• Journal of Microbiology and Biotechnology
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• 제16권5호
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• pp.667-672
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• 2006

Tyrosinase is an enzyme that catalyzes the biosynthetic pathway of melanin pigments participating in the coloring of skin, hair, and eyes, and is widely distributed in nature. The inhibitory compounds of tyrosinase have been extensively used as a cosmetic agent with a skin-whitening effect. In this paper, several plant extracts were screened using Melan-a cells for the melanin biosynthesis inhibition activity, and Idesia polycarpa was selected. A melanin biosynthesis inhibitor was isolated from I. polycarpa fruits by activity-guided fractionation, and the inhibitor was identified as 6-hydroxy-2-[[[(1-hydroxy-6-oxo-2-cyclohexenl-yl)carbonyl]oxy]methyl]phenyl$\beta$-D-glucopyranoside (idescrapin) by comparing it with reported spectral data. Idescarpin $(IC_{50}=8{\mu}g/ml)$ reduced melanin content compared with the vehicle. In addition, the inhibitory activity of idescarpin for melanin synthesis is mediated by decreasing tyrosinase protein rather than directly inhibiting the tyrosinase activity. These results suggest that idescarpin isolated from I. polycarpa fruits may be used as a skin-whitening agent.

• Bulletin of the Korean Chemical Society
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• 제27권8호
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• pp.1164-1170
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• 2006

The synthesis of a new series of 1$\beta$-methylcarbapenems having 5-($\alpha,\beta$-disubstituted ethyl)pyrrolidine moiety is described. Their in vitro antibacterial activities against both Gram-positive and Gram-negative bacteria were tested and the effect of substituents on the pyrrolidine ring was investigated. A particular compound (VIh) having $\alpha$-hydroxy-$\beta$-piperazinylethyl substituted moiety showed the most potent activity.

• 한국식품영양과학회지
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• 제12권3호
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• pp.212-218
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• 1983

토끼에 마그네슘 칼슘이 첨가된 식이를 급여하여 토끼의 liver microsomal protein에 함유된 HMG-CoA reductase의 활성과 혈청 콜레스테롤, 트리글리세리드, 마그네슘 및 칼슘의 양을 측정하여 다음과 같은 결과를 얻었다. 1. 혈청 마그네슘의 경우 대조군이 9.5mg% 인데, 마그네슘 첨가군은 평균 8.27이었고, 칼슘을 첨가하여 사육한 실험군에서 상당히 낮은 값 T-D : 3.5, T-E : 3.0, T-F : 4.0, T-G : 7.3으로 평균 4.45를 보였다. 2. 혈청 칼슘의 경우 대조군이 15.3mg %인데, 마그네슘 첨가 실험군은 평균 14.6이나 칼슘 첨가 실험군에 있어서 평균 14.1로서 큰 차이가 없었다. 3. 혈청 트리글리세리드의 경우 대조군 82.8에 비하여 마그네슘첨가 실험군은 평균 60.3이었으나, 칼슘 첨가 실험군은 평균 69.5로서 다소 높은 값을 보여 주었다. 4. 혈청 콜레스테롤의 경우 대조군이 80mg%인데 반하여, 마그네슘 첨가 실험군은 평균 64.3이었고, 칼슘 첨가 실험군은 평균 56.3으로 상당히 낮은 값을 보여 주었다. 5. microsomal protein의 HMG-CoA reductase의 활성의 경우는 대조군이 0.995nmol/min/mg 인데, 마그네슘 첨가 실험군은 평균 0.948을 보였고 칼슘 첨가 실험군은 평균 0.849를 보여 주었다.

• Archives of Pharmacal Research
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• 제20권6호
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• pp.647-651
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• 1997

The 6, 6-dibromopenam 6 was treated with $CH_{3}/MgBr$ and carbaldehyde 5 to afford the 6-bromo-6-(1-hydroxy-1-methyl)penicillanate 7, which was reacted with acetic anhybride to give acetoxy compound 8. The deacetobromination of 8 with zinc and acetic acid gave 6-exomethylenpenams, Z-isomer 9 and E-isomer 10, which were oxidized to sulfones 11 and 12 by m-CPBA. The p-methoxybenzyl compounds were deprotected by $AlCl_{3}$ and neutralized to give the sodium salts 13, 14, and 15.

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1669-1678
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• 2011

Six new binuclear copper(II) complexes have been prepared by template condensation of the dialdehydes 1,8-[bis(3-formyl-2-hydroxy-5-methyl)benzyl]-l,4,8,11-tetraazacyclotetradecane (PC-a) and 1,8-[bis(3-formyl-2-hydroxy-5-bromo)benzyl]-l,4,8,11-tetraazacyclotetradecane (PC-b) with appropriate aliphatic diamines, and copper(II) perchlorate. The structural features of the complexes have been confirmed by elemental analysis, IR, UV-vis and mass spectra etc. The electrochemical behavior of all the copper(II) complexes show two irreversible one electron reduction process. The room temperature magnetic moment studies depict the presence of an antiferromagnetic interaction in the binuclear complexes. The catechol oxidation and hydrolysis of 4-nitrophenylphosphate were carried out by using the complexes as catalyst. The antimicrobial screening data show good results. The binding of the complexes to calf thymus DNA (CT DNA) has been investigated with absorption and emission spectroscopy. The complex [$Cu_2L^{1a}$] displays significant cleavage property of circular plasmid pBR322 DNA in to linear form. Spectral, electrochemical, magnetic and catalytic studies support the distortion of the copper ion geometry that arises as the macrocyclic ring size increases.

• Applied Biological Chemistry
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• 제38권6호
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• pp.570-576
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• 1995

새로운 16종의 ortho 이치환 benzenesulfonyl urea계 제초성 화합물인 N-2-(1-hydroxy-2-fluoroethyl)-6-치환(X)-benzenesulfonyl-N'-4,6-dimethoxypyrimidinyl-2-yl urea 유도체들을 합성하고 벼(Orysa sativa L.)를 위시하여 논 잡초인 강피(Echninochloa orizola) 및 올챙이고랭이(Scirpus juncoides)를 대상으로 측정된 제초활성값$(pI_{50})$과 ortho-치환기{X)들의 변화에 따른 물리-화학적 파라미터와 가수분해 반응 속도상수로 부터 구조-활성 관계(SAR)를 검토하였다. 잡초들의 제초활성에 미치는 물리-화학적 파라미터의 영향은 입체상수가 음의값$(Es,\;L_1,$ 및 $B_4<0)$이고 반응 속도상수는 양의 값(logk>0)으로 ortho-치환기에 의한 입체효과보다 반응속도 상수에 의존적이었다. 초종간의 선택성은 나타나지 않았으나, 강피>볍씨>올챙이고랭이>벼 3엽기의 순으로 halogen(2 및 5), methyl(15) 및 비(H)치환체(1) 등이 가장 큰 제초활성을 보였다. Ortho-치환기(X)는 전자를 밀수록 제초활성이 증가되었고 수용액 중에서 잔류성은 단축되었으며 pH 6.0의 $45^{\circ}C$에서 반감기(T1/2)는 14시간${sim}$58일 범위였다. 그리고 가수분해와 제초활성 반응이 유사한 경로로 진행될 것임을 예상 할 수 있었다.

• 한국염색가공학회지
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• 제20권4호
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• pp.8-14
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• 2008

Flame-retardant cotton fabrics were prepared by UV curing of photocurable aqueous formulations of phosphorous-containing methacrylate monomers and 2-hydroxy-2-methyl-1-phenyl-1-propanone as flame retardants and a photoinitiator respectively, which is an environmentally friendly and energy-saving process. The characterization of the UV-coated cotton fabric was made by ATR, TGA and limited oxygen index measurement. UV cured coating onto cotton fabrics reduced the first thermal decomposition temperature and mass loss as well as increase in the amount of char residue compared with the untreated cotton fabric presumably due to modified thermal decomposition process. The LOI values up to 28.5 and 27.2 were obtained by the UV curing of MMEP and TMEP respectively. The treatment was durable to five laundering cycles, which was more prominent in the case of trifunctional TMEP treatment.

• Archives of Pharmacal Research
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• 제27권11호
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• pp.1123-1126
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• 2004

The bioassay-guided fractionation of protective agents against sepsis-induced lethality from the root cortex of Paeonia suffruticosa ANDREWS (Ranunculaceae) led to the isolation of eight known compounds: paeonol (1), 2,5-dihydroxy-4-methoxyacetophenone (2), acetovanillone (3), paeonoside (4), paeoniflorin (5), oxypaeoniflorin (6), apiopaeonoside (7), and methyl 3-hydroxy-4-methoxybenzoate (8). Among them, 3 showed the highest survival rate (100% with a dose of 30 mg/kg versus 17% for the control experiment) and reduced alanine aminotransferase level to be a half of the control value on the sepsis model induced by lipopolysaccharide/D-galactosamine.

• 유변학
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• 제5권2호
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• pp.161-169
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• 1993

Glucomannan(G.M.)은 Amorphophallus Konjac C. Koch의 tuber로부터 분리되었고. 이 G.M.은 다시 침전제로 메탄올을 사용하여 4단계로 분별되었다.(F.1, F.2, F.3, F.4,). 각분 별물에 비하여 직선으로부터 벗어남을 보였다. Low shear viscometer로 G.M. 용액의 viscosity를 측정하였고 농도와 zero shear specific viscosity의 logarithm을 도시한 결과 inflection point를 나타내었다. 이것은 G.M. 분자들의 coil overlap의 시작에서 기인한 것이 고 묽은 용액에서 진한 용액으로의 전이행동은 임계농도. C＊=4/[η]에서 일어났고 이때의 zero shear specific viscosity는 10을 나타내었다. 또한 specific viscosity는 묽은 용액에대해 서는 C14로써 변화하였고 진한 요액에서는 C3.0으로변화하였다. G.M.의 고체상태에 대한 유 전성($\varepsilon$＇,$\varepsilon$＂)과 점탄성(C＇,C＂)계수들을 액체질소 온도에서부터 15$0^{\circ}C$ 온도범위에 걸쳐 4단계로 film을 건조시키면서 10Hz에서 측정하였다. G.M. film의 유전성과 점탄성의 허수부 분은 ($\varepsilon$＂, C＂), -10$0^{\circ}C$에서 peak를 나타내었고 이 peak는 hydroxy methyl 기들의 회전 운동에서 생겨난 것이다. 건조시키지 않은 상태의 G.M. film의 유전성과 점탄성의 허수부분 의 값들은 -5$0^{\circ}C$에서 물 분자의 운동에 의하여 생긴 peak를 보였다.

• Bulletin of the Korean Chemical Society
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• 제10권5호
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• pp.434-437
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• 1989

The pH dependence of the absorption and fluorescence of 4-hydroxy-2-methyl-1,2-benzothiazinenecarboxylat es, piroxicam and HMBDC have been measured and compared with the solvent dependence of the spectra reported previously. Four different prototropic species are observed in both ground and excited states of piroxicam ; the cation, the neutral, the anion and the dianion, while three different species such as the cation, the neutral and the anion are observed in HMBDC. The $pK_a$ and $pK_a^{\ast}$ have been determined by absorptiometric titration and Forster cycle method, respectively. The probable structure of each species has been proposed on the basis of the intramolecular phototautomerism.