• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2018년도 추계학술대회
• /
• pp.254-254
• /
• 2018

• Bulletin of the Korean Chemical Society
• /
• 제4권4호
• /
• pp.189-191
• /
• 1983

• 멤브레인
• /
• 제24권2호
• /
• pp.113-122
• /
• 2014

상전이 과정을 통하여 poly(L-lactic acid) 재질의 다공성 스캐폴드 막을 제조하였다. 비용매로는 에탄올을 사용하였고, 용매로서 chloroform, dichloromethane 및 1,4-dioxane을 사용하였으며, 제조한 스캐폴드 막의 모폴로지와 기계적 강도 및 물질전달 특성은 각각 SEM, 인장강도실험 및 당 확산실험을 통하여 측정, 평가하였다. chloroform을 용매로 사용한 스캐폴드 막과 dichloromethane을 용매로 사용한 스캐폴드 막은 서로 유사한 모폴로지와 기계적 특성을 보였다. 이들 스캐폴드 막은 공극 직경 $3-10{\mu}m$의 다공성 스펀지 구조를 보였으며, 범위 50-80%의 공극률을 보였다. 1,4-dioxane 용매의 용액으로부터 제조된 스캐폴드 막은 공극률 80% 이상의 나노섬유 형태를 보였다. 캐스팅 용액 내의 고분자 함량이 4% 이하로 낮추었을 때에는 나노섬유 구조의 바탕에 수십 ${/mu}m$의 거대 공극이 존재하는 높은 공극률(90%)을 갖는 스캐폴드 막이 얻어졌다. 이러한 결과를 통하여 스캐폴드 막의 구조에 대하여 용매는 중요한 효과를 미치며, 상전이 과정에서 용매선택과 캐스팅 용액의 농도 조절을 통하여 다양한 구조의 스캐폴드 막을 제조할 수 있다는 결론을 도출하였다.

• 생명과학회지
• /
• 제27권5호
• /
• pp.561-566
• /
• 2017

황칠나무(Dendropanax morbifera Lev.)는 황금빛의 수액과 약리효과로 한국에서 알려져 있으며, 잎 및 줄기 추출물의 다양한 효능은 피부질환, 편두통, 월경통, 근육통 및 전염성 질환 등의 질병을 개선하는 약리 성분을 공급하는 우수한 공급원이 될 수 있는 것을 시사한다. 그러나, 황칠나무 추출물의 효능에 관해서는 다양한 연구가 보고되어 있으나, 부위별 휘발성 성분의 조성에 대한 보고는 전무한 상황이다. 따라서, 본 연구는 황칠나무의 잎, 줄기 및 수액의 주요 휘발성 성분을 규명하기 위하여, 유기용매 및 초임계유체추출법을 이용한 추출물을 가스크로마토그래피-질량분석법으로 분석하였다. 잎 추출물에서는 15가지 화합물이 검출되었으며, 줄기 및 수액에는 각각 29가지 및 3가지 성분이 확인되었다. 또한 용매와 초임계유체추출법을 사용하여 얻은 휘발성 성분의 프로파일은 다르게 나타났다. 잎의 용매 추출물과 줄기의 초임계유체 추출물에서는 에스테르와 방향족 탄화수소가, 잎의 초임계유체 추출물 및 줄기의 초임계유체 추출물에는 테르페노이드가 주요 성분으로 나타났다. 한편, limonene (96.3%), ${\alpha}$-pinene, 그리고 ${\beta}$-myrcene은 수액 용매 추출물의 휘발성 성분으로 확인되었다. 잎 및 줄기의 용매 추출물의 암세포 증식 억제 효과를 평가한 결과, 잎의 용매 추출물이 HepG2 세포의 증식을 유의적으로 감소시키는 것으로 나타났다.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제40권1호
• /
• pp.28-32
• /
• 2020

Recently, many studies have been undertaken on the wet spinning and electrospinning of silk because wet-spun fibers and electrospun webs of silk can be applied in the biomedical and cosmetic fields owing to the good biocompatibility of silk. The rheological properties of silk solution are important because they strongly affect the spinning performance of the silk solution and the structures of resultant fibrous materials. Therefore, as a preliminary study on the effect of solvent composition on the rheological properties of silk fibroin (SF) solution and structure of the resultant film, in the reported work, methanol was added to the SF formic acid solution. A small amount of methanol (i.e. 2%) added to the SF formic acid solution significantly altered the rheological properties of the solution: its shear viscosity increased by 10 folds at low shear and decreased on increasing the shear rate, demonstrating shear thinning behavior of the SF solution. Dynamic tests for the SF solution indicated that the addition of 2% methanol altered the viscous state of the SF formic acid solution to elastic. However, the molecular conformation (i.e. β-sheet conformation) of the regenerated SF film cast from formic acid remained unchanged on the addition of 2% methanol.

• 대한기계학회논문집B
• /
• 제30권7호
• /
• pp.663-670
• /
• 2006

The presented study aims to investigate the colloidal droplet deposition caused by evaporation of the liquid. In the numerical analysis, the evaporation is carried out by using different evaporation function intended to obtain different shape of solute deposition. In the experiment, the colloidal droplets of different solvents are placed on a glass plate and the surface profiles are measured after drying the solvents of the droplets to investigate the effect of the solvent evaporation on the final deposition profile. Comparing the surface profiles obtained under different conditions, the optimum drying conditions of colloidal droplets are, determined to obtain uniform surface profiles. The numerical results showed that ring-shaped deposition of solute was formed at the edge of the droplet due to the coffee stain effect and the height of the ring was reduced at the lower evaporation rate. The experiments showed that the boiling point of a solvent was critical to the surface uniformity of the deposition profile and the mixture of solvents with different boiling points influenced the uniformity as well.

• 약학회지
• /
• 제31권1호
• /
• pp.33-39
• /
• 1987

In order to elucidate the defence mechanism of Cyprinus carpio nudus to Clonorchis sinensis, clonorchicidal substance in the epidermal mucus of this fish was isolated by silica gel column and thin layer chromatography and analyzed for its chemical nature by UV, IR and NMR-spectroscopy. The epidermal mucus of the fish was extracted by ethyl ether and separated into 2 fractions by column chromatography using petroleum ether/chloroform(30/70,v/v) as first solvent and methanol as second solvent. The second fraction with greyish white colour showed clonorchicidal effect. The second was again fractionated into greyish white precipitate and clonorchicidal greenish yellow supernatant fraction, by adding petroleum ether and standing the mixture for 5 days at $5^{\circ}C$. The latter was divided into 7 fractions in column chromatography with acetone/ benzene (10/90, v/v) as carrier. The fraction on equivalent to the spot of Rf. 0.225 value among them disclosed the strongest clonorchicidal effect. By this purification procedure, clonorchicidal substance was purified 154-fold with 0.9% yield from the mucus of the fish, and 10mg of the final fraction killed tne metaceicariae in 22 min. Infra red, nuclear magnetic resonance and ultraviolet spectrometric analysis of the purified substance revealed that the substance is linoleic acid. According to the results of the present studies it seemed that this fish could not be proper intermediate host of Clonorchis sixensis, and that defence mechanism of this fish to the worm seems to be correlated with clonorchicidal substance in epidermal mucus.

• 생약학회지
• /
• 제46권3호
• /
• pp.229-233
• /
• 2015

The anti-nociceptive effect of an ethanol extract and its various solvent fractions from Curcuma longa Linne ethanol extract was studied using the writhing test in mice. Different fractions by various solvent extraction from Curcuma longa Linne ethanol extract were administered orally 1 hr or time-course (0.5, 1, 2 and 5 hr) before intraperitoneal injection of acetic acid. After treatment with 30% ethanol extract and n-butanol fraction, CB-1, at a dose of 250 mg/kg, the significant writhing responses were 87.5 ± 13.4 (inhibition rate 31%, p<0.01) and 75.1 ± 11.1 (inhibition rate 41%, p<0.01) lower than the control group. At the dose of CB-1 50 mg/kg and 250 mg/kg, CB-1 showed a similar activity comparing to diclofenac of 10 mg/kg. A time-course experiment was performed, which involved oral administration of CB-1 (250 mg/kg) at 0, 0.5, 1, 2, and 5 hr before acetic acid intraperitoneal injection. The most effective time of CB-1 was 30 min before treatment and persisting until 2 hr. This study showed that Curcuma longa Linne has anti-nociceptive properties comparable with those of diclofenac, which suggests promise for the treatment of intractable visceral pain in humans. Major components of the active fraction are identified as curcumin, cyclocurcumin and demethoxycurcumin.

• Bulletin of the Korean Chemical Society
• /
• 제32권6호
• /
• pp.1897-1901
• /
• 2011

This report shows the rates of solvolyses for phenyl methanesulfonyl chloride ($C_6H_5CH_2SO_2Cl$, I) in ethanol, methanol, and aqueous binary mixtures incorporating ethanol, methanol, acetone, 2,2,2-trifluroethanol (TFE) and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) are reported. Three representative solvents, studies were made at several temperatures and activation parameters were determined. The thirty kinds of solvents gave a reasonably precise extended Grunwald-Winstein plot, coefficient (R) of 0.954. The sensitivity values (l = 0.61 and m = 0.34, l/m = 1.8) of phenyl methanesulfonyl chloride (I) were smaller than those obtained for benzenesulfonyl chloride ($C_6H_5SO_2Cl$, II; l = 1.01 and m = 0.61) and 2-propanesulfonyl chloride ($(CH_3)_2CHSO_2Cl$, III; l = 1.28 and m = 0.64). As with the two previously studied solvolyses, an $S_N2$ pathway with somewhat ionization reaction is proposed for the solvolyses of I. The activation parameters, ${\Delta}H^{\neq}$ and ${\Delta}S^{\neq}$, were determined and they are also in line with values expected for a bimolecular reaction mechanism. The kinetic solvent isotope effect of 2.34 in $CH_3OH/CH_3OD$ is in accord with a bimolecular mechanism, probably assisted by general-base catalysis.

• Preventive Nutrition and Food Science
• /
• 제14권1호
• /
• pp.76-85
• /
• 2009

This study determined the effect of refrigerated and thermal storage on the volatile profile of commercial aseptic soymilk. Volatile components in commercial aseptic soymilk stored either under refrigerated ($4^{\circ}C$) or thermal ($55^{\circ}C$) conditions for 30 days were periodically analyzed by combined solvent-assisted flavor evaporation-gas chromatography-mass spectrometry (SAFE-GC-MS). The concentrations of most of the volatile components, including aldehydes, ketones, alcohols, acids, nitrogen- and sulfur-containing compounds, alkylfurans, furan derivatives and phenolic compounds, were affected to a greater extent by thermal storage compared with refrigerated storage. Profound increases in some volatile compounds with low odor detection thresholds, such as hexanal, octanal, (E)-2-octenal, (E,E)-2,4-decadienal, 1-octen-3-ol, 3-ethyl-2,5-dimethylpyrazine, 2,3-diethyl-5-methylpyrazine, 2-pentylfuran, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, dimethyl trisulfide, guaiacol, 4-vinylguaiacol and 4-vinylphenol, were observed in thermal stored soymilk. The volatile profile changes caused by thermal storage may influence the aroma quality of thermal-stored aseptic soymilk.