• Journal of the Korean Chemical Society
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• v.51 no.2
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• pp.115-124
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• 2007

A series of α, β-unsaturated ketones are synthesized by Crossed - Aldol condensation reaction, from ecofriendly 6-methoxy-2-naphthyl ketones and substituted benzaldehydes under solvent free conditions using silica-sulfuric acid as a catalytic reagent. The yields of ketones are more than 90% and the catalyst was reusable for further run. There is no appreciable decrease in the yield of product and the activity of catalyst. These chalcones were characterized by their physical constants and spectral data (IR, 1H-, 13C-NMR and Mass). These spectral data are subjected to correlate various Hammett substituent constants with single and multiparameter correlation equations. From the results of statistical analysis the influence of electronic effects of substituents on the spectral data of the ketones were explained.

• Journal of the Korean Chemical Society
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• v.40 no.8
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• pp.565-570
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• 1996

A simple and efficient new synthetic method of 4'-[N-(9-acridinyl)]-1'-(N-methanesulfonyl)-3'-methoxyquinonediimide(AMQD, 5) was developed and six new nucleophilic adducts(6a-6f) were prepared by the addition of thiophenol derivatives to AMQD. The structures of these compounds were confirmed by elemental analysis, mass, ir and nmr spectra.

• Applied Biological Chemistry
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• v.42 no.3
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• pp.262-266
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• 1999

Thirty plants were screened for their antioxidative activity. The extracts of Agastache rugosa, Schizonepeta tenuifolia and Lycopus lucidus had high free radical(2,2-diphenyl-1-picrylhydrazyl) scavenging activities. Methanol extract of Agastache rugosa was fractionated with hexane, chloroform, ethyl acetate, and water. The ethyl acetate fraction showed the highest antioxidant activity in the DPPH test. The ethyl acetate fraction was applied to Sephadex LH-20 column, and the fractions showing antioxidative activity were collected and used for identification of the substance. The purified substance was applied to mass, IR, UV and NMR spectroscopy. The spectra of mass, IR, UV and NMR implied that the substance is a rosmarinic acids as a kind of phenolic compound. The rosmarinic acid has more antioxidative effect than those of BHT and ${\alpha}-tocopherol$ in the Rancimat test.

• Bulletin of the Korean Chemical Society
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• v.1 no.4
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• pp.121-123
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• 1980

$C_4$-Photocycloaddition of 5,7-dimethoxycoumarin(DMC) to 5-fluorouracil(5-FU) was studied in frozen aqueous solution. The major photoproduct was diagnosed and isolated by TLC and column chromatography. The structure of isolated photoproduct was identified as a $C_4$-cycloaddition product of DMC and 5-FU by the characteristics of its UV, IR, NMR, mass spectra, elemental analysis, and photosplitting.

• Korean Journal of Pharmacognosy
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• v.16 no.3
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• pp.155-159
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• 1985

Isomotiol $(fern-8-en-3{\beta}-ol)$ was isolated from the n-hexane fraction of Euphorbia supina Rafin. The structure of isomotiol was identified by IR, NMR, Mass spectra and compared with the authentic sample. Isomotiol was first isolated from the family of Euphorbiaceae.

• Korean Journal of Pharmacognosy
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• v.18 no.4
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• pp.207-209
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• 1987

Bergenin was isolated from the ethylacetate fraction of the rhizomes of Astilbe divaricata. The structure of bergenin was identified by IR, UV, NMR, mass spectra and compared with the authentic sample.

• Journal of the Korean Chemical Society
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• v.29 no.4
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• pp.406-413
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• 1985

We synthesized Pd(II) complexes containing sulfoxide and cycloamine series on the basis of the fact that many workers had the foresight to suggest anticancer activites using Pd(II) complexes with sulfur, nitrogen, or nucleic acid relatives as ligands particulary. The identification and characterization of these complexes are followed; content rates of atoms and molecular weights are confirmed by Elemental Analysis and Mass spectra, bonding of metal and ligands by UV-Vis. spectra and NMR spectra, and donor sites of ligands and configuration of complexes by IR spectra. These are yellow crystals, soluble in methanol and chloroform, and insoluble in H2O and the other common organic solvents.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.131-131
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• 1998

In the course of screening for new natural compounds having antioxidant activity from microbials, mushrooms as well as plants. We have isolated novel sesquiterpenoid and officinalic acid from methanolic extracts of Stereum ostrea. The dried fruit body( 450 g) of Stereum ostrea was extracted with methanol, then methanolic extract was partitioned between water and hexane, chloroform, and ethyl acetate, subsequently. The chloroform extract was subjected on silica gel, Sephadex LH-20 and RP-18 column chromatography, successively. And two compounds were isolated and identified as new triterpenoids and officinalic acid using $^1$H - NMR, $\^$13/C - NMR as well as Mass spectra.

• Natural Product Sciences
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• v.6 no.2
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• pp.91-95
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• 2000

A phytochemical investigation of the aqueous ethanolic flower extract of Tamarix tetragyna led to the isolation and characterization of the hitherto unknown conjugates, kaempheride 3,7-dipotassium sulphate and kaempferol 3,4'-dipotassium sulphate as well. Twelve known flavonol compounds, including kaempheride 3-potassium sulphate and kaempheride $3-O-{\beta}-glucuronide$ were also isolated and identified. $^1H-\;and\;^{13}C-NMR$ spectra for the known kaempheride derivatives have been recorded and assigned for the first time. Structures of all compounds were established by conventional methods of analysis and confirmed by $^1H-,\;^{13}C-NMR$ and mass spectral analysis.

• Journal of Microbiology and Biotechnology
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• v.25 no.2
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• pp.174-177
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• 2015

A potent α-glucosidase inhibitor (compound I) was isolated from coffee brews by activity-based fractionation and identified as a β-carboline alkaloid norharman (9H-pyrido[3.4-b]indole) on the basis of mass spectroscopy and nuclear magnetic resonance spectra (¹H NMR, ¹³C NMR, and COSY). The norharman showed potent inhibition against α-glucosidase enzyme in a concentration-dependent manner, with an IC₅₀ value of 0.27 mM for maltase and 0.41 mM for sucrase. A Lineweaver-Burk plot revealed that norharman inhibited α-glucosidase enzyme uncompetitively, with a K_i value of 0.13 mM.