• 제목/요약/키워드: Acetyl radical

검색결과 49건 처리시간 0.03초

천연자원의 라디칼 소거능과 최종당화산물의 생성저해활성 검색 (Screening of Natural Resources with Inhibitory Activity on Free Radicals and Advanced Glycation end Products (AGEs) Formation)

  • 김민석;김동욱;류동영
    • 생약학회지
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    • 제37권4호
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    • pp.307-313
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    • 2006
  • Reactive oxygen species (ROS) and formation of advanced glycation end products (AGEs) play an important role in the pathogenesis of diabetic nephropathy by hyperglycemia. To find natural agents improving diabetic nephropathy, 63 natural resources which used to the treatment of diabetes mellitus in a folk remedy were investigated with an in vitro system employing radical scavenging activity and inhibitory activity of AGEs formation. In results, the extracts of Aspalathus linearis, Rubus coreanus, Rosa rugosa, and Epimedium koreanum significantly inhibited the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical with $IC_{50}$ values less than $10{\mu}g/ml$. The extracts of Zea mays, Cucurbita moschata, Cudrania tricuspidata, and Aspalathus linearis effectively reduced the formation of AGEs compared with the positive control $N-acetyl-_L-cystenine$ (NAC) and aminoguanidine (AG). In addition, the extracts of Aspalathus linearis, Commelina communis, Cornus officinalis, and Lespodeza cuneata showed the all inhibitory activity against DPPH radical and AGEs formation. Also, these resources definitely showed the radical scavenging activity against peroxynitrite $(ONOO^-)$ and hydroxyl radical $({\cdot}OH)$ relating to high glucose-induced ROS production. Thus, these results suggest that some natural resources may regulate the initiation and progression of diabetic nephropathy through inhibition of ROS production and AGEs formation.

광 알킬화 반응에 의한 Aspartylphenylalanyl Methyl Ester의 합성 (Photochemical Synthesis of Aspartylphenylalanyl Methyl Ester)

  • 심상철;채규호
    • 대한화학회지
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    • 제19권5호
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    • pp.367-374
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    • 1975
  • N-X-glycylphenylalanine methyl ester(X-trifluoroacetyl or acetyl)의 글리신잔기를 광 알킬화 반응에 의해 aspartic acid 의 유도체로 전환하였다. 이 반응은 diacetyl/di-t-butyl peroxide(DBP)를 광 개시제로, acetic anhydride를 알킬화제로 하여 350nm 파장의 램프를 사용하므로써 일어난다. DBP와 acetic anhydride에 의한 열반응의 경우에도 같은 알킬화 반응을 관찰하였다. 이 열알킬화 반응은 자유라디칼 반응을 거쳐 일어나기 때문에 이와 비교하여 광 알킬화 반응도 자유라디칼 메카니즘에 의해 일어난 것으로 추측된다.

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Synthesis and Biological Activity of Poly[(tri-O-acetyl-D-glucal)-alt-(maleic anhydride)] Derivatives

  • Han, Man-Jung;Lee, Choong-Whan;Kim, Ki-Ho;Lee, Won-Young
    • Bulletin of the Korean Chemical Society
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    • 제12권1호
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    • pp.85-87
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    • 1991
  • Poly[(tri-O-acetyl-D-glucal)-alt-(maleic anhydride)] was synthesized by free radical copolymerizations of the relevant comonomers. The alternating sequence of the copolymer was confirmed by $^1$H-NMR, elemental analysis, and titration of anhydride groups incorporated into the copolymer. Hydrolysis of the copolymer under different conditions resulted in poly[(2-acetoxymethyl-3,4-diacetoxytetrahydropyran-5,6-diyl) (1,2-dicarboxyethylene)] and poly[(2-hydroxymethyl-3,4-dihydroxytetrahydropyran-5,6-diyl) (1,2-dicarboxyethylene)]. The cytotoxicities of these polymers measured against normal and tumor cells (3LL, B16) in vitro were found to be higher than that of DIVEMA, a prototype polymer having a high antitumor activity.

정향(Eugenia caryophyllata Thunb.) Eugenol 및 그 유도체의 항산화 및 항염증활성 (Antioxidant and Anti-Inflammatory Activities of Eugenol and Its Derivatives from Clove (Eugenia caryophyllata Thunb.))

  • 임현희;김은옥;서미자;최상원
    • 한국식품영양과학회지
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    • 제40권10호
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    • pp.1361-1370
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    • 2011
  • 본 연구는 한방스킨의 원료로 널리 사용되고 있는 8가지 생약의 휘발성증류추출액 중 항산화 및 항염증활성이 가장 강한 정향의 증류추출액으로부터 주된 향기성분을 SDE법으로 추출한 후 GC-MS로 확인하였으며, 주된 향기성분인 eugenol과 그 유도체를 합성한 후 항산화 및 항염증활성을 측정하고 비교하였으며, 아울러 HPLC를 이용하여 정향의 eugenol 및 그 유도체를 정량분석 하였다. 8가지 생약의 휘발성증류추출액 중 정향의 증류추출액이 가장 강한 항산화활성($IC_{50}$=8.85 ${\mu}g/mL$) 및 COX-2 저해활성(10 ${\mu}g/mL$ 농도에서 저해율은 58.15%)을 나타내었으며, 반면 15-LOX 저해 활성(25 ${\mu}g/mL$ 농도에서 저해율은 86.15%)은 당귀 다음으로 가장 높았다. 정향 증류추출액의 휘발성 향기성분을 SDE법으로 추출한 후 GC-MS를 이용하여 분석한 결과, eugenol, trans-caryophyllene 및 acetyl eugenol을 확인하였다. 한편, eugenol 및 그 유도체(methyl eugenol 및 acetyl eugenol)의 항산화 및 항염증 활성을 측정한 결과, eugenol($IC_{50}$=5.99 ${\mu}g/mL$)이 가장 높은 항산화활성을 나타낸 반면, methyl eugenol 및 acetyl eugenol은 거의 활성을 나타내지 않았다. COX-2의 경우 20 ${\mu}g/mL$ 농도에서 eugenol(85.35%)이 가장 강한 저해활성을 나타낸 반면, 15-LOX는 20 ${\mu}g/mL$ 농도에서 methyl eugenol(83.29%)이 가장 높은 저해활성을 나타내었다. 정향 에탄올추출물의 eugenol 및 유도체의 함량을 HPLC로 분석한 결과, eugenol 및 acetyl eugenol이 각각 6.95%, 1.85% 함유되어 있었으며 methyl eugenol은 검출되지 않았다. 이와 같이 정향 유래의 eugenol 및 그 유도체는 안전성이 문제시되고 있는 합성항산화제 및 항염증제를 대체할 수 있는 천연 유래의 항산화 및 항염증물질로서 잠재적 가치가 있어 향후 기능성식품, 화장품 및 의약품 소재로 널리 사용될 수 있을 것으로 생각된다.

Biological Activity of Phenolic Compounds in Seeds and Leaves of Safflower (Carthamus tinctorius L.)

  • Lee, Won-Jung;Cho, Sung-Hee;Lee, Jun-Young;Park, Sang-Won
    • 한국식품저장유통학회:학술대회논문집
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    • 한국식품저장유통학회 2003년도 춘계총회 및 제22차 학술발표회
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    • pp.22-39
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    • 2003
  • Biological activity of phenolic compounds in seeds and leaves of safflower (Carthamu tinctorius L.) were evaluated using several in vitro and in vivo assays. Six phenolic constituents were isolated from the seeds and identified as N-feruloylserotonia, N- (p-coumaroyl)serotonin, matairesinol, 8′-hydroxyarctigenin, acacetin 7-O-$\beta$-D-glucoside (tilianine) and acacetin. Six phenolic compounds exhibited considerable antioxidative activity, and especially two serotonins showed potent DPPH radical scavenging activity and antiperoxidative activity against rat liver microsomal lipid peroxidation induced by the hydroxyl radical generated via a Fenton-type reaction. Additionally, six phenolic compounds possessed comparable cytotoxicity against three cancer cells, Hela cell, MCF-7 and HepG2 cell, and particularly acacetin and its glycosides had the most potent cytotoxicity. Moreover, we found that feeding safflower seeds attenuated bone loss, and lowered levels of plasma and liver lipids in ovariectomized rats. Serotonins, lignans and flavones stimulated proliferation of the osteoblast-like cells in a dose-dependent manner (10$^{-15}$ ~10$^{-6}$ M), as potently as E$_2$ (17$\beta$-estradiol). Particularly, serotonins were mainly responsible for bone-protecting and lipid lowering effects in ovariectomized rats. Meanwhile, eight flavonoids, including a novel quercetin-7-O-(6"-O-acetyl)-$\beta$-D-glucopyranoside and seven kown flavonoids, luteolin quercetin, luteolin 7-O-$\beta$-D-glucopyranoside, luteolin-7-O-(6"-O-acetyl)-$\beta$-D-gluco-pyranoside, quercetin 7-O- -glucopyranoside, acacetin 7-O-$\beta$-D-glucuronide and apigenin-6-C-$\beta$-D-glucopyranosyl-8-C-$\beta$-D-glucopyranoside were first isolated and identified from safflower leaf. Among these flavonoids, luteolin-acetyl-glucoside and $\beta$quercetin- acetyl-glucoside showed potent antioxidative activities against 2-deoxyribose degradation and lipid peroxidation in rat liver microsomes. Luteolin, quercetin and their corresponding glycosides also exhibited strong antioxidative activity, while acacetin glucuronide and apigenin-6, 8-di-C-glucoside were relatively less active. Finally, changes in phenolic compositions were also determined by HPLC in the safflower seed and leaf during growth stages and roasting process to produce standardized supplement powerds. These results suggest that phenolic compounds in the roasted safflower seed and leaf may be useful as potential sources of therapeutic agents against several pathological disorders such as carcinogenesis, atherosclerosis and osteoporosis.

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Free Radicals during the Oxidation and Reduction of Methylglyoxal-Modified Protein

  • Lee, Cheolju;Kang, Sa-Ouk
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 1997년도 학술발표회
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    • pp.36-36
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    • 1997
  • Protein glycation was studied with bovine serum albumin (BSA) as a model protein and methylglyoxal, a 3-carbon ${\alpha}$-ketoaldehyde. Methylglyoxal reacted with BSA, forming a radical as observed in the reaction of methylglyoxal wtih L-alanine or N-acetyl-L-lysine.(omitted)

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Oxidative Modification of Neurofilament-L Induced by Endogenous Neurotoxin, Salsolinol

  • Kang, Jung-Hoon
    • Bulletin of the Korean Chemical Society
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    • 제32권9호
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    • pp.3421-3424
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    • 2011
  • The endogenous neurotoxin, 1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (salsolinol), has been considered a potential causative factor for the pathogenesis of Parkinson's disease (PD). In this study, we examined oxidative modification of neurofilament-L (NF-L) induced by salsolinol. When disassembled NF-L was incubated with salsolinol, the aggregation of protein was increased with the concentration of sasolinol. The formation of carbonyl compound was obtained in salsolinol-mediated NF-L aggregates. This process was protected by free radical scavengers, such as N-acetyl-L-cysteine and glutathione. These results suggest that the aggregation of NF-L is mediated by salsolinol via the generation of free radicals. We also investigated the effects of copper ion on salsolinol-mediated NF-L modification. In the presence of copper ions, salsolinol enhanced the modification of NF-L. We suggest that salsolinol might be related to abnormal aggregation of NF-L which may be involved in the pathogenesis of neurodegenerative diseases and related disorders.

Aggregation of α-Synuclein Induced by Oxidized Catecholamines as a Potential Mechanism of Lewy Body

  • Kim, Kyung-Sik;Kang, Jung-Hoon
    • Bulletin of the Korean Chemical Society
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    • 제26권8호
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    • pp.1255-1259
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    • 2005
  • Lewy bodies (LBs) are neuronal inclusions that are closely related to Parkinson's disease (PD). The filamentous component of LB from patients with PD contains biochemically altered $\alpha$-synuclein. We have investigated the effect of the oxidized products of catecholamines on the modification of $\alpha$-synuclein. When $\alpha$-synuclein was incubated with the oxidized 3,4-dihydroxyphenylalanine (L-DOPA) or dopamine, the protein was induced to be aggregated. The oxidized catecholamine-mediated $\alpha$-synuclein aggregation was enhanced by copper ion. Radical scavengers, azide and N-acetyl cysteine significantly prevented the oxidized catecholamine-mediated $\alpha$-synuclein aggregation. The results suggest that free radical may play a role in $\alpha$-synuclein aggregation. Exposure of $\alpha$-synuclein to the oxidized products of catecholamines led to the formation of dityrosine. Antioxidant dipeptides carnosine, homocarnosine and anserine significantly protected $\alpha$-synuclein from the aggregation induced by the oxidized products of catecholamines.

Jacaranone and Related Compounds from the Fresh Fruits of Ternstroemia japonica and their Antioxidative Activity

  • Jo Youngmi;Suh Jiyoung;Shin Myoung Hee;Jung Jee H.;Im Kwang Sik
    • Archives of Pharmacal Research
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    • 제28권8호
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    • pp.885-888
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    • 2005
  • Jacaranone and related compounds (1-3) were isolated, along with three triterpenes (4-6), from the fresh fruits of Ternstroemia japonica. The compounds were identified as jacaranone (1), 3-hydroxy-2,3-dihydrojacaranone (2), 3-methoxy-2,3-dihydrojacaranone (3), 3-O-acetyl­oleanolic acid (4), 3-O-acetylursolic acid (5), and ursolic acid (6). Jacaranone and its derivatives were isolated for the first time from Theaceae. Of the isolated compounds, compound 3 is a new compound. Jacaranone (1) exhibited weak antioxidative effect on 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) radical.

Simplified the Screening and In Vitro Appraisal of Antioxidant, Cytotoxic, Thrombolytic, Antimicrobial and Membrane Stabilizing Activities of Lablab Purpures at a Time

  • Rahman, M. Saifur;Uddin, M. Gias;Alam, M. Badrul;Yoo, Jin Cheol
    • 통합자연과학논문집
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    • 제7권3호
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    • pp.173-182
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    • 2014
  • To simplify the different biological investigation of the methanolic extract and solvent-solvent partitioning of Lablab purpures (L. purpures) bark. In-vitro anti-oxidant study was determined using total DPPH radical scavenging assay. In vitro antimicrobial study was measured by observing zone of inhibition. The cytotoxic activity was studied using brine shrimp lethality bioassay and thrombolytic activity by clot disruption method. The antioxidant potential was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and Folin-Ciocalteau reagents using butylated hydroxytolune (BHT) and ascorbic acid as standards. The Aqueous soluble fraction revealed the highest free radical scavenging activity ($IC_{50}=48.76{\mu}g/mL$). The antimicrobial screening of the bark of L. purpures exhibited mild to moderate activity in test microorganisms. The CSF showed the maximum relative percentage inhibition against Salmonella parathyphi (34.2%) for bacteria and C. albicans (28.8%) for fungi whereas, lowest relative percentage inhibition against Sarcina lutea (22.0%) for bacteria and Aspergillus niger (24.4%) for fungi. In the brine shrimp lethality bioassay, The $LC_{50}$ values of Carbon tetrachloride and N-Hexane soluble fraction were found $92.18{\mu}g/mL$, and $68.95{\mu}g/mL$ respectively while the $LC_{50}$ values of standard Vincristine sulphate was $1.37{\mu}g/mL$. The methanolic extract and its organic soluble fractions of Lablab purpureus at concentration 2.0 mg/mL, significantly protected the lysis of erythrocyte membrane induced by hypotonic solution and heat as compared to the standard, acetyl salicylic acid (0.10 mg/mL). The MSF and AQSF produced 61.48 % and 53.75% inhibition of hemolysis of RBC caused by hypotonic solution respectively, whereas acetyl salicylic acid (0.10 mg/mL) showed 76.42%. Ethanol extract of L. purpures and all of its different partitions exhibited moderate thrombolytic activity of 37.25%-2.40%. Very good preliminary screening and simplified experiments were able to show the different biological activity of methanolic extract and its soluble fractions of L. purpures at a time.