• 한국식품과학회지
• /
• 제33권4호
• /
• pp.497-500
• /
• 2001

본 연구의 목적은 홍미삼의 기능성 연구의 일환으로 총 페놀성 화합물의 추출방법과 DPPH에 대한 수소공여능, linoleic acid의 산화방지활성 및 LDL에 의한 항산화활성 등을 중심으로 연구한 결과이다. 홍미삼에 60% 에탄올를 첨가하여 추출회수별 총 페놀성 화합물을 조사한 결과 3회까지 추출했을 때 대부분이 추출되었기 때문에 추출횟수는 3회가 적당한 것으로 판단되었다. 60% 에탄올 추출액의 수율은 3회까지 추출했을 때 약 37.35%가 추출되었다. 추출 용매에 따른 총 페놀성 화합물의 추출 효율은 물 추출구를 100%로 했을 때, 60% 에탄올 용액으로 추출한 뒤 농축하여 물로 부피를 재조정한 시험구는 122%로 조사되었다. 항산화활성 조사에서 DPPH에 대한 수소공여능에서 시간이 경과함에 따라 항산화 활성이 약간씩 증가하나 활성은 약한 편이었다. Linoliec acid 산화에 대한 산화억제 효과는 1,500 ppm 농도에서 약 72.23%의 저해율을 나타났으며, LDL에 대한 산화방지 효과는 250 ppm 농도에서 그 저해율이 약 22.52%로 나타났다.

• Food Science and Biotechnology
• /
• 제16권3호
• /
• pp.409-414
• /
• 2007

Antimicrobial and antioxidative effects of 14 different herbal flower extracts on skin microorganisms and oxidation were tested in this research. Herbal flower extracts were prepared with 70% ethanol. Among the herbal flower extracts, roselle (Hibiscus sabdariffa L.) flower extract showed the highest antimicrobial activity against Staphylococcus epidermidis as determined by a paper disc method. The seventy % ethanol extract of roselle flower was fractionated by sequential hexane, chloroform, ethyl acetate, n-butanol, and water fractionation. The growth of S. epidermidis, Streptomyces collinus, Streptomyces coeruleoprunus, Salmonella enteritidis, Vibrio parahaemolyticus, and Malassezia pachydermatis was most efficiently inhibited by ethyl acetate fraction of roselle flower extract as determined by a paper disc method and growth inhibition curves. In addition, the ethyl acetate fraction, water fraction and butanol fraction showed free radical scavenging and DNA cleavage inhibition activities. These results demonstrate that roselle flowers hold antimicrobial and antioxidative activities against skin microorganisms and oxidants.

• Journal of Microbiology and Biotechnology
• /
• 제24권12호
• /
• pp.1673-1678
• /
• 2014

The interactive inhibitory effects of pH and chloride on the catalysis of laccase from Trametes versicolor were investigated by studying the alteration of inhibition characteristics of sodium chloride at different pHs for the oxidation of 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid). At pH 3.0, the addition of sodium chloride (50 mM) brought about a 40-fold increase in $K{_m}^{app}$ and a 4-fold decrease in $V_{max}{^{app}}$. As the pH increased to 7.0, the inhibitory effects of sodium chloride became significantly weakened. The mixed-inhibition mechanism was successfully used to quantitatively estimate the competitive and uncompetitive inhibition strengths by chloride at two different pHs (pH 3.0 and 6.0). At pH 3.0, the competitive inhibition constant, $K_i$, was 0.35 mM, whereas the uncompetitive inhibition constant, $K{_i}^{\prime}$, was 18.1 mM, indicating that the major cause of the laccase inhibition by chloride is due to the competitive inhibition step. At a higher pH of 6.0, where the inhibition of the laccase by hydroxide ions takes effect, the inhibition of the laccase by chloride diminished to a great extent, showing increased values of both the competitive inhibition constant ($K_i=23.7mM$) and uncompetitive inhibition constant ($K{_i}^{\prime}=324mM$). These kinetic results evidenced that the hydroxide anion and chloride share a common mechanism to inhibit the laccase activity.

• 생약학회지
• /
• 제20권2호
• /
• pp.101-109
• /
• 1989

Purification of polyphenol oxidase(PPO) from Korean native tobacco variety leaves was carried out through the procedure of acetone preciptation, ammonium sulfate fractionation, and Sephadex G-150 gel filtration, resulting in a 84-fold increase in specific activity. The enzyme was stable in a range of pH 7.5 to 8.0 with an optimum of pH 7.5. The optimum temperature for the enzymic reaction was about $60^{\circ}$. It was thermostable with a half-life equal to 20 min at $70^{\circ}$. Km values for (+)-catechin and pyrogallol were $1.6{\times}10^{-3}$ and $0.5{\times}10^{-3}M$, respectively. It possesses high catecholase activity but little or no cresolase activity. Lineweaver-Burk analysis of inhibition data revealed that the inhibition of (+)-catechin oxidation by potassium cyanide, 4-nitrocatechol, cystein and 2-mercaptoethanol was competitive with Ki values of $1.1{\times}10^{-6}$, $1.8{\times}10^{-6}$, $8.9{\times}10^{-6}$ and $1.3{\times}10^{-5}$, respectively.

• Journal of Ginseng Research
• /
• 제29권1호
• /
• pp.44-48
• /
• 2005

홍삼에서 분리한 수용성 갈변물질의 항산화 활성을 DPPH 수소공여능 및 미토콘드리아 분획을 이용한 지질과산화, 산소 소모율 및 단백질 산화율을 조사한 결과 다음과 같은 결론을 얻었다. DPPH 수소공여능을 조사한 결과 수용성 갈변물질 S-1, S-2 분획은 반응시간이 경과함에 따라 완만하게 DPPH가 감소하였고, L 분획은 S-1, S-2 분획보다 시간이 경과함에 따라 감소폭이 증가하였다. 미토콘드리아 분획을 이용한 지질과산화 및 산소 소모율의 변화에서 첨가 농도가 높을수록 억제율이 높았으며, 특히, L분획이 S-1 및 S-2 분획보다 높은 활성을 보였다. 또한 수용성 갈변물질을 농도별로 각각 첨가했을시 단백질 산화에서 L분획에서 반응초기에 약간 급속히 진행되는 것으로 보이나, S-1과 S-2 분획에서는 비교적 농도 의존적으로 나타났으며, S-2 분획은 S-1 및 L 분획보다 억제율이 현저히 낮았다.

• Preventive Nutrition and Food Science
• /
• 제4권1호
• /
• pp.75-78
• /
• 1999

Acetylcarnitine, a metabilite of carnitine, has been porven to be a potent inhibitor of ethanol oxidation in hepatocytes. It inhibits the activity of alcohol dehydrognase (ADH), but not the microsomal ethanol oxidizing system. which was significatly inhibited by acetylcarnitine at NAD ; acetylcarnitine $\leq$1. the main objectives of his study were to ascertain the interaction between acetylcarnitine and NAD on ADH activity and to elucidate whether different species have different effects. Tehpost-mocrosomal supernatant (PMS) was prepared from normal rat, guinea pig, mouse and broilers by differential centrifugation . Horse and yeast ADH were purchased from the Sigma Chemical Co. Prepared and purchased ADH are used for determination of ADH activity in the presence or absence of carnitine and acetylcar- nitine. Binding studies showed that acetylcarnitine did bind to ADH in a dose realted manner when low NAD ; acetylcar- nitine ratio was provided. It was found that the inhibitionof ADH activity occurred only when NAD concentration was less than the inhibitor concentration . Crystalline and crude ADH preparation from different vertebrate species wer inhibited by acetylcarnitine, whereas the yeast ADH was not affected by acetylcarnitine.

• 대한수의학회지
• /
• 제36권3호
• /
• pp.565-570
• /
• 1996

Cardiac, hepatic and renal mitochondria in rats fed lead containing diets were isolated and their activities were studied in terms of NADH oxidation. In normal rats, cardiac and renal mitochondria had similar activities and showed activity values of higher than those in hepatic mitochondria. Cardiac mitochondiral activities in rats fed lead containing diets were increased after 4 weeks of feeding but decreased to activity values close to normal. Renal mitochondrial activities showed a trend of inhibition in all groups fed lead containing diets but were no differenes by feeding periods of 4 and 8 weeks. Feeding of lead containing diets could not be attributed to any changes in the hepatic mitochondrial antivities at experimental doses during 4~8 weeks.

• 한국토양비료학회지
• /
• 제37권1호
• /
• pp.7-13
• /
• 2004

본 연구는 숙주의 발아 과정 중 오옥신 과련 대사작용에서의 strontium의 역할을 구명코자 실시하였다. 오옥신 첨가 용액에 strontium을 첨가하여 발아시킨 결과 침지 한 후 IAA 산화가 일어남이 밝혀졌다. 3-5배의 IAA 산화효소 활성화가 측정되었다. 이러한 결과는 strontium에 의한 생장억제의 직접적인 증거였다. 더 나아가 1-10 mM의 strontium 첨가 용액에서 생장한 배축에서의 spermine과 spermine 함량이 2-3배 높은 것으로 밝혀졌다. 이러한 증가는 생체중에 근거한 결과였다. 결론적으로 strontium에 의한 배축생장 억제는 오옥신 산화 및 polyamine 생합성과 관계가 있는 것으로 밝혀졌다.

• 한국대기환경학회지
• /
• 제12권2호
• /
• pp.121-130
• /
• 1996

The catalysts composed of Pt, Pd and W as active-components, $Al_{2}O_{3}$ and $SiO_{2}$ as supports, were perpared on the honeycomb type substrate and characterized by BET, SEM, TGA, FT-IR and XRD for diesel emission control. CO, $C_{3}H_{6}$, and $SO_{2}$ oxidation was carried out over these catalysts in a fixed bed continuous flow reactor at the temperatures between 100-500.deg.C and reactant gas was composed of 10 vol.% $O_{2}$, 1 vol.% CO, 0.8 vol.% $C_{3}H_{6}$ and 88.2 vol.% $N_{2}$. It was found that under these experimental conditions, the CO, $C_{3}H_{6}$ oxidation activity of Pt-W catalyst was higher than that of any other prepared catalyst, and this catalyst had also a good inhibition effect on $SO_{2}$ oxidation. Also it was show that the influence of $SO_{2}$ on $Al_{2}O_{3}$ was more sever than that of $SO_{2}$ on $SiO_{2}$.

• 한국환경성돌연변이발암원학회지
• /
• 제9권2호
• /
• pp.87-96
• /
• 1989

Studies on the biodisposition of beta-nicotyrine by lung and liver microsomes was examined in order to provide a better understanding of its fate in this tissue. beta-nicotyrine (100$\mu$M) was incubated with microsomes (1 mg/ml) prepared from New Zealand White rabbits. The rate of oxidation observed in lung microsomal incubations was 1.7 nmoles $\beta$-nicotyrine oxidized mg$^{-1}$ min$^{-1}$ compared with 2.7 nmoles $\beta$-nicotyrine oxidized mg$^{-1}$ min$^{-1}$ by the liver microsomal preparation. However, when these rates were expressed as a function of cytochrome P-450 content, the specific activity of the metabolic oxidation catalyzed by lung (8.3 nmoles $\beta$-nicotyrine oxidized nmole cytochrome P-450$^{-1}$ min$^{-1}$) was approxiamtely 4 times greater than liver microsomes (2.3 nmoles $\beta$-nicotyrine oxidized nmole cytochrome P-450$^{-1}$ min$^{-1}$). Isozyme studies on the oxidation of $\beta$-nicotyrine employed several methods of altering activities of specific isozymes present in pulmonary microsomes, including the use of the isozyme 2 and 6 specific inhibitor $\alpa$-methyl ABT, metabolic inhibitor(MI) complex formation. The results of this inhibition study would appear to indicate the $\beta$-nicotyrine is metabolized predominantly by pulmonary isozyme 5.