• 한국환경과학회지
• /
• 제7권3호
• /
• pp.393-400
• /
• 1998

A microorganism, Klebsiella gr. 47, capable of degrading BTX(benzene, toluene and xylene) was isolated from oil-contaminated soil and its characteristics of BTX degradation were investigated. When benzene and toluene were fed to Klebstella gr. 47 simulataneously, they showed competitive ingibition. The degradation rate of xylene was enhanced as much as 3 times when xylene was fed with benzene or toluene. Degradation rate of benzene and toluene was also enhanced by cocultured with Alcaligenes xylosoxidans. When benzene-adapted microorganism was used, each BTX compound was degraded efficiently within 5 hours.

• 한국감성과학회:학술대회논문집
• /
• 한국감성과학회 2004년도 추계학술대회 논문집
• /
• pp.29-29
• /
• 2004

• International Journal of Industrial Entomology and Biomaterials
• /
• 제9권1호
• /
• pp.29-33
• /
• 2004

Low molecular weight silk fibroin (LMSF), which was prepared by hydrolysis of silk fibroin using high-temperature and high-pressure method, was found to inhibit the oxidation of L-3,4,-dihydroxyphenylalanine (L-DOPA) catalyzed by mushroom tyrosinase (EC 1.14.18.1). LMSF contained mostly free amino acids such as L-glycine, L-alanine, and L-serine and oligopeptides, mainly glycine-alanine dimer. As a result of analyzing the inhibition kinetics from Lineweaver-Burk plots, L-glycine and glycine-alanine dimer showed noncompetitive behavior while uncompetitive behavior was observed in L-alanine, and L-serine. When weight percent concentration of ${ID_50}$ was compared, L-glycine was most effective on the inhibition and LMSF was also good enough for the inhibition effect of tyrosinase activity. LMSF showed a mixed-type inhibition and the inhibitory mechanism of LMSF might be caused by free amino acids and oligopeptides. As a result of spectroscopic observation with time, initial rate of increase of DOPAchrome decreased remarkably and the time to reach maximum absorbance increased as an increase of the concentration of L-glycine, meaning that L-glycine made itself mainly responsible for the formation of chelate with ${Cu^2+}$ in tyrosinase. However, in case of L-alanine, L-serine, and especially glycine-alanine dimmer, the production of DOPAchrome after an arrival at maximum absorbance decreased, indicating the production of adducts through the reaction with DOPAquinone.

• Mycobiology
• /
• 제43권2호
• /
• pp.137-149
• /
• 2015

In the search for novel potent fungi-derived bioactive compounds for bioinsecticide applications, crude ethyl acetate culture filtrate extracts from 110 mangrove fungal endophytes were screened for their toxicity. Toxicity tests of all extracts against brine shrimp (Artemia salina) larvae were performed. The extracts with the highest toxicity were further examined for insecticidal activity against Spodoptera litura larvae and acetylcholinesterase (AChE) inhibition activity. The results showed that the extracts of five isolates exhibited the highest toxicity to brine shrimp at 50% lethal concentration ($LC_{50}$) values of 7.45 to 10.24 ppm. These five fungal isolates that obtained from Rhizophora mucronata were identified based on sequence data analysis of the internal transcribed spacer region of rDNA as Aspergillus oryzae (strain BPPTCC 6036), Emericella nidulans (strains BPPTCC 6035 and BPPTCC 6038), A. tamarii (strain BPPTCC 6037), and A. versicolor (strain BPPTCC 6039). The mean percentage of S. litura larval mortality following topical application of the five extracts ranged from 16.7% to 43.3%. In the AChE inhibition assay, the inhibition rates of the five extracts ranged from 40.7% to 48.9%, while eserine (positive control) had an inhibition rate of 96.8%, at a concentration of 100 ppm. The extracts used were crude extracts, so their potential as sources of AChE inhibition compounds makes them likely candidates as neurotoxins. The high-performance liquid chromatography profiles of the five extracts differed, indicating variations in their chemical constituents. This study highlights the potential of culture filtrate ethyl acetate extracts of mangrove fungal endophytes as a source of new potential bioactive compounds for bioinsecticide applications.

• 한국잡초학회지
• /
• 제17권4호
• /
• pp.407-412
• /
• 1997

약용작물의 allelopathy 효과를 구명하기 위하여 메탄올 추출물을 이용하여 생물검정한 결과 피의 발아, 신초 및 뿌리생육 억제는 공시식물, 사용부위, 사용농도에 따라 다르게 나타났는데 피의 발아, 신초 생장 및 뿌리는 천궁 및 감초 뿌리추출물에 의해서 가장 억제가 되었다. 1g 농도에서 피의 발아, 신초생장, 뿌리생장이 각각 88%, 95%, 100%, 감초추출물에서 87%, 96%, 100% 억제되었다. 천궁의 부위별 억제정도는 뿌리에서 가장 크게 나타났는데 0.5g에서 피는 완전히 억제가 되었으나 줄기 잎추출물에서는 억제효과가 크지 않았다. 용매극성별 피의 억제 정도는 에틸아세테이트에서 가장 크게 억제되었다. 피의 발아는 3분획 모두 억제가 되지 않았으나 신초 및 뿌리생장은 에틸아세테이트분획이 에틸에테르나 메탄올 분획보다 억제가 더 컸다. 이상의 결과에서 천궁뿌리에 함유하고 있는 allelochemicals은 중간정도의 극성을 띤 물질일 것으로 사료되며 allelochemicals의 분리정제에 귀중한 재료가 될 것으로 사료된다.

• 한국식생활문화학회지
• /
• 제20권3호
• /
• pp.341-345
• /
• 2005

감국에 존재하는 항충치활성 물질 및 glucosyltransferase 저해 효과에 대한 정보를 얻고자 본 연구를 시도하였다. 감국 ethanol 추출물의 항충치활성을 S. mutans 및 구강세균에 대해 검색한 결과, S. mutans와 2종의 구강세균에 대하여 활성이 높게 나타났다. 감국 ethanol 추출물의 농도에 따라 GTase 저해효과는 $78.4{\sim}92.3%$의 범위로 나타나 농도가 증가할 수록 활성도 함께 증가하는 경향을 나타냈다. 감국을 ethanol로 추출, 용매분획하여 얻어진 활성성분을 silica gel adsorption chromatography, Sephadex LH-20 chromatography, TLC 그리고 HPLC 등의 방법으로 분석한 결과, 감국에 존재하는 항충치활성 물질은 약간의 극성을 띠는 중성물질로 분자량이 200-400정도 되는 저분자 물질인 것으로 확인되었다.

• Archives of Pharmacal Research
• /
• 제17권5호
• /
• pp.364-370
• /
• 1994

A microscopic mass balance approach has been developed to estimate the extent and rate of absorption for camier-mediated comounds. For the case competitive inhibition in the presence of an inhibitor which shares the same camier, the fraction dose absorbed (F) and absorption rate constant ($K_a$) of a drug can be calculated from its concentration profile in the intestinal lumen. Absorption parameters obtained by single-pass perfusion experiments were used in the simultaion of the absorption of some aminopenicilins. Predicted fractions dose absorbed and absorption rate constants of ampicilin and amoxicilin were significantly reduced in the presence of a 6-times higher molar dose of cyclacilin. The drug-drug interactions on the competitive absroption of camier-mediated compounds were determined with regard to F and $K_a$. Predicted decreases in F for some aminopenicilins corrlated well with decrease in the urinary recovery in humans reported in the literature. Predicted decrease in the mean absorption rate constant ($\barK_a$) explain the delays in the time of peak plasma concentration ($T_{max}$) reported in humans.

• 농약과학회지
• /
• 제2권2호
• /
• pp.10-15
• /
• 1998

Carbofuran 및 N-dimethoxyphosphinothioyl carbofuran (PSC)의 AChE에 대한 이분자 저해 속도상수(bimolecular inhibition rate constant, $k_{i}$)를 관찰하였다. Carbofuran은 $7.7{\times}10^{5}\;M^{-1}{\cdot}min^{-1}$으로 높은 저해효과를 보이고 있는 반면, PSC는 $1.2{\times}10^{3}\;M^{-1}{\cdot}min^{-1}$으로 carbofuran에 비하여 AChE에 대한 저해력이 600배 정도 낮은 저해력을 갖고 있는 것으로 관찰되어 독성발현을 위하여 활성화 과정이 필요한 것으로 확인되었다. AChE/mixed function oxidase(mfo) coupling system을 이용한 microsomal oxidative activation 실험에서 PSC의 AChE에 대한 저해력이 control에 비하여 NADPH가 첨가된 oxidase 처리구에서 800배 더 강하게 나타났으며, cytochrome $P_{450}$의 저해제를 첨가한 oxidase+PBO 처리구에서는 control의 저해 경향과 유사하였다. 또한 생쥐 뇌 AChE에 대한 PSC의 $I_{50}$은 28 mg/kg인 반면 PBO를 전처리하였을 경우 $I_{50}$은 57 mg/kg으로 나타나 cytochrome $P_{450}$ 저해제로 인하여 PSC의 저해력이 2배정도 감소된 것을 관찰할 수 있었고, PSC는 독성발현을 위하여 활성화 과정을 거쳐야 하며, 이 과정에서 cytochrome $P_{450}$ 이 작용함을 확인할 수 있었다. PSC와 MCPBA를 반응시켜 산화 과정을 통하여 생성된 독성대사물을 분석한 결과 반응산물의 약 55%가 carbofuran임을 확인할 수 있었다. 본 연구를 통하여 PSC의 활성화 과정을 통한 독성발현에 cytochrome $P_{450}$이 중요한 역할을 하는 효소임을 확인할 수 있었고, PSC의 산화적 활성화 과정을 통한 주된 독성대사물이 carbofuran임을 확인할 수 있었다.

• BMB Reports
• /
• 제28권6호
• /
• pp.527-532
• /
• 1995

Human taurine transporter has 12 transmembrane domains and its molecular weight is 69.6 kDa. The long cytoplasmic carboxy and amino termini might function as regulatory attachment sites for other proteins. Six potential protein kinase C phosphorylation sites have been reported in human taurine transporter. In this report, we studied the effects of phorbol 12-myristate 13-acetate (PMA) and glucocorticoid hormone on taurine transportation in the RAW 264.7, mouse macrophage cell line. When the cells were incubated with $[^{3}H]taurine$ in the presence or absence of $Na^+$ ion for 40 min at $37^{\circ}C$, the [$[^{3}H]taurine$ uptake rate was 780-times higher in the $Na^{+}-containing$ buffer than in the $Na^{+}-deficient$ buffer, indicating that this cell line expresses taurine transporter protein on the cell surface. THP1, a human promonocyte cell line, also showed a similar property. The $[^{3}H]taurine$ uptake rate was not influenced by the inflammatory inducing cytokines such as interleukin-1, gamma-interferon or interleukin-1+gamma-interferon, but was decreased by the PMA in the RAW 264.7 cell line. This suggests that activation of protein kinase C inhibits taurine transporter activity directly or indirectly. The inhibition of $[^{3}H]taurine$ uptake by PMA was time-dependent. Maximal inhibition occurred in one hr stimulation with PMA Increasing the treatment time beyond one h reduced the $[^{3}H]taurine$ uptake inhibition due to the depletion or inactivation of protein kinase C. The cell line also showed concentration-dependent $[^{3}H]taurine$ uptake under PMA stimulation. The phorbol-ester caused 23% inhibition at the concentration of 1 ${\mu}m$ PMA. The inhibition was significant even at a concentration as low as 10 nM PMA The reduced $[^{3}H]taurine$ uptake could be recovered by treatment with glucocorticosteroid hormone. Dexamethasone led to recover of the reduced taurine uptake induced by phorbol-ester, recovering maximally after one hr. This may suggest that macrophage cells require higher taurine concentration in a stressed state, for the secretion of glucocorticoid hormone is increased by hypothalamo-pituitary-adrenocortical (HPA) axis activation in the blood stream.

• 한국식품영양과학회지
• /
• 제36권1호
• /
• pp.1-7
• /
• 2007

된장제조 중 녹차추출물 첨가 및 죽염을 사용할 경우 돌연변이 억제작용 및 in vitro 항암 기능이 증진되는 것으로 나타났다. 돌연변이원 $AFB_1$에 대해 시료처리 농도 1.25 mg/plate에서는 녹차추출물을 첨가하지 않은 된장, 1% 및 2% 첨가 된장은 각각 63%, 85%, 87%의 항돌연변이 효과를 보여서 녹차 첨가에 의해 활성이 현저히 높아졌으나 녹차 1% 와 2%첨가에서 큰 차이는 보이지 않았다. MNNG에 대해서도 이러한 경향은 마찬가지였고, 녹차추출물 1% 첨가된장에 죽염을 사용했을 때는 더욱 높은 항돌연변이 효과를 나타냈다. 녹차추출물을 첨가한 된장의 in vitro 항암효과를 살펴 본 결과, PC-3인체 전립선암세포에서 0.5 mg/mL로 시료를 처리했을 때 대조군인 일반된장이 46%의 항암활성을 나타낸 데 비하여 녹차추출물을 1% 첨가한 시료는 70%, 2% 첨가한 시료는 77%의 암세포 생존저해효과를 나타내어 첨가 농도가 증가할수록 인체 전립선암세포의 생존을 더 크게 억제함을 알 수 있었다. 또한 죽염을 사용했을 때(녹차 1% 첨가군) 항암활성이 더욱 높아졌으며, 녹차 2% 첨가와 비슷하거나 더 높은 항암효과를 보였다. 다른 인체 전립선암세포인 DU145를 이용한 항암효과 실험에서도 같은 경향을 보여서 녹차추출물을 첨가하거나 죽염을 사용함으로써 된장의 항돌연변이 및 항암활성을 증진시킴을 알 수 있었다.