Higher Gallic Acid Research Articles

Assessment of Size Reduction and Extraction Methods on the Yield of Gallic Acid from Labisia pumila Leaf via Microstructures Analysis

Abstract The effect of size reduction and extraction methods on the gallic acid (GA) extraction yield from Labisia pumila leaf is presented. The GA extraction from a dried powdered L. pumila leaves with particle size distribution ranging from 66.66 to 1055.18 μm was performed using 10% aqueous ethanol. Three different extraction methods such as microwave assisted extraction (MAE), ultrasonic assisted extraction (UAE) and maceration extraction (ME) were used for comparison. Scanning electron microscopy (SEM) was used for microstructures analysis of the untreated and treated plant. The SEM analysis showed that the MAE led to a stronger disruption on the epidermal cells and glandular trichomes of L. pumila compared to other extraction methods. The highest GA extraction yield at 0.32 mg/g DW was obtained using MAE method, followed by UAE (0.11 mg/g DW) and ME (0.08 mg/g DW). It was found that the particle size about 252.15 μm yielded a higher extraction yield of GA at 0.083 mg/g DW compared to the other particle size. The finding in this work may serve as a useful guide to obtain highest GA extraction yield from L. pumila.

Development of cotton fabric impregnated with antioxidant mango polyphenols by means of supercritical fluids

Cotton fabrics loaded with mango polyphenols were developed by means of supercritical solvent impregnation (SSI). Gallic acid (GA) was used as the model substance to determine the influence of pressure (P) and temperature (T) on the process. This method allows high GA loads under 300 bar and at 45 °C. These conditions were later implemented to the SSI of mango leaf extract (MLE) and other parameters such as cosolvent %, contact time and depressurizing rate were also studied. High loads of mango polyphenols from different families (GA, iriflophenones, mangiferin and quercetin glycosides) were deposited on cotton fibres using CO2 + 6% ethanol under 300 bar and 45 °C, at a fast depressurizing rate of 5 bar/min during 24 h. The antioxidant capacity of the processed samples was also verified by DPPH assay, and the structural changes of the cotton as well as the success of the SSI process by SEM.

Gallic acid mediated oxidation of pentachlorophenol by the Fenton reaction under mild oxidative conditions

AbstractBACKGROUNDThe present study demonstrates the decomposition of pentachlorophenol (PCP) by the Fenton reaction in the presence of gallic acid (GA). Unlike other studies, catalytic Fe2+ concentrations were used with respect to PCP in an effort to evaluate an environmentally benign Fenton system, studying the effect of phenolic‐type compounds widely found in the environment. The effect of operating variables was evaluated.RESULTSAt initial reaction times or at low H2O2 and Fe concentrations, GA enhanced PCP removal. At high H2O2 and Fe concentrations GA enhanced PCP removal only at initial reaction times. GA was the determinant factor controlling activity acting both as a chelating agent and reducer of Fe3+. Electron paramagnetic resonance (EPR) spectroscopy was applied to shed light on mechanistic aspects, verifying the interaction of GA with Fe ions. GA accelerated significantly the Fe3+/Fe2+ redox cycling. This enhanced the formation of hydroxyl radicals (HO·) as confirmed by in situ EPR spin trap experiments. A reaction mechanism was proposed including the redox cycle of GA quinoide forms.CONCLUSIONThe operational variables of a GA modified Fenton system are provided and mechanistic steps are discussed including PCP degradation, GA/Fe interaction, Fe3+/Fe2+ redox cycling and HO· formation. GA concentration controls the catalytic degradation of PCP. © 2017 Society of Chemical Industry

Changes of phenolic-acids and vitamin E profiles on germinated rough rice (Oryza sativa L.) treated by high hydrostatic pressure

This study was performed to investigate changes in the phenolic acid and vitamin E profiles of germinated rough rice following high hydrostatic pressure treatment (HPT). Rough rice was germinated at 37°C for two days and subjected to 0.1, 10, 30, 50, and 100MPa pressures for 24h. The total phenolic acid content increased from 85.37μg/g at 0.1MPa to 183.52μg/g at 100MPa. The highest gallic acid (4.29μg/g), catechin (9.55μg/g), p-coumaric acid (8.36μg/g), ferulic acid (14.99μg/g), salicylic acid (14.88μg/g), naringin (6.18μg/g), trans-cinnamic acid (45.23μg/g), and kaempferol (40.95μg/g) contents occurred in the sample treated at 100MPa after germination. The maximum vitamin E content of about 2.56 (BG) and 4.34mg/100g (AG) were achieved at 30MPa. These result suggest that a combination of HPT and germination are efficient method for enhancement of functionality in rough rice, and clarify the influence of HPT conditions on the vitamin E and phenolic acid in germination rough rice.

Influence of leaf removal and reflective mulch on phenolic composition and antioxidant activity of Merlot, Teran and Plavac mali wines (Vitis vinifera L.)

Two years study was conducted to evaluate if leaf removal and red geotextile reflective mulch affect phenolic composition of wines from three red wine grape cultivars, Merlot, Teran and Plavac mali (Vitis vinifera L.). Leaf removal (LR) and reflective mulch (RM), made from weave of aluminum platelets protected by a transparent film and sewn together with red polypropylene threads, were tested separately and combined (LR+RM) on vines of Merlot, Teran and Plavac mali in 2009 and 2010 years, and compared with untreated control. All treatments were applied at veraison. LR had the strongest influence on phenolic composition of experimental wines, particularly in terms of increasing gallic acid, catechin, malvidin-3-glucoside, delphinidin-3-glucoside and peonidin-3-glucoside content. LR+RM resulted in higher gallic acid and malvidin-3-glucoside concentrations. RM treatment had the least effect on phenolic composition of wines but still affected higher epicatechin and gallic acid content. The total phenols, anthocyanins and flavan-3-ols contents in wines exhibited strong correlation with antioxidant activity.

Gallic acid grafting effect on delivery performance and antiglaucoma efficacy of antioxidant-functionalized intracameral pilocarpine carriers

Functionalization of therapeutic carrier biomaterials can potentially provide additional benefits in drug delivery for disease treatment. Given that this modification determines final therapeutic efficacy of drug carriers, here, we investigate systematically the role of grafting amount of antioxidant gallic acid (GA) onto GN in situ gelling copolymers made of biodegradable gelatin and thermo-responsive poly(N-isopropylacrylamide) for intracameral delivery of pilocarpine in antiglaucoma treatment. As expected, increasing redox reaction time increased total antioxidant activities and free radical scavenging abilities of synthesized carrier biomaterials. The hydrophilic nature of antioxidant molecules strongly affected physicochemical properties of carrier materials with varying GA grafting amounts, thereby dictating in vitro release behaviors and mechanisms of pilocarpine. In vitro oxidative stress challenges revealed that biocompatible carriers with high GA content alleviated lens epithelial cell damage and reduced reactive oxygen species. Intraocular pressure and pupil diameter in glaucomatous rabbits showed correlations with GA-mediated release of pilocarpine. Additionally, enhanced pharmacological treatment effects prevented corneal endothelial cell loss during disease progression. Increasing GA content increased total antioxidant level and decreased nitrite level in the aqueous humor, suggesting a much improved antioxidant status in glaucomatous eyes. This work significantly highlights the dependence of physicochemical properties, drug release behaviors, and bioactivities on intrinsic antioxidant capacities of therapeutic carrier biomaterials for glaucoma treatment. Statement of SignificanceDevelopment of injectable biodegradable polymer depots and functionalization of carrier biomaterials with antioxidant can potentially provide benefits such as improved bioavailability, controlled release pattern, and increased therapeutic effect in intracameral pilocarpine administration for glaucoma treatment. For the first time, this study demonstrated that the biodegradable in situ gelling copolymers can incorporate different levels of antioxidant gallic acid to tailor the structure-property-function relationship of the intracameral drug delivery system. The systematic evaluation fully verified the dependence of phase transition, degradation behavior, drug release mechanism, and antiglaucoma efficacy on intrinsic antioxidant capacities of carrier biomaterials. The report highlights the significant role of grafting amount of gallic acid in optimizing performance of antioxidant-functionalized polymer therapeutics as new drug delivery platforms in disease treatment.

Effects of chitosan, gallic acid, and algicide on the physiological and biochemical properties of Microcystis flos-aquae.

The effects of chitosan, gallic acid, and algicide chitosan-gallate on the activities of antioxidant enzymes, malonaldehyde (MDA) content, and photosynthetic activity of Microcystis flos-aquae were investigated to explore the physiological and biochemical mechanisms of algicides. Results demonstrated that chitosan did not significantly affect catalase (CAT) and superoxide dismutase (SOD) activities, MDA content, and photosynthetic activity in this alga. At 30mgL(-1), gallic acid, CAT, and SOD activities and MDA of M. flos-aquae cells showed maximums of 2.872 × 10(-10)mg·cell(-1)min(-1), 0.787 × 10(-8)U·cell(-1), and 0.626 × 10(-8)nmol·cell(-1), respectively. Photosynthetic organs in algal cells were severely damaged under the stress of high gallic acid concentrations, inducing blockage of photosynthetic electron transport and resulting in the inability to restore normal photosynthetic activity. CAT and SOD activities and MDA content with lower algicide concentration were significantly higher than the control group (p < 0.05) and, in higher algicide groups, significantly lower than the control (p < 0.05). Algicide releasing gallic acid in groups treated with 60, 90, and 130mg/L algicide was strong enough to cause severe damage to photosynthetic organs in these algal cells. The algicide suppression time was longer than that of directly added gallic acid.

In vitro fibroblast growth stimulatory and in vivo wound healing activity of Cleome viscosa

Cleome viscosa L. (Cleomaceae) is known as Asian spider flower distributed throughout the greater part of India and widely used traditional medicine of Indian-Ayurvedic and Chinese-medicine system. In the present study, petroleum ether, chloroform, methanol and water successive extracts of C. viscosa leaves were evaluated for in vitro antioxidant, antimicrobial and in vitro fibroblast proliferation. In vivo wound healing activity performed on mice excision model using gentamicin sulfate (0.01 % w/w) hydrogel as reference standard. Petroleum ether (CvPE) and chloroform (CvCE) extracts of C. viscosa were found inactive in antioxidant evaluations, whereas methanol extract (CvME) showed potent DPPH (IC50-56.39 μg/ml) and superoxide scavenging activity (IC50-919.70 μg/ml) with highest gallic acid equivalency, among all other extracts. CvME showed with 0.5 mg/ml MIC against B. subtilis and S. aureus. In vitro evaluation for fibroblast proliferation showed that CvPE (59.73 %, 200 μg/ml) and CvCE (71.95 %, 200 μg/ml) decreased the cell viability as compared to normal control, whereas CvME (119.72 %, 50 μg/ml) and water (CvWE) extract (103.80 %, 25 μg/ml) induced the fibroblast proliferation. In vivo wound healing experiment showed that topical application of CvME (2.5 % w/w) and gentamicin sulfate hydrogel significantly increased the wound contraction (75.30 % and 78.74 %), respectively as compared to vehicle control group on 12th post-operative day. Histopathological evaluation also suggested the increased infiltration of fibroblast and abundant hair follicle growth in CvME and gentamicin sulfate and supported the in vitro findings of fibroblast proliferation. Thus the above results justify the rationale of the traditional use of C. viscosa as a wound healing medicine.

Comparative study on anti-oxidant and anti-inflammatory activities of Caesalpinia crista and Centella asiatica leaf extracts.

Background:Amyloidosis, oxidative stress and inflammation have been strongly implicated in neurodegenerative disorders like Alzheimer's disease. Traditionally, Caesalpinia crista and Centella asiatica leaf extracts are used to treat brain related diseases in India. C. crista is used as a mental relaxant drink as well as to treat inflammatory diseases, whereas C. asiatica is reported to be used to enhance memory and to treat dementia.Objective:The present study is aimed to understand the anti-oxidant and anti-inflammatory potential of C. asiatica and C. crista leaf extracts.Materials and Methods:Phenolic acid composition of the aqueous extracts of C. crista and C. asiatica were separated on a reverse phase C18 column (4.6 x 250 mm) using HPLC system. Antioxidant properties of the leaf extracts were determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay and the reducing potential assay. The anti-inflammatory activities of aqueous extracts of C. crista and C. asiatica were studied using 5-lipoxygenase assay. Polymorphonuclear leukocytes (PMNLs) were isolated from blood by Ficoll-Histopaque density gradient followed by hypotonic lysis of erythrocytes.Results:Gallic, protocatechuic, gentisic, chlorogenic, caffeic, p-coumaric and ferulic acids were the phenolic acids identified in C. crista and C. asiatica leaf aqueous extracts. However, gallic acid and ferulic acid contents were much higher in C. crista compared to C. asiatica. Leaf extracts of C. asiatica and C. crista exhibited antioxidant properties and inhibited 5-lipoxygenase (anti-inflammatory) in a dose dependent manner. However, leaf extracts of C. crista had better antioxidant and anti-inflammatory activity compared to that of C. asiatica. The better activity of C. crista is attributed to high gallic acid and ferulic acid compared to C. asiatica.Conclusions:Thus, the leaf extract of C. crista can be a potential therapeutic role for Alzheimer's disease.

QUANTIFICATION OF GALLIC ACID AND ELLAGIC ACID FROM THE SEED OF CORNUS OFFICINALIS BY UHPLC METHOD AND THEIR ANTIOXIDANT ACTIVITY

Gallic acid and ellagic acid have been identified in the seed of Cornus officinalis by the use of an ultrahigh performance liquid chromatography (UHPLC) method coupled with a diode array detector (DAD). The water extract of C. officinalis seed contained the highest gallic acid content (3.03 ± 0.10 mg/g seed), which was followed by aqueous methanol extract (2.43 ± 0.10 mg/g seed) and aqueous ethanol extract (1.53 ± 0.25 mg/g seed). But a higher concentration (12.32 ± 0.45 mg/g seed) of ellagic acid was obtained from extraction with aqueous methanol than with aqueous ethanol (11.03 ± 0.42 mg/g seed) and water (7.28 ± 0.16 mg/g seed). After heat treatment and acid hydrolysis, C. officinalis seed had higher concentrations of gallic acid and ellagic acid, contributing to more potent antioxidant activity. The results demonstrated a rich source of gallic acid and ellagic acid in C. officinalis seed, which might provide a novel source of these natural antioxidants.

In vitro production of phenolic compounds and antioxidant activity in callus suspension cultures of Habenaria edgeworthii: A rare Himalayan medicinal orchid

An in vitro method was developed for the production of phenolic compounds from callus suspension cultures of Habenaria edgeworthii Hook. f. ex. Collett, a rare Himalayan medicinal orchid. Friable and light yellow coloured callus was induced within eight weeks when seeds were cultured on Murashige and Skoog (MS) or ½ MS medium supplemented with 1μM α-naphthaleneacetic acid (NAA). In order to increase the biomass, following another 2 weeks these calli were repeatedly subcultured (4 week interval) onto ½ MS liquid medium supplemented with 0.1μM 6-benzyladenine (BA).The effect of BA (0.0–3.0μM) and methyl jasmonate (MeJA; 10–1000μM) treatment on callus growth, total phenolic content and corresponding antioxidant activity was also determined following 4 weeks of culture on ½ MS medium (liquid). Maximum callus biomass (2.61g fresh weight) was obtained in medium containing 1.0μM BA. The total phenolic content varied significantly (p<0.05) in callus grown on BA, and ranged between 10.33 and 14.30mg gallic acid equivalent (GAE) per g dry weight (DW) (compared to control 10.17mg GAE per g DW). Antioxidant activity, measured by three in vitro assays, i.e., 2,2′- azinobis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging, 1,1-diphenyl-2 picrylhydrazyl (DPPH) radical scavenging and ferric reducing antioxidant power (FRAP) assays showed maximum activity in callus grown on 3.0μM BA containing medium. High performance liquid chromatography (HPLC) analysis showed the presence of high gallic acid content (143.63mg/100g DW) when compared to wild tuber (5.5mg/100g DW). The result indicate that callus grown on medium supplemented with 3.0μM BA showed high phenolic content along with increased antioxidant activity, however, callus growth was higher with 1.0μM BA. The result of this investigation has commercial applications as increased biomass production will yield active compounds, much needed by the pharmaceutical and neutraceutical industries.

Antiobesity Effects of Chinese Black Tea (Pu‐erh Tea) Extract and Gallic Acid

The antiobesity effects of Chinese black tea (Pu-erh tea) and of gallic acid (GA) were investigated using in vitro and in vivo assays. Chinese black tea extract (BTE) and GA inhibited pancreatic lipase activity in a dose-dependent manner in vitro; the IC(inhibitory concentration)(50) values were 101.6 and 9.2 µg/mL, respectively. Black tea extract (50, 100 mg/kg body weight (b.w.)) and GA (15, 45 mg/kg b.w.) significantly suppressed the elevation of blood triglyceride after oral administration of a corn oil emulsion (8 mL oil/kg b.w.) to male ddY mice. Moreover, the antiobesity effects of BTE and GA were also evaluated in a mouse model of diet-induced obesity. Female ddY mice were divided into seven groups; normal diet (ND) group, high fat diet (HFD) group, BTE (0.2% and 0.6% of diets) groups, and GA (0.007%, 0.02% and 0.1% of diets) groups; the experimental groups were fed the test diets for 12 weeks. The BTE 0.6% and GA 0.1% groups showed significant suppression of weight gain. The weight of parametrial adipose tissue was strongly correlated with the body weight. These results suggest that GA contributes to the antiobesity effect of BTE as an active constituent by inhibiting pancreatic lipase activity.

Improvements of mean body mass index and body weight in preobese and overweight Japanese adults with black Chinese tea (Pu-Erh) water extract

Water-soluble black Chinese (Pu-Erh) tea extract (BTE), which contains high gallic acid content, has been demonstrated to elicit antiobese effects in animals. Because gallic acid is related with the reduction of visceral fat and cholesterol contents and improvement of obesity in animals, we investigated the effects of BTE intake on 36 preobese Japanese adults (body mass index [BMI], >25- <30 kg/m(2)) in a 12-week double-blind, randomized, placebo-controlled group comparison study using powdered barley tea with or without (placebo) BTE. A follow-up 4-week period after BTE intake termination was monitored to observe the withdrawal effect. All subjects ingested barley tea with or without BTE (333 mg) before each of the 3 daily meals. In the BTE-treated group, the mean pretreament values of body weight and BMI significantly decreased after intake and after BTE withdrawal. However, the corresponding values scored significant differences only from 8 weeks after intake (vs the placebo-treated group). The mean values of the waist circumference indicated a similar tendency. Furthermore, coronal navel section (same anatomical position) images of computed tomography of all BTE- and non-BTE-treated subjects revealed that the visceral fat areas (cm(2)) were significantly (P < .05) less in the former 12 weeks after BTE ingestion. Measured biochemical parameters did not indicate significant differences, and BTE-treated subjects did not complain of any adverse effects (abdominal distension, etc). Ingestion of BTE exhibited significant effects in reducing the mean waist circumference, BMI, and visceral fat values and might be useful for weight control and prevention of obesity development (or metabolic syndrome) in humans.

DETERMINATION OF GALLIC ACID IN LONGAN FRUITS BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

High performance liquid chromatography (HPLC) method was used to determine the content of gallic acid in the different parts of longan fruits. HPLC chromatograms with very good separate effect were obtained. The method was simple and quick with the high coefficient of correlation, delicacy, recovery and repeatability in detecting gallic acid. The gallic acid content in fruit of six longan (Dimocarpus longan Lour.) cultivars grown in Fujian province showed difference. The content of gallic acid in different parts of the fruit was the following sequence: seed > pericarp > aril. The content of gallic acid in seed was about 4.6-7.4 and 5.7-10.5 times higher than that of pericarp and aril, respectively. In seed, 'Lidongben' had the highest gallic acid content and 'Dongbao' had the lowest ones. In pericarp, 'Fuyan' and 'miaoqiao' had the highest gallic acid content and 'Dongbao' had the lowest ones. In aril, 'Miaoqiao' and 'Lidongben' had the highest gallic acid content and 'Dongbao' had the lowest ones.

The Effect of Vineyard Cover Crop on Main Monomeric Phenols of Grape Berry and Wine in Vitis viniferal L. cv. Cabernet Sauvignon

This study was conducted to determine the effect of cover crop inter-row in vineyard on main mono-phenol content of grape berry and wine. Three such cover crops, two perennial legumes (white clover and alfalfa) and a perennial gramineous grass (tall fescue) were sown in vineyard. The main phenolic compounds of mature grape berry and wines vinified under the same conditions were extracted with ethyl acetate and diethyl ether and analyzed by high-performance liquid chromatography (HPLC) by comparing to soil tillage. A total of ten phenolic compounds were identified and quantified in the different grape berry and wines, including nonflavonoids (hydroxybenzoic and hydroxycinnamic acids) and flavonoids (flavanols and flavonols). The concentration of flavonoid compounds (409.43 to 538.63 mg kg −1 and 56.16 to 81.30 mg L −1) was higher than nonflavonoids (76.91 to 98.85 mg kg −1 and 30.65 to 41.22 mg L −1) for Cabernet Sauvignon grape and wine under different treatments, respectively. In the flavonoid phenolics, Catechin was the most abundant in the different grapes and wines, accounting for 74.94 to 79.70% and 48.60 to 50.62% of total nonanthocyanin phenolics quantified, respectively. Compared to soil tillage, the sward treatments showed a higher content of main mono-phenol and total nonanthocyanin phenolics in grapes and wines. There were significant differences between two cover crop treatments (tall fescue and white clover) and soil tillage for the content of benzoic acid, salicylic acid, caffeic acid, catechin, and total phenolics in the grape berry ( P < 0.05 or P < 0.01). The wine from tall fescue cover crop had the highest gallic acid, caffeic acid and catechin. Cover crop system increased the total nonanthocyanin phenolics of grapes and wines in order of the four treatments: tall fescue, white clover, alfalfa, and soil tillage (control). Cover crop in vineyard increased total phenols of grape berry and wine, and thus improved the quality of wine evidently.