standard deviations (RSDs) are lower than 3.8% and 5.3%, respectively. The recoveries of GA from pomegranate rind extract are in the range 98.2-103.6% with RSDs lower than 4.3%.

Hydrophilic gallic acid–imprinted polymers over magnetic mesoporous silica microspheres with excellent molecular recognition ability in aqueous fruit juices

Hydrophilic molecularly imprinted polymers (MIPs) for gallic acid (GA) were prepared with excellent recognition ability in an aqueous solution. The proposed MIPs were designed by self-polymerization of dopamine (DA) on magnetic mesoporous silica (Fe3O4@SiO2@mSiO2, MMS) using GA as template. Resulting Fe3O4@SiO2@mSiO2@MIPs (MMS–MIPs) were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA), Brunauer–Emmett–Teller (BET), vibrating sample magnetometer (VSM), and evaluated by adsorption isotherms/kinetics and competitive adsorption. The adsorption behavior between GA and MMS–MIPs followed Langmuir and Sips adsorption isotherms with a maximum adsorption capacity at 88.7mg/g and pseudo-second-order reaction kinetics with fast binding (equilibrium time at 100min). In addition, MMS–MIPs showed rapid magnetic separation (10s) and stability (retained 95.2% after six cycles). Subsequently, MMS–MIPs were applied for the selective extraction and determination of GA from grape, apple, peach and orange juices (4.02, 3.91, 5.97, and 0.67μg/g, respectively). Generally, the described method may pave the way towards rationally designing more advanced hydrophilic MIPs.

Research on Extraction Process of Gallic Acid from <i>Penthorum chinense</i> Pursh by Aqueous Ethanol

Penthorum chinense Pursh is rich in gallic acid, which has antioxidant, anti-inflammatory, anti-fungal and antitumor activities. In order to optimize their extraction conditions, various extraction parameters were chosen to identify their effects on gallic acid extraction. With extraction amount of gallic acid as index, based on single factor analysis, influence of solid/liquid ratio, ethanol concentration, fetch time and extraction temperature on extraction technology were investigated by orthogonal test. The optimization conditions for gallic acid extraction were determined as follows: ethanol concentration 60%, extraction time 2.5 h, temperature 90°C and solid/liquid ratio 1:30. The corresponding gallic acid content was 4.85%. This optimized extraction process was stable and feasible.

Effect of some polymerization methods on the imprinting performance of molecularly imprinted polymers for molecularly imprinted solid-phase extraction application

The present work describes a solid-phase extraction (SPE) procedure using the molecularly imprinted polymers (MIPs) in order to obtain a cleaner extract and high recovery from a highly complex and aqueous herbal matrix. MIPs with a similar composition of precursors were synthesized by bulk (MIPB), precipitation (MIPP) and reverse microemulsion polymerization (MIPR) methods, and the resulting MIPs were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. The MIPs were used as sorbent in SPE procedure to study their imprinting performance in the aqueous conditions. The molecularly imprinted solid-phase extraction (MISPE) procedure for selective extraction of gallic acid (GA) from the herbal extract was performed. MIPR have shown the superior performance with the 86% extraction of GA. It was observed that the morphology of the MIPs can be enhanced using various polymerization methods for improved SPE application.

Potassium Phosphate Salts-Based Aqueous Two-Phase Systems Applied in the Extraction of Gallic Acid from Guava

Aqueous two-phase systems (ATPS) consisting of potassium phosphate salt + alcohol or polyethylene glycol were investigated to extract gallic acid. The partitioning process was studied using purity gallic acid (GA). The constituents either promote the partition process of GA to bottom or top phase, leading to the creation of versatile systems. The salt acts as a drive force of process because it influences the value of phase pH, and consequently the deprotonation of biomolecule and its partition. The results using GA from guava are in close agreement with the model systems, validating the experimental data and supporting their applicability in real systems.

Fractionation of Labisia Pumila using Solid-Phase Extraction for Extraction of Gallic Acid

Phenolics are the most ample secondary metabolites of plants and have drawn increasing attention in their applications in health supplement and functional cosmetic. This is due to their strong antioxidant properties and their marked effects in the inhibition of several oxidative stress associated metabolic disorder such as cancer and aging. In Labisia pumila, gallic acid (3,4,5-Trihydroxybenzoic acid) was found to be one of the most abundant secondary metabolite. It has been proposed as a biomarker in cosmetic and food supplement applications. In this research the identification and isolation of gallic acid were carried out. Different sorbent of solid-phase extraction (SPE) column were used for the fractionation of Labisia pumila var Alata water extract and the amount of gallic acid present in the fractions were quantified. The aim is to identify the better sorbent-solvent combination in SPE that result in higher recovery of gallic acid from Labisia pumila var Alata water extract. A range of solvent mixtures of 20%, 40%, 60% and 80% methanol (Me Oh)-water was used. Gallic acid was successfully extracted and identified from Labisia pumila. From this discovery, C18 silica reversed phase solid phase extraction column could extracts highest gallic acid from Labisia pumila var Alata water extract. Retention of analyte from the sample from second elution using 80% methanol-water Solvent may be used as the best method to extract the compound from Labisia Pumila var Alata since it has been reported to have various bioactivities such as high antioxidant activity and cytotoxic against many diseases. Using C18 silica reversed phase in SPE as a fractionation and extraction of gallic acid from Labisia pumila var Alata can be achieved for application purpose or future studies.

Molecularly imprinted microspheres and nanoparticles prepared using precipitation polymerisation method for selective extraction of gallic acid from Emblica officinalis

This paper reports the preparation of gallic acid (GA) molecularly imprinted polymers (MIPs) by the precipitation polymerisation and highlights the effect of porogen on particle size and specific molecular recognition properties. MIP, M-100 prepared in the porogen acetonitrile and MIP, M-75 prepared in a mixture of acetonitrile-toluene (75:25 v/v), resulted in the formation of microspheres with approximately 4μm particle size and surface area of 96.73m2g−1 and nanoparticles (0.8–1000nm) and a surface area of 345.9m2g−1, respectively. The Langmuir–Freundlich isotherm study revealed that M-75 has comparatively higher number of binding sites which are homogenous and has higher affinity for GA. The MIPs selectively recognised GA in presence of its structural analogues. Pure GA with percent recovery of 75 (±1.6) and 83.4 (±2.2) was obtained from the aqueous extract of Emblica officinalis by M-100 and M-75, respectively and hot water at 60°C served as the eluting solvent.

Comparison of Extraction Techniques on Extraction of Gallic Acid From Stem Bark of Jatropha curcas

In this study, effectiveness of three different commonly applied extraction techniques for the determination of gallic acid in the stem bark of Jatropha curcas has been compared. The three different techniques that were used are namely as Soxhlet extraction, Ultrasonic-Assisted Extraction (UAE) and Microwave-Assisted Extraction (MAE). Quantification of gallic acid in the extracts was done using HPLC. In general, all extraction techniques were capable of extracting gallic acid from the stem bark, but the recovery obtained using modern extraction techniques was higher than using conventional extraction techniques. In particular, MAE extracts presented a higher amount of gallic acid than Soxhlet and UAE extracts. Therefore, MAE was a simple and rapid technique that was useful for extraction of Jatropha curcas stem bark. In contrast, Soxhlet extraction only results in slightly ruptured cell pores, which could explain its low amount of gallic acid produced.

Optimization of the gallic acid extraction using ionic-liquid-based aqueous two-phase systems

Gallic acid is an interesting natural compound because of its antioxidant, anti-inflammatory, antifungal and antitumor properties. It is present in relatively high concentrations in a number of biomass sources and in industrial wastes from where it could be extracted. Aiming at developing benign and efficient extraction/purification processes for gallic acid, aqueous two-phase systems (ATPS) composed of ionic liquids (ILs) and inorganic salts were investigated. Several combinations of ionic liquids and inorganic salts were studied to understand the influence of the ionic liquid structure and of the pH of the aqueous medium on the gallic acid partitioning. It is here shown that at low pH values the non-charged form of gallic acid (or other phenolic compounds) preferentially migrates for the ionic-liquid-rich phase whereas its conjugate base preferentially partitions for the salt-rich phase. The results indicate that IL-based ATPS can be the basis of new extraction/purification processes of gallic acid from natural matrices, and improved extractions are obtained using acidic aqueous solutions.

PRELIMINARY INVESTIGATION OF GALLIC ACID EXTRACTION FROM JATROPHA CURCAS LINN. LEAVES USING SUPERCRITICAL CARBON DIOXIDE WITH METHANOL CO‐SOLVENT

ABSTRACTThe leaves of Jatropha curcas Linn. contain antioxidant, anticancer and anti‐HIV compounds. This research investigated the extraction of the phenolic compound, gallic acid (GA), from Jatropha curcas Linn. leaves using supercritical carbon dioxide (SCCO2) and methanol co‐solvent. The SCCO2 pilot plant extractor, which was 10 times the capacity of a lab scale unit, was designed and built by our research group using a hydraulic pump instead of high pressure pump. The operating pressure was varied from 20 to 40 MPa; the temperature was varied from 40 to 60C; the particle size was varied from 10 to 40 mesh and the modifier concentration was varied from 0 to 70% (v/v) aqueous methanol. An orthogonal L9 (3)4 experimental design was applied to determine the optimal extracting condition and the effect of the parameters. The largest extraction yield from the experiment was 75.39 mg/kg dry weight of leaves at 40 MPa, 50C and 10–16 mesh particles using a 70% (v/v) methanol modifier. However, from the analysis of L9 (3)4, the optimal operating conditions were at 20 MPa, 50C and 10–16 mesh particles using a 70% (v/v) methanol modifier. It was found that temperature, particle size and modifier concentration had a statistically significant influence (at 85% confidence level) on the GA extraction yield. The fact that pressure was not found to be statistically significant is possibly due to the difficulty in controlling pressure in the pilot plant.PRACTICAL APPLICATIONSA pilot plant scale supercritical fluid extraction unit, which was 10 times the size of typical laboratory units, was designed and built in our lab using a low cost hydraulic pump to replace a high pressure pump. The pilot plant was able to reasonably extract gallic acid from the leaves of Jatropha curcas Linn. Preliminary experiments resulted in an optimal set of operating conditions which can be used as a starting point in future work. The system will eventually be instrumented and controlled to access operating data as well as maintain the operation of the extractor at desired set‐points. The advantage of using SCCO2 for the extraction is to achieve pure quality product. Gallic acid, which is one of the phenolic compounds in physic nut leaves, is characterized by various properties such as anti‐inflammatory, antimutagenic, anticancer, antioxidant and antiviral agent.

RESPONSE SURFACE METHODOLOGY APPLIED TO THE EXTRACTION OF PHENOLIC COMPOUNDS FROM JATROPHA CURCAS LINN. LEAVES USING SUPERCRITICAL CO2 WITH A METHANOL CO‐SOLVENT

ABSTRACTResponse surface methodology was used to analyze the results of experiments designed using the Box–Behnken method to extract three phenolic compounds, gallic acid (GA), corilagin (CG) and ellagic acid (EA), from Jatropha curcas Linn. leaves using supercritical CO2 and methanol as a cosolvent. Experiments were carried out from 10 to 30 MPa, 40 to 80C and 30 to 70% (v/v) aqueous methanol. A 3 × 3 Box–Behnken design was used to design the experiments to determine the effects of pressure, temperature and concentration of methanol (MeOH) as well as their interaction on the extraction yield. Three nonlinear equations and 3‐D plots (one for each product) with 10 terms were developed. Analytical and numerical techniques were used to locate the optimal operating conditions. The highest experimental yields were obtained at 10 MPa, 60C and 30% (v/v) methanol modifier for GA; 20 MPa, 80C and 30% (v/v) methanol modifier for CG; and 30 MPa, 40C and 50% (v/v) methanol modifier for EA. The response surface models predicted that the maximum extraction yields of GA, CG and EA were 1,567.68 mg/kg of GA at 10 MPa, 80C and 30% (v/v) aqueous MeOH; 4,693.60 mg/kg of CG at 30 MPa, 80C and 30% (v/v) aqueous MeOH; and 1,089.02 mg/kg of EA at 10 MPa, 80C and 70% (v/v) aqueous MeOH, respectively. Because the theoretical optimum was on the limit of the range of the experiments, future work should focus on new experiments designed around the predicted optimum.PRACTICAL APPLICATIONSThe purpose of this research was to study the extraction of gallic acid (GA), corilagin (CG) and ellagic acid (EA) from Jatrapha curcas Linn. leaves using supercritical carbon dioxide (SCCO2) with a methanol cosolvent. Polar organic cosolvents or modifiers can be used to enhance extraction yield of polar solutes by increasing the CO2 polarity. Because methanol (MeOH) has a high polarity index, it was used to extract the three phenolic compounds (polar compounds) in the SCCO2 process. In addition to extracting GA, CG and EA, this research determined the maximum yield and the effect of operating parameters (pressure, temperature and MeOH concentration) using a response surface quadratic model to determine the location of the optimum operating conditions.

Estimation of Cholinesterase Inhibitory and Antioxidant Effects of the Leaf Extracts of AnatolianFicus caricavar.domesticaand their Total Phenol and Flavonoid Contents

Ficus carica var. domestica Tsch. & Rav. (common fig) is widely grown in Turkey and exported for its edible fruits. In this study, the n-hexane, chloroform, acetone, methanol, n-butanol, and water extracts of the leaves of F. carica var. domestica were screened for their cholinesterase inhibitory and antioxidant activities. Cholinesterase inhibition against acetyl- (AChE) and butyrylcholinesterase (BChE) was measured by the spectrophotometric method of Ellman at concentrations of 25, 50, and 100 microg/mL., while antioxidant activity was tested using three in vitro methods; 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, metal-chelation capacity, and ferric-reducing antioxidant power (FRAP). Total phenol and flavonoid contents of the extracts were determined spectrophotometrically. Our results revealed that the n-hexane and acetone extracts exerted a notable inhibition against both AChE (62.9 +/- 0.9% and 50.8 +/- 2.1%, respectively) and BChE (76.9 +/- 2.2% and 45.6 +/- 1.3%, respectively). However, they had low activity in the antioxidant tests. The chloroform extract was found to be the richest in total flavonoid content (252.5 +/- 1.1 mg/g quercetin equivalent), while the n-butanol extract had the highest total phenol amount (85.9 +/- 3.2 mg/g extract gallic acid equivalent).

Recovery of catechins and proanthocyanidins from winery by-products using subcritical water extraction

The aim of this work was to study the recovery of catechins and proanthocyanidins from grape seeds obtained as by-products from wineries using superheated water. The effect of temperature in the extraction process was studied. For this purpose, five different assays were carried out. In three of them, samples were extracted once with water at 50, 100 and 150 °C, respectively, working at pressures around 1500 psi to keep the water in the liquid state. In the fourth, samples were treated twice using sequentially 50 and 100 °C, and in the fifth a three-stage sequential extraction was used at 50, 100 and 150 °C. The composition of the extracts obtained was performed by HPLC–DAD–MS. The results were compared with those obtained using conventional analytical extraction with methanol/water (75:25) at atmospheric pressure. The results showed that superheated water is a good solvent for extracting flavanols, in some cases better than methanol/water (75:25). In general, major recoveries were found when the material was submitted to three sequential extractions at 50, 100 and 150 °C, but selective extractions of compounds with different degrees of polymerisation can be achieved using one-step extraction at different temperatures. Better recoveries for flavanol dimers and trimers, showing higher antioxidant activity, were obtained using a single extraction at 150 °C. Furthermore, gallic acid, with antioxidant characteristics similar to the catechin and epicatechin monomers, is obtained in greater quantities by a single extraction at 150 °C. The greater the temperature the greater extraction of gallic acid, which reaches approximately 70% of the total of polyphenols extracted.

Solvent effects on focused microwave assisted extraction of polyphenolic acids from Eucommia ulmodies

An open microwave-assisted extraction system was used to extract gallic acid, protocatechuic acid, chlorogenic acid and caffeic acid from Eucommia ulmodies. The effect of extraction variables, especially solvent, on the recoveries of these polyphenolic compounds was investigated using factorial design. As extracting solvent for these compounds, methanol produced a higher recovery than pure water. For straight chain alcohol solvents, the lower the carbon number, the higher the recoveries of the polyphenolic acids. The optimal ratio of methanol:water:glacial acetic acid in the solvent mixture used in microwave-assisted extraction was 2:8:0.3 (v/v) and this solvent could be directly used as the mobile phase in HPLC separation without additional intermittent treatment as reported in literature. The extraction under the condition of 50% microwave power and 30 s irradiation at a solvent:sample ratio of 10 (mL/g) was found to be the most advantageous. The repeatability test of extraction and chromatographic analysis was satisfactory for the analysis of these polyphenolic compounds.

Ultrasonic studies on the molecular interaction of gallic acid in aqueous methanol and acetone solutions and the role of gallic acid as viscosity reducer

Gallic acid (GA), a basic structural unit of hydrolysable tannin has been chosen as a model compound to investigate the solute-solvent interactions in polar media and to obtain clear insight into the more scientific facts in the extraction of hydrolysable tannins from plant source. Ultrasonic velocities (u), densities (ϱ), and viscosities (η), are measured for aqueous methanol and aqueous acetone solutions of GA in the temperature range 20–40°C. Acoustical parameters such as characteristic impedance (Z), adiabatic compressibility (β), free volume (V f), internal pressure ( π i), available volume (V a), absorption coefficient (α/f 2), viscous relaxation time (τ), free length (L f), molecular interaction parameter (χ) and cohesive energy are calculated for these solutions to study solute-solvent interactions. An attempt has been made to optimise the condition for efficient extraction of GA from the results obtained in acoustical and viscosity studies. Interestingly, it has been found that GA functions as viscosity reducer for aqueous acetone at a characteristic composition.

Determination of gallic acid with 4-nitrobenzenediazonium tetrafluoroborate by diffuse reflectance spectrometry on polyurethane foam

AbstractThe present work describes a rapid and cost-effective analytical procedure for the determination of gallic acid. It is basedon the solid-phase extraction of gallic acid in the form of the azo compound by polyurethane foam (PUF) and measurementby diffuse reflectance spectrometry. The calibration graphs are linear over the range 0.2–6 gml −1 . The developed procedurewas applied to the determination of gallic acid in alcoholic beverages.© 2002 Elsevier Science B.V. All rights reserved. Keywords: Gallic acid; Polyurethane foam; Sorption; Diffuse reflectance spectrometry 1. IntroductionGallic acid (2,3,4-trihydroxybenzoic acid) is a natu-ral phenolic compound which is widely distributed inplants. Some pharmacological properties of this sub-stance have been described previously. For example,it has strong antimutagenic, anticarcinogenic and an-tioxidant activities [1–3]. The antioxidant activity andantiradicalar power of gallic acid have been estimatedquantitatively [1].Along with other polyphenolic compounds, gallicacid is often used as an indicator of adulteration of fruitjuices [2,4] and different alcoholic beverages [5–7].For instance, cognac and scotch whisky contain gal-lic acid, and as was shown [5], there was a good

Determination of gallic acid in wood dust as an indicator of oak content.

A high-performance liquid chromatography (HPLC) method was developed for the detection of extracted gallic acid in wood dust. Gallic acid is a polyphenol present in carcinogenic oak wood dust, but not in beech, ash, pine or spruce dusts, as confirmed by HPLC analyses. The method involved the extraction of gallic acid from the oak dust, followed by liquid chromatographic analysis. The correlation coefficient for the share of oak dust vs. the gallic acid concentration of wood dust was 0.995. The method was tested with oak wood dust samples collected on polycarbonate membrane filters during an 8 h workshift in a floor board factory, where the dust content of the air samples was determined gravimetrically. The oak dust and the gallic acid concentrations varied from 0.2 to 13.8 mg m-3 and from 0.03 to 3.8 micrograms m-3, respectively. These parameters were linearly correlated with a correlation coefficient of 0.95. The airborne gallic acid determination is a useful technique to confirm occupational exposure to oak wood dust, a recognized human carcinogen.

Microbial production of gallic acid by modified solid state fermentation

Bioconversion of tannin to gallic acid from powder of teri pod (Caesalpinia digyna) cover was achieved by the locally isolated fungus, Rhizopus oryzae, in a bioreactor with a perforated float for carrying solid substrate and induced inoculum. Modified Czapek-Dox medium, put beneath the perforated float, with 2% tannic acid at pH 4.5, temperature 32°C, 93% relative humidity, incubated for 3 days with 3-day-old inoculum was optimum for the synthesis of tannase vis-a-vis gallic acid production. Conversion of tannin to gallic acid was 90.9%. Diethyl ether was used as the solvent for extraction of gallic acid from the fermented biomass.

Analytical Studies on Tara Tannins

In this paper, an extract from fruits pods of Caesalpinia spinosa (tara) a native leguminosae widely distributed in Peru, known by its high tannin content is evaluated for its utilization in wood adhesives. Commercial pods of tara were extracted for 1 hour with water (1:4w/v) at 65°C. The extract was spray-dried to obtain tara tannin. Spectrophotometric and chromatographic analysis were performed before and after hydrolysis to quantify amounts of free and combined components. Gallic acid concentration in the extract reached up to 53% and these results encourage us to further develop a method to extract gallic acid from tara pods (25% yield). The thermal behaviour of tara tannin-formaldehyde reaction at different pH conditions were investigated by thermoanalytical methods (Borchardt-Daniels and ASTM E-698). Kinetic parameters obtained were compared with those obtained for gallic acid-formaldehyde reaction.

Extracellular enzymes of some additional fungi associated with mushroom culture

Twenty-four fungus isolates from the compost utilized in commercially growing Agaricus brunnescens were tested for their ability to produce extracellular enzymes involved in the degradation of cellulose, lignin and xylan, the major components of the straw of the compost. All 24 isolates were able to degrade carboxymethyl cellulose. Most were classified as weak or moderate producers of exo-β-glucanase. Twenty of the 24 were also able to hydrolyze filter paper, a crystalline cellulose. Nineteen of the 24 were able to hydrolyze xylan, a hemicellulose. The production of extracellular polyphenol oxidases was detected utilizing two tests; the blueing of alcoholic gum guaiacol, which indicates tyrosinase production, and the browning of malt extract-gallic acid agar, which indicates laccase production. Twenty produced tyrosinase, but only eight produced laccase. Agaricus brunnescens was also included in all of the tests. It produced exo-β-glucanase, hemicellulase, tyrosinase and lactase.