• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.169-169
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• 1998

Three analgesic constituents: FB2c, FB6Fc, and FB10E5c from the hexane extract of Mentha cordifolia Opiz. (Yerba buena) leaves were isolated by solvent partitioning and sequential repeated vacuum liquid chromatography. Spectral analysis of the three constituents show that FB2c is ${\beta}$-sitosterol; FB10E5c is ${\beta}$-sitosteryl-${\beta}$-D-glucopyranoside; and FB6Fc is a cis-8- pentadecenyl with lactone variety. At a dosage of 100 mg/kg mouse, isolates FB2c, FB6Fc, and FB10E5c decreased the number of squirms induces by acetic acid by 70.0 %, 67.3 %, and 73.0 %, respectively.

• Journal of the Korean Wood Science and Technology
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• v.24 no.2
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• pp.81-93
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• 1996

To elucidate the structure of procyanidin in Korean red pine (Pinus densiflora S. et Z.), bark, the extractives were extracted with acetone-water mixture(7:3, v/v) from inner bark of Korean red pine. The extracts separated three fractions which were extracted by liquid-liquid extraction. The extracting solvents were chloroform and ethyl acetate and water. The part of ethylacetate soluble was chromatographed by liquid chromatography. The ethylacetate soluble portion yielded four natural procyanidin dimers, two known epicatechin-($4{\beta}{\rightarrow}6$)-catechin, catechin-($4{\alpha}{\rightarrow}8$)-catechin and two unknown catechin-($4{\beta}{\rightarrow}6$)-catechin and conformational isomer of epicatechin-($4{\alpha}{\rightarrow}6$)-catechin. The additional catechins was also isolated. The structures of these procyanidins were elucidated by their $^{13}C$-NMR spectra.

• YAKHAK HOEJI
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• v.45 no.6
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• pp.599-603
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• 2001

The node of lotus rhizome (Nelumbo nucifera, Nymphaeaceae) have been used as a traditional medicine for the remedy of hemorrhage, blood stagnancy and thirstiness. To investigate phenolic compound from the node of Nelumbo nucifera, phytochemical isolation and structure elucidation were conducted. Four phenolic compounds were isolated from aqueous methanolic extract and the structure of these compounds were identised as (+)-catechin (1), (+)-gallocatechin (2), (+)-gallocatechin (4u-8)-catechin (3) and scolpoletin (4) respectively by the analysis of spectroscopic evidences and comparisions with the data of authentic samples.

• YAKHAK HOEJI
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• v.41 no.5
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• pp.588-594
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• 1997

N-(tert-Butoxycarbonyl)-O-(dicyanoethylthiophosphono)-L-tyrosine(7), the key intermediate for the synthesis of thiophosphotyrosine-containing peptide derivat ives, was prepared. For the phosphorylation, we used t-Boc-tyrosine and phosphoramidite in the presence of 1H-tetrazol. For the protection of thiophosphate moiety, cyanoethyl protecting group was used. Thiophosphotyrosine-containing peptides could be used as tools for the elucidation of mechanism of signal transduction pathway and also prepared as PTK inhibitors, PTPase inhibitors and cytosolic protein binding blockers. It may be contributed for the development of potential anticancer agents.

• YAKHAK HOEJI
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• v.41 no.1
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• pp.14-17
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• 1997

(${\pm}$)-3-Deoxygericudranin A was designed and synthesized for the development of novel antitumour agent and for the elucidation of the effect of 3-hydroxyl group in gericudranin A on antitumour activity. 2,4.6-Trihydroxyacetophenone was converted to 3-deoxygericudranin A in 5 steps via sequential protection, aldol condensation, Michael tvpe-cyclization, regioselective, C-benzylation and deprotection.

• YAKHAK HOEJI
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• v.42 no.6
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• pp.552-557
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• 1998

Acyl CoA synthetase inhibitor, was purified from the culture broth of a Bacillus sp. B-6, which had been isolated from soil, by chloroform extract, silica gel column chro matography and preparative TLC. The purified acyl CoA synthetase inhibitor showed higher Antifungal activity against C. al-bicans (MIC: 8${\mu}$g/ml). Though the analysis of UV spectrum, melting point, IR spectrum, Mass-spectrum, $^1H$-NMR and $^{13}C$-NMR spectrum, the inhibitor could be identified as phenazine-l-carboxylic acid.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2398-2402
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• 2009

Ten steroidal compounds as impurities in canrenone were isolated from the enriched mother liquor by using various chromatographic methods. Their structures were elucidated by spectrometric analysis, among which three new compounds were characterized as 3-(3-oxo-7$\alpha$-(ethoxycarbonyl)methyl-17$\beta$-hydroxy-4-androsten-17$\alpha$-yl) propionic acid $\gamma$-lactone (1), 3-(3-oxo-7$\alpha$-ethoxy-17$\beta$-hydroxy-4-androsten-17$\alpha$-yl) propionic acid $\gamma$-lactone (2) and 3-(3-oxo- 5$\beta$-propionic acid-$\gamma$-lactone-6$\beta$,17$\beta$-hydroxy-4-androstan-17$\alpha$-yl) propionic acid $\gamma$-lactone (3).

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2449-2452
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• 2009

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.2990-2994
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• 2014

The studies on design and synthesis of new monocyclic ${\beta}$-lactam esters 4(R/S)-(1'-methoxycarbonylpropyl- 2'(R/S)-thio)-3(R)-phenylacetamidoazetidin-2-one (3a) and 4(R/S)-(1'-methoxycarbonyl-2'-methylpropyl-2'- thio)-3(R)-phenylacetamidoazetidin-2-one (3b) were described. Compounds 3a and 3b were specifically designed to retain all penicillin substructures except the bicyclic system, which would be conceived by cleaving the C(3)-N(4) bond of penicillin G. Compounds 3a and 3b are of particular interest in the context of the structural elucidation of monocyclic ${\beta}$-lactams originated from penicillin. Key intermediates, ${\beta}$-mercapto esters 6a and 6b, were synthesized from conjugate acids 4a and 4b using three-step synthetic sequences, respectively, and 4(S)-acetoxy-3(S)-phenylacetamidoazetidin-2-one (7) was obtained from the degradation of penicillin G. Reactions of 6a and 6b with 7, thus obtained, provided the target compounds 3a and 3b, respectively.

• Journal of the Korean Chemical Society
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• v.7 no.2
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• pp.106-114
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• 1963

The products from polymer pyrolysis at $450^{\circ}$ are cooled with ice, then liquid and gaseous portions are analysed by gas chromatography. Di-2-ethyl hexyl sebacate column, silicone oil column, silica gel column and tetraethyleneglycol dimethylether column, which was most effective for the separation of hydrocarbon gases, are used. Identification of isomers could be secured more effectively by gas chromatography than mass spectrometry. Elucidation of the mechanism for thermal decomposition of polymers could be done through the identification of pyrolysis products. Although more extensive work is needed, some patterns of polymer pyrolysis are discussed.