• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.6
• /
• pp.821-832
• /
• 1997

The aim of this study was to separate or purify some bioactive compounds from flowers of alfalfa(Medicago sativa L.) and to test of the isolated compounds on alfalfa for their autotoxicity and on Echinochloa crus-galli for their allelopathy for seed germination and seedling weight. Using thin layer chromatography(TLC) of $CHCl_3$ extracts, the most inhibitory band to alfalfa seed germination was determined. Germination inhibition of this extract suggested a complex chemical interaction. Separation and purification of compounds with CHCl$_3$ extract of fresh alfalfa flowers were conducted by a silica gel TLC, and microcrystalline cellulose TLC(MCTLC), followed by droplet countercurrent chromatography(DCCC) bioassay. Preliminary identification was done by high perfomance liquid chromatography(HPLC) on the most inhibitory fractions in DCCC. Ferulic acid, caffeic acid, vanillic acid, rutin, narringin were identified in fraction 5 and ferulic acid, caffeic acid, vanillic acid, rutin, coumarin in fraction 6. The phytotoxicity of their individual compound was tested on alfalfa and Echinochloa crus-galli seed germination and seedling weight. Coumarin and ferulic acid showed the most inhibitory effect on alfalfa seed germination and Echinochloa crus-galli seedling fresh and dry weight. These compounds may be, at least in part, involved in autotoxicity and allelopathy.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.50 no.4
• /
• pp.443-451
• /
• 2023

The purpose of this study was to evaluate whether the newly introduced calcium silicate-based materials with fast-setting properties could be appropriately used as basement materials in indirect pulp treatment (IPT). This was performed by quantifying the durability of adhesion between the material and composite resin, measured by the shear bond strength (SBS). Five calcium silicate-based materials, TheraCal LC^® (TLC), TheraCal PT^® (TPT), TheraBase^® (TB), Well-Root^TM PT (WPT), and Endocem^® MTA (EMTA), as well as two glass ionomer-based materials, Fuji II and Fuji II LC, were included. Specimens containing these materials were manufactured and bonded to composite resin with a universal adhesive applied in self-etch mode. The SBS values and failure modes were recorded, and the mean SBSs of the materials were compared. Both TPT and TB exhibited SBS values that were similar to TLC, while both WPT and EMTA appeared to have statistically lower SBS values. Mixed failure was commonly observed in TLC and TPT, while all WPT and EMTA samples showed cohesive failure. In comparison with TLC and TPT, more samples with cohesive failure were observed in TB, implying that this material forms a stronger bond with composite resin. Together with the ability of TB to chemically bind to dentin due to its 10-methacryloyloxydecyl dihydrogen phosphate component, TB seems to be a promising material for IPT within the limitations of this in vitro study.

• Tuberculosis and Respiratory Diseases
• /
• v.46 no.4
• /
• pp.489-499
• /
• 1999

Background: The patient with bronchiectasis may have obstructive ventilatory impairment combined with mild restrictive ventilatory impairment due to fibrosis of surrounding lung parenchyme and pleural adhesions caused by chronic recurrent pulmonary infections. Since hyperinflation or emphysematous change can be occured in bronchiectasis, pulmonary functions such as lung volumes and diffusing capacity may also vary with associated emphysema. Methods: For the evaluation of lung volumes and diffusing capacity in bronchiectasis with respect to the anatomic types and severity of bronchiectasis, a total of 40 cases comprising 24 cases of tubular, and 16 cystic type of bronchiectasis were analyzed retrospectively. Correlation between lung functions and extent of bronchiectasis or associated emphysema detected in HRCT were also evaluated. Results: Vital capacity(VC) tended to decrease in cystic type than in tubular type. As the severity of bronchiectasis became serious, the VC were significantly reduced, whereas the total lung capacity(TLC), residual volume(RV) and its ratio to the total lung capacity(RV/TLC) had no significant difference. Lung clearance index(LCI) was significantly increased in cystic type than in tubular type, whereas the slope of phase III in single breath nitrogen curve($\triangle$N2/L) was not significantly changed regard to the type and severity of bronchiectasis. DLCO and DLCO/VA reflecting diffusing capacity were significantly decreased in cystic type and also as the severity of bronchiectasis became serious. The correlation coefficient of VC, DLCO and LCI with the extent of bronchiectasis were -0.322, -0.339 and 0.487, respectively, whereas other parameters were not significantly correlated with the extent of bronchiectasis. VC and DLCO correlated negatively with the extent of emphysema while RV, RV/TLC, LCI and $\triangle$N2/L correlated positively. Conclusion: These findings suggest that the reduction of VC and diffusing capacity or uneven distribution of inspired gas in bronchiectasis are related to both the extent of bronchiectasis and associated emphysema while increased residual volume be related to the extent of associated emphysema alone.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2015.08a
• /
• pp.59.1-59.1
• /
• 2015

In the Linford group at Brigham Young University we have recently developed three new sets of materials for three different areas of separations science: thin layer chromatography (TLC), high performance liquid chromatography (HPLC), and solid phase microextraction (SPME). First, via microfabrication we have grown patterned carbon nanotube (CNT) forests on planar substrates that we have infiltrated with inorganic materials such as silicon nitride. The coatings on the CNTs are conformal and typically deposited in a process like low pressure chemical vapor deposition. The resulting materials have high surface areas, are porous, and function as effective separation devices, where separations on our new TLC plates are typically significantly faster than on conventional devices. Second, we used the layer-by-layer (electrostatically driven) deposition of poly (allylamine) and nanodiamond onto carbonized poly (divinylbenzene) microspheres to create superficially porous particles for HPLC. Many interesting classes of molecules have been separated with these particles, including various cannabinoids, pesticides, tricyclic antidepressants, etc. Third, we have developed new materials for SPME by sputtering silicon onto cylindrical fiber substrates in a way that creates shadowing of the incoming flux so that materials with high porosity are obtained. These materials are currently outperforming their commercial counterparts. Throughout this work, the new materials we have made have been characterized by X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, scanning electron microscopy, transmission electron microscopy, etc.

• KSBB Journal
• /
• v.17 no.3
• /
• pp.302-306
• /
• 2002

The chemical analysis and surface chemical properties of biosurfactant formed by Rhodococcus sp. strain IGTS8, which is widely used in biodesulfurization process, in hexadecane/water mixture have been studied. For the chemical analysis, TLC technique was employed. The surface tension, CMC, and emulsion stability of biosurfactant solution were also investigated. The major components of biosurfactant formed by Rhodococcus sp. strain IGTS8 were glucose mycolate and trehalose monomycolate. The CMC of aqueous biosurfactant solution was 0.1 ~0.15 g/100 mL of Water at pH 6.0-6.5 and pH 10~10.5. But the demulsification was faster at pH 10 than at pH 6.3.

• Journal of Food Hygiene and Safety
• /
• v.15 no.3
• /
• pp.235-240
• /
• 2000

Various separation techniques of antimicrobial compounds from food materials have proven to be ineffective, involving liquid-liquid extraction and chromatography. We established efficient separation procedure for partially purifying antimicrobial compounds from Korean leek. Separation procedures consisted of ultrafiltration, liquid-liquid extraction, TLC and HPLC. Molecular weight of antimicrobial compounds were less than 5,000 dalton. Major compounds were propenyl methyl disulfide, S-methyl methylthiosulphonate and dimethyl disulfide.

• The Korean Journal of Food And Nutrition
• /
• v.10 no.4
• /
• pp.480-484
• /
• 1997

Sugars in Korean ginseng(Panax ginseng C. A. Meyer) were studied by HPLC, TLC and NMR. The sugars in Korean ginseng were crushed and extracted by boiling for 30min. Korean ginseng was found to contain 3.77% of sucrose, 3.50% of maltose, 0.09% of fructose and 0.04% of glucose and 3.90% of starch. No other mono- and oligosaccharides were detected in the test of TLC and HPLC. Starch in ginseng showed only signal of $\alpha$-1, 4-glucosidic linkage by proton NMR analysis, and showed 92% of absorbance by iodine reaction compared with amylose(DP 117). These results indicated that starch in Korean ginseng is composed by only amylose. Pectin content in ginseng showed 0.22% as galcturonic acid by carbazole analysis.

• Applied Biological Chemistry
• /
• v.30 no.1
• /
• pp.40-45
• /
• 1987

Degradation of polychlorinated biphenyls(PCBs) and organochlorine pesticides by Alcaligenes aquamarinus has been studied and also degradation product of PCB-42 was investigated by TLC and GC. The less chlorinated members of PCBs such as Aroclor 1016 was degraded readily by the strain and rates of the microbial degradation of several organochlorine pesticides were found to decrease in the order of p,p'-DDT, r-BHC and Thiolix. Approximately 40 percent of PCB-42 was degraded when incubated with non-autoclaved soil for 25 days at $25^{\circ}C$. The yellow compound from PCB-42 was tentatively identified as p-chlorobenzoic acid.

• Proceedings of the Ginseng society Conference
• /
• 1993.09a
• /
• pp.206-214
• /
• 1993

Ginseng saponins have been known as main active principles and analyzed as the index components in ginseng and its products for quality control. But it is generally difficult to analyze the saponins in crude drug preparations. Saponins, Prosapogenins and sapogenins of crude drug preparation were identified by TLC and determined quantitatively by HPLC. $Prosapogemins-Rg_3\;-Rg_2\;and\;{\Delta}^{20}-prosapogenin$ were extracted with ethyl acetate from $50\%$ acetic acid hydrolyzates of saponin fractions and identified by TLC with lower phase of $CHCl_3/MeOH/H_2$ O\65:35:10. v/v)on silica gel plate, and quantified by HPLC on $Lichrosorb-NH_2$ column with $CH_3CN/H_2O(90:10,\;v/v).$ Sapogenins. panaxadiol and panaxatriol. were extracted with ethyl ether from $7\%-sulfuric$ acid hydrolyzates of saponin fractions and identified by TLC with chloroform/acetone(1 : 1 v/v) on silica gel plate. and quantified by HPLC on u - Bondapak $C^{18}$ column with $CH_3CN/MeOH/CHCl_3(83:10:7.\;v/v).$ These analyses of prosapogenins and sapogenins are more useful for quality control than those of saponins in crude drug preparations such as So - Shi - Ho - Tang(소시호탕), Sa - Kun - Ja - Tang(사군자탕), Yook - Kun - Ja - Tang(육군자탕), and In - Sam -Tang(인삼탕)

• Biomolecules & Therapeutics
• /
• v.1 no.1
• /
• pp.58-64
• /
• 1993

DNA addicts induced by putative chemical related to carcinogenesis were detected and determined by $^{32}$P-Postlabelling assay after exposure of 4 compounds comprising two auto dyes (amaranth, new coccine) and two flavonoid compounds (rutin, quercetin) to ICR mouse. DNA was isolated from mouse liver and digested enzymatically to deoxyribonucleoside 3'-monophosphate. The postincubation of DNA digests with nuclease Pl before $^{32}$P-labelling enhanced the technique's sensitivity. Nuclease Pl cleaves deoxyribonucleoside 3'-mono-phosphates of normal nucleotides to deoxyrihonucleosides which do not serve as substrates for polynucleotide kinase, while most of addicts were found to be totally or partially resistant to the 3'-dephosphorylating action of nuclease Pl. The adducted deoxyribonucleoside 3'-monophosphate was converted to 5'-$^{32}$P-labelled deoxynucleoside 3',5'-bisphosphate by T4 polynucleotide kinase. The nucleotides were separated by anion-exchange thin layer chromatography(TLC) on polyethyleneimine cellulose by 4-dimensional or 2-dimensional TLC then detected by autoradiography. The results show that DNA addicts were detected in liver DNA of ICR mouse after administration of amaranth and quercetin by 2-dimensional and/or 4-dimensional TLC.