• 청정기술
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• 제26권4호
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• pp.263-269
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• 2020

정수슬러지를 이용하여 제올라이트(zeolite)를 수열합성하고, 제올라이트의 결정화에 대한 반응온도, 반응시간, Na2O/SiO2 몰비의 영향을 살펴보았다. 제조한 제올라이트의 결정구조, 물성 및 열적 특성은 각각 X-선 회절분석, FTIR, BET 질소흡착 및 TGA로 분석하였다. 제올라이트의 흡착성능을 조사하기 위해 암모니아성 질소, 중금속이온 및 TOC 제거효율을 측정하였다. 정수슬러지의 주성분은 Al2O3와 SiO2로서 각각 28.79%와 27.06%을 나타내었으며, 제올라이트 합성을 위한 실리카 및 알루미나 원료는 정수슬러지 이외에 어떠한 화학원료도 추가로 첨가하지 않고 합성을 진행하였다. 정수슬러지를 이용하여 제조한 제올라이트는 A형 제올라이트의 구조를 나타내었으며, 반응기질의 조성을 2.1Na2O-Al2O3-1.6SiO2-65H2O으로 하고, 반응온도 90 ℃, 반응시간 5시간, Na2O/SiO2 몰비가 1.3인 경우에 가장 높은 결정성을 나타내었다. 합성 제올라이트의 비표면적은 55 ㎡ g-1로서 상업용 제올라이트 A 보다 높게 나타났다. 합성 제올라이트의 암모니아성 질소(NH4+) 제거율은 3시간 반응한 경우 68%를 나타내었으며, 제올라이트의 Pb2+ 및 Cd2+ 이온에 대한 흡착실험 결과 제거율은 각각 99.1% 및 99.3%를 나타내었다. 이는 제올라이트의 격자 내에 존재하는 Na+ 이온과 Pb2+ 및 Cd2+ 이온 간의 원활한 이온교환이 이루어졌음을 나타낸다. 300 ppm 부식산 용액에 제올라이트의 첨가량을 변화시켜 3시간 동안 흡착실험을 수행한 결과 제올라이트 5 g을 첨가한 경우 TOC 제거율이 83%로서 가장 높게 나타났다.

• Applied Microscopy
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• 제10권1_2호
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• pp.7-17
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• 1980

Electron microscope radioautography introduced by Liquier-Milward (1956) is now used routinely in many laboratories. Most of the technical difficulties in specimen preparation have been overcome. This method is modified from loop method for improvement of EM radioautographic techniques. The advantages of this method are: 1. the use of single specimens on small corks and of a large wire loop, allows the experimenter to avoid the blemishes in the membrane; 2. the surfactant dioctyl sodium sulphosuccinate is added to diluted ILford L4, thus greatly prolonging the period of time over which good emulsion layers can be made; 3. corks can be handled in perspex holder which allows about 20 specimens to be developed simultaneously. The steps of the method comprise: 1. Cut ribbons of ultrathin sections of silver interference colour 2. Pick them up on formvar-coated 200 mesh grids 3. Prestaining of tissues 4. Coat the specimens with a thin layer of carbon by evaporation (30-60A) 5. Mount the specimens on corks (about 1cm apical diameter) using double-sided scotch tape 6. Emulsion coating; a. Take a 250m1 beaker, place it on the pan of a sliding weight balance and weigh it. Add 10 grams extra to the beam. Add pieces of ILford L4 emulsion to the beaker until the balance is swinging freely. Add the 20ml of distilled water that was previously measured out. b. Surfactant dioctyl sodium sulphosuccinate is added to diluted ILford L4. 7. Prepare a series of membranes of gelled emulsion with the wire loop and apply one to each cork-borne specimen. 8. Put the specimens away to expose by pushing the corks into short length of PVC tubing, each tube having a small hole in the side 9. Place the tubes in small boxes together with silica gel. 10. Exposure 11. Developer - Kodak Microdol X for 3 minutes 12. Fixer - A perspex holder can be manufactured which allows 20 specimens to be developed simultaneously. 12. Fixer - 30% sodium thiosulfate for 10 minutes 13. Examination with Siemens Elmiskop 1A electron microscope

• 한국환경농학회지
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• 제15권1호
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• pp.37-45
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• 1996

수도재배환경(水稻栽培環境) 및 현탁배양세포(懸濁培養細胞) 조건에서 생성된 PCP의 수용성대사물(水溶性代謝物)을 확인에 필요한 정보를 확보하기 위해서 이를 여러 chromatography로 충분히 정제한 다음 이것의 aglycons과 glycon(전보(前報)에서 ${\beta}-glucose$ conjugates인 것으로 추정)을 GC/MS로 분석, 동정하였다. Glycon, 즉 대사물의 polar부위(endocon)가 glucose임을 확인하므로써 전보에서 효소특이성을 통해 추론한 것을 입증할 수 있었다. 또한 conjugates의 source에 따라 다르기는 하였지만 배양세포에서의 aglycon(exocon)s는 주로 PCP, tetrachlorophenol이성체 및 tetra chlorocatechol을, 그리고 수도재배환경에서는 이 외에도 2,4,5- 및 2,4,6-trichlorophenol을 각각 확인할 수 있었다. 이러한 사실은 PCP glucose conjugates의 구조는 PCP뿐만 아니라 이것의 대사물인 Polychlorinated phenols가 개별적으로 glucose와 ${\beta}-anomeric$ conjugation을 이루고 있는 것으로 판단할 수 있었다. 그리고, 대사초기에 이미 여러 종류의 aglycon이 생성되는 것으로 보아 PCP자체도 빠르게 PCPs로 전환되는 것을 알 수 있었다.

• Toxicological Research
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• 제16권2호
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• pp.125-131
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• 2000

The ethanol extract of Rhus verniciflua Stokes (RVS), the Korean Lacquer tree, was subsequentely isolated and fractioned into two portions using distilled water (SED) and 99% ethanol (SEE) as elution buffers through silica gel column (4x28 em, 22 $\AA$. 28~200 mesh). To know the antioxidative effect of the RVS extracts, primary hepatocytes were exposed to hydroxyl radical generated by 20 mU/$m\ell$ glucose oxidase with SED or SEE for 4 hr. The addition of 100$\mu\textrm{g}$/$m\ell$ SED in culture medium showed good protection from glucose oxidase (GO)-mediated cytotoxicity of hepatocytes, showing approximately equivalent to control. When the hepatocytes were incubated with 100 $\mu\textrm{g}$/$m\ell$ SED or SEE only for 4 hr. the activities of cell-associated superoxide dismutase (SOD) and catalase were elevated up to 1.22 fold and 1.4 fold, respectively, compared to control. Further increase, 1.88fold in SOD activity or 1.64fold in catalase activity, was also observed when the hepatocytes were incubated with 100 units/$m\ell$ of commercial SOD or catalase for 4 hr. Moreover. the glucose oxidase-mediated cytotoxicity in cultured hepatocytes was generally reduced upon addition of lysate obtained from SED or SEE-stimulated hepatocytes in a dose-dependent manner. From these results, we suggest that, in cultured hepatocytes, RVS ethanol extract can efficiently reduce cytotoxicity induced by glucose oxidase and may increase the activity of cell-associated SOD and/or catalase, thereby preventing and/or scavenging superoxides and hydroxyl radicals in this experiment.

• 한국약용작물학회지
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• 제8권2호
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• pp.94-101
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• 2000

천연물로부터 새로운 항산화물질을 구명하기 위하여 국내에서 생산된 약용작물 38종을 수집하여 항산화 활성물질을 탐색한 결과 가시오갈피, 구절초, 건강, 목단, 시호, 산수유, 삼백초, 산사, 유근피, 작약, 천궁, 홍화씨, 및 황금등 13종이 항산화 활성이 높은 생약재로 선발되었다. 선발된 13종의 생약재중 홍화씨에 대한 활성물질을 추적, 분리하여 NMR로 물질구조를 동정한 결과 N-feruloylserotonin이 항산화 물질이라는 것을 처음 밝혀냈다. DPPH radical소거 활성에 의한 기존 항산화제인 ${\alpha}$-tocopherol, BHA 및 BHT를 N-feruloylserotonin과 항산화력를 비교한 결과 N-feruloylserotonin이 $6.6{\mu}g/ml$로 활성이 가장 높은 것으로 밝혀졌다.

• 한국결정성장학회지
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• 제13권5호
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• pp.217-221
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• 2003

본 연구에서는 섬유의 표면 거칠기를 조사하기 위하여 tetraethyl orthosilicate, 에탄올, 증류수 및 염산의 혼합 용액을 이용하여 실리케이트 섬유를 제조하였다. $80^{\circ}C$에서 증발시킨 점성용액으로부터 섬유를 인상하여 제조하였으며, 건조된 겔 섬유는 건조공기를 흘려보내며(flow rate = ∼200 m1/min) $1000^{\circ}C$, $1100^{\circ}C$, $1200^{\circ}C$ 및 $1300^{\circ}C$로 60분간 최종열처리를 행하였다 열처리된 섬유의 결정화도는 X-선 회절 $\theta$-2$\theta$ 분석을 통하여 행하였으며, 표면 특성을 조사하기 위하여 전계 방사 주사 전자현미경과 원자간력 현미경을 이용하였다. $1300^{\circ}C$로 열처리된 실리케이트 섬유는 높은 root mean square 거칠기 값을 보였으며, 비교적 불균질한 표면 구조를 가지고 있었다.

• Natural Product Sciences
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• 제26권3호
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• pp.214-220
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• 2020

Brassica oleracea var. gongylodes (red kohlrabi) is a biennial herbaceous vegetable whose edible bulbotuber-like stem and leaves are consumed globally. Sliced red kohlrabi tubers were extracted using methanol and the concentrated extract was partitioned successively with dichloromethane (CH₂Cl₂), ethyl acetate (EtOAc), n-butanol (n-BuOH) and water (H₂O). Repeated column chromatography of EtOAc fraction through silica, sephadex LH-20 and RP-18 gel led to isolation of eleven compounds of which compound 1 was a new glycosylated indole alkaloid derivative, 1-methoxyindole 3-carboxylic acid 6-O-β-D-glucopyranoside. Others were known compounds namely, β-sitosterol glucoside (4), 5-hydroxymethyl-2-furaldehyde (5), methyl-1-thio-β-D-glucopyranosyl disulfide (6), 5-hydroxy-2-pyridinemethanol (7), (3S,4R)-2-deoxyribonolactone (8), n-butyl-β-D-fructopyranoside (9), uridine (10) and three fructose derivatives, D-tagatose (11), β-D-fructofuranose (12) and β-D-fructopyranose (13). Similarly, isolation from CH₂Cl₂ fraction gave two known indole alkaloids, indole 3-acetonitrile (2) and N-methoxyindole 3-acetonitrile (3). The structure elucidation and identification of these compounds were conducted with the help of ¹³C and ¹H NMR, HMBC, HMQC, EIMS, HR-ESIMS and IR spectroscopic data, and TLC plate spots visualization. Compounds 2, 3, 4, 5, 6, 7, 8 and 9 are noted to occur in kohlrabi for the first time. Different bioactivities of these isolated compounds have been reported in literature.

• Parasites, Hosts and Diseases
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• 제22권1호
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• pp.127-134
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• 1984

As a series of studies to clarify clonorchicidal substances in body surface mucus of some freshwater fishes, the substance in the epidermal mucus of Cyprinus carpio was isolated by silica gel column and thin layer chromatography and analysed for its chemical nature. Wormicidal trial was done in vitro, and the results obtained are summarized as follows: The mucus was extracted by ethyl ether and separated into 4 fractions by column chromatography using benzene as solvent. The second fraction with yellowish red colour among them showed the strongest clonorchicidal effect. The yellowish red fraction obtained by column chromatography was then fractionated into 6 spots by thin layer chromatography with petrol/ etherjchloroform (30/70, v/v), and the Rf. 0.714 spot among the 6 spots showed the strongest effect. The Rf. 0.714 spot was further fractionated into 6 spots by thin layer chromatography with benzene/acetone (90/10, vlv), and the Rf. 0.800 spot among the later 6 spots revealed the strongest effect. The Rf. 0.800 spot was chromatographed on column with benzene and 2 fractions were obtained. The second fraction of light brown colour represented the final purified fraction. By these Purification Procedures, clonorchicidal substance was Purified 15-fold with 0.035 yield from the mucus of C. carpio, and 10mg of the final fraction killed the cercaria in 26 min, the metacercaria in 115 min, and the adult in 443 min. Infra red and nuclear magnetic resonance spectrometric analysis of the purified substance revealed that the substance belongs to an ethyl ester of unsaturated fatty acid with 2 double bonds, 15 methylene groups and 1 methyl group.

• Applied Biological Chemistry
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• 제44권3호
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• pp.202-205
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• 2001

건강을 80% MeOH수용액으로 추출하고, 얻어진 추출물을 EtOAc, n-BuOH및 $H_2O$로 용매 분획하였다. 그 중에서 뚜렷한 활성을 보인 EtOAc 분획으로부터 DPPH(1-diphenyl-2-picryl hydrazyl) radical 포획법으로 항산화 활성을 추적하여 항산화 활성을 갖는 화합물 2종을 분리하였다. 각각을 NMR 및 MS 데이터의 해석과 문헌 자료를 조사하여 6-shogaol 및 12-shogaol로 구조를 결정하였다. 각 화합물의 $EC_{50}$값은 26.4 ${\mu}M$과 22.5 ${\mu}M$로 상용항산화제인 BHA, BHT 및 ${\alpha}-tocopherol$보다 뚜렷이 높은 활성을 나타내었다.

• Journal of Microbiology and Biotechnology
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• 제15권5호
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• pp.1001-1010
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• 2005

Bacillus megaterium KL39, an antibiotic-producing plant growth promoting rhizobacterium (PGPR), was selected from soil. The antifungal antibiotic, denoted KL39, was purified from culture filtrate by column chromatography using Dion HP-20, Silica gel, Sephadex LH-20, and prep-HPLC. Thin layer chromatography, employing the solvent system of ethanol:ammonia:water=8:1:1, showed the $R_{f}$. value of 0.32. The antibiotic KL39 showed a negative reaction with ninhydrin solution, positive with iodine vapor, and also positive with Ehrlich reagent. It was soluble in methanol, ethanol, butanol, and acetonitrile, but insoluble in chloroform, toluene, hexane, ethyl ether, or acetone. Its UV spectrum had the maximum absorption at 208 nm. Amino acid composition, FAB-mass, $^{1}H-NMR,\;^{13}C-NMR$, and atomic analyses showed that the antibiotic KL39 (MW=1,071) has a structure very similar to iturin E. The antibiotic KL39 has a broad antifungal spectrum against a variety of plant pathogenic fungi including Rhizoctonia solani, Pyricularia oryzae, Monilinia froeticola, Botrytis cinenea, Altenaria kikuchiana, Fusarium oxysporum, and F. solani. An MIC value of $10\;{\mu}g/ml$ was determined for Phytophthora capsici. Macromolecular incorporation studies with P. capsici using radioactive [$^{3}H-adenine$] as the precursor, indicated that the antibiotic KL39 strongly inhibits the DNA biosynthesis of the fungal cell. Microscopic observation of the antifungal action showed abnormal hyphal swelling of P. capsici. The purified antibiotic KL39 was very effective for the biocontrol of in vivo Phytophthora-blight disease of pepper.