Propolis collected from botanical sources by honey bee, has been used as a popular natural remedies in folk medicine throughout the world. This study was conducted to assess growth inhibitory effects of ethanol extracts of propolis (EEPs) from 20 different regions in South Korea on human intestinal bacteria as well as BACE-1, AChE inhibitory, antioxidant, antiproliferative, and anti-human rhinovirus activities. Correlation coefficient (r) analysis of the biological activities of EEP samples was determined using their 50% inhibition concentration or minimal inhibitory concentration values and their polyphenol or flavonoid contents in 20 Korean EEP samples. Correlation coefficient analysis showed that total polyphenol contents may be negatively correlated with DPPH free radical scavenging activity (r = –0.872) and total flavonoid content has no correlation with the activity (r = 0.071). No direct correlation between BACE-1 inhibition, AChE inhibition, or antiproliferative activity and total polyphenol or total flavonoid content in Korean EEP samples was found.

This study attempted to investigate the antioxidant properties of four different species of sand dune plants (Calystegia soldanella, Messerschmidia sibirica, Vitex rotundifolia and Rosa rugosa). In order to validate the antioxidant activity of these plants, we first determined the total amount of flavonoid versus phenolic contents (TFC/TPC) and extracted crude flavonoids for measuring antioxidant activities that were determined by DPPH, ABTS and FRAP assays with radical scavenging effects. We found that highest amounts of TPC were detected in R. rugose with values of 110.20 ㎎/g (leaves) and 65.71 ㎎/g (stems), while the highest amounts of TFC in V. rotundifolia with values of 38.07 ㎎/g (leaves) and 6.55 ㎎/g (stems). We further examined how closely related the amounts of TFC/TPC in antioxidant activities and found that R. rugose has the highest activities of radical scavenging with values of 63.4 ㎍/㎖ and 51.2 ㎍/㎖ determined by DPPH and ABTS assays compared with the value of 21.2 ㎍/㎖ by FRAP assay. It is of note that there is a statistically significant correlation between the resulting antioxidant activities and the total ratio of TFC and TPC, suggesting that the different amounts of TFC/TPC may directly contribute to the various antioxidant activities.

There has been little research on the harvesting time-dependent changes in the antioxidant activities of new varieties of highland cultures of Gomchwi (Ligularia fischeri) crossed with Turcs (Ligularia fischeri (Ledeb.)) and Nakai (Ligularia fischeri var. spiciformis), namely Sammany (S), Gommany (G) and Damogy (D). This study was conducted to assess the effect of different harvesting times on nutritional and health-related properties such as total phenolic contents, flavonoids, DPPH (1,1-diphenyl-2-picrylhydrasyl) free radical scavenging activities and reducing power. From these harvests, extracts were prepared using methanol. Total phenolic content in Jul 14-G (Gommany harvested on July 14, 0.172 ㎎·GAE/㎖) was higher than that in other products harvested after the same period (S, 0.154; D, 0.141 ㎎·GAE/㎖). Flavonoid content was higher in Jul 3-G (0.114 ㎎·QE/㎖), compared to Jul 3-S (0.113 ㎎·QE/㎖) and Jul 14-D (0.089 ㎎·QE/㎖). Antioxidant activities were higher in samples harvested after June 12 in all cases. On July 14, the highest DPPH free radical scavenging activities among all harvest dates were seen (92.875~94.595%). The reducing power was also dependent on harvest day (Abs 0.5~0.6 on July 14), showing a pattern similar to that of DPPH free radical-scavenging activities. Antioxidant activity and harvesting times seem to correlate with total polyphenol and flavonoid contents.

Flavonoids and total polyphenols are important secondary plant metabolites, as they play a role in reducing the oxidative stress caused by ROS In this study, we investigated for flavonoid contents, total polyphenol contents, and antioxidant activities in 27 accessions from 10 Vicia species. Among 27 vicia accessions, NAC17 (V. monantha) and NAC14 (V. hyrcanica) had the highest total flavonoid (1.42 ± 0.09 mg/g) and total polyphenol (124.2 ± 0.5 μg/GAE mg) contents, respectively. In four flavonoids, naringenin showed the highest concentrations in Vicia species. The DPPH and ABTS were the range from 0.2 (NAC24, V. sativa subsp. nigra) to 18.5 (NAC13, V. faba) μg/ASC mg and 19.1 (NAC7, V. cracca) to 253.4 (NAC13, V. faba) μg/Trolox mg, respectively. Among the 10 Vicia species, V. monantha and V. hyrcanica had the highest flavonoid (1.31 ± 0.09 mg/g) and total polyphenol (116.5 ± 2.0 μg/GAE mg) contents, respectively. The highest antioxidant activity was detected in V. faba. These results will expand the flavonoid database and provide information on Vicia species valuable for development of functional foods or feed-additives resources.

본 연구는 강릉, 대관령에서 재배된 아마란스 품종별로 수량, 생육특성, 항산화활성, 총페놀함량 그리고 유리아미노산의 차이를 조사하고 국내 적응이 가능한지 살펴보고자 실시하였다. 수량은 125~465 kg 10a-1의 범위였으며 RRC 1027 품종이 가장 많았다. 천립중은 0.42~0.82 g으로 아주 작았고 특히 Kerala Red 품종이 가장 가벼웠다. DPPH를 이용한 항산화 활성 분석에서 지역별로는 강릉과 대관령 사이의 유의차는 없었으나 품종별로는 유색품종인 Kerala Red가 가장 높았다. 총 폴리페놀 함량을 분석한 결과 994~1,732 mg kg-1의 범위를 보였다. 종실의 유리아미노산 함량 분석 결과 glutamic acid 30.5 mg 100 g-1, aspartic acid 26.1 mg 100-1, arginine 24.3 mg 100 g-1 순이었다. 이러한 결과를 종합해 볼 때 국내에서 아마란스 재배는 수량 등에서도 안정적이었고 glutamic acid, aspartic acid, arginine 등 곡물에 부족할 수 있는 유리아미노산을 포함하고 있어 새로운 작물로 개발 가능성이 높을 것으로 기대된다. 그러나 항산화활성능을 측정하기 위하여 DPPH 방법 이외에 다른 방법을 모색할 필요가 있을 것으로 생각된다.

국내에서 제조 및 시판되고 있는 사과를 비롯한 과일 주스 5종, 포도 주스 10종의 총 페놀 함량과 항산화 활성을 DPPH 방법과 FRAP 방법으로 조사하였다. 시판 과일 주스 중 오렌지의 총 페놀 함량이 114.09 nlg/L로 가장 높게 나타났고, 포도주스 10종은 의 함량으로 제품 별로 다양하게 나타났다. 과일 주스의 DPPH radical 소거 활성은 자몽이 가장 높았으며 사과, 파인애플이 낮았다. 포도주스의 항산화 활성은 제품에 따라 다