• Korean Chemical Engineering Research
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• 제46권1호
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• pp.189-193
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• 2008

본 연구는 zinc aluminate 촉매를 사용한 고압연속식 고정층 반응시스템에서의 대두유와 메탄올의 transesterification에 관한 것이다. 바이오디젤 제조를 위한 고압 연속식 고정층 촉매 반응에서 반응 조건이 메틸에스터 생성에 미치는 영향이 주로 조사되었다. 촉매가 없는 경우, 거의 모든 반응 조건에서 메틸에스터의 수율이 4.5% 이하로 매우 낮았지만, $300^{\circ}C$, 1,200 psi 조건에서는 19%의 메틸에스터 수율을 보여 주었다. 이는 반응 조건이 메탄올의 초임계점에 근접하였기 때문으로 보인다. 촉매 반응에서는 무촉매 반응과 비교하여 비교적 낮은 온도와 압력에서도 높은 메틸에스터 수율을 보여주었다. 또한 수율에 미치는 반응 조건의 영향을 살펴본 결과, 반응온도, 압력, 반응물에서 메탄올 몰비가 높을수록 높은 메틸에스터 수율을 보여주었다. 반응 변수 중에서도 반응온도가 메틸에스터 수율에 가장 큰 영향을 미치는 것으로 확인되었다.

• 생약학회지
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• 제42권4호
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• pp.323-328
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• 2011

We investigated antioxidative activity, tyrosinase inhibitory activity, and melanin production inhibitory activity of the methanol extract of Paeoniae Radix and its fractions. The total polyphenol content of the extract was 73.45 mg/g, and content of the ethyl acetate fraction was 514.50 mg/g as the highest content of fractions. In DPPH radical scavenging ability, $SC_{50}$ values of the ethyl acetate was 3.86 ${\mu}g/ml$ as a result of greater activity in the positive control (ascorbic acid). Moreover, tyrosinase inhibitory activity of the ethyl acetate fraction showed higher activity than arbutin used as a positive control. In the cytotoxicity measurement by MTT assay, the extract and fractions were exhibited cell viabilities of 76.96~157.26% against Raw 264.7 and B16F10 cell in concentration of 10~100 ${\mu}g/ml$. In nontoxic concentration range, the ethyl acetate fraction showed strong melanin production inhibitory effect in ${\alpha}$-melanocyte stimulating hormone (${\alpha}$-MSH)-stimulated B16F10 cell. As a result, the ethyl acetate fraction of the methanol extract from Paeoniae Radix could be applicable to functional materials for skin-whitening agents.

• 한국약용작물학회지
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• 제19권5호
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• pp.368-372
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• 2011

In this study, we investigated on antioxidative activity and nitric oxide production inhibitory activity of various solvent extracts of Lespedeza bicolor. The total polyphenol content of the methanol extract was 192.6 mg/g and flavonoid content of the acetone extract was 40.6 mg/g, as the highest content. In DPPH radical scavenging ability, $SC_{50}$ values of the ethanol and methanol extract were exhibited $0.69mg/m{\ell}$ and $0.89mg/m{\ell}$, respectively. However, in nitric oxide(NO) scavenging ability, $SC_{50}$ values of the acetone was exhibited $0.72mg/m{\ell}$ as the highest activity. Moreover, the acetone extract showed strong NO production inhibitory effect in lipopolysaccharide(LPS)-stimulated Raw 264.7 cell. In the cytotoxicity measurement by MTT assay, the extracts were exhibited Raw 264.7 cell viabilities of 92.57~129.04% as nontoxic result in concentration of $65{\sim}650{\mu}g/m{\ell}$. As a result, the acetone extract of L. bicolor could be applicable to functional materials for anti-inflammatory related fields.

• Biomolecules & Therapeutics
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• 제19권1호
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• pp.90-96
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• 2011

Automated HPLC/SPE/HPLC coupling experiments using the Sepbox system allowed the rapid identification of four bioactive principles reducing the production of amyloid $\beta$-peptide ($A{\beta}$) from two South African plants, Euclea crispa subsp. crispa and Crinum macowanii. The structures of biologically active compounds isolated from the methanol extract of Euclea crispa subsp. crispa were assigned as 3-oxo-oleanolic acid (1) and natalenone (2) based on their NMR and MS data, while lycorine (3) and hamayne (4) were isolated from the dichloromethane-methanol (1:1) extract of Crinum macowanii. These compounds were shown to inhibit the production of $A{\beta}$ from HeLa cells stably expressing Swedish mutant form of amyloid precursor protein (APPsw).

• 생약학회지
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• 제43권2호
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• pp.173-178
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• 2012

In this study, we investigated antibacterial activity and nitric oxide production inhibitory effect of the methanol extract and its fractions from Paeoniae Radix. In antibacterial activity by the disc diffusion assay against S. aureus, S. epidermidis and P. aeruginosa, the ethyl acetate fraction showed stronger antibacterial activity than other fractions and the extract. Moreover, the ethyl acetate fraction showed strong nitric oxide (NO) production inhibitory effect in lipopolysaccharide (LPS)-stimulated RAW 264.7 cell. However, in NO scavenging ability, the chloroform fraction was higher than the other fractions and the extract. In the lactate dehydrogenase (LDH) assay against RAW 264.7 cell, the extract and fractions were exhibited normal LDH release level as nontoxic result without the ehtyl acetate fraction of 100 ${\mu}g/ml$. As a result, the ethyl acetate fraction and chloroform fraction of the methanol extract from Paeoniae Radix could be applicable to functional materials for antibacterial and anti-inflammatory related fields, respectively.

• 대한본초학회지
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• 제33권5호
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• pp.73-79
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• 2018

Objectives : Coriandrum sativum is a medicinal herb that is used to enhance organoleptic quality and food flavor and as source of natural antioxidants. This research investigated the anti-inflammatory activity of Coriandrum sativum stem methanol extract (CSSE) using RAW 264.7 cells. Methods : Production of tumor necrosis factor-${\alpha}$(TNF-${\alpha}$), interleukin (IL)-$1{\beta}$, IL-6, and nitric oxide (NO) in the culture supernatant, protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and nuclear factor-kappa B (NF-${\kappa}B$) in the extract were assayed. Results : Treatment with CSSE ($100{\mu}g/m{\ell}$) resulted in inhibited levels of protein expression of lipopolysaccharide- (LPS-) induced iNOS, COX-2, and NF-${\kappa}B$ as well as production of TNF-${\alpha}$, IL-$1{\beta}$, IL-6, and NO induced by LPS. Conclusions : These results demonstrate that CSSE exhibits anti-inflammatory activities via decreasing production of pro-inflammatory mediators through suppression of the pathways of NF-${\kappa}B$ in LPS-induced RAW 264.7 cells. Thus, CSSE may have therapeutic potential for a variety of inflammation-mediated diseases.

• Journal of Applied Biological Chemistry
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• 제64권3호
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• pp.197-203
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• 2021

본 연구에서는 보리 어린 순의 기능성 성분인 saponarin의 정량적 추출을 위한 최적의 추출 분석 조건을 methanol, ethanol, acetonitrile 및 water를 대상으로 반응표면분석법을 통해 실시하였다. 이를 통해 용매의 농도, 추출 시간에 따른 saponarin과 색소 추출율을 확인한 결과, 53.7% methanol 수용액에서 3.9 h 동안 진탕추출하는 것이 높은 saponarin 추출율을 유지하면서, 불필요한 색소의 추출을 최소화하는 최적 추출조건으로 확인되었다. 보리 어린 순의 재배에 필요한 인공광의 saponarin 생성 영향 평가를 광 주기, 광량, 광질을 달리한 조건에서 시험한 결과, saponarin 고함유 보리 어린 순의 인공광 최적 재배 조건은 8 h day^-1의 광 주기에서 6500K LED와 적색보광을 통한 총 광량 220-320 μmol m^-2 s^-1 에서 가장 효과적임을 확인 할 수 있었고, 청색광이 saponarin 생합성에 주요 인자로 작용함을 확인할 수 있었다.

• KSBB Journal
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• 제10권2호
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• pp.176-182
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• 1995

Methylobacterium organophilum을 이용하여 다당류(메틸란)와 poly-${\beta}$-hydroxybutyrate(PHB)의 생산에 영향을 주는 환경 및 생리적 인자들을 조사하였다. PHB 축적을 위하여는 $38^{\circ}C$, 다당류의 생산을 위하여는 $30^{\circ}C$가 최적이었다. pH의 경우는 P PHB의 축적은 pH 7 ~ 8, 다당류의 생산은 pH 6~7 이 최적이였다. 질소원 제한 상태하에서의 $Mo^{2+}, Mg^{2+} 또는 Mn^{2+}$ 등의 결핍조건에셔는 질소원만의 제한조건보다 P PHB 축적은 증가하였으나, 다당류 생산은 감소하였 다. 질소원의 제한없이 $K^+$만의 결핍조건에서는 균 체증식도 억제되었고 다당류도 생성되지 않았지만 건조균체당 PHB 함량은 60%까지 증가하였다. PHB와 다당류의 동시 생산을 위한 C/N 비율의 효 는 C/N 비율이 높을수록 질소원의 제한효과 때문에 균체증식은 감소되었지만 건조균체량당 PHB 함량과 다당류의 생성은 현저히 증가하였다.

• Journal of Microbiology and Biotechnology
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• 제11권2호
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• pp.329-332
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• 2001

It has been known that, in enzymatic synthesis of cephalexin, the conversion yield was reduced by high loading of ampicillin acylase. In order to elucidate this phenomena, pH-controlled synthesis of cephalexin was examined using a purified Acetobacter turbidans acylase. When the pH of the reaction mixture was maintained at $6.20{\pm}0.04$, the reduction of the maximal conversion rate was not observed even with high enzyme loading. The kinetic parameters also suggest that pH drop during the enzymatic synthesis of cephalexin was mainly attributed to the rapid hydrolysis of D-${\alpha}$-phenylglycine methyl ester to D-${\alpha}$-phenylglycine, rather than the disappearance of 7-amino-3-deacetoxycephalosporanic acid for cephalexin synthesis. At higher molar ratio of two substrates, [D-${\alpha}$-phenylglycine methyl ester]/[7-amino-3-deacetoxycephalosporanic acid], the conversion rate was also elevated under pH-controlled enzymatic synthesis, which implies that the main reason for the pH drop is due to the production of D-${\alpha}$-phenylglycine methyl easter, the effect of a water-methanol cosolvent system on the ester, the effect of a water-methanol cosolvent system on the conversion profile was also examined. Even the though the conversion rate was increased in 10% methanol solution, a higher than 16% methanol in the reaction mixture caused an inactivation of enzyme.

• 조명전기설비학회논문지
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• 제25권10호
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• pp.116-124
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• 2011

In this work, the effect of the initial concentration of methanol and ethanol, and the addition of oxygen molecules were discussed to improve the hydrogen generation using non-thermal plasma reactor effectively. In addition, the effect of ozone decomposition catalyst of manganese dioxide and its quantity was investigated. First, hydrogen concentration increased until an initial concentration of about 40,000[ppm] of methanol and thereafter it was saturated. Henceforth, hydrogen concentration decreased with increasing the oxygen percent on the carrier gas of nitrogen about both substances. Related with the effect of catalyst, it increased upto 60[g], but it was not changed largely after that. Consequently, it is confirmed that the hybrid process using plasma process and catalytic surface chemical reaction is a very promising way to increase the efficiency of hydrogen generation as investigated in this work.