• Food Science and Biotechnology
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• 제14권3호
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• pp.424-427
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• 2005

The cleavage products formed by the autoxidation of phytofluene were evaluated in order to elucidate possible oxidation products of phytofluene in the oxidative condition. Among a number of oxidation products formed, the following five in the carbonyl compound fraction were identified: 6, 10, 14-trimethylpentadeca-3,5,9,13-tetraen-2-one, phytapentaenal, 5,9,13,17-tetramethyloctadeca-2,4,6,8,12,16-hexaenal, 5,9,13,17-tetramethyloctadeca-2,4,8,12, 16-pentaenal, 2,7,11,15,19-pentamethylicosa-2,4,6,10,14,18-hexaenal and 4,9,13,17,21-pentamethyldocosa-2,4,6,8,12,16,20-heptaenal. In addition, 4,5-didehydrogeranyl geranoic acid was formed by the autoxidation of phytofluene in liposomal suspension. The pig liver homogenate was able to convert phytapentaenal to 4,5-didehydrogeranyl geranoic acid, in a manner comparable to the conversion of all-trans-retinal to all-trans-retinoic acid. These results suggest firstly that phytofluene is cleaved into a series of long-chain and short-chain carbonyl compounds under the oxidative condition in vitro and secondly that phytapentaenal is further enzymatically converted to 4,5-didehydrogeranyl geranoic acid.

• 한국식품과학회지
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• 제32권6호
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• pp.1227-1233
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• 2000

Lycopene을 dichloromethan에 용해하고 dry ice 상에서 ozonolysis을 행하였다. Ozonolysis에 의해 생성된 산화개열산물은 silica gel chromatography를 행하여 분획하고, photodiode array detector를 이용하여 ODS-HPLC와 LC-MS를 이용하여 분석하였다. Lycopene으로부터 생성된 carbonyl 화합물로 acycloretinal, apo-14'-lycopenal, apo-12'-lycopenal, apo-10'-lycopenal, apo-8'-lycopenal 그리고 apo-6'-lycopenal이 동정되었다. Lycopene을 toluene 및 Tween 40 수용액에 용해하고 $37^{\circ}C$에서 자동산화시킨 결과, 다수의 carbonyl 화합물이 생성되었다. Lycopene의 자동산화에 의해 생성된 carbonyl 화합물의 대부분은 ozonolysis에 얻어진 산화개열산물이 나타내는 HPLC상의 거동과 분광학적 특성이 서로 잘 일치하였다. 이러한 결과는 in vitro 상의 산화적 조건하에서 lycopene 자동산화에 의해 eccentric cleavage가 생성됨을 알 수 있었다.

• Preventive Nutrition and Food Science
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• 제5권4호
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• pp.234-238
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• 2000

The cleavage products formed by autoxidation of phytofluene were evaluated in order to elucidate possible oxidation products of phytofluene under oxidative conditions. Phytofluene solubilized at 50$\mu$M in liposomal suspension was oxidized by incubating at 37$^{\circ}C$ for 72 h. Among a number of oxidation products formed, five products in the carbonyl compound fraction were identified as 6, 10, 14-trimethylpentadeca-3,5,9,13-tetraen-2-one, phytapentaenal, 5,9,13,17-tetramethyloctadeca-2,4,6,8,12,16-hexaenal, 5,9,13,17-tetramethyloctadeca-2,4,8,12,16-pentaenal, 2,7,11,15,19-pentamethylicosa-2,4,6,10,14,18-hexaenal and 4,9,13,17,21-pentamethyldocosa-2,4,6,8,12,16,20-heptaenal. These correspond to a series of products formed by cleavage in the respective eight conjugated double bonds of phytofluene. Also, 4,5-didehydorgeranyl geranoic acid was formed by autoxidation of phytofluene in liposomal suspension. The pig liver homogenate had the ability to convert phytapentaenal to 4,5-didehydrogeranyl geranoic acid, comparable to the conversion of all-trans-retinal to all-trans-retinoic acid. These results suggest that phytofluene is cleaved to a series of long-chain and short-chain carbonyl compounds under the oxidative condition in vitro and that phytapentaenal is further enzymatically converted to 4,5-didehydrogeranyl geranoic acid.

• 한국식품영양과학회지
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• 제29권4호
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• pp.568-574
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• 2000

Phytofluene를 dichloromethane에 용해하고 dry ice 상에서 ozonolysis를 행하였다. Ozonolysis에 의해 생성된 화합물은 silica gel chromatography를 행 하여 분획하고, photodiode array detector를 이용하여 ODS-HPLC로 분석하였다. Phytofluene을 5% Tween 40 수용액에 용해하고 37$^{\circ}C$, 24시간 자동산화시킨 결과, 다수의 carbonyl 및 acidic 화합물의 생성되었다. Phytofluene의 자동산화로부터 생성된 carbonyl 화 합물의 대부분은 ozonolysis에 얻어진 산화개열산물이 나타내는 HPLC상의 거동과 분광학적 특성이 서로 잘 일치하였다. 또한 phytofluene의 자동산화에 의해 생성된 중앙개열 acidic 화합물은 생성활성을 나타내는 4,5-didehydrogeranyl geranyl acid 표준품과 동일한 분광학 적 특성을 나타냈다. 이러한 결과는 in vitro 상의 산화적 조건하에서 phytofluene의 자동산 화에 의해 eccentric cleavage가 생성됨을 알 수 있었다.

• 한국식품과학회지
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• 제32권5호
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• pp.985-990
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• 2000

${\zeta}-Carotene$를 dichloromethane에 용해하고 dry ice 상에서 ozonolysis을 행하였다. Ozonolysis에 의해 생성된 화합물은 silica gel chromatography를 행하여 분획하고, photodiode array detector를 이용하여 ODS-HPLC로 분석하였다. Toluene에 ${\zeta}-carotene$을 용해하고 $37^{\circ}C$, 72시간 자동산화시킨 결과, 다수의 carbonyl 및 acidic화합물이 생성되었다. ${\zeta}-Carotene$의 자동산화로부터 생성된 carbonyl 화합물의 대부분은 ozonolysis에 의하여 얻어진 산화개열산물이 나타내는 HPLC상의 거동과 분광학적 특성이 서로 잘 일치하였다. 또한 ${\zeta}-carotene$의 자동산화에 의해 생성된 중앙개열 acidic 화합물은 생물활성을 나타내는 4,5-didehydrogeranyl geranyl acid 표준품과 동일한 분광학적 특성을 나타냈다. 이러한 결과는 in vitro상의 산화적 조건하에서 ${\zeta}-carotene$ 자동산화에 의해 eccentric cleavage가 생성됨을 알 수 있었다.

• BMB Reports
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• 제46권4호
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• pp.225-229
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• 2013

Methylglyoxal (MG) is an endogenous metabolite which is present in increased concentrations in diabetics and reacts with amino acids to form advanced glycation end products. In this study, we investigated whether ferritin enhances DNA cleavage by the reaction of MG with lysine. When plasmid DNA was incubated with MG and lysine in the presence of ferritin, DNA strand breakage was increased in a dose-dependent manner. The ferritin/MG/lysine system-mediated DNA cleavage was significantly inhibited by reactive oxygen species (ROS) scavengers. These results indicated that ROS might participate in the ferritin/MG/lysine system-mediated DNA cleavage. Incubation of ferritin with MG and lysine resulted in a time-dependent release of iron ions from the protein molecules. Our data suggest that DNA cleavage caused by the ferritin/MG/lysine system via the generation of ROS by the Fenton-like reaction of free iron ions released from oxidatively damaged ferritin.

• Journal of the Korean Wood Science and Technology
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• 제31권3호
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• pp.11-16
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• 2003

On nitrobenzene oxidation of aspen, spruce, and knauf wood meals gave rise to vanilline, syrigaldehyde, p-hydroxybenzoaldehyde, vanillic acid, and other minor oxidation products. The phenolic aldehydes (p-hydroxybenzaldehyde, vanilline, and syringaldehyde) are derived from oxidative degradation of the corresponding 4-hydroxyphenylpropane units and their ethers. The lignin content of knauf wood meals was different as the concentration of NaOH solution and cooking temperature. The lignin contents of aspen, spruce, and knauf wood meals were decreased as laccase treatment. The laccase caused C-oxidation, demethylation, cleavage in phenolic groups and C-C cleavage in syrigyl structures.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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• pp.67-67
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• 2003

Minocycline is known to protect neurons from microglia-mediated cell death in many experimental models of brain diseases including ischemic stroke, Huntingtons disease (HD), amyotrophic lateral sclerosis (ALS), traumatic brain injury, multiple sclerosis, and Parkinsons disease. When the activity of caspases was assessed using their fluorescent peptide substrates, activation of caspase-2, 3, 8, and 9 was evident within 2 8 hr following oxidative insult with 0.5 mM hydrogen peroxide in PC12 cells. Minocycline significantly attenuated activation of these caspases up to 18 hr, resulting a significant increase in the cell viability as assessed by MTT assay as well as trypan blue staining. However, cleavage of alpha-spectrin and a cdk5 activator p35, which are known to be substrates for calpain, remained unchanged in the presence of minocycline, suggesting that minocycline did not block caspase-3-independent cell death or necrosis. Moreover, co-treatment with minocycline and a calpain inhibitor calpeptin synergistically inhibited hydrogen peroxide-induced cell death. These data suggest that minocycline directly inhibited apoptosis, but not necrosis, after oxidative insult in PC12 cells.

• 한국식품영양과학회지
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• 제33권5호
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• pp.847-851
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• 2004

미역의 부위별 fucoxantin함량은 미역엽 87.6 mg/100g, 미역줄기에 62.4 mg/100 g그리고 미역귀에 127.7 mg/100 g를 나타내어 미역귀에 함유되어 있는 fucoxanthin함량이 미역엽에 비해 1.4배, 미역줄기에 비해 2.0배 더 함유되어 있는 것으로 나타났다. Fucoxanthin은 444 nm에서 최대흡수극대를 나타내는 전형적인 carotenoids의 분광학적 특성을 나타냈다. 미역에 존재하는 fucoxanthin은 용매 분획, silica gel column chromatography와 HPLC를 이용하여 분리 정제하고, 얻어진 fucoxanthin을 인공생체막인 인지질에서의 자동산화에 이용하였다 인지질에서 50 $\mu$M fucoxanthin을 37$^{\circ}C$에서 72시간 자동산화시킨 결과, 5개의 산화물이 생성되었다. 이러한 산화물은 in uitro상의 산화적 조건하에서 fucoxanthin자동산화에 의해 생성된 산화개열산물로 생각되었다.

• Archives of Pharmacal Research
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• 제24권5호
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• pp.446-454
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• 2001

Peptide fragments, isolated from proteolytic cleavage of thyroglobulin at specific sites, were examined for the iodination of tyrosine residues. The 50 kDa polypeptide, which was prepared from digestion of bovine thyroglobulin and continuous preparative SDS-PAGE, was subjected to reduction with DTT and alkylation with iodoacetic acid to generate S-car-boxymethylated peptide derivative, which was further hydrohysed by endoproteinase-Asp-N. Peptide products were separated by RP-HPLC, and each fraction was analyzed by LC/ESI-MS and MALDI-MS analyses. Based on the specificity of endoproteinase-Asp-N andthe mass spectra data, a peptide fragment turned out to correspond to a peptide, DALCCVKCPEGSYFQ (1438-1452), characterized by the presence of a thioredoxin box (CVKC) and a tyrosine residue. In addition, another peptide fragment (1453-1465) containing a thioredoxin box (CIPC) and a tyrosine residue was also observed. However, any evidence of iodination of the tyrosine residue present in these peptides was not provided. Meanwhile, tyrosine residues in the peptides, DVEEALAGKYLAGRFA (1366-1381) and DYSGLLLAFQVFLL (1290-1303) were found to be iodinated; mono- or diiodinated tyrosine residues, characteristic of a hormogenic site, existed in both peptides. In addition, the tyrosine residue in the peptide (1218-1252), corresponding to a hormonogenic site was also iodinated. Thus, there was a sharp difference of the susceptibility to oxidative iodination between the tyrosine residue in a hormonogenic site and that in a thioredoxin region. From these results, it is suggested that polypeptide region adjacent to tyrosine residues may govern the susceptibility of tyrosine to oxidative iodination.