ABTS Radical Cation Scavenging Activity Research Articles

발효숙성생강의 항산화 및 항균 활성

Zingiber officinale Roscoe, commonly known as ginger, has long been used as a powerful health-promoting antioxidant that supports cellular health of the human body. The objective of this study was to compare the antioxidant and antimicrobial activities of the samples with aging and fermentation. Antioxidant activities of the samples were compared using total phenol, flavonoid contents, ABTS cation radical scavenging activity and DPPH radical scavenging activity. Antimicrobial activities were also examined using the paper disc method and minimum inhibitory concentration (MIC). Acidity of the fermented ginger (FG) with lactic acid bacteria showed a significantly higher value than that of the ginger (GG). The content of 6-gingerol, a bioactive component in ginger, decreased in all fermented gingers but 6-shogaol which is also one of the main valuable ingredients showed the increased content at ginger fermented with Streptococcus thermophilus and Lactobacillus acidphilus. Flavonoid contents of the FG and GG did not show significant differences. However, ABTS cation radical scavenging activity and DPPH radical scavenging activity were 10-30% increased in the samples with fermentation (p<0.05), respectively. The samples of the disc showed an inhibitory effect on growth of gram positive Staphylococcus aureus and Listeria monocytogenes. Zinger with fermentation showed higher antioxidant and antimicrobial activities. Thus, we conclude that aging and fermentation can be a helpful process to increase the functional effects of ginger.

Two new 2,5-diketopiperazines produced by Streptomyces sp. SC0581

Two new diketopiperazines, cyclo(l-Phe-l-NMe-DOPA) (2) and cyclo[l-Phe-l-(NMe-3-(NMe-3-O-α-l-rhamnopyranosyl)-DOPA] (3), along with a known diketopiperazine (1), were isolated from the cultures of Streptomyces sp. SC0581. Their structures were elucidated by extensive spectroscopic analysis, single-crystal X-ray crystallographic analysis, and chemical correlation. Compounds 1−3 exhibited more potent ABTS radical cation scavenging activity (IC50 values: 3.7−14.6μM) than l-ascorbic acid (IC50: 17.7μM). Compounds 2 and 3 also showed remarkable DPPH radical scavenging activity.

Composition and structure of an antioxidant acetic acid lignin isolated from shoot shell of bamboo (Dendrocalamus Latiforus)

Bamboo shoot shell (BSS), which contains a large amount of insoluble fibre and lignin, is the main agricultural waste from the production of bamboo shoots. To utilize this waste in a value-added manner, the acetic acid lignin (AL) fraction from BSS was extracted via a combination of hot water pre-treatment and acetic acid post-treatment in the present study. The chemical composition, structural characteristics, and antioxidant activity of AL were investigated and compared to the corresponding milled wood lignin (MWL). The results showed that AL had a higher yield (74%) and lower content of associated carbohydrates (2.96%) than MWL (5.16%). GPC analysis revealed that AL possessed a moderate molecular weight (Mw=2789Da) and narrow polydispersity index (Mw/Mn=1.54). Structural characterization via FT-IR, 1H NMR, 2D-HSQC, and 31P NMR indicated that AL from BSS was a typical HSG-type lignin and was partially acylated at the γ-carbon of the side chain by p-coumarate. Moreover, the bonds between lignin units were predominately β-O-4⿲ linkages. Compared to MWL, AL possessed a characteristically higher phenolic hydroxyl group content and S/G ratio. In terms of the DPPH radical scavenging activity, ABTS radical cation scavenging activity and ferric reducing antioxidant power, AL showed stronger antioxidant activity than MWL and was superior to the commercial synthetic antioxidant BHT. In summary, by applying a modified two-step procedure, which included hot water pre-treatment and acetic acid extraction, AL from BSS was effectively extracted, and the antioxidant potential of AL was characterized.

The influence of light-emitting diodes on the phenolic compounds and antioxidant activities in pea sprouts

The effects of various light-emitting diodes (LEDs), such as red, blue, and yellow LED lamps, as well as white fluorescent lamps and darkness, on the levels of phenolic compounds and antioxidant activities in pea sprouts were evaluated. The total phenolic (TPC) and total flavonoid contents (TFC) of the pea sprouts under the blue and red LED light, as well as the white fluorescent lamps, were 1.46, 1.25, 1.45 times and 24.55, 21.01, 24.29 times, respectively, when compared to the dark environment control. The ABTS cation radical-scavenging activity, ferric reducing activity power (FRAP), and reducing power of the pea sprouts under blue LED light were 1.75, 3.52, and 1.97 times, respectively, compared to the control. The blue LED light significantly increased all of the individual phenolic contents when compared to the control. These results indicate that blue LED light should be recommended as a light source for enhancing the content of phenolic compounds.

목이버섯(Auricularia auricula-judae) 추출물의 항산화 활성 및 항균 효과

This study investigated the antioxidant and antimicrobial activities of various solvents (acetone, ethyl acetate, and ethanol) for extraction of Auricularia auricula-judae. Antioxidant activity was evaluated by determining total polyphenol and flavonoid contents, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical scavenging activity. Total polyphenol and flavonoid contents were not significantly different among the extracts, whereas DPPH radical scavenging activity and ABTS cation radical scavenging activity were significantly higher in ethanol and acetone extracts. DPPH radical scavenging activities of ethanol and acetone extracts showed high values (58.7% and 46.7%, respectively). The antimicrobial properties of these extracts were determined against six bacterial pathogens (Bacillus subtilis, Staphylococcus aureus, Micrococcus luteus, Escherichia coli, Pseudomonas aeruginosa, and Enterobacter cloacae) by the disc diffusion method. The acetone extracts showed antimicrobial activities against all tested bacteria, and all extracts showed the highest antimicrobial activity against B. subtilis.

Antioxidant activity of Ruscus species from Serbia: Potential new sources of natural antioxidants

The antioxidant activity, total phenolic and flavonoid content of ethanolic, acetone and ethyl acetate extracts of Ruscus hypoglossum L. and Ruscus aculeatus L. (aerial parts) from Serbia were investigated in this paper. The best total antioxidant capacity (23.329 ?g AA g-1) and the highest DPPH scavenging activity (IC50 = 182.54 ?g mL-1) were found in acetone and ethyl acetate extract of R. aculeatus L. Ethanolic extract of R. hypoglossum L. showed the highest ABTS radical cation scavenging activity (IC50 = 3.04 ?g mL-1) as well as reducing power (IC50 = 0.143 ?g mL-1). The best inhibitory activity against lipid peroxidation (IC50 =651 ?g mL-1) and the best ferrous ion chelating ability (IC50 = 110 ?g mL-1) were found in acetone and ethyl acetate extract of R. hypoglossum L. The highest total phenolic (8.569 mg GAE g-1) and flavonoid content (0.136 mg RU g-1) were found in ethanolic and acetone extract of R. hypoglossum L. and R. aculeatus L, respectively.

구름버섯(Coriolus versicolor)의 용매 추출물에 대한 항균 및 항산화 활성 조사

Antioxidant activities of various solvent extracts from Coriolus versicolor were investigated for their total polyphenol content, total flavonoid content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical scavenging activity. C. versicolor ex- tracts were produced by organic solvents such as ethanol, ethyl acetate, and methanol. Total polyphenol and flavonoid contents in the ethanol and ethyl acetate extracts were higher than those in the methanol extract. DPPH radical scaveng- ing activity of methanol extract showed the highest value of 80.3%, which was similar to that of ascorbic acid (85.5%). All extracts showed good (>90.0%) ABTS cation radical scavenging activity. The antimicrobial activities of these extracts from C. versicolor were evaluated against six strains of bacteria using the disc diffusion method. All extracts showed antimicrobial activities against all tested bacteria except Staphylococcus aureus. These results indicate that various extracts from C. versicolor could be useful as natural antioxidant and antimicrobial agents.

Quinones and coumarins from Ajania salicifolia and their radical scavenging and cytotoxic activity

1,4-Naphthoquinone (1) and a new coumarin (3) were isolated from Ajania salicifolia, together with two known compounds (2, 4). The structures and stereochemistry of new compounds were elucidated using spectroscopic methods. Two compounds exhibited potent ABTS cation radical scavenging activities with IC50 values ranging 7.97–8.44 μM. Two quinones (1, 2) exhibited moderate cytotoxic activity against the human cancer cell lines (Hela, HepG2, and K562) with IC50 values of 11.24–35.15 μM in vitro. This is the first report of naphthoquinone in the genus Ajania.

Attenuation of Inflammatory Mediators (TNF-α and Nitric Oxide) and Up-Regulation of IL-10 by Wild and Domesticated Basidiocarps of Amauroderma rugosum (Blume & T. Nees) Torrend in LPS-Stimulated RAW264.7 Cells.

Amauroderma rugosum, commonly known as “Jiǎzī” in China, is a wild mushroom traditionally used by the Chinese to reduce inflammation, to treat diuretic and upset stomach, and to prevent cancer. It is also used by the indigenous communities in Malaysia to prevent epileptic episodes and incessant crying by babies. The aim of this study was to compare the wild and domesticated basidiocarps of A. rugosum for antioxidant and in vitro anti-inflammatory effects in LPS-stimulated RAW264.7 cells. The wild basidiocarps of A. rugosum were collected from the Belum Forest, Perak, Malaysia and the domesticated basidiocarps of A. rugosum were cultivated in the mushroom house located in the University of Malaya, Kuala Lumpur, Malaysia. Both the wild and domesticated basidiocarps were subjected to ethanolic extraction and the extracts were tested for antioxidant and anti-inflammatory activities. In this study, the crude ethanolic extract of wild (WB) and domesticated (DB) basidiocarps of A. rugosum had comparable total phenolic content and DPPH scavenging activity. However, WB (EC50 = 222.90 μg/mL) displayed a better ABTS cation radical scavenging activity than DB (EC50 = 469.60 μg/mL). Both WB and DB were able to scavenge nitric oxide (NO) radical and suppress the NO production in LPS-stimulated RAW264.7 cells and this effect was mediated through the down-regulation of inducible nitric oxide synthase (iNOS) gene. In addition, both WB and DB caused down-regulation of the inflammatory gene TNF-α and the up-regulation of the anti-inflammatory gene IL-10. There was no inhibitory effect of WB and DB on nuclear translocation of NF-κB p65. In conclusion, the wild and domesticated basidiocarps of A. rugosum possessed antioxidant and in vitro anti-inflammatory properties. WB and DB inhibited downstream inflammatory mediators (TNF-α and NO) and induced anti-inflammatory cytokine IL-10 production. No inhibitory effects shown on upstream nuclear translocation of NF-κB p65. WB and DB exhibited antioxidant activity and attenuation of proinflammatory mediators and therefore, A. rugosum may serve as a potential therapeutic agent in the management of inflammation.

Effect of Sesame Sprouts Powder on the Quality and Oxidative Stability of Mayonnaise

Sesame (Sesamumindicume L.) and its oil contain antioxidative lignin polyphenols, λ-tocopherol and other bioactive compounds. The aim of present research was to investigate the effect of sesame sprouts on quality and oxidative stability of mayonnaise during storage. Antioxidant activity of sesame sprouts determined through phenolic contents and DPPH free radical scavenging activity, ABTS cation radical-scavenging activity and ferric reducing antioxidant power (FRAP), increased with increasing germination days showing maximum value at day 7. The sesame sprouts showing highest antioxidant potential were was used in mayonnaise at the concentration of 0.5%, 0.75%, 1.0% and 1.25 % along with control, EDTA (0.0075%) and BHT (0.02%). During 45 days of storage period at 25±5 °C, mayonnaise was examined at 0, 15, 30 and 45 days for oxidative potential using DPPH free radical scavenging activity, ABTS cation radical-scavenging activity and ferric reducing antioxidant power (FRAP). Antioxidant potential decreased with storage and highest potential was observed for SSP4 at end and was comparable to the EDTA and higher than BHT. Oxidative stability was determined through peroxide, ρ-anisidine, iodine and FFA. Although oxidation increased with storage but sesame sprouts powder was effective in retarding the oxidation especially at higher ratios. Quality was determined through pH, viscosity and sensory evaluation. The investigation suggested that sesame sprouts powder is effective in controlling oxidation in mayonnaise but not found worthy in sensory perception. This proved that sesame sprouts powder has good antioxidant potential to be utilized in various foods to control oxidation.

Protective effect of p-coumaric acid against doxorubicin induced toxicity in H9c2 cardiomyoblast cell lines

Doxorubicin (Dox) has been used for more than four decades to treat cancer, particularly solid tumours and haematological malignancies. However, the administration of this drug is a matter of concern in the clinical community, since Dox therapy is commonly associated with dose-dependent cardiotoxicity. Attempts at alleviating drug generated cardiac damage using naturally occurring compounds with radical scavenging property are a promising area of research. p-Coumaric acid (pCA) is one such compound which has significant antiradical scavenging effect. This study aims to investigate the effect of pre and co-administration of pCA on mitigating or preventing Dox induced cardiotoxicity in vitro using H9c2 cardiomyoblast cell lines. Addition of pCA and Dox were performed for both treatment and control sets on H9c2 cells. Sulphorhodamine B assay was used to study the cytotoxic effect of pCA and Dox. The effect of the drug on cell morphology, cell viability and nuclear damage was studied using AO/EB and DAPI staining. ROS production was studied using DCFH-DA staining. Mitochondrial membrane potential and intracellular calcium levels were assessed by rhodamine 123 and Fura 2AM staining. pCA showed strong ABTS cation radical scavenging activity and FRAP activity in a dose dependent manner. The results showed that Dox has significant cytotoxic effect in a dose dependent manner while pCA, even at higher concentrations did not display any significant cytotoxicity on H9c2 cells. Both pre treatment and co- administration of pCA reduced the drug induced toxic effects on cell morphology and enhanced the number of viable cells in comparison to the Dox treated cells as evident from the AO/EB and DAPI staining images. The Dox induced ROS production was found to be significantly reduced in pCA pre-treated and co-administered cells. Dox induced changes in mitochondrial membrane potential and intracellular calcium levels were remarkably improved following pre and co-treatment of H9c2 cells with pCA. These results clearly suggest that pre-treatment and co-administration of pCA is a promising therapeutic intervention in managing Dox mediated cardiotoxicity.

Antioxidant properties of pancreatic hydrolysates from various protein sources

Antioxidant activity of pancreatic hydrolysates of casein, spent brewer’s yeast, bovine liver and tendon was evaluated in comparison to unhydrolised substrates by ABTS assay. In the result of enzymic treatment ABTS cation radical scavenging activity of spent brewer’s yeast, bovine liver and bovine tendon was increased in 4.8, 3.3, and 2.3 times respectively, except casein. The IC50 values of ABTS cation radical scavenging for casein and it’s hydrolysate were similar. The IC50 values of DPPH radical scavenging activity for pancreatic hydrolysates of casein, spent brewer’s yeast, bovine liver and tendon were 1.8±0.1 mg/ml, 1.3±0.1 mg/ml, 1.7±0.1 mg/ml, and 6.2±0.1 mg/ml respectively. Above mentioned hydrolysates of various origin were produced at the same conditions (temperature 50oC, pH 7.5-8.9, duration 5 hours) using fresh bovine pancreatic tissue as an enzyme source. The extent of hydrolysis expressed as AN/TN (amino nitrogen/total nitrogen) for hydrolysates had values from 0.36±0.02 to 0.46±0.04.DOI: http://doi.dx.org/10.5564/mjc.v15i0.321 Mongolian Journal of Chemistry 15 (41), 2014, p43-46

Chemical profile and biological activities of Veronica thymoides subsp. pseudocinerea

Context: In Turkey, Veronica species (Plantaginaceae) have been used as a diuretic and for wound healing in traditional medicine.Objective: To examine the fatty acid and essential oil profiles, the antioxidant, anticholinesterase, antimicrobial, and DNA damage effects of Veronica thymoides P.H. Davis subsp. pseudocinerea M.A. Fischer as a potential source of natural active compounds.Materials and methods: GC/MS was used to analyze essential oil and fatty acid obtained from whole plant. The antioxidant activity was evaluated by the β-carotene-linoleic acid test system, DPPH-free and ABTS cation radicals scavenging, and cupric reducing antioxidant capacity assays. The anticholinesterase and antimicrobial activities were determined by Ellman and broth macrodillution methods, respectively. The effect of the methanol extract on DNA cleavage was investigated.Results: Hexatriacontene (21.0%) was found to be the main constituent in essential oil, and linoleic acid (25.2%) and palmitic acid (20.6%) in fatty acid. Methanol extract demonstrated the best IC50 values in lipid peroxidation (49.81 ± 0.31 µg/ml) and DPPH-free radical scavenging activity (15.32 ± 0.17 µg/ml). Methanol and water extracts possessed strong ABTS cation radical scavenging activity with IC50 values 9.15 ± 0.28 and 8.90 ± 0.14 µg/ml, respectively. The acetone extract exhibited moderate butyrylcholinesterase inhibitory activity. The highest antimicrobial activity was determined in methanol extract against Escherichia coli with 31.25 µg/ml MIC value. Inhibition of methanol extract on plasmid DNA cleavage by OH radicals was found to be 93.32% at 500 µg/ml.Conclusion: The methanol extract having strong antioxidant and DNA damage effects could be investigated phytochemically to find natural active compounds.

A comparative assessment of antioxidant properties, total phenolic content of einkorn, wheat, barley and their malts

Two einkorn wheat, one barley, three optional winter cultivation wheat and five winter cultivation wheat samples harvested in Hungary in 2011, and their malts were evaluated for their DPPH radical and ABTS radical cation scavenging activity, ferric reduction capacity (FRAP) and total phenolic content (TPC).All einkorn and barley samples exhibited significant antioxidant activities determined by DPPH and ABTS radical scavenging activities. The einkorn samples show higher polyphenol content than the other wheat samples. In all cases the barley sample had the highest antioxidant potential and polyphenol content. The einkorn malts had high DPPH and ABTS radical cation scavenging activities, but the phenolic content was lower against wheat samples. There was significant difference between the antioxidant potential of optional and winter cultivation wheat samples except on ABTS scavenging activities.Einkorn wheat is potentially a new raw material to produce organic beer that might have beneficial effects with its increased antioxidant potential.

천연 항산화제로의 활용을 위한 사과, 포도, 및 고구마 껍질 에탄올 추출물의 항산화 효과

본 연구에서는 천연 항산화제로써의 활용을 위해 부산물인 사과 껍질, 포도 껍질과 고구마 껍질의 에탄올 추출물의 총 폴리페놀, 총 플라보노이드, DPPH 라디칼 소거능, ABTS 양이온 소거능, FRAP 환원능과 ORAC 지수를 측정하였다. 결과적으로 총 폴리페놀과 총 플라보노이드의 함량은 사과 껍질 1g에 각각 7.76 ${\mu}M$ quercetin 당량과 1.03 ${\mu}M$ quercetin 당량으로 존재하여 포도 껍질과 고구마 껍질 보다 유의적으로 다량 함유되어 있는 것으로 관찰되었다. 또한 DPPH 라디칼 소거능은 사과껍질 1 g이 각각 포도 껍질보다는 3.2배, 고구마 껍질보다는 4.6배로 나타났고, ABTS 양이온 소거능 또한 사과껍질 1g이 각각 포도 껍질보다는 2.8배, 고구마 껍질보다는 5.4배로 강력하게 소거하는 것으로 나타났다. 뿐만 아니라, FRAP 환원능과 ORAC 지수 또한 사과 껍질이 포도 껍질이나 고구마 껍질보다 유의하게 우수한 것으로 나타났다. 이와 같은 결과로 사과껍질을 이용한 천연 항산화제로의 활용이 가능할 것으로 사료된다. 【This study examined the antioxidant capacities of apple peel, grape peel, and sweet potato peel. The antioxidant activities were evaluated using total phenolic contents, total flavonoids contents, DPPH radical scavenging activity, ABTS radical cation scavenging activity, FRAP reducing power, and ORAC assay. The total phenolic (7.76 ${\mu}M$ quercetin equivalent/g peel) and total flavonoids (1.03 ${\mu}M$ quercetin equivalent/g peel) contents in apple peel were significantly higher than in grape peel and sweet potato peel (P】

In vitro antioxidant activities and anti-proliferative properties of the functional herb Abrus cantoniensis and its main alkaloid abrine.

Abrus cantoniensis is a common and popular vegetative food consumed as beverage, soup and folk medicine in the tropical and subtropical areas of Asia. It has been claimed valuable for cleansing toxicants in the liver. However, the functional effects of A. cantoniensis have not yet been scientifically explored. This study comprehensively evaluated the in vitro antioxidant and anti-proliferative capacities of the herbal extract and the main alkaloid abrine. Abrine was qualitatively and quantitatively determined in methanol extract (ME) using HPLC-DAD and LC-MS/MS. The results showed that ME, ethyl acetate fraction (EF) and abrine exhibited comparable ABTS radical cation scavenging activities and reducing power to two commercial antioxidants (BHT and Trolox). The EF exerted strong cellular antioxidant activity and selective cytotoxicity against three cancer cell lines in a dose-dependent manner. Biological assays revealed that the EF induced cell cycle arrest at G2/M and apoptosis in MCF-7 and Hep3B cells after 48 h of treatment. Thus, A. cantoniensis exerted potent cellular antioxidant and anti-proliferative properties, highlighting why it has been traditionally used as a functional food.

Screening Study on Antioxidant Activity of Plants Grown Wildly in Mongolia

In this study, 50% ethanol extract prepared from dry leaves of eight plants grown wildly in Mongolia were characterized for DPPH radical scavenging activity, ABTS radical cation scavenging activity, superoxide anion scavenging activity, ferric reducing power, iron chelating ability, and content of total phenol, flavonoid, and flavanol in order to find good sources of natural antioxidant from plant kingdom. Correlation coefficients between antioxidant parameters and contents of polyphenolic compounds were also calculated. Among them, leaves of Vaccinium vitis-idaeae, Paeonia anomala, Rosa acicularis, and Hippophae rhamnoides were rich in polyphenolics and exerted strong scavenging activity against DPPH radical, ABTS radical cation, and superoxide anion and reducing power.

Evaluation of antioxidant efficacy of different fractions of Tagetes erecta L. Flowers

Oxidative stress is an important pathogenesis of numerous chronic diseases. Free radicals and other reactive oxygen species are recognized as agents involved in the pathogenesis of sicknesses. The main characteristic of an antioxidant is its ability to trap free radical. Plants rich in phenolic compounds are generally reported to show good antioxidant activity. Tagetes erecta L (Marigold) belongs to the family Asteraceae. The flowers are especially employed to cure eye diseases, colds, conjunctivitis, coughs, ulcer, bleeding piles and to purify blood. The extractive efficiency of phenolic compounds from plant material is greatly dependent on the choice of solvent. In this study, six solvents of different polarity viz., hexane, toluene, ethyl acetate, acetone, methanol and water have been used for the extraction of Tagetes erecta L. flower by individual cold percolation method. Phenolic and flavonoid content of extracts were determined using Folin- ciocalteu assays and aluminium chloride colorimetric method respectively. Antioxidant activity was carried out by DPPH radical scavenging activity assay, superoxide free radical scavenging (SO) assay, ABTS radical cation scavenging activity, ferric reducing antioxidant power (FRAP), Reducing capacity assessment. Maximum extractive yield was in water extract followed by methanol extract. There was a direct correlation between phenolic content and antioxidant activity. Methanolic extract had maximum phenolic content and maximum FRAP and SO activity. ABTS and DPPH did not show positive correlation with total phenol content in ethyl acetate extract. Ethyl acetate extract had maximum flavonoid content. T. erecta flowers can be used as a natural source of antioxidants to combat the oxidative stress related disorders. Key word: Tagetes erecta, Influence of solvent, Antioxidant activity, positive correlation

Antioxidant, anticholinesterase, and antimicrobial activities and fatty acid constituents of Achillea cappadocica Hausskn. et Bornm.

This study was the first fatty acid analysis and biological activity report on an endemic Achillea species, Achillea cappadocica Hausskn. et Bornm. The major compounds in the fatty acid were identified as oleic (34.7 %), palmitic (23.1 %), and linoleic acids (20.6 %). The methanol and water extracts indicated higher ABTS cation radical scavenging activity than that of \alpha-tocopherol and BHT at 100 \mu g/mL. The acetone extract showed 70.62 % inhibitory activity against butyrylcholinesterase at 200 \mu g/mL. The acetone and methanol extracts exhibited moderate antimicrobial activity.

Characterization of Indian beers: chemical composition and antioxidant potential.

Chemical composition, antioxidant potential and corresponding lipid preoxidation of Indian commercial beers were evaluated. The presence of polyphenolic compounds such as tannic acid, gallic acid, catechol, vanillin, caffeic acid, quercetin, p-coumaric acid and rutin was quantified using LC-MS while the organic acids including tartaric, malic, acetic, citric and succinic acids were analysed using HPLC. Beer sample B8 had the greatest concentration of phenolic and flavonoid components (0.620 ± 0.084mg/mL and 0.379 ± 0.020mg/mL respectively) among the beer samples studied. The DPPH radical scavenging activity was observed in the range of 68.34 ± 0.85% to 89.90 ± 0.71% and ABTS radical cation scavenging activity was in the range of 59.75 ± 0.20% to 76.22 ± 0.50%. Percent protection in lipid peroxidation was quantified to be maximum (54.45 ± 3.39%) in sample B5. Total phenolic content positively correlates with antioxidant assays, DPPH and ABTS (r = 0.35 and r = 0.58 respectively) with p < 0.001 and also with lipid peroxidation (r = 0.04) with p < 0.001. Negative correlation was observed between total flavonoid content with ABTS and lipid peroxidation (r = -0.1 and r = -0.05) respectively. The process of brewing warrants additional research to determine how the concentration of selected phenolic compounds can be increased.