• Journal of the Korean Chemical Society
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• v.45 no.5
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• pp.500-504
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• 2001

• Journal of the Korean Chemical Society
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• v.45 no.3
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• pp.274-276
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• 2001

• Bulletin of the Korean Chemical Society
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• v.25 no.8
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• pp.1117-1118
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• 2004

• Journal of the Korean Chemical Society
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• v.29 no.3
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• pp.328-331
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• 1985

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.231.1-231.1
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• 2000

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.387-392
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• 2012

A series of Pd-based catalysts were prepared and examined for the amination of 2,6-dimethylphenol in a fixedbed reactor. The best results were obtained for Pd/$Al_2O_3$-BaO with a conversion of 99.89% and a selectivity of 91.16%. These catalysts were characterized using BET, XRD, XPS, TEM and $NH_3$-TPD. Doped BaO not only improved the dispersion of the Pd particles but also decreased the acidity of the catalyst, which remarkably enhanced the selectivity and stability of the catalyst. The generality of Pd/$Al_2O_3$-BaO for this kind of reaction was demonstrated by catalytic aminations of o- and p-alkyl phenols.

• Food Science and Preservation
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• v.4 no.3
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• pp.323-330
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• 1997

Changes in antioxidative substance levels in eleven different cultivars of persimmon leaves during growth were investigated. In general, the contents of soluble phenols, L-ascorbic acid and flavonoids in astringent persimmon leaves(APL) were higher than those of nonastringent persimmon leaves(NAPL). The soluble phenol contents in APL and NAPL showed a tendency to decrease throughout leaf growth. L-ascorbic acid content in APL decreased rapidly during growth, whereas its content in NAPL reached its highest value at the late of July, and then decreased rapidly. Major flavonoids in APL and NAPL were quercetin and Kaempferol which were present in conjugate forms. Before acid hydrolysis, the contents of kaempferol and quercetin in APL and NAPL remained at a relatively constant level until the late of July, and then decreased slightly. After acid hydrolysis, kaempferol contents in APL and NAPL varied significantly by cultivar and growth stage, while quercetin contents decreased slowly until the late of July, and then increased drastically, reached a maximum at the early of August, afterward continuously decreased. These results suggest that APL harvested at the early of June may be useful as potential sources of natural antioxidants.

• Elastomers and Composites
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• v.14 no.2
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• pp.83-102
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• 1979

The purpose of this dissertation is to study some of the vulcanization characteristics of rubber-bound antioxidants such as G-1, [N-(3-methacryloyloxy-2-hydroxypropyl)-N'-phenyl-p-phenylene diamine] and acryl, acrylamide & acrylester substituted hindered phenols. The influence of these antioxidants upon vulcanization characteristics in NR and SBR compounds in the presence of vulcanizing accelerators such as MSA, TT, DM, M & D was evaluated by means of Oscillationg Disk Cure Meter. The comparison was also made between the influence of rubber-bound antioxidants and that of conventional non-reactive antioxidants such as N-alkyl substituted PADA series. Regarding the influence of reactive type antioxidant G-1 mixed with accelerator TT upon vulcanization characteristics, rapid onset of vulcanization and higher degree of cross-linking were discovered, whereas in the case of accelerator M and DM, the result was slow onset of vulcanization and lesser degree of cross-linking. The comparison of vulcanizing characteristics among acrylic substituted hindered phenols as antioxidants was made under several vulcanization accelerator systems. Under such systems, MSA-S combined accelerator caused the onset of vulcanization to slow down and lowered the degree of cross-linking. Finally in the case of hindered phenol derivatives containing longer substituent, the delayed onset of vulcanization and the lowered degree of cross-linking could be discerned.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.9
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• pp.1362-1370
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• 2015

This study was performed to investigate the effect of different levels of dietary crude protein (CP) on composition of odorous compounds and bacterial communities in pig manure. A total of 48 male pigs (average initial body weight 45 kg) fed diets containing three levels of dietary CP (20%, 17.5%, and 15%) and their slurry samples were collected from the pits under the floor every week for one month. Changes in composition of odorous compounds and bacterial communities were analyzed by gas chromatography and 454 FLX titanium pyrosequencing systems, respectively. Levels of phenols, indoles, short chain fatty acid and branched chain fatty acid were lowest (p<0.05) in CP 15% group among three CP levels. Relative abundance of Bacteroidetes phylum and bacterial genera including Leuconostoc, Bacillus, Atopostipes, Peptonphilus, Ruminococcaceae_uc, Bacteroides, and Pseudomonas was lower (p<0.05) in CP 15% than in CP 20% group. There was a positive correlation (p<0.05) between odorous compounds and bacterial genera: phenol, indole, iso-butyric acid, and iso-valeric acid with Atopostipes, p-cresol and skatole with Bacteroides, acetic acid and butyric acid with AM982595_g of Porphyromonadaceae family, and propionic acid with Tissierella. Taken together, administration of 15% CP showed less production of odorous compounds than 20% CP group and this result might be associated with the changes in bacterial communities especially whose roles in protein metabolism.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.3
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• pp.537-542
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• 1998

The present study was performed to elucidate desmutagenic principles from Ecklonia stolonifera extracts against 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine(PhIP) and 2-amino-3,8-dime-thylimidazo[4,5-f]duinoxaline(MeIQx) with Salmonella/mammalian-microsome mutagenicity test. Alginate, phenols, chlorophyll and carotenoids from Ecklonia stolonifera were extracted and their desmutagenicities were assayed. Alginate hydroysates showed desmutagenic activities against PhIP and MeIQx at high level dose. Phenol fractions and bromophenol showed desmutagenic activity of about MeIQx at high level dose. Phenol fractions and bromophenol showed desmutagenic activity of about 90% per 0.5mg against PhIP and MeIQx. Chlorophyllin among chlorophyll derivatives exhibited remarkable desmutagenic activities of 92.9% and 82.7% at 20uM against PhIP and MeIQx, respectively. Carotenoids, such as lutein and $\alpha$-cryptoxanthin isolated from Ecklonia stolonifera exerted also high desmutagenic activity. Major desmutagenic substances from Ecklonia stolonifera are considered to be chlorophyllin, phenols, lutein, $\alpha$-cryptoxanthin and low molecular alginates.