• 대한화학회지
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• 제57권2호
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• pp.246-251
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• 2013

With -$OCH_2CO$- as a linker, a non ${\beta}$-substituted cationic bisporphyrin (4a) and a ${\beta}$-substituted cationic bisporphyrin (4b) were prepared through methylation of the intermediate which was obtained from ${\beta}$-amino-5,10,15,20-tetra (4-cyanophenyl) porphyrin or 5-hydroxylphenyl-10,15,20-tris(4-cyanophenyl) reacting with 5-hydroxy-10,15,20-trispyridinylporphyrin. Their structures were confirmed by $^1H$ NMR, IR, UV-vis, MS and elemental analysis. DNA photocleavage ability and the singlet oxygen ability of those cationic bisporphyrins were investigated. DNA photocleavage activity of ${\beta}$-substituted cationic bisporphyrin was significantly weaker than that of $H_2TMPyP$, but similar to that of non ${\beta}$-substituted cationic bisporphyrin. While 4a and 4b showed substantial photocleavage activities toward DNA, with 68% and 66% observed at 10 ${\mu}M$. The assessment of indirectly measured $^1O_2$ production rates against $H_2TMPyP$ were described and the relative singlet oxygen production yields were: free cationic bisporphyrins > $H_2TMPyP$. The results showed the cationic bisporphyrins with ${\beta}$-substitution and non ${\beta}$-substitution could be developed as potential photodynamic agents.

• Bulletin of the Korean Chemical Society
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• 제14권1호
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• pp.107-109
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• 1993

Non-enzymatic glycosylation and fragmentation of collagen molecule were investigated by irradiating Ultraviolet A(UV-A) with or without scavengers of reactive oxygen species (ROS) in the presence of glucose. Non-enzymatic glycosylation was increased by UV-A at high concentration of glucose. It was reduced in the presence of the scavengers of superoxide radical and singlet oxygen, but not reduced in the presence of hydroxy radical scavenger. Fragmentation of collagen was increased by UV-A, but it was decreased in the presence of all ROS scavengers tested. Superoxide radical and singlet oxygen produced by autoxidation of glucose without UV-A may encounter the initial phase of glycosylation. Data presented here suggest that UV-A affects only on the fragmentation process, but all ROS except hydroxy radical act on both processes. It appears that hydroxy radical does not act on the glycosylation process.

• Journal of Photoscience
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• 제9권2호
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• pp.412-414
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• 2002

Several peroxovanadium(V) complexes with an organic chelate ligand decompose spontaneously, depending on the nature of the chelate ligand. The self-decomposition reactions of the dinuclear peroxovanadium(V) complex with 2-oxo-l,3-diaminopropane-N,N,N',N'-tetraacetate (dpot) and the peroxovanadium(V) complexes with N-carboxymethylhistidinate (cmhist) and histamine-N,N-diacetate (histada) accompany the reduction of vanadium(V) to vanadium(IV). This implies that the peroxide anion acts as a reducing agent and thus the peroxide is oxidized in the decomposition process of the peroxovanadium(V) complexes. The oxidized dioxygen species have been characterized spectrophotometrically. Superoxide anion has been detected in 2-3 % yields using the reduction of cytochrome c method and chemiluminescence method utilized MCLA as a fluorescer. Singlet oxygen has also been detected in higher yields on the basis of chemiluminescence of tryptophan.

• Bulletin of the Korean Chemical Society
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• 제33권5호
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• pp.1608-1612
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• 2012

Singlet oxygen ($^1O_2$) is an important species for oxidation in biological processes. $^1O_2$ is implicated in the genotoxic effect, and plays an important role in the cell-signaling cascade and in the induction of gene expression. However, the rapid detection of $^1O_2$ in biological environments with sufficient specificity and sensitivity is hampered by its extremely low emission probability. Here, a layer-by-layer (LbL) film of CdTe quantum dots (QDs), polymers, and ascorbate have been designed as a rapid, highly selective, and sensitive fluorescence probe for $^1O_2$ detection. Upon reaction with $^1O_2$, the probe exhibits a strong photoluminescence (PL) response even at trace levels. This remarkable PL change should enable the probe to be used for $^1O_2$ detection in many chemical and biological systems and as an environmental sensor.

• Journal of Ginseng Research
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• 제14권2호
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• pp.191-199
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• 1990

It has been well known that extended exposure to reactive oxygens causes severe damage to susceptible biomolecules. In this study, the effects of flavonoids including trifolin and kaempferol from Ginseng leaves on singlet oxygen induced photohemolysis of erythrocytes and free radical scavenging activities were investigated. Each flavonoid aglycone (5-50$\mu$M) such as kaempferol, quercetin or baicalein exhibited a high protective effect against the photohemolysis. They protected the cells by scavenging $^1O_2$ and free radicals Although the free radical scavenging activities of the flavonoid glycosides were not much lower than those of their corresponding aglycones, their insolubility into lipid bilayers of membrane made them less effective in preventing the photohemolysis induced by $^1O_2$. The $^1O_2$ and free radical scavenging activities of flavonoids were estimated by the decomposition of the flavonoid by $^1O_2$ and the bleaching of free radicals by the flavonoid, respectively. The solubilization of the flavonoid into micells or erythrocytes was deduced from spectrophotometric and microscopic observations. The cooperation of L-ascorbic acid and a flavonoid, and a possible involvement of lipoxygenase or cyclooxygenase in the photohemolysis mechanism were discussed.

• 농약과학회지
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• 제15권2호
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• pp.87-96
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• 2011

광학 살충활성 연구를 위하여 H, 4'-methoxy phenoxy 및 4'-tert butyl phenoxy의 치환기가 도입된 3가지 구조의 dihydroxyl phoshorus triazatetrabenzocorrole 유도체를 합성하였다. 도입된 치환체에 따른 바닥상태의 흡광도와 aggregation 유무를 확인하였으며, 빛에 의해 singlet oxygen을 생성하는 것을 확인하였다. 이를 토대로 아메리카잎굴파리를 대상으로 광학 살충 활성 시험을 실시한 결과 500 ppm의 농도에서 전체적으로 100~85.7%의 방제가를 나타내었으며, 특히 H로 치환된 dihydroxy1 phosphorus(V) triazateterabenzocorrole은 100%의 살충활성을 보였다.

• 대한화장품학회지
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• 제13권1호
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• pp.45-71
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• 1987

${\beta}$-Carotene has been known as an effective quenching agent of singlet oxygen and the carotenoid pigments in general are expected to protect cells against photosensitized oxidations. We are determined the quenching rate constants of several Ketocarotenoids including capsanthin, capsanthin diester, astaxanthin and fucoxanthin, and the relative quenching actiyities against singlet oxygen were compared with those of ${\beta}$-carotene and reported carotenoids. Nevertheless the ketocarotenoids exhibited lower quenching rate constants than ${\beta}$-carotene, they showed more pronounced protective activitives than ${\beta}$-carotene against photohemlysis induced by singlet oxygen. Among the ketocarotenoids investigated, fucoxanthin indicated a significant protective activity for the cell. The results suggested that. 1) 1O2 may be alikely initiator of photohemolysis, but this reaction is followed by slow dark reactions involving secondary reactive species. 2) For protection of RBC against photodynamic action with carotenoids, carotenoids having functional groups such as -C=0 and -OH groups are most efficient. This suggests that partition of carotenoids between the buck and the mombrane and/or their specific binding to membrane proteins are more critical for the photo-protection by carotenoids than is a diffusional quenching of 1O2.

• Journal of Plant Biotechnology
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• 제49권3호
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• pp.257-270
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• 2022

The aim of this work was to prepare a new biodegradable polyhydroxybutyrate (PHB) submicron fiber mat loaded with hypericin-rich Hypericum perforatum raw extract by centrifugal spinning technology, an alternative approach to the traditional method of electrospinning to fabricate nanofibers or microfibers from solutions at high speed and low cost. Hypericins in methanol/acetone extract of H. perforatum were determined by UHPLC-MS/MS and HPLC/PDA. Submicron fiber mats composed of pure PHB or PHB enriched with H. perforatum extract were prepared using a pilot plant demonstrator for the centrifugal spinning technology and characterized by SEM. Singlet oxygen production was quantified by the 1,3-diphenylisobenzofuran (DPIBF) method in hexane. The results proved a significant production of singlet oxygen by the prepared submicron fiber mat. We also found a significant antibacterial activity against the bacterial strain Escherichia coli CCM 5417 by a method in accordance with JIS Z 2801/ISO 22196 standards. The H. perforatum extract-enriched PHB submicron fiber mats showed potential for the development of self-cleaning and antimicrobial air filters.

• 한국식품저장유통학회지
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• 제23권3호
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• pp.387-392
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• 2016

이 연구의 목적은 이종산업인 섬유산업에서 사용되고 있는 천연염색의 원료인 천연염료의 항산화 활성을 확인하는 것으로 이를 위해 총 페놀 함량 분석, DPPH 라디칼소거능, ABTS 라디칼 소거능 및 단일항산소 억제 효과를 분석하였다. 7종의 천연염료 열수추출물에서 DPPH 라디칼 소거 활성을 나타내는 $IC_{50}$ 값은 0.012~0.239 mg/mL를 나타내어 일부 색소 추출물의 DPPH 소거 활성이 우수하다는 것을 알 수 있었다. 특히 폴리페놀함량이 높은 자단향과 아선약 추출물의 $IC_{50}$ 값이 각각 $12.4{\mu}g/mL$, $24.2{\mu}g/mL$로 높은 DPPH 라디칼 소거 활성을 확인하였다. 단일항산소 억제 효과 역시 아선약, 자단향 추출물에서 각각 0.19, 0.21 mg/mL을 나타내어 높은 소거 활성을 띄는 것으로 강한 빛에 의해 야기되는 단일항산소(singlet oxygen)를 억제할 수 있는 것을 알 수 있었다. 총 페놀 함량도 열수추출물에서 높은 수준을 나타내었다. 반면, 플로라워터의 항산화 활성은 열수추출물 대비 미비한 효과를 보였으나 한련초의 경우 열수추출물 보다 우수한 결과를 나타내었다. 플로라워터의 경우 액상시료를 첨가하여 수행되는 실험 방법에 의해 정량적 수치를 명확히 나타내기 어렵기 때문에 연구 방법적 측면에서 개선이 필요할 것으로 판단된다. 결론적으로 일부 천연색소 추출물은 생물체의 산화적 스트레스로부터 야기되는 활성산소를 억제하는 중요한 역할을 하며, 보다 심도 깊은 연구를 진행한다면 새로운 생물 소재로 활용성이 높을 것으로 사료된다.

• 대한환경공학회지
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• 제35권2호
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• pp.124-130
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• 2013

모든 브롬화난연제 중 가장 많이 사용되고 있는 것은 TBBPA이다(상용화되고 있는 브롬화난연제물질 중 50%를 차지). TBBPA는 환경 중에서 유해하기 때문에 환경 중에서의 그들의 분해반응기전에 대한 연구가 흥미롭다. 본 연구에서는 UV-A (${\lambda}=352nm$) 조사에 의한 TBBPA의 광분해반응속도가 조사세기 의존적으로 증가하였다. 또한 TBBPA의 광분해반응에 의해서 2,6-dibromo-p-benzosemiquinone radical ($a_{2H}=2.36G$, g = 2.0056)이 생성되고 그 생성반응에 singlet oxygen ($^1O_2$)이 주요 반응 인자로서 영향을 미치는 것으로 나타났다. 한편, HA와 TBBPA의 혼합용액을 광조사하면 semiquinone radical의 전형적인 ESR 스펙트럼이 생성되었다. 그리고 HA는 TBBPA의 광분해반응속도를 농도의존적으로 감소시키는 것으로 나타났다. 또한 라디칼 생성과 광분해반응속도는 singlet oxygen ($^1O_2$) 소거제인 sodium azide를 주입하면 감소되었다. 이러한 결과로부터, UV-A 조사에 의한 HA와 $^1O_2$의 반응속도는 TBBPA와 $^1O_2$의 것보다 더 빠르다는 것을 제시한다.