• Bulletin of the Korean Chemical Society
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• 제23권3호
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• pp.385-390
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• 2002

Laccase could be successfully assembled on an amine-derivatized platinum electrode by glutaraldehyde coupling. The enzyme layer formed on the surface does not communicate electron directly with the electrode, but the enzymatic activity of the surf ace could be followed by electrochemical detection of enzymatically oxidized products. The well-known laccase substrates, ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)) and PPD (p-phenylenediamine) were used. ABTS can be detected down to 0.5 ${\mu}M$ with linear response up to 15 ${\mu}M$ and current sensitivity of 75 nA/ ${\mu}M.$ PPD showed better response with detection limit of 0.05 ${\mu}M$, linear response up to 20 ${\mu}M$, and current sensitivity of 340 nA/ ${\mu}M$ with the same electrode. The sensor responses fit well to the Michaelis-Menten equation and apparent $K_M$ values are 0.16 mM for ABTS and 0.055 mM for PPD, which show the enzymatic reaction is the rate-determining step. The laccase electrode we developed is very stable and more than 80% of initial activity was still maintained after 2 months of uses.

• Preventive Nutrition and Food Science
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• 제18권3호
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• pp.196-202
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• 2013

Citron seed extracts (CSEs) were made using distilled water (CSEW), ethanol (CSEE), and n-hexane (CSEH), to measure the total polyphenol contents, DPPH and ABTS radical scavenging activities, and anti-complementary activity. The total polyphenol content was observed the highest in CSEE (188.71 ${\mu}g/mL$), and occurred in the following order: CSEE>CSEW (141.11 ${\mu}g/mL$)>CSEH (26.19 ${\mu}g/mL$) at 10 mg/mL. CSEE (63.56%) and CSEW (56.61%) showed significantly higher DPPH radical scavenging activities when compared with CSEH (28.57%). ABTS radical scavenging activities of CSEE (45.53%) and CSEW (40.02%) were also observed to be higher, whereas CSEH did not show ABTS radical scavenging activity. Anti-complementary activity of CSEE (26.85%) showed a greater activity than that of CSEW (7.84%) at 1,000 ${\mu}g/mL$. Limonin and nomilin contents had the highest values (1.882% and 2.089%) in CSEE, and with 0.327% and 0.139% in CSEW; however, CSEH showed relatively very low values at 0.061% and 0.026%, respectively. Among the CSEs tested, CSEE as a by-product from citron may provide an important source of dietary antioxidant compounds with rich polyphenol and limonoid contents, and immunopotentiating activity, including the complement activation factor.

• 한국식품저장유통학회지
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• 제30권6호
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• pp.960-968
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• 2023

The rhizome of Phragmites communis Trin. is used for vomiting and belching by clearing stomach and the sprout is used as tea. Phragmites japonica is similar with P. communis except the color of sheath is purple. This study is aimed to compare the in vitro antioxidant activity, total polyphenol and flavonoids contents of P. communis and P. japonica. The antioxidant activities of fractions from the two Phragmites plants were evaluated by 1,1-diphenyl-2- picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assay. The antioxidant activity varied with plant parts and extract solvents. The fractions of leaf extract from the two Phragmites plants (4.06±1.32-16.47±1.28%) showed higher antioxidant activity by DPPH assay compared with rhizome fractions of two Phragmites plants (0.00±0.00-14.15±0.07%), these are lower compared with ascorbic acid and butylhydroxyanisole (BHA). The highest ABTS radical scavenging activity was found for rhizome ether fraction, namely 74.95±0.56% and 73.04±1.85% for P. communis and P. japonica, these are higher than BHA. The total polyphenol and flavonoids contents were different with plant parts and extract solvents, likewise antioxidant activity. A significant correlation was shown between DPPH and ABTS radical scavenging activity. Considering the results of this study, the leaves and stems of P. communis and P. japonica are expected to be used as natural antioxidants.

• Fisheries and Aquatic Sciences
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• 제19권4호
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• pp.22.1-22.7
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• 2016

One of the main compounds in Ishige okamurae, diphlorethohydroxycarmalol (DPHC), is known to exhibit antiviral and anti-inflammatory effects. However, it has not been investigated extensively. In this study, preparative centrifugal partition chromatography (CPC) coupled with 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) ($ABTS^+$) online HPLC was employed for effectively separating considerable amounts of antioxidant compounds from marine algae. Two main antioxidant compounds, DPHC and octaphlorethol A (OPA), respectively, were confirmed and isolated from the ethyl acetate (EtOAc) fraction of I. okamurae by $ABTS^+$ online HPLC and preparative CPC systems. The presence of DPHC and OPA was confirmed in the EtOAc fraction of I. okamurae by both liquid chromatography with diode array detection and electrospray ionization mass spectrometry (LC-DAD-ESI/MS) and $ABTS^+$ online HPLC systems: DPHC (39 mg) and OPA (23 mg) were successfully isolated from I. okamurae (500 mg) with optimum solvent composition (0.5:10:4:6; n-hexane/EtOAc/MeOH/water, v/v) with corresponding partition coefficients (K) of 1.62 and 2.71, respectively, by preparative CPC. Hence, CPC coupled with $ABTS^+$ online HPLC is convenient for the efficient and simple isolation of these antioxidant compounds from I. okamurae.

• 한국식품저장유통학회지
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• 제22권4호
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• pp.577-584
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• 2015

본 연구에서는 수입산 열대 아열대 과일의 항산화 효과를 비교하기 위하여 총 폴리페놀 함량, DPPH radical 소거능, ABTS radical 소거능, superoxide anion radical 소거능, FRAP 활성, tyrosinase 저해효과, 환원력 등을 측정하였다. 총 폴리페놀 함량은 석류가 12.22 mg GAE/g으로 가장 높았고 그 다음 순으로 파인애플이 3.77 mg GAE/g이었으며, 용과, 그린키위, 파파야, 옐로우망고가 2.45~2.99 mg GAE/g의 범위로 나타났다. 석류는 DPPH, ABTS, superoxide anion radical 소거능, 환원력에서 다른 과일보다 높은 활성을 보여주었고 그 다음으로 파인애플이 높은 활성을 보였다. 특히 석류는 추출물의 농도가 증가함에 따라 전반적으로 활성이 증가하는 경향을 보였고 시료 농도 5 mg/mL에서는 DPPH radical 소거능과 ABTS radical 소거능 및 환원력이 양성대조군으로 사용한 ascorbic acid와 대등한 효과를 보였다. 반면에, 용과와 파파야는 대부분의 항산화 효과 실험에서 낮은 활성을 나타내었다.

• 융합정보논문지
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• 제11권11호
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• pp.296-303
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• 2021

본 연구에서는 생강나무 꽃 발효 추출물의 항산화능 및 항염능을 확인하였다. 항산화능 측정을 위해 DPPH 실험, ABTS 실험을 실시하였다. 동시에 폴리페놀 농도 측정, 플라보노이드 농도 측정을 통해 항산화 물질의 정량을 실시하였다. 플라보노이드, DPPH, ABTS에서는 발효 후의 항산화능이 증가한 것을 확인하였다. 이 때 플라보노이드 농도는 5.0%, DPPH 실험에서는 33.27%, ABTS 실험에서는 29.82%의 항산화능 개선 효과가 나타났다. 항염능 실험에서는 세포 독성 실험과 LPS로 유도된 염증에 대한 항염능을 알아보기 위한 NO 생성 억제능 실험을 실시하였다. 세포독성의 경우 대조군과 발효군 모두 낮은 세포독성을 보였지만 발효군에서 더 낮은 세포독성을 보였다. NO 생성 억제능의 경우 발효군이 대조군에 비해 50% 이상의 항염능 증가를 보여 발효 생강나무꽃이 기존 생강나무 꽃에 비해 더 개선된 화장품 원료로서 사용가능함을 보였다.

• 한국응용과학기술학회지
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• 제41권2호
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• pp.386-392
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• 2024

COVID-19로 인하여 현대인들은 유해환경 및 다양한 자극에 따른 불안 심리가 높아지게 되면서 천연물질을 선호하게 되었다. 따라서 전통의학에서 무독성 식물로 인정한 히비스커스를 천연화장품 소재로서의 적절성을 알아보고자 히비스커스 추출물의 항산화 효과(폴리페놀, 플라보노이드, DPPH, ABTS)를 연구하여, 다음과 같은 결과를 얻었다. 첫째, 히비스커스의 총 폴리페놀은 HSE 100%일 때 433 ㎍/mL로 나타났다. 둘째, 총 플라보노이드는 HSE 100%에서 488 ㎍/mL로 항산화 능력이 높게 나타났다. 셋째, DPPH radical 소거능은 원액 HES 100%에서 94.04%, 희석액 HSE 20%에서 89.54%로 나타났다. 넷째, ABTS radical 소거능은 HSE 원액 100%에서 98.95%, 희석액 HSE 20%에서 94.84%로 각각 90% 이상의 높은 소거능을 나타냈다. 이러한 연구 결과 히비스커스 추출물은 향후 화장품 천연소재의 항산화 원료로 사용이 가능하다고 사료된다.

• 생명과학회지
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• 제33권2호
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• pp.138-148
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• 2023

본 연구는 Peucedanum insolens Kitagawa의 잎과 뿌리에서 추출한 용매 분획물들의 항산화 활성을 비교 분석하기 위해 수행되었다. 본 연구를 위해 P. insolens Kitagawa의 건조된 잎과 뿌리를 각각 70% 에탄올로 먼저 추출한 후 hexane, chloroform, ethyl acetate, n-butanol, 물의 순서로 분획하였다. 실험 결과 유기용매 분획별 총 폴리페놀 함량은 P. insolens Kitagawa의 잎과 뿌리 모두에서 동일한 분포 양상을 보였다. 유기용매 분획 중 총 폴리페놀 함량은 에틸아세테이트 분획(101.1±1.0 ㎍ vs 128.8±15.6 ㎍ GAE/mg)에서 가장 높게 나타났으며, 헥산 분획에서 가장 낮은 함량(9.51±0.2 ㎍ vs 6.8±0.8 ㎍ GAE/mg)을 보였다. P. insolens Kitagawa의 잎과 뿌리 모두에서 유기용매 분획에 의한 총 플라보노이드 함량 분포는 총 폴리페놀 함량과 동일한 양상을 보였다. P. insolens Kitagawa 잎과 뿌리의 유기용매 추출물을 DPPH, ABTS, FRAP assay를 통해 활성산소 소거 활성을 측정한 결과, 잎과 뿌리 추출물에서도 동일한 패턴으로 활성산소 소거 활성을 보였으며, 유기용매 분획 중 에틸아세테이트 분획이 가장 높은 자유 라디칼 소거 활성을 보였다. P. insolens Kitagawa의 잎과 뿌리의 유기용매 분획물에서 총 페놀 함량과 자유 라디칼 소거 활성 사이에 유의한 상관 관계(R=0.903, p<0.0001, DPPH 라디칼, R=0.891, p<0.001, ABTS 라디칼, R=0.745, p<0.05, FRAP 라디칼)와 P. insolens Kitagawa의 잎 또는 뿌리의 용매 분획물에서 DPPH, ABTS 및 FRAP assay들 사이에서도 중요한 상관관계(R=0.867, p<0.001, DPPH vs ABTS 라디칼, R=0.882, p<0.0001, DPPH vs FRAP 라디칼, R=0.973, p<0.0001, ABTS vs FRAP 라디칼)가 있음이 확인되었다. 본 연구 결과에서 얻은 결론은 왕산방풍 식물의 뿌리에서와 마찬가지로 왕산방풍의 잎에서도 강한 항산화 활성을 가지고 있으며, 잎을 주요 항산화 물질의 소재로 사용할 수 있다.

• Natural Product Sciences
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• 제19권2호
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• pp.186-191
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• 2013

Screenings of potential antioxidant activities of Crataegus pinnatifida BUNGE Major. fruits extracted 80% methanol were performed using four antioxidant assays. Significant differences were observed both in total phenolic contents (TPC) and total flavonoid contents (TFC), DPPH radical scavenging activity, nitric oxide scavenging activity, ABTS radical scavenging assay, and reducing power assay. The total polyphenol content and total flavonoid content in the extract were measured to be $224.4{\pm}0.52$ mg GAE/100 g and $12{\pm}0.25$ mg QE/100 g, respectively. When the tested concentration was $500{\mu}g/mL$, DPPH and ABTS radical-scavenging activities of methanolic extracts were 84.15% and 88.8%, respectively. The reducing power and nitric oxide scavenging activity were increased at the manner of dose-dependently. These results suggest that methanolic extracts of Crataegus pinnatifida Bge. fruits possess excellent radical scavenging activities and may serve as a potential source of natural antioxidant.

• Natural Product Sciences
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• 제13권1호
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• pp.40-45
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• 2007

The methanol extract of Coscinium fenestratum, commonly own as tree turmeric, which is widely used in the indigenous system of medicine was studied for its in vitro scavenging activity in different methods viz DPPH scavenging, nitric oxide scavenging, iron chelation activity, superoxide scavenging, ABTS radical scavenging and lipid peroxidation. The results were analyzed statistically by regression method. Its antioxidant activity was estimated by $IC_{50}$ value and the values are $57.1\;{\mu}g/ml$ for DPPH radical scavenging, $36.5\;{\mu}g/ml$ for iron chelating activity, $51.7\;{\mu}g/ml$ for nitric oxide scavenging, $53.63\;{\mu}g/ml$ for ABTS scavenging, $44.2\;{\mu}g/ml$ for superoxide scavenging, and $40\;{\mu}g/ml$ for lipid peroxidation. In all the methods, the extract showed its ability to scavenge free radicals in a concentration dependent manner. The results indicate that C. fenestratum has potent antiofidant activity.