• Korean Journal of Medicinal Crop Science
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• v.15 no.5
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• pp.335-338
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• 2007

Five samples (Bakwoonbae, Chungsilbae, Sandolbae, Dolbae, and Chuwhangbae) of Pyrus species differing in their origin of production were analyzed for total phenolic content, vitamin C content, and antioxidant activities. Two antioxidant activities were measured by the free-radical scavenging activity and reducing power method. Total phenolic content of the Chungsilbae extract (20.35 mg/g) was higher than those of other pears. Vitamin C content in five Pyrus species ranged from $420.32\;{\mu}g/g$ in Sandolbae to $659.75\;{\mu}g/g$ in Bakwoonbae. Chungsilbae also had the highest free radical scavenging activity (76.56%) and reducing power (0.35).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.2
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• pp.82-88
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• 2004

The objective of this study was to determine the role of storing years with the variation of total phenol and individual phenolic compounds in soybean (Glycine max L.) seeds. The total phenol content varied from 0.36 to 0.42% over four years, with the highest value (0.42%) found at storage for two and three years. Among the nine soybean varieties examined, Daweonkong had the highest total average phenol content (0.58%). The total content of 11 phenolics varied from 730.0 to 1812.8 $\mu\textrm{g}\;\textrm{g}^{-1}$ over storage for four years, and the highest concentration (1812.8 $\mu\textrm{g}\;\textrm{g}^{-1}$) was found at storage for two years. Myeongjunamulkong (1465.4 $\mu\textrm{g}\;\textrm{g}^{-1}$) had the highest mean content among the nine soybean varieties. The total content of 11 phenolic compounds measured in this study occupied from 20.96 to 47.73% of the total phenol contents. The highest total phenol contents were in seeds with black coats (5279.4 $\mu\textrm{g}\;\textrm{g}^{-1}$), while the highest concentration of individual phenolic compounds were in seeds with green coats (1419.5 $\mu\textrm{g}\;\textrm{g}^{-1}$). Our study suggests that it may be feasible to improve soybean varieties with high functional substances such as phenolic compounds.

• Food Science and Biotechnology
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• v.14 no.2
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• pp.212-215
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• 2005

Ethanol crude extracts of wood, bark, leaf, and fruit of Callistenwn citrinus were compared for their antioxidant activities based on DPPH (1, 1-diphenyl-2-picrylhydrazyl) radical-scavenging activity and reducing power. Bark extract showed the most potent radical-scavenging activity and reducing power, showing 94.1 and 0.64% at 25 and $100\;{\mu}g/mL$, respectively. Total phenolic content of the bark extracts (275.0 mg GAE/g) was higher than those of others. Further fractionation of the bark extract using hexane, $CH_2Cl_2$, and EtOAc showed EtOAc fraction had the highest antioxidant activity ($IC_{50}\;6.7\;{\mu}g/mL$) and reducing power (0.82 at $100\;{\mu}g/mL$), with total phenolic content of 611.1 mg GAE/g. Total phenolic contents correlated with antioxidant activity ($R^2\;=\;0.7061$) and reducing power ($R^2\;=\;0.7399$).

• Journal of Korean Medicine for Obesity Research
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• v.23 no.1
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• pp.10-17
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• 2023

Objectives: The aim of this study was to compare the total phenolic content of Korean Acanthopanax senticosus stems harvested in different seasons and provide basic data for developing functional reinforcement products based on the optimal harvesting time. Methods: Each sample harvested in different seasons was extracted and concentrated twice for 2 hours using 70% ethyl alcohol. Phenolic compounds were analyzed using high-performance liquid chromatography for simultaneous multi-component analysis of 14 compounds, including syringaresinol and so on. Results: The results showed that the stem of Korean Acanthopanax senticosus harvested in winter (November 29th) (EAS-5) had the highest phenolic content of 1.038%. The stem of Korean Acanthopanax senticosus harvested in autumn (October 1st) (EAS-4) showed the second-highest phenolic content of 0.764%, followed by the stem of Korean Acanthopanax senticosus harvested in spring (February 2nd) (EAS-1) with a content of 0.390%. On the other hand, the stem of Korean Acanthopanax senticosus harvested in the summer (June 2nd) (EAS-3) showed the lowest content at 0.342%. In conclusion, the stem of Korean Acanthopanax senticosus harvested in winter (EAS-5) showed the highest phenolic compound content. Conclusions: Considering the extraction yield and the total phenolic content, as well as the concentrations of key functional components such as eleutheroside B, chlorogenic acid, and syringaresinol in the 70% ethyl alcohol extract of Korean Acanthopanax senticosus, it is suggested that the stems of Korean Acanthopanax senticosus harvested during the winter season are suitable for the development of novel materials with enhanced anti-obesity functionality.

• Journal of Applied Biological Chemistry
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• v.65 no.2
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• pp.89-92
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• 2022

In this study, the effects of soil conditions on antioxidant activities of the aerial and underground parts of rosemary were assessed to determine the most effective soil conditions for cultivation. The antioxidant activity was the highest (51.58±2.93 ㎍/mL) when cultivated in the mixture of gardening soil and vermiculite using DPPH assay. The antioxidant activity of underground parts the highest (127.48±12.38 ㎍/mL) when cultivated in the mixture of soil, vermiculite, and perlite. ABTS assay showed that the antioxidant activity of aerial parts was 230.34±57.93 ㎍·mL^-1 when cultivated in the mixture of gardening soil and vermiculite and that of underground parts was 320.98±16.04 ㎍·mL^-1 when cultivated in the mixture of gardening soil, vermiculite, and perlite. The total phenolic content of aerial parts was the highest (155.25±2.96 mg GAE/g) when cultivated in the mixture of gardening soil. The total flavonoid content of aerial parts was the highest (67.32±5.27 mg QE/g) when cultivated in the mixture of gardening soil. Therefore, the mixture of gardening soil, vermiculite, and perlite is superior to gardening soil alone for cultivation of rosemary to increase its antioxidant activity as well as total phenolic and flavonoid content.

• Korean Journal of Food Science and Technology
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• v.25 no.1
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• pp.9-14
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• 1993

The free, ester and insoluble bound phenolic acids in the extracts from defatted perilla seed flour were isolated and their antioxidative activities were evaluated in comparison with commercial synthetic antioxidants. Total phenolic content of the perilla seed was 0.75% as chlorogenic acid. Each percent ratio of the content of free, ester, and insoluble bound phenolic acid to total phenolic content was 87.5, 7.5 and 5.0% respectively. Chlorogenic acid was identified as a major phenolic acid and a small amount of caffeic acid was also identified in the free phenolic acid extract, but they were not found in soluble ester and insoluble bound phenolic extracts by two dimensional paper chromatography. Each type phenolic extract from 30g of deffated perilla flour showed antioxidant activity similar to that of BHT (0.02%, w/w) in 200g of soybean oil substrate inspite of the difference of each phenolic content.

• Natural Product Sciences
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• v.29 no.1
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• pp.24-30
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• 2023

Adenanthera pavonina L. is an important medicinal plant for Indonesian traditional medicine ("Jamu"). The present study is to determine the phenolic content and evaluate the antioxidant activity of ethyl acetate and ethanolic extracts of leaves and bark of A. pavonina. The total phenolic content was determined using the Folin-Ciocalteu reagent methods, and the antioxidant activity was performed by phosphomolybdate assay, through EC₅₀ values. The highest phenolic content (81.379 mg GAE/g) was found in the hydro-ethanolic extract of the leaves and (80.630 mg GAE/g) in the bark. The antioxidant activity of the two samples was 42.270 ㎍/mL (leaves) and 45.261 ㎍/mL (bark). Plants have the potential as drugs with good antioxidant potential and phenolic compound content. Further scientific studies of this plant are supported to evaluate the antioxidant activity using other methods to validate these preliminary experiments properly.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.667-671
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• 2003

The total phenolic and flavonoid contents of Lentinus edodes extracts were determinated by spectrophotometrical .method, and antihepatotoxic activity was detected on glutathione S-Transferases(GST). The total phenolic contents was highest water extract than solvent(ethanol, methanol) extracts, but flavonoid content was appear on opposite. GST activity was the highest appears in water extract. This fact verified of anticancer effect indirectly of Lentinus edodes.

• Journal of Korean Society of Forest Science
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• v.102 no.4
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• pp.566-570
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• 2013

Vaccinium oldhamii Miq. is a Korean native tree, which is deciduous and shrub tree with broad leaf. To develop superior cultivars for edible or medicinal purposes, we evaluated total phenolic content and antioxidant activity. Total phenolic content was measured by folin-denis method and antioxidant activity was measured by DPPH free radical scavenging activity (DPPH method) and reducing power (potassium ferricyanide method). Total phenolic content, DPPH free radical scavenging activity (at 400 ppm) and reducing power (at 700 ppm) were 15.8~19.9 mg/g, 69.1~91.4% and 0.56~0.96, respectively. A linear correlation was shown between DPPH-radical scavenging activity and reducing power (r=0969).

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1464-1469
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• 2009

Jiwhang (Rehmannia glutinosa), one of the most widely used medicinal herbs, was dried with various methods such as sun drying, hot air drying, vacuum drying, and freeze drying methods, and their effects on the antioxidant capacity in relation with the content of total phenolic compounds were studied with a steamed-and-dried rehmannia (sookjiwhang) for comparison. Generally, total phenolic contents decreased significantly by all of the drying treatments except the steamed-and-dried rehmannia, in which total phenolic contents increased 2.4 fold compared with fresh rehmannia. Content of verbascoside, a functional phenolic compound, was the highest in the freeze-dried rehmannia ($177.97{\pm}0.02\;{\mu}g/g$ d.m.) followed by vacuum-dried ($105.55{\pm}0.07\;{\mu}g/g$ d.m.), hot air-dried ($23.01{\pm}0.02\;{\mu}g/g$ d.m.), and sun-dried ($4.89{\pm}0.13\;{\mu}g/g$ d.m.) ones comparable to the fresh rehmannia ($80.15{\pm}1.26\;{\mu}g/g$ d.m.). Antioxidant capacity determined by both 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis (3-ethyl-benzthiazoline-6-sulphonic acid) (ABTS) methods agreed with the result of total phenolic contents, that is, the antioxidant capacity was the highest in the steamed-and-dried rehmannia followed by fresh rehmannia, vacuum-dried, hot air-dried, sun-dried, and freeze-dried ones. Conclusively, the total phenolic contents and antioxidant capacity of rehmannia were greatly affected by the drying methods used.