Isolation Of Catechin Research Articles

Anticholinesterase and antioxidant activity of Drynaria quercifolia and its ameliorative effect in scopolamine-induced memory impairment in mice

Ethnopharmacological relevanceDrynaria quercifolia is an epiphytic fern distributed all over Bangladesh with traditional use in treating neurological disorders and other ailments. Although several pharmacological activities of D. quercifolia have been investigated, the neuroprotective potential of this plant is still unexplored. Aim of studyIn this study, we evaluated the in vitro anticholinesterase and antioxidant activities of D. quercifolia and the neuroprotective effect in scopolamine-induced memory-impaired mouse model. Materials and methodsThe crude methanol extract (DCM) of the plant was fractionated to prepare n-hexane (DHF), chloroform (DCF), ethyl acetate (DEF), and aqueous (DAF) factions. All the fractions were evaluated for anticholinesterase activity by modified Ellman's method and the antioxidant activity by several in vitro assays such as DPPH and hydroxyl free radicals scavenging, reducing power, and inhibition of brain lipid peroxidation. The effect of the most active fractions (both DCF and DEF) on learning and memory was assessed in scopolamine-induced mouse model of memory-impairment by Morris water maze tasks. Biochemical assays were performed in brain tissue. The active compound was isolated and characterized by chromatographic, spectroscopic, and molecular docking methods. ResultsPhytochemical analysis demonstrated a high content of phenolic and flavonoid in DEF. In vitro studies revealed a strong antioxidant power of DEF and anticholinesterase activity of DCF. Both the DCF and DEF significantly (P˂0.05) reduced the escape latency time in the Morris's water maze tasks, and increased the time spent in the northeast quadrant in the probe trial. Biochemical data demonstrated that treatment with DCF and DEF at different doses significantly (P˂0.0001) inhibited acetylcholinesterase activity, restored GSH levels, and reduced MDA levels in the brain of scopolamine-induced memory-impaired mice, indicating the protective effect of D. quercifolia, possibly by acetylcholinesterase inhibition and oxidative stress prevention. Chromatographic methods of separation led to he isolation of catechin and protocatechuric acid from DEF and 3,4-dihydroxy benzoic acid from DCF. The structure of the compounds was determined by studies of their 1H-NMR spectra. Molecular docking as well as in vitro study suggests the anticholinesterase and antioxidant activity of the isolated compounds. ConclusionOur study suggested that the extracts of D. quercifolia, due to anticholinesterase and antioxidant activity, ameliorate the scopolamine-induced memory impairment in mice and thus may represent therapeutics in the treatment of Alzheimer's disease.

Alpha-glucosidase and tyrosinase inhibiton of polyphenols isolated from Potentilla speciosa var. speciosa: In vitro and in silico perspectives

In order to explore the antidiabetic and anti-pigmentation potential of Potentilla species, which have been used for the treatment of diabetes and some skin problems, α-glucosidase and tyrosinase inhibitory effects of Potentilla speciosa Willd. var. speciosa Willd. were tested. The n-butanol extract showed significant α-glucosidase inhibition (IC50 = 3.08 ± 0.48 ppm). Phytochemical studies on this extract led to isolation of catechin, miquelianin, tiliroside, and cinnamtannin D1, the occurrence of the latter in the genus Potentilla is reported for the first time in this study. Miquelianin showed the highest inhibitory effect on tyrosinase with an IC50 value of 86.60 ± 1.90 μM. Cinnamtannin D1 emerged as an excellent α-glucosidase inhibitor with an IC50 value (0.849 ± 0.014 μM), approximately 53 times higher than the value of the positive control, acarbose. It was found to inhibit α-glucosidase in a noncompetitive manner with a Ki value of 0.240 ± 0.010 μM. Molecular modeling studies showed that cinnamtannin D1 most likely bound to an allosteric site of the enzyme.

Isolation of potential liver x receptor alpha agonist and antioxidant compounds from Hypericum microcalycinum Boiss. & Heldr.

Background and Aims: Hypericum microcalycinum Boiss. & Heldr. is used for inflammatory diseases in Anatolia. The involvement of liver X receptors (LXRs) and free radicals in inflammatory diseases, activation of LXRs, and high radical contents in cancerous tissue and organs prompted us to determine the radical scavenging and LXRα agonist activity of aqueous fraction of methanol extract and fractions of H. microcalycinum along with the isolation studies from active fractions. Methods: Isolation studies were carried out on chromatographic techniques. DPPH, NO, and SO radical scavenging activity methods were used for the determination of antioxidant activity, and a LXRE reporter gene assay was used for the determination of LXRα agonist activity. Results: While the extract showed weak LXRα agonist activity, phenolic compounds- rich fractions showed moderate activity. DPPH radical scavenging capacities of the extract and some fractions seemed to be very high as well as some isolated compounds. Bioactivity- guided studies resulted in the isolation of catechin (1), epicatechin (2), apigenin-8-C-(2-O-acetyl)- glucopyranoside (3), quercetin-3-O-β-glucopyranoside (4), quercetin-3-O-β-arabinopyranoside (5), kaempferol-3-O-βarabinopyranoside (6), luteolin-8-C-β-glucopyranoside (orientin) (7). Conclusion: According to our results, compounds 1, 2, 4, and 5 may be responsible for the anti-inflammatory effects of H. microcalycinum as a function of LXRα agonist and free radical scavenging effects.

Isolation of Catechins from Roscoea purpurea

Background: Roscoea purpurea also known as Kakoli is an endangered species of “Ashtawarga” group which faces immense identification and authentication crisis in Ayurvedic literature. Due to less availability and high medicinal value of Kakoli plant, adulteration and substitution was done by drug manufacturers. Objectives: This scientific investigation was carried out to isolate discrete and specific chemical compounds from Kakoli using chromatographic and spectral analysis techniques for quality standardization and identification of Kakoli containing herbal formulations. Materials and Methods: The methanol root extract of plant was used for phytochemical screening and isolation of marker compounds. Two compounds with Rf values 0.51 and 0.73 respectively were isolated and purified by using mobile phase ethyl acetate: n-hexane: formic acid (07: 03: 0.1 v/v/v). Characterization of isolated compounds was done with help of melting point and spectral analysis. Results: The blackish brown methanol extract showed the presence of flavonoids, alkaloids, terpenoids, phenolic phytosterols and amino acid. The final isolated compounds were of off white and yellowish white with melting point range of 217-220°C and 239- 242°C respectively and molecular ion peak at m/z 329 (M+Na) and at 291 (M+H) being according to the proposed structure of Epigallocatechin and Epicatechin respectively. Conclusion: In present study Epigallocatechin and Epicatechin were isolated for the first time and may prove potential tools for differentiation and accurate identification of the authentic plant from its official substitutes and cheap common adulterants.

Isolation of catechins from Cycas armstrongii Miq. of an Egyptian origin

A validated stability indicating HPLC method for the determination of Valsartan in tablet dosage formsDella Grace Thomas Parambi,Molly Mathew, V.Ganesan

Antioxidant activity of polyphenolic compounds isolated from ethyl-acetate fraction of Acacia hydaspica R. Parker

BackgroundAcacia hydaspica belongs to family leguminosae possess antioxidant, anti-inflammatory and anticancer activities. During our search for antioxidant compounds from A. hydaspica, we carried out bioassay guided fractionation and obtained antioxidant compounds with free radical scavenging activity.Materials and methodsThe polyphenol compounds in the plant extract of A. hydaspica were isolated by combination of different chromatographic techniques involving vacuum liquid chromatography and medium pressure liquid chromatography. The structural heterogeneity of isolated compounds was characterized by high pressure liquid chromatography, MS–ESI and NMR spectroscopic analyses. The antioxidant potential of isolated compounds has been investigated by 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide scavenging potential, hydroxyl radical scavenging potential, ferric reducing/antioxidant power (FRAP) model systems and total antioxidant capacity measurement.ResultsThe isolated compounds show the predominance of signals representative of 7-O-galloyl catechins, catechins and methyl gallate. Flash chromatographic separation gives 750 mg of 7-O galloyl catechin, 400 mg of catechin and 150 mg of methyl gallate from 4 g loaded fraction on ISCO. Results revealed that C1 was the most potent compound against DPPH (EC50 1.60 ± 0.035 µM), nitric oxide radical (EC50 6 ± 0.346 µM), showed highest antioxidant index (1.710 ± 0.04) and FRAP [649.5 ± 1.5 µM Fe(II)/g] potency at 12.5 µM dose compared to C2, C3 and standard reference, whereas C3 showed lower EC50 values (4.33 ± 0.618 µM) in OH radical scavenging assay.ConclusionPresent research reports for the first time the antioxidant activity of polyphenolic compounds of A. hydaspica. Result showed good resolution and separation from other constituents of extract and method was found to be simple and precise. The isolation of catechin from this new species could provide a varied opportunity to obtain large quantities of catechin and catechin isomers beside from green tea. Free radical scavenging properties of isolated catechin isomers from A. hydaspica merit further investigations for consumption of this plant in oxidative stress related disorders.

Isolation of Catechin and Gallic Acid from Colombian Bark of Pinus patula

Pine bark is a rich source of natural polyphenols, compounds which have attracted increasing attention in the fields of nutrition, health and medicine. Extractive components include large amounts of phenolic compounds. The ethanolic extract was obtained from Pinus patula bark grown in the forests of the Cauca Department in Colombia South America. The Gallic acid, catechin, epicatechin and procyanidin B2 contents in ethanolic extract were 3.12, 1.99, 0.80, and 0.71%, respectively, these compounds were determined using HPLC with UV-Vis detection. Ethanolic extract was divided using column chromatography to obtain an ethanol-soluble fraction with tannins and phlobaphenes as well as an ethanol-insoluble fraction mainly composed of Phenolic acids. Catechin and Gallic acid finally isolated were characterized using UV-Vis, IR, NMR, 13C, 1 H, HSQC, HMBC and GC-MS spectrometry.

Comparison of Some Extraction Methods for Isolation of Catechins and Caffeine from Turkish Green Tea

Effective extraction of anticancer and antioxidant principles from Turkish green tea were main purpose of this work. The pre-optimized experimental condition for liquid extraction was employed for comparative appraisal. Not only extraction methods also nature of the green tea samples (fresh, dried or frozen) and quantitative yields related to collection periods were investigated. After extraction of the green tea with various techniques the extract was partitioned with chloroform to remove caffeine, after that the extract was partitioned with ethyl acetate to obtain catechin mixture. Quantification of individual catechins was carried out by HPLC and analysis results proved that epigallocatechin gallate (EGCG) was main catechin specie present in all extracts. The results indicate that hot water extraction (at 80 0C) provides higher catechin yield when compared to other methods. The highest extract yields were obtained with dried leaves collected in second collection period. The crude catechin mixture contains high amount of EGCG and might be used as raw material for production of plant remedies at industrial scale.

THE FREE RADICAL SCAVENGING AND ANTI-HYPERGLYCEMIC ACTIVITIES OF VARIOUS GAMBIERS AVAILABLE IN INDONESIAN MARKET

Gambier (Uncaria gambier) is known to have antioxidant properties, and some studies have attributed it to the presence of polyphenols such as catechin. The objective of this study is to investigate the potential of various gambiers available in Indonesian market as a scavenger of reactive free radicals and evaluate its anti-hyperglycemic activity as α- glucosidase inhibitor. Isolation of catechin was done by extraction method with technical grade of ethyl acetate as solvent. Analysis of catechin in the dried gambier extract was carried out with TLC method. The molecular weight and content of catechin of dried gambier extract was determined by analyzing its mass spectra and spectrophotometer, respectively. The free radical scavenging activity of catechin of the resultant extracts was measured by using 1,1- diphenyl-2-picrylhydrazyl (DPPH) as stable free radical compound. The anti-hyperglycemic activity of catechin of ethyl acetate extracts was analyzed as α-glucosidase inhibitor. The result showed that various gambiers available in the market are very active as antioxidant, indicated by IC50 of catechin of ethyl acetate extracts which were 4.6 to 18.2 μg/mL for DPPH inhibition. The IC50 for α-glucosidase inhibition is ranged from 40.45 to 52.43 μg/mL, so they can be classified as anti-diabetic.

Efficient isolation of catechins from green tea and characterization of interaction property of catechins with proteins by HPLC–UV/DAD combined with ultrafiltration

The aim of this study was to ascertain systematically interaction properties of active compounds in green tea extract (GTE) and involved proteins in the path of drugs delivery by high performance liquid chromatography–UV/DAD combined with ultrafiltration. GTE prepared by 50% methanol was separated successfully into fourteen components under optimized chromatographic conditions. Binding degrees of (−)-catechin (C), (−)-epigallocatechin gallate (EGCG), caffeine, and (−)-epicatechin gallate (ECG) in GTE with human plasma protein, rat plasma protein, human serum albumin (HSA), pancreas membrane protein (PMP), and rat pancreas cell membrane (PCM) were determined, respectively. The binding degrees of C, EGCG, ECG, and caffeine were above 80% of the total plasma (human or rat), and the binding degrees of four components were still above 65% at 0.6 mM HSA solution. The binding degrees of C, EGCG, and ECG with PMP were 36.9, 37.4, and 39.2%, and the binding degrees of EGCG and ECG to PCM were 78.8 and 91.5%, respectively. These results showed that there were high binding degrees between these components and transportation proteins in plasma, and receptor proteins on cell membrane. Compared with C and caffeine, EGCG and ECG had always higher binding degrees with different proteins, which meant EGCG and ECG were true active components. Based on these results, we suggest that the inhibition of the pathogenesis of some diseases by green tea should be associated with the high binding degrees of catechins to target receptors.

Isolation of Green Tea Catechins and Their Utilization in the Food Industry

Tea is a rich source of catechins, which are well-known antioxidants. Tea consumption has been found to promote human health; however, only drinking tea may not provide a sufficient level of catechins to achieve health benefits. Thus, the utilization of catechins in foods is an alternative way to supplement catechin consumption. Furthermore, catechins can prevent lipid oxidation and improve color and flavour of foods; hence, addition of catechins can also prolong the shelflife of foods. Therefore, catechins have recently been isolated from green tea for utilization in food products to enhance their shelflife and health benefits. This article outlines several methods for the isolation of catechins from green tea, discusses the challenges involved, and reviews the utilisation of catechins in the food industry.

Preparation of tea catechins using polyamide

An adsorption separation method using Polyamide-6 (PA) as an adsorbent was developed to separate catechins from green tea extract. The adsorption capacity of total catechins for PA was 193.128 mg g⁻¹ with an adsorption selectivity coefficient K(A)(B) of total catechins over caffeine 21.717, which was better than macroporous resin model HPD 600. The Langmuir model and the pseudo-second order mode were primely fitted to describe its equilibrium data and adsorption kinetics, respectively. PA column separation by two-step elution using water and 80% (v/v) aqueous ethanol was established to prepare catechins complex which contained 670.808 mg g⁻¹ total catechins and 1.828 mg g⁻¹ caffeine. It is considered that PA was a promising adsorbent for selective isolation of catechins.

Extraction and isolation of catechins from tea

Tea is a major source of catechins, which have become well known for their antioxidant potential. Numerous human, animal, and in vitro studies have linked tea catechins with prevention of certain types of cancers, reduction of the risks for obesity, diabetes, and cardiovascular disease, and improvement of the immune system. Tea catechins are widely used in various neutraceuticals, pharmaceuticals, and cosmetics for either enhancing product shelf-life or for enhancing human health. Thus, the demand for catechins has increased considerably. Catechins have been extracted and isolated from tea leaves by numerous methods through several steps including: treatment of the tea leaves, extraction of catechins from teas into solvents, isolation of catechins from other extracted components, and drying the preparations to obtain catechin extracts in a powder form. This paper outlines the physical and chemical properties of the tea catechins and reviews the extraction steps of the various extraction methods, as a basis to improve and further develop the extraction and isolation of the tea catechins.

Effect of plant derived-phenolic extracts on antioxidant enzyme activity and mucosal damage caused by indomethacin in rats

In this study, the antiulcerogenic effect of the hdroacoholic extracts obtained from of Acacia nilotica leaves and Retama raetam seeds were investigated using indimethacin-induced ulcer model in rats. Antiulcerogenic activities of hydroacoholic extract of A. nilotica (30 mg/kg body wt.) and hydroalcoholic extract of R. raetam (25 mg /kg) were determined by comparing the negative treated only with indomethacin and positive ranitidine control group. Although the dose of the hydroacoholic extract of A. nilotica and R. raetam showed significant antiulcerogenic activity as compared to negative control, the highest activity was observed with mixed (30 mg/kg) of A. nilotica and (25 mg /kg) of R. raetam (81%). The activities of enzymes superoxide dismutase (SOD), catalase (CAT) and gluthioneS-transferase (GST) were determined in the stomach tissues of rats and compared with those of negative and positive control groups. The enzymes activities in indomethacin-adminstrated were reduced significantly SOD, CAT, GST and increased by the plants extracts and ranitidine (p < 0.05). Phytochemical investigation of A. nilotica leaves resulted in the isolation of catechin, catechin 7-O- gallate, catechin 3’-O- gallate, catechin 4’-O-gallate, catechin 7, 3’-di -O-gallate, catechin 7, -4’-di-O-gallate. Genistein 8-C-glucoside, orobol 8-C-glucoside, apigenin 8-C-glucoside, orobol, genistein and apigenin have been isolated from the aqueous alcoholic extract of R. raetam seeds. The presence of these phenolic compounds may probably explain the antiulcerogenic and antioxidant effect of the plant extracts.

Preparative Isolation of Catechins from Green Tea Powders Using Intermediate Polar Adsorbent

An adsorption separation method using intermediate polar adsorbent (Amberlite XAD-7HP resin) was applied for isolating a mixture of tea catechins from the green tea powders, where the percentages of content (purities) of the total catechins, comprising the four major catechins: epigallocatechin (EGC), epicatechin (EC), epigallocatechin gallate (EGCG), and epicatechin gallate (ECG), ranged from 13.0 to 16.0 wt%. First, the batch adsorption experiments were performed. The adsorption equilibrium data of the total catechins were fitted closely by a Langmuir isotherm model. Then, the dynamic adsorption and desorption experiments were performed using the column packed with the XAD-7HP resin. In the adsorption step, to avoid the loss of tea catechins, the loading volume was selected according to the elution volume at the break point of the dynamic adsorption curve. In the elution step, under a proper step gradient elution program, the majority of tea catechins were efficiently eluted by the eluent ranged from 20 to 50% ethanol and the fractions were collected as the concentrated product. The purities of the total catechins and EGCG, being the most important catechin, in the concentrated product were ∼49 wt% and ∼28 wt%, respectively. The contents of the total catechins and EGCG were efficiently concentrated ∼3.5 times in high recovery yields (> 75%) using the current column chromatographic method.

Catechin derivatives in Jatropha macrantha stems: Characterisation and LC/ESI/MS/MS quali–quantitative analysis

A phytochemical investigation on methanol extract of stems of Jatropha macrantha led to the isolation of catechin, catechin-7- O-β-glucopyranoside and proanthocyanidin B-3 along with other catechin polymers. Their structures were established by NMR and ESI/MS experiments. Additionally, an LC/ESI/MS qualitative study and an LC/ESI/MS/MS quantitative study of the phenolic fraction of J. macrantha stems were performed. Combination of high performance liquid chromatography (HPLC) (DAD) with positive electrospray ionisation (ESI) and tandem mass spectrometry (MS/MS) performed with Ion Trap analyser permitted to have qualitative data on catechin derivatives: several other proanthocyanidins were detected. A mixture of proanthocyanidin polymers was characterised by direct introduction ESI-MS analysis. An LC/ESI/MS/MS method was developed and validated for separation and quantification of catechin, catechin-7- O-β-glucopyranoside and proanthocyanidin B-3. Due to the sensitivity and the repeatability of the assay, we suggest this method as suitable for industrial quality control of raw materials and final products. Quantitative analyses results confirmed that compounds 1– 3 are major compounds of the plant and, in particular, proanthocyanidin B-3 appears to be the most abundant.

Anti-HIV Activity Directed Fractionation of the Extracts of Margyricarpus Setosus

As part of our screening of anti-HIV agents from medicinal plants, the in vitro anti-HIV activity of the CHCl 3, CHCl 3 :MeOH 9:1 and MeOH extracts of the aerial parts of Margiricarpus setosus (Rosaceae) were tested. Since the MeOH extract showed significant activity, a bioassay-directed fractionation was carried out. This investigation resulted in the isolation of catechin, epicatechin, quercetin-3- O -(6"- p -coumaroyl)-ß-D-glucoside, ß-hydroxy-3',4'dimethoxy-phenyl-ethyl-glucoside, ß-hydroxy-3',4'-dimethoxyphenylethylrutinoside, ß-hydroxy-phenylethyl- O -a-L-rhamnopyranosyl (1 ? 6)-ß-D-glucopyranoside, benzyl- O -a-L-rhamnopyranosyl (1 ? 6)-ß-D-glucopyranoside, 4–methoxybenzyl- O -a-L-rhamnopyranosyl (1 ? 6)-ß-D-glucopyranoside, tormentic acid 3ß- O -ß-D-quinovopyranoside, tormentic acid 3ß- O -ß-D-fucopyranoside and tormentic acid 3ß- O -a-L-rhamnopyranoside. Two of these compounds, catechin and epicatechin, have been identified as the principles responsible for anti-HIV activity. This finding is in good agreement with our previous investigations which demonstrated catechin, epicatechin and their derivatives inhibited the in vitro HIV replication.