Isolation Of Antioxidant Compounds Research Articles

Effect of various solvents on the extraction of antioxidants from dried Basella alba Leaves

Basella alba, an edible perennial vine, is an underutilized plant which possesses many potential health benefits including antioxidant property. Isolation of antioxidant compounds from the plant was attempted through extraction with different solvents. The solvents of varying polarities, using six extracting solvents (distilled water, ethyl acetate, hexane, ethanol, methanol and acetone) were evaluated to assess the extraction of antioxidant phenolics from dried leaves of B. alba. Each extract was analyzed for total phenols, flavonoids and total antioxidant activity using 2-diphenyl-1-picrylhydrazyl radical scavenging activity assay (DPPH-RSA), 2,2, azinobis, 3 ethyl benzothiazolin, 6-sulphonic acid assay (ABTS-RSA), reducing power assay (RPA) and ferric reducing antioxidant power (FRAP). Results revealed that methanol could extract maximum phenols (779.58 mg GAE 100 g-1) while ethanol yielded maximum flavonoid (2726.43 mg RE 100 g-1) content. Methanol extract was found the most potent scavenger of DPPH-RSA and ABTS-RSA (92.97 and 196.47 mg TE 100 g-1, respectively) as well as depicted maximum RPA and FRAP values (2303.66 and 5.46 mg TE 100 g-1, respectively). Pearson correlation indicated a positive significant relationship of total phenols and flavonoids with DPPH-RSA, ABTS-RSA and RPA. FRAP revealing a strong correlation with flavonoids. Overall, methanol was the most effective solvent for the extraction of antioxidant phenolics from B. alba leaves and can be a useful source of natural antioxidants.

Antioxidant Compounds from The Stem Bark of Syzygium samarangense L

Ogan ethnic community in South Sumatera has been used a decoction of the stem bark of Syzygium samarangense L (locally named “jambu air” in Indonesia) for hypertension medicine. Hypertension is a degenerative disease caused by free radical activity in the body. This study aims to scientifically prove the use of a decoction of the stem bark of S. samarangense so that its use by the Ogan ethnic community can be justified. The research began with fractionation of the stem bark by gradient solvents, and each fraction was tested for antioxidant activity. Isolation of antioxidant compounds from active fractions was carried out by chromatographic techniques. Antioxidant tests on fractions and pure compounds were carried out by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Based on spectroscopic data analysis and by comparing with literature, the pure compounds were identified as quercetin and gallic acid. Both of these compounds have strong antioxidant activity with IC50 quercetin 11.16 and gallic acid 11.43 µg/mL. This research proves that the use of the stem bark of S. samarangense for a degenerative disease by the Ogan ethnic community contains the truth.

Bioactive compounds from Nauclea latifolia leaf extracts

The leaf extracts of Nauclea latifolia (Smith) were investigated for its bioactive constituents to validate it reported ethnomedicinal uses (infectious and oxidative stress related diseases). Isolation of antioxidant compounds from the ethyl acetate fraction was achieved by a DPPH directed fractionation, which resulted in trans-3,4-dihydroxycinnamic acid (caffeic acid) (1), quercetin (2), quercetin-3-O-β-glycopyranoside (3), 3-caffeoylquinic acid (chlorogenic acid) (4), and 3,5-O-dicaffeoylquinic acid (5). The extracts and isolated compounds were evaluated for antioxidant activities using five complementary assays: total antioxidant capacity (TAC), inhibition of nitric oxide (NO) radical activity, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, ferric reducing antioxidant potential (FRAP) and metal chelating ability (MCA) spectrophotometrically. The total phenolic content (TPC) was also determined. Antimicrobial activities of the samples were evaluated using agar cup plate diffusion and broth microdilution method. Compound (2) was more potent in the DPPH assay [IC50 = 0.59 ± 0.04 to 21.3 ± 1.01 µg/mL] than the ascorbic acid [8.82 ± 0.23 µg/mL] used as a standard. All the isolated compounds exhibited a higher degree of inhibition of NO radical than the standard. The IC50 ranged from 5.17 ± 2.59 to 55.2 ± 0.66 µg/mL compared with the standard, ascorbic acid [IC50 = 69.3 ± 1.78 µg/mL]. In the metal chelating ability (MCA) assay, compound (5) had better activity [IC50 = 105 ± 2.73 µg/mL] than the standard, EDTA [IC50 = 122 ± 1.17 µg/mL]. Compound (2) had the best TAC and FRAP results, 10.9 ± 2.14 mg AAE/g and 1.68 ± 0.09 mg AAE/g respectively. N. latifolia extracts exhibited less antibacterial activities than the isolated compounds. The MIC of quercetin (2) against S. aureus was 0.156 mg/mL while quercetin 3-O-β-glucopyranose exhibited wider spectrum of activities with MIC in the range of 1 mg/mL for most of the bacteria strains. Also, 3,5-O-dicaffeoylquinic acid had an MIC of 1.25 mg/mL against P. aeruginosa. Compounds 4 and 5 are reported from N. latifolia for the first time.This study concluded that some of the isolated compounds had strong antioxidant and moderate antimicrobial activities.

Phytochemical analysis and antioxidant activity of different plant parts of Pellacalyx axillaris

Pellacalyx axillaris or locally known as ‘membuloh’ is a mangrove species belonging to the Rhizophoraceae family. Till date, there has been only one phytochemical study found on this particular plant species and that without any documentation on its biological activities. Therefore, the present work aimed to reveal the phytoconstituents and the antioxidant activity of different crude extracts from different plant parts of P. axillaris. Experimentally, three organic solvents of different polarities i.e. n-hexane, ethyl acetate and methanol were used to prepare the crude extracts from the dried leaves, twigs and barks of P. axillaris. The preliminary phytochemical screening of this species indicated the presence of terpenoids, phenolic compounds, tannins, flavonoids, alkaloids, anthraquinone glycosides and carbohydrates. The in vitro antioxidant activity of the species evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging assay, and ferric reducing antioxidant power (FRAP) suggested that the methanolic bark extract contained potential source of natural antioxidants. Further research into isolation of antioxidant compounds from this species is highly recommended.

Flavon Compound from The Ethyl Acetate Extract of The Stem of Supit (Tetracera indica Merr.)

Tetracera indica Merr. in Musi Banyuasin, is one of the traditional medicine used by the community for the treatment of kidney stone disease and gout, but this claim is not recorded in the treatment of kidney stones and gout in Indonesia. In this study, isolation of antioxidant compound from ethyl acetate extracts of supit (Tetracera indica) was done. The isolation was carried out through step gradient polarity extraction, and separated and purified by chromatography technique. The determination of the structure of the isolated compound was performed by spectroscopy method including UV, IR, and NMR 1D and 2D, and antoxidant activity was determined by DPPH method. An active antioxidant compound was isolated from ethyl acetate extract in form of yellow solid (15 mg). Based on spectroscopic analysis the isolated compound was 5,8-dihydroxy-7-methoxyflavone. The compound showed strong antioxidant activity (IC50 8.25 μg/mL) higher than standard ascorbic acid (IC50 11.3 μg/mL). This data concluded that efficacy of supit (Tetracera indica) for the treatment related to antioxidant activity (uric acid) is proven by the identification of one antioxidant compound of this plant.

Antioxidant Compound Quercetin-3-O-α-L-rhamnoside(1→6)- β-D-glucose (Rutin) isolated from ethyl acetate leaf extracts of Memecylon edule Roxb (Melastamataceae)

Introduction: The present study was aimed to isolate antioxidant principle from leaf ethyl acetate extract of Memecylon edule for the first time. M. edule belongs to melastomataceae family; possess various biological properties and folklore uses. Methods: Isolation of antioxidant compound was carried out by DPPH radicals scavenging activity guided method and employing chromatography techniques (TLC and column chromatography). The structure of isolated bioactive compound (Rutin) was confirmed by using various spectral data like UV, FT-IR, LC-MS, CHNS analysis, 1 H-NMR, 13 C-NMR, DEPT-135, HMBC and HSQC. In vitro antioxidant activity of isolated compound was evaluated by using DPPH radical, nitric oxide radical, superoxide radical, hydroxyl radical scavenging assays and ferric reducing antioxidant power assay (FRAP) with reference to ascorbic acid and butylated hydroxyanisole (BHA). One way analysis of variance (ANOVA) and Tukey’s multiple comparison tests were performed. Results: DPPH activity guided isolation resulted isolation of Rutin. Isolated rutin exhibited remarkable scavenging capacity on all tested radicals in a concentration dependent manner. The results also showed that Rutin harbor strong reductive capacity on hydroxyl radicals with lowest IC 50 value (17.06 µg/ml) and strong ferric ion (Fe 3+ ) chelation (EC 50 value 17.29 µg/ml) potential. Conclusion: The results of the present investigation concluded that the leaf ethyl acetate extract of M. edule is a good source of Rutin which harbor significant antioxidant potential.

Isolation of Antioxidant Compound from Endophytic Fungi Acremonium sp. from the Twigs of Kandis Gajah

The endophytic fungi Chrisonilia sitophila, Acremonium sp., and Penicillium sp. have been isolated from the tissues of the twigs of kandis gajah. All of the fungi strains were grown in 3 L potatoe dextrose broth medium (PDB) at a room temperature for 28 days. To extract the antioxidant compounds, the culture broth were filtered for mycelia removal followed by extraction and evaporation. All of the extracts were evaluated for their antioxidant activities by using 1,1diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. The extract of Acremonium sp. have strong activity with IC50 value of 10.3 μg/mL, which is equivalent to ascorbic acid activity with IC50 value of 9.8 μg/mL. The extract was subjected to column chromatography on Si gel twice to obtain a high purity antioxidant compound in the form of yellow oil. The molecular structure was determined based on spectroscopic data, including H-NMR, C-NMR, HMQC, HMBC, and COSY. The compound was determined as sesquiterpene 3,5-dihydroxy-2,5-dimethyltrideca-2,9,11-triene4,8-dione.

Synthese and characterization of boronic acid functionalized macroporous uniform poly(4-chloromethylstyrene-co-divinylbenzene) particles and its use in the isolation of antioxidant compounds from plant extracts

Aminophenyl boronic acid (APBA) carrying uniform-macroporous poly(chloromethylstyrene-co-divinylbenzene), poly(CMS-co-DVB) particles were synthesized for selective separation of cis-diol-containing flavonoids from plant extracts. For this purpose, 2.5μm polystyrene seed particles were first swelled by a mixture of dibutyl phthalate (DBP), toluene and dodecanol, then by a monomer mixture including CMS and DVB. The repolymerization of the monomer phase in the swollen seed particles provided macroporous and uniform particles, approximately 7μm in size. Chlorine atoms on the surface of these particles were derivatized with APBA to gain affinity properties for flavonoids containing vicinal hydroxyl groups. Model adsorption studies showed that these particles selectively adsorbed quercetin and rutin containing cis-diol groups, but did not adsorb apigenin similar to quercetin and not carrying cis-diol groups. These particles were also tested in adsorption/desorption studies for ethanol and ethyl acetate extracts of the Hypericum perforatum (HP) stems to obtain high antioxidant mixtures. With ethanol extract, the antioxidant activity of the desorption solution was a bit higher than that of the post-adsorption solutions. However, the DPPH radical scavenging activity of the desorption solution decreased with respect to the original extract and post-adsorption solutions. A similar result was obtained for the antioxidant activity of the desorption solution using ethyl acetate extract. An interesting result was obtained that DPPH radical scavenging activity of the post-adsorption solution was higher than that of the original ethyl acetate extract and desorption solutions. These results were attributed to selective adsorption of antioxidant characterized cis-diol-containing apolar molecules much more rather than that radical scavenger characterized polar molecules.

ChemInform Abstract: Isolation of Antioxidative Compounds from Brazilian Propolis: 3,4-Dihydroxy-5-prenylcinnamic Acid, a Novel Potent Antioxidant.

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Isolation of Antioxidative Compounds from Ginger (Zingiber officinale Roscoe) and the Effect of Heat Treatment

Isolation of Antioxidative Compounds from Ginger (Zingiber officinale Roscoe) and the Effect of Heat Treatment

Isolation of antioxidant compounds from orange juice by using countercurrent supercritical fluid extraction (CC-SFE).

Antioxidants from orange juice are isolated by the use of countercurrent supercritical fluid extraction (CC-SFE) and characterized by reversed-phase liquid chromatography (RPLC) coupled to mass spectrometry (MS) and diode-array detection (DAD). A pilot-scale SFE plant equipped with a packed column has been employed for countercurrent extraction and fractionation of raw orange juice with carbon dioxide. Several experiments have been performed in order to study the effect of the countercurrent conditions on the content of antioxidative compounds. In this study, the main variable that has been considered is the solvent-to-feed ratio (S/F) because it plays an essential role in the extraction efficiency. The values tested covered a wide range of sample and solvent (CO(2)) flow rates. In each experimental run, two different extracted fractions and the residual nonextracted juice were obtained and characterized. Different flavonoids have been identified in the fractions obtained after CC-SFE. The possibility of using this process for antioxidant compounds enrichment is discussed.

Isolation of Antioxidative Compounds from Brazilian Propolis: 3,4-Dihydroxy-5-prenylcinnamic Acid, a Novel Potent Antioxidant.

One new and 11 previously known antioxidative compounds were isolated from Brazilian propolis. The new compound was determined as 3, 4-dihydroxy-5-prenylcinnamic acid (3-[3, 4-dihydroxy-5-(3-methyl-2-butenyl)-phenyl]-2-(E)-propenoic acid) by various physical analyses (MS, IR, 1H-NMR, 13C-NMR, and 2D-NMR). The inhibitory activity of each compound against peroxidation of linoleic acid in a micelle solution was measured. We found that the novel compound possessed the highest potency (IC50, 0.17 μM) among them and was more effective than butylated hydroxytoluene (BHT; IC50, 0.36 μM) under the experimental conditions employed. Among the isolated antioxidative compounds, 3, 5-diprenyl-4-hydroxycinnamic acid (artepillin C; IC50, 0.44 μM) was found to be most abundant in Brazilian propolis.