• 약학회지
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• 제43권6호
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• pp.809-817
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• 1999

The effect of 2-(4-cyanophenyl)amino-1,4-naphthalenedione-3-pyridinium perchlorate (PQ5) on pla-telet aggregation and its action mechanisms were investigated with rat platelet. PQ5 inhibited the platelet aggregation induced by collagen ($6{\;}{\mu\textrm{g}}/ml$), thrombin (0.4 U/ml) and A23187 ($3{\mu}M$) in concentration-dependent manner with $IC_{50}$ values of 5.50, 25.89 and $37.12{\;}{\mu}M$, respectively. PQ5 also significantly reduced the thromboxane $A_2$ (TXA2) formation in a concentration dependent manner. The collagen-induced arachidonic acid (AA) release in [-3H]-AA incorporated platelet, an indication of the phospholipase $A_2$ activity, was decreased by PQ5 pretreatment PQ5 significantly inhibited the activity of thormboxane synthase only at high concentration ($100{\mu}M$), but did not affect the cyclooxygenase activity at all. Collagen-induced ATP release was significantly reduced by PQ5. Calcium-induced platelet aggregation experiment suggests that the elevation of intracellular free $Ca^{2+}$ concentration ($[Ca^{2+}]_i$) by collagen stimulation is decreased by the pretreatment of PQ5, which is due to the inhibition of calcium release from intracellular store and influx from outside of the cell. PQ5 did not showed the effect of anticoagulation as prothrombin time (PT) or activated partial thromboplastin time (APTT). Form these results, it is suggested that PQ5 exerts its antiplatelet activity through the inhibition of the intracellular $Ca^{2+}$ mobilization and the decrease of the $TXA_2$ synthesis.

• 한국식품저장유통학회지
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• 제9권2호
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• pp.228-233
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• 2002

뽕나무 어린줄기를 이용하여 새로운 기능성 추출 음료개발을 위한 목적으로 뽕나무 줄기의 화학성분, 항산화 및 항균활성을 조사하였다. 일반성분은 조섬유 51.12%, 회분 13.46%, 총당 10.38%, 조지방 9.10% 및 조단백 5.01% 순으로 나타났다 뽕나무 어린줄기에 가장 많은 무기성분으로는 P(295.9 mg%)으로 나타났으며, 그 외 Ca 289.6 mg%, K 209.6 mg%, Na 58.3 mg%, Mg 45.0 mg% and Fe 4.6 mg% 순으로 나타났다. 유리당은 총 4종이 분리, 동정되었으며, 그 중 glucose가 1.08%로 높게 나타났고, galactose 0.22%, sucrose 0.20% 및 fructose 0.16%로 함유되어 있었다. 지방산은 8종이 분리되었으며, 주된 지방산으로는 linoleic acid, palmitic acid 및 linolenic acid로 나타났다. 분리된 18종의 총 아미노산 중 proline이 313.7mg%로 가장 높은 함량을 차지하였으며, 총 아미노산함량은2,450.5 mg%로 나타났다. 항산화 효과는 용매별 추출물에서는 methanol 추출물이 77.24%, 용매분획별 추출물에서는 ethyl acetate 분획층에서 80.08%로 각각 높게 나타났다. 뽕나무 어린 줄기의 메탄올 추출물은 Bacillus subtilis와 Bacillu scereus에 대하여 강한 항균활성을 나타내었다. 메탄을 추출물의 chloroform 분획층과 ethyl acetate분획층에서 병원성 미생물에 대하여 9.0~l9.0 mm의 저해활성을 나타내었다.

• Bulletin of the Korean Chemical Society
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• 제28권8호
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• pp.1335-1340
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• 2007

β-Ketoacyl acyl carrier protein synthase (KAS) III is a particularly attractive target in the type II fatty acid synthetic pathway, since it is central to the initiation of fatty acid synthesis. Enterococcus faecalis, a Grampositive bacterium, is one of the major causes of hospital acquired infections. The rise of multidrug-resistant of most bacteria requires the development of new antibiotics, such as inhibition of the KAS III. In order to block the fatty acid synthesis by inhibition of KAS III, at first, three dimensional structure of Enterococcus faecalis KAS III (efKAS III) was determined by comparative homology modeling using MODELLER based on x-ray structure of Staphylococcus aureus KAS III (saKAS III) which is a gram-positive bacteria and is 36.1% identical in amino acid sequences with efKAS III. Since His-Asn-Cys catalytic triad is conserved in efKAS III and saKAS III, substrate specificity of efKAS III and saKAS III and the size of primer binding pocket of these two proteins are expected to be similar. Ligand docking study of efKAS III with naringenin and apigenin showed that naringenin docked more strongly with efKAS III than apigenin, resulting in the intensive hydrogen bond network between naringenin and efKAS III. Also, only naringenin showed antibacterial activity against E. faecalis at 256 μg/mL. This study may give practical implications of flavonoids for antimicrobial effects against E. faecalis.

• Journal of Photoscience
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• 제11권2호
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• pp.77-81
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• 2004

Deoxygadusol (DO) and structurally related mycosporine-like amino acids, i.e. mycosporine glycine (MO) and mycosporine taurine (MT), were isolated from phytoplankton Prorocentrum micans and studied for the reactivity toward singlet oxygen. These water-soluble compounds with a cyclohexenone chromophore were all shown to be highly effective in quenching singlet oxygen ($^1$ $O_2$), with the efficiencies being significantly larger compared with histidine, a well-known $^1$ $O_2$ quencher. The $^1$ $O_2$ reaction rate constant ( $k_{Q}$) of DG was determined to be 5.4 ${\times}$ 10$^{7}$ $M^{-1}$ $s^{-1}$ by a steady state method based on competitive inhibition of rubrene oxidation. The feasibility of this method was confirmed by estimating the $k_{Q}$ values for MG and two other quenchers, furfuryl alcohol and 1,4-diazabicyclo [2,2,2]octane, and comparing with those values determined by the time-resolved $^1$ $O_2$ decay method in the previous work.ork.

• 생명과학회지
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• 제17권8호통권88호
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• pp.1141-1146
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• 2007

현미와 먹기에 용이하고 영양적 가치를 높인 발아현미 및 발아현미에 상황버섯 균사체를 배양액을 침지한 상황버섯 발아현미의 항산화, 변역기능과 여러 가지 생리호적 기능을 하는 유리아미노산 함량을 비교하였다. 발아현미 및 상황버섯발아현미의 주요 유리아미노산은 pro, ile, leu, aromatic amino acid, GABA 및 lysine 등으로 현미에 비하여 발아과정에서 유리아미노산함량이 크게 증가 하는 것으로 나타났으며, 그 중에서도 상황버섯발아현미의 유리아미노산이 가장 높게 나타났다. 일반현미와 발아현미 및 상황버섯발아현미의 메탄올 추출물의 DPPH 소거능과 SOD 유사활성은 모든 시료에서 농도 의존적으로 증가하였으며, 특히 발아현미의 전자공여능 및 SOD 유사활성이 높게 나타났다. 상황버섯발아현미 추출물의 항산화력은 DPPH 법에서 5 mg/ml 농도에서 65% 이상의 라디칼 소거능을 보였으며, SOD 유사활성은 10 mg/ml 농도에서 약 70% 의 SOD 유사 활성을 나타내었다. 일반현미와 발아현미 및 상황버섯발아현미의 면역기능은 세균의 LPS를 처리하여 유도된 RAW264.7 세포에서 조사되었는데 LPS를 처리하여 유도된 NO 활성을 400 μg/ml 농도로 상황버섯발아현미 추출물을 첨가함으로써 약 80%까지 NO합성을 현저히 감소시켰으며, 이 농도에서 세포독성이 없는 것으로 MTT assay 에 의하여 확인하였다.

• 미생물학회지
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• 제24권2호
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• pp.113-118
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• 1986

Optimum temperature and pH of glutamine synthetase activity (E.C. 3.6.1.2.) of R. sphaeroides D-230 was $35^{\circ}C$ and 6.8, respectively. The adenylated state of GS in R. sphaeroides D-230 was stabilized by addition of 0.2mg/ml of cethyltrimethylammoniumbromide. Valine, histidine, proline, isoleucine, and lysine were good nitrogen source for the growth of R. sphaeroides D-230. The growth of R. sphaeroides D-230 in $N_2,\;NaNO_3\;or\;NH_4Cl$ as sole nitrogen source was lower than in any otherculture conditions. GS activity was inhibited, more or less, by various amino acid. THe relative inhibition rate of the enzyme by added 7mM arginine, $NH_4Cl,\;N_2,\;and\;NaNO_3$ was 63.8%, 26.79%, 6.24%, and 10.64%, drespectively. THe hydrogen evolution of R. sphaeroides D-230 grown in N-limited media was inhibited by 0.1mM MSX, irreversible GS inhibitor. GS activity was completely inhibited by 1.0mM MSX but ammonia released maximally at the same concentration of MSX. Ammonia release by added MSX was increased up to 1.0mM MS, but decreased above 1.0mM MSX. It is probably due to inhibition of nitrogenase actixity by MSX. Nitrogenase activity was not inhibited at low concentration of MSX. These results suggests that the inhibition of nitrogenase activity by ammonia is mediated by products of ammonia assimilation rather than by ammonia itself.

• Corrosion Science and Technology
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• 제21권2호
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• pp.77-88
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• 2022

Schiff base quinazoline derivative viz., 3-((2-hydroxy-3-methoxybenzylidene)amino)-2-methylquinazolin-4(3H)-one (SB-Q), was synthesized in this study. Its corrosion protection impact on mild steel (MS) in 1 M hydrochloric acid solution was examined by performing weight loss measurements. The protective efficacy of SB-Q on MS in 1 M HCl was investigated based on its concentrations, immersion period, and immersion temperature. SB-Q was found to be an efficient inhibitor for the corrosion of MS. Its inhibition efficiency was improved by increasing the concentration of SB-Q to an optimal concentration of 500 ppm. Its inhibition efficacy was 96.3% at 303K. Experimental findings revealed that its inhibition efficiency was increased with increasing immersion time, but decreased with an increase in temperature. The adsorption of SB-Q molecules was followed the Langmuir adsorption isotherm model. The adsorption of the examined inhibitor molecules on the surface of mild steel was studied by density functional theory (DFT). DFT investigation confirmed weight loss findings.

• Archives of Pharmacal Research
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• 제21권3호
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• pp.241-247
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• 1998

This study was designed to determine biochemical and pharmacological properties of a newly synthesized benzimidazole derivative, 2-amino-4, 5-dihydropyrido [1, 2-a] thiazolo [5, 4-g] benzimidazole (YJA20379-5) in vitro and in vivo. In the leaky membrane vesicles of pig gastric mucosa, YJA20379-5 inhibited the $K^+$-stimulated $H^+$, $K^+$-ATPase activity in a concentration- and time-dependent manner, with $IC_{50}$ values being $43{\mu}\textrm{M}$ and $43{\mu}\textrm{M}$ at pH 6.4 and 7.4, respectively. YJA20379-5, given intraduodenally, had a potent inhibitory effect on the gastric acid secretion in pylorus-ligated rats. The $ED_{50}$ value for acid secretion was 15.4 mg/kg. YJA20379-5, administered orally, also suppressed gastric damages induced by water-immersion stress, indomethacin and ethanol, and duodenal damage induced by mepirizole in rats; the $ED_{50}$ values were 17.6, 4.7, 3.0 and 18.7 mg/kg, respectively. Furthermore, repeated oral administration of YJA20379-5 accelerated the spontaneous healing of acetic acid-induced gastric ulcers in rats. It is concluded that the a-ntisecretory activity of YJA20379-5 appears to be associated with inhibition of $H^+$, $K^+$-ATPase, while its antigastric and antiduodenal lesion activities are primarily related to the antisecretory effect.

• 한국식품영양과학회지
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• 제40권11호
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• pp.1493-1500
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• 2011

본 연구는 함초를 이용한 응용제품의 하나로 자연발효된 함초발효액에 대한 기초자료를 제공하고자, 함초와 당을 혼합하여 2년 혹은 6년간 발효시킨 다음 여과하여 얻어진 여액을 상온에서 자연 발효시키며 함초발효액의 이화학적 특성 및 생리활성을 조사하였다. 함초발효액의 당 함량은 45%내외로 이는 당침출에 의한 제조 방법 때문이며, Na을 제외한 주요 무기질은 K, Mg 그리고 Ca으로, 그중 K 함량이 가장 높게 나타났다. 주요 유리아미노산은 alanine, proline, aspartic acid 그리고 lysine으로, 이들 일반성분들의 발효기간에 따른 차이는 거의 없었다. 총페놀성 화합물 함량은 약 50 CAE mg/100 mL이고, DPPH와 ABTS$^+$ radical-scavenging 활성은 ascorbic acid와 거의 유사할 정도의 활성을 보였다. 또한 함초발효액은 ACE 및 ${\alpha}$-glucosidase에 대해서도 저해 활성을 보였으며, 특히 ${\alpha}$-glucosidase 저해 활성은 장기 발효된 함초발효액(LFGJ)에서 좀 더 높은 활성을 나타냈다. 이에 장기 발효된 함초발효액(LFGJ)을 4%의 고염식이군 실험쥐(SD rat)에 급여한 결과, 일반적인 특성은 대조군(4% 고염식이군)과 차이가 없었으나, 함초발효액군(FGJ; 4% 고염식이+2% LFGJ)의 체중증가량이 통계적 유의성은 없었으나 더 낮은 경향을 보였고, 포도당 내성 실험 결과, 함초발효액군(FGJ)에서 포도당 내성이 더 개선되는 것으로 조사되었다.

• 한국식품영양과학회지
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• 제23권1호
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• pp.137-142
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• 1994

Glucose-아미노산(Lys, Gly, His, Arg)모델계 반응을 통해 생성된 Maillard반응생성물과 비투석성 melanoidin의 NDMA생성억제능에 대한 영향을 검토하였는데 그 결과를 요약하면 다음과 같다. 1. Maillard반응생성물과 비투석성 melanoidin의 모든 시료에서 NDMA생성억제능이 나타났으며, 환원능을 소멸시키고 난 후의 NDMA생성억제능은 환원능이 소실되기 이전보다 1/2이하로 감소하여 이들 시료에 존재하는 환원능이 NDMA생성억제에 있어서 주요 인자로 나타났다. 2. Melanoidin과 ascorbic acid를 동량 첨가하였을 때, NDMA생성억제능은 ascorbic acid를 동량 첨가하였을 때, NDMA생성억제능은 ascorbic acid와 비슷한 경향을 나타내어 비투석성 melanoidin의 NDMA생성억제능이 우수한 것으로 나타났다. 3. Maillard반응생성물에 의한 NDMA생성억제작용은 Maillard반응생성물에 존재하는 비투석성 melanoidin이 크게 관여하고 이들 억제작용에는 Maillard반응생성물의 환원능이 크게 관여 하는 것으로 나타났다.