• Journal of Applied Biological Chemistry
• /
• 제44권2호
• /
• pp.87-91
• /
• 2001

Extracts from Geum japonicum (Bammu in Korean) were analyzed for their antioxidative activities and scavenging effects on free radicals. The ethyl acetate fraction of G. japonicum methanol extract (EFGJ) showed a remarkable scavenging activity on the 1,1-diphenyl-2-picrylhydrazyl radical. EFGJ also showed excellent antioxidative activity on linoleic acid during long-period storage and on rat liver microsome peroxidation system, and good anti-peroxidation effect on lipid in Rancimat system using lard, palm oil, and perilla oil, as compared with BHT and ${\alpha}$-tocopherol. Varying effects of antioxidative activity of the EFGJ on various fatty acids were observed. The prevention of linoleic acid and linolenic acid peroxidation was superior to ${\alpha}$-tocopherol, but inferior to BHT. The methanol extract of G. japonicum did not show mutagenicity as revealed through SOS chromotest. Based on the results, the extracts of G. japonicum may be useful source as natural antioxidants.

• 한국염색가공학회지
• /
• 제21권4호
• /
• pp.33-38
• /
• 2009

Poly(vinyl acetate) films containing benzophenone were photocrosslinked by continuous UV irradiation.UV irradiation of PVAc film containing 5% benzophenone induced bulk crosslinking of the polymer indicated by 84.1% of gel fraction after ethyl acetate extraction. The crosslinking was attributed to the recombination of tertiary polymer radicals generated upon UV irradiation, which was enhanced by the hydrogen abstraction of benzophenone. Also the UV irradiation resulted in scission of ester linkage and photooxidation of PVAc surface, which was verified by ATR and zeta potential analysis, implying that the PVAc surface became more polar and hydrophilic. The zeta potential proportionally increased from +4.5mV to -26.8 mV with increasing UV irradiation. Also the surface energy of the PVAc film increased with higher UV irradiation upto 56.5 $mJ/m^2$ by the enhanced Lewis acid/base component with larger contribution of Lewis acid parameter. Accordingly the crosslinked PVAc showed higher thermal stability with increasing UV energy.

• Preventive Nutrition and Food Science
• /
• 제12권4호
• /
• pp.267-272
• /
• 2007

The objective of this study was to investigate antioxidant activities of Panax ginseng extracted with various solvents including n-hexane, chloroform, EtOAC, n-butanol and water. Among the various ginseng extracts, ethyl acetate (EtOAC) extracts showed the most powerful scavenging activities against DPPH radicals. Among the other solvent extracts, the butanol extract seemed relatively more effective in scavenging activity, followed by chloroform, water and hexane extracts. Moreover, the highest reducing power and ferrous ion chelating activity were found in the EtOAC extract followed by other extracts of ginseng. EtOAC extracts, which exhibited the best antioxidant activities of all solvent extracts of ginseng, possessed higher concentrations of total phenolics (777.61 mg/100 g) than other extracts. These results suggest that EtOAC extracts of ginseng (P. ginseng C.A. Meyer) have the most effective antioxidant capacity compared to n-hexane, chloroform, n-butanol and water tested in this study, and has important applications for the pharmaceutical and food industries.

• Bulletin of the Korean Chemical Society
• /
• 제15권2호
• /
• pp.154-161
• /
• 1994

Studies have been conducted to explore single electron transfer (SET) induced photocyclization reactions of N-(trimethylsilylmethylthioalkyl)phthalimides (alkyl=ethyl, n-propyl, n-butyl, n-pentyl, and n-hexyl). Photocyclizations occur in methanol in modest to high yields to produce cyclized products in which phthalimide carbonyl carbon is bonded to the carbon of side chain in place of the trimethylsilyl group. Mechanism for these photocyclizations involving intramolecular SET from sulfur in the ${\alpha}$-silylmethylthioalkyl groups to the singlet excited state phthalimide moieties followed by desilylation of the intermediate ${\alpha}$ -silylmethylthio cation radicals and cyclization by radical coupling is proposed. In contrast, photoreactions of N-(trimethylsilylmethylthioalkyl)phthalimides in acetone follow different reaction routes to produce another cyclized products in which carbon-carbon bond formation takes place between the phthalimide carbonyl carbon and the carbon ${\alpha}$ to silicon and sulfur atoms via triplet carbonyl hydrogen abstraction pathway. The normal singlet SET pathway dominates this triplet process for photoreactions of these substances in methanol while the triplet process dominates the singlet SET pathway for those in acetone. The efficient and regioselective cyclization reactions observed for photolyses in methanol represent synthetically useful processes for construction of medium and large ring heterocyclic compounds.

• 대한화학회지
• /
• 제67권2호
• /
• pp.145-149
• /
• 2023

Talipariti hamabo is a plant growing around salt marshes in the Lava Coast region of Jeju Island, Korea. In this study, the extract of T. hamabo leaves was investigated for the anti-inflammatory, anti-oxidative and anti-bacterial activities and their active constituents were identified. In the anti-inflammatory tests using lipopolysaccharide-stimulated RAW264.7 cells, the ethyl acetate (EtOAc) fraction inhibited the nitric oxide production without causing cell toxicity. Moreover, the EtOAc fraction reduced pro-inflammatory cytokines (tumor necrosis factor-α, interleukin-6) as well as prostaglandin E₂. In the anti-oxidative studies with DPPH and ABTS⁺ radicals, potent scavenging activities were observed in the EtOAc and n-butanol fractions. Upon the anti-bacterial tests using Staphylococcus epidermidis, EtOAc and n-butanol fractions exhibited good activities. Through the phytochemical studies on EtOAc fraction, three components were isolated by repeated column chromatography; oleic acid (1), p-hydroxyphenethyl-trans-ferulate (2), nicotiflorine (3). Based on these results, the extract of T. hamabo leaves can be developed as natural resources for cosmetic applications.

• 대한화학회지
• /
• 제67권2호
• /
• pp.137-144
• /
• 2023

In this study were evaluated the whitening and anti-oxidative activities from the extracts of Sorbus alnifolia branches, and identified the chemical structures of the active ingredients. In the whitening tests using α-MSH stimulated B16F10 melanoma cells, the 70% ethanol extract and n-butanol (n-BuOH) fractions concentration-dependently inhibited cellular melanogenesis and intracellular tyrosinase activities without causing cell toxicity. The total polyphenol content of n-BuOH and ethyl acetate (EtOAc) fractions were measured to be respectively 241.1 ± 1.1 and 222.9 ± 2.4 (mg/g GAE), and the total flavonoid content of EtOAc fraction was 75.3 ± 2.0 (mg/g QE). Upon anti-oxidant studies with DPPH and ABTS⁺ radicals, potent radical scavenging activities were observed in the EtOAc and n-BuOH fractions. Moreover, in the study of cell protection efficacy using HaCaT keratinocytes damaged by H₂O₂, the EtOAc and n-BuOH fractions showed a very positive results on prevention of oxidative stress. Phytochemical studies for this extract resulted in the isolation of four compounds; 2-oxopomolic acid (1), euscaphic acid (2), epi-catechin (3), prunasin (4). These results suggested that the extract of S. alnifolia branches containing compounds 1-4 as natural ingredients could be used as whitening and anti-oxidant ingredients in cosmetic formulations.

• 한국자원식물학회:학술대회논문집
• /
• 한국자원식물학회 2022년도 추계학술대회
• /
• pp.108-108
• /
• 2022

Pine (Pinaceae family such as Pinus densiflora, P. rigida, and P.taeda) has been used as traditional medicine, its various parts (pine needle, bark, sap) have been used for hemostasis, bruises, and burns. These species were reported that have phenolics and flavonoids. We evaluated the anti-inflammation effects of PRT in lipopolysaccharide (LPS)-induced macrophages. These results showed that the ethyl acetate fraction of cone from Pinus rigida x P.taeda (ECRT) stabilized free radicals by reducing reactive oxygen species (ROS) and decreasing the production of nitric oxide (NO). ECRT decreased the expressions of nitric oxide synthase (iNOS) and cyclooxygenase (COX-2). In addition, ECRT significantly suppressed mRNA levels of inflammation-related factors such as cytokines, iNOS, and COX-2. As a result, ECRT was related to alleviating various pro-inflammatory mediators through IκB/NF-κB signaling pathways, including p65 translocation to the nucleus.

• 생명과학회지
• /
• 제22권9호
• /
• pp.1166-1172
• /
• 2012

비파 잎의 항산화 활성을 탐색하고 활성물질을 분리하여 규명하기 위하여, 동결 건조한 비파 잎을 마쇄하여 n-hexane, ethyl acetate (EtOAc)와 methanol (MeOH)로 용매 분획하였다. 각 추출물에 대하여 정량적으로 DPPH 소거활성, SOD 유사활성을 측정하고, 페놀 화합물과 플라보노이드 함량을 측정하였으며, 각 용매에 따른 추출물 중 비교적 활성이 강한 EtOAc 추출물과 MeOH 추출물에 대하여 column chromatography를 이용하여 얻은 분획물들 중 강한 활성을 보인 각 1개의 분획물에서 3개의 화합물을 분리하였으며, GC/MS 분석에서 phytol, ${\beta}$-sitosterol 및 (-)-Loliolide으로 동정하였다.

• 한국수산과학회지
• /
• 제48권4호
• /
• pp.439-446
• /
• 2015

Inflammation is a protective response to infection or injury. However, prolonged inflammation can contribute to the pathogenesis of many diseases, such as cancer, diabetes, arthritis, atherosclerosis, and Alzheimer's disease. Recent studies have shown that activated macrophages, inflammatory effector cells, can react to tissue insults in a polarized manner, in which their phenotypes are polarized into two major subtypes, categorized as M1 or M2. Classical M1 activation involves the production of pro-inflammatory cytokines, such as interleukin (IL)-6 and tumor necrosis factor (TNF)-${\alpha}$, and free radicals, while M2 or alternative activation is an anti-inflammatory phenotype involved in homeostatic processes, such as wound healing, debris scavenging, and the dampening of inflammation via the production of very low levels of pro-inflammatory cytokines and high levels of anti-inflammatory mediators, including IL-10. As part of our ongoing effort to isolate anti-inflammatory compounds from seaweeds, we investigated the effects of phlorotannins isolated from the brown alga Ecklonia stolonifera on macrophage polarization. Mouse peritoneal macrophages were treated with various concentrations of the extracts, and real-time RT-PCR analyses were performed to examine the expression of polarization markers: IL-$1{\beta}$, IL-6, and TNF-${\alpha}$ for M1 and arginase-1, peroxisome proliferator-activated receptor (PPAR)-${\gamma}$, found inflammatory zone-1 (Fizz-1), chitinase 3-like 3 (Ym1), and$Kr{\ddot{u}}ppel$-like factor 4 (Klf-4) for M2. The pretreatment of cells with eckol, dieckol, and phlorofucofuroeckol-A (PFF-A), isolated from the ethyl acetate fraction of E. stolonifera ethanolic extract, potentiated the anti-inflammatory M2 phenotype of the macrophages. These results indicate that phlorotannins derived from E. stolonifera can be used to enrich macrophages with markers of the M2 anti-inflammatory state.

• 생명과학회지
• /
• 제33권1호
• /
• pp.43-49
• /
• 2023

어성초(Houttuynia cordata)는 삼백초과(Saururacease)에 속하는 다년생 초본으로 잎, 줄기 및 뿌리의 전초를 약제로 사용하고 있으며, 민간에서는 혈행개선, 폐렴, 급만성기관지염, 장염, 요로감염증, 종기 치료에 주로 이용되고 있다. 최근에는 항산화, 항염증, 항균 및 암세포 성장억제, 간손상 및 신경세포 사멸 억제, 카드뮴 독성 감소효과 등이 보고되고 있다. 본 연구에서는 어성초 지상부의 에탄올 추출물 및 이의 헥센 분획물, 에틸아세테이트 분획물, 부탄올 분획물 및 물 잔류물을 조제하여 항혈전, 항당뇨, 항산화 및 적혈구용혈활성을 평가하였다. 어성초의 총 폴리페놀 및 총 플라보노이드 함량은 에틸아세테이트 분획물에서 가장 높았으며, 상기 분획물은 5 mg/ml 농도에서 용매 대조구보다 2.09배, 2.19배 및 1.69배 연장된 TT, PT, aPTT를 보여 강력한 항혈전 활성을 나타내었으며, DPPH, ABTS 및 nitrite radical에 대해 각각 30.9, 19.9 및 49.6 ㎍/ml의 RC50을 보여, 9.8, 5.2 및 11,8 ㎍/ml의 RC₅₀를 나타낸 vitamin C의 항산화력에 비교되었다. 트롬빈 저해활성이 강력한 헥센 분획물이 강력한 적혈구 용혈활성을 나타내는 바와 달리, 상기 에틸아세테이트 분획물은 1 mg/ml 농도까지 전혀 용혈활성이 나타나지 않았다. 본 연구결과는 어성초의 항혈전 활성에 대한 최초의 보고로, 어성초의 quercitirin, hyperoside, orientin 및 isoquercitrin이 항혈전 및 항산화 활성에 관련되어 제시하고 있으며, 향후 어성초를 이용한 기능성 항혈전 식품소재 개발 가능함을 제시하고 있다.