• Archives of Pharmacal Research
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• v.28 no.2
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• pp.172-176
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• 2005

Phytochemical investigation of the whole plant of Amberboa ramosa led to the isolation of six sesquiterpene lactones which could be identified as $8{\alpha}$-hydroxy-$11{\beta}$-methyl-$1{\alpha}H,\;5{\alpha}H,\;6{\beta}H,\;7{\alpha}H,\;11{\alpha}H-guai-10(14)$, 4(15)-dien-6, 12-olide(2), $3{\beta},\;8{\alpha}-dihydroxy-11{\alpha}-methyl-1{\alpha}H,\;5{\alpha}H,\;6{\beta}H,\;7{\alpha}H,\;11{\beta}H-guai-10(14)$, 4(15)-dien-6, 12-olide (2), $3{\beta},\;4{\alpha},\;8{\alpha}-trihydroxy-4{\beta}(hydroxymethyl)-1{\alpha}H,\;5{\alpha}H,\;6{\beta}H,\;7{\alpha}H-guai-10(14)$, 11(13)-dien-6, 12-olide (3), $3{\beta},\;4{\alpha},\;8{\alpha}-trihydroxy-4{\beta}-(chloromethyl)-1{\alpha}H,\;5{\alpha}H,\;6{\beta}H,\;7{\alpha}H-guai-10(14)$, 11(13)-dien-6, 12-olide(4), $3{\beta},\;4{\alpha},\;dihydroxy-4{\beta}-(hydroxymethyl)-1{\alpha}H,\;5{\alpha}H,\;6{\beta}H,\;7{\alpha}H-guai-10(14)$, 11(13)-dien-6, 12-olide(5), $3{\beta},\;4{\alpha}-dihydroxy-4{\beta}-(chloromethyl)-8{\alpha}-(4-hydroxymethacrylate)-1{\alpha}H,\;5{\alpha}H,\;6{\beta}H,\;7{\alpha}H-guai-10(14)$, 11(13)-dien-6, 12-olide (6) by spectroscopic methods. All of them showed inhibitory potential against butyrylcholinesterase.

• YAKHAK HOEJI
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• v.37 no.1
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• pp.49-53
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• 1993

Arylalkanoic acid derivatives are known as good non-steroidal antiinflamatory and antirheumatic agents. The new arylalkanoic acid derivatives were synthesized when 2-chloro-3-($\alpha$-cyano-$\alpha$-ethoxycarbonyl-methyl)-1, 4-naphthoquinone was reacted with some arylamines.

• YAKHAK HOEJI
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• v.34 no.1
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• pp.15-21
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• 1990

-4,9-dione derivatives were prepared from $2-chloro-3-({\alpha}-accetyl-{\alpha}-ethoxycarbonyl-methyl)-1,4-naphthoquinone$ and 2-chloro-3-N-phenylamino-1,4-naphthoquinone. $2-Chloro-3-({\alpha}-acetyl-{\alpha}-ethoxycarbonyl-methyl)-1,4-naphthoquinone$ was reacted with amines to give $2-amino-3-({\alpha}-acetyl-{\alpha}-ethoxycarbonyl-methyl)-1,4-naphthoquinone$ derivatives. Subsequent treatment of $2-amino-3-({\alpha}-acetyl-{\alpha}-ethoxycarbonyl-methyl)-1,4-naphthoquinone$ with sodium ethoxide gave -4,9-dione derivatives. When 2-chloro-3-N-phenylamino-1,4-naphthoquinone reacted with sodium ${\alpha}-cyano$ ethyl acetate, 2-amino-3-ethoxycarbonyl-N-phenyl--4,9-dione was obtained. However, with sodium diethyl malonate, not -4,9-dione but 2-chloro-3-bis-(methoxycarbonyl)-methyl-2H-3-N-phenylamino-1,4-naphthoquinone was obtained.

• Journal of the Korean Ceramic Society
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• v.25 no.5
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• pp.502-508
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• 1988

The $\alpha$ to $\beta$ phase transformation of $\alpha$-Si3N4 whisker and related microstructural changes have been investigated. When only $\alpha$-Si3N4 whisker was heat treated in the range 1650~175$0^{\circ}C$, the $\alpha$ to $\beta$ phase transformation occured. In this case, it eas suggested that the oxygen content in $\alpha$-Si3N4 whisker affected the transformation behavior. Although $\alpha$-Si3N4 whisker with Si was heat treated under the same condition, however, the variation of $\beta$- fraction had a similar tendency with heat treating time. Therfore, it was considered that the oxygen content in $\alpha$-Si3N4 whisker affected the transformation behavior dominently rather than the content of added Si. The added $\beta$ phase did not affect the transformation behaviro of $\alpha$-Si3N4 whisker.

• YAKHAK HOEJI
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• v.45 no.2
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• pp.147-152
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• 2001

The phytochemical study of the aerial parts of Artemisia sylvatica (Asteraceae) led to the isolation of nine sesquiterpene lactones, l$\alpha$-hydroperoxy-rupicolin A acetate (1), rupicolin B acetate (2), rupicolin A acetate (3), l$\alpha$-hydroxy-4$\alpha$-hydroperoxy-bishopsolicepolide (4), 1$\alpha$-hydroperoxy-4$\beta$-hydroxy-8$\alpha$-acetoxy-guaia-2,9,11 (13)-triene-6$\alpha$,12-oxide (5), 1$\alpha$-hydroperoxy-4$\alpha$-hydroxybishopsolicepolide (6), l$\alpha$,4$\beta$-dihydroxy-8$\alpha$-acetoxy-guaia-2,9,11(13)-triene-6$\alpha$,12-olive (7), rupicolin A (8) and l$\alpha$,4$\alpha$-dihydroxy-bishopsolicepolide (9). Their structures were established by chemical and spectroscopic methods.

• Archives of Pharmacal Research
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• v.20 no.6
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• pp.525-528
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• 1997

Steroid $9{\alpha}$.-hydroxylase is a key enzyme system in steroid nucleus degradation in company with ${\Delta}$-dehydrogenase. To examine $9{\alpha}$-hydroxylase activity during microbial transformation of steroids, 9(11)-dehydro-$17{\alpha}$-methyl-testosterone was adopted as a stable substrate for preventing the rupture of steroid nucleus. Using Nocardia restrictus ATCC 14887 capable of introducing a $9{\alpha}$-hydroxyl group into steroids, $9{\alpha}$,$11{\alpha}$-oxido-$17{\beta}$-hydroxy-$17{\alpha}$-methyl-4-androstene-3-one and $9{\alpha}$-hydroxyl group into steroids,$9{\alpha}$,$11{\alpha}$-oxido-$17{\beta}$-hydroxy-$17{\alpha}$-methyl-1,4-androstadiene-3- one were obtained. These microbiologically transformed products could be used as reference compounds in the enzyme assay.

• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.332-338
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• 2002

A strain YB-4 producing the extracellular $\alpha$-galactosidase was isolated from soil, and has been identified as Streptomyces sp. on the basis of its cultural, morphological and physiological properties. The partially purified $\alpha$-galactosidase was most active on paranitrophenyl-$\alpha$-D-galactopyranoside at pH 6.0 and 6$0^{\circ}C$. The enzyme retained 90% of its maximum activity between pH 4.0 and pH 10.0 after pre-incubation for 1 h. The enzyme was able to hydrolyze oligomeric substrates such as melibiose, raffinose and stachyose to liberate galactose residue, indicating that the $\alpha$-galactosidase of Steptomyces sp. YB-4 hydrolyzed $\alpha$-1,6 linkage.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.67.1-67.1
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• 2003

Three new guaianolide type of sesquiterpene lactones, 8${\alpha}$-angeloyloxy-1${\alpha}$-hydroxy-3${\alpha}$,4${\alpha}$-epoxy-5${\alpha}$, 7${\alpha}$H-10(14), 11(13)-guaiadien-12,6${\alpha}$-olide (1), 8${\alpha}$-methylbutyryloxy-1${\alpha}$-hydroxy-3${\alpha}$, 4${\alpha}$-epoxy-5${\alpha}$, 7${\alpha}$H-10(14),11(13)-guaiadien-12,6${\alpha}$-olide (2), and 8${\alpha}$-isovaleryloxy-1${\alpha}$-hydroxy-3${\alpha}$, 4${\alpha}$-epoxy-5${\alpha}$, 7${\alpha}$H-10(14),11 (13)- guaiadien-12,6${\alpha}$-olide (3), together with six known sesquiterpenes, artemisolide (4), 3-methoxytanapartholide (5), deacetyllaurenobiolide (6), moxartenolide (7), arteminolide B (8), and arteminolide D (9) were isolated by bioassay-guided fractionation using the NF-kB mediated reporter gene assay system. (omitted)

• YAKHAK HOEJI
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• v.35 no.4
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• pp.314-318
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• 1991

A convenient method for the synthesis of indoprofen, which is a potent antiinflammatory agent, w described. Ethyl $\alpha$-(4-aminophenyl)propionate was prepared by nitration of ethyl $\alpha$-phenylpropionate, followed by reduction. Ethyl $\alpha$-[4-(1, 3-dioxo-2-iso-indolinyl)phenyl]propionate was obtained from condensation reaction of phthatic anhydride and ethyl $\alpha$-(4-aminophenyl)propionate. Indoprofen was prepared by reduction of ethyl $\alpha$-[3-(1, 3-dioxo-2-iso-indolinyl)phenyl]propionate with zinc dust-acetic acid, followed by hydrolysis of the resultant ethyl $\alpha$-[4-(1-oxo-2-iso-indolinyl)pheriyl]propionate.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.345.2-345.2
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• 2002

Recently. 4'${\alpha}$-C homologated furanose nucleosides. especially alkyl branches. are molecules of considerable current interest. One of reasons for this prominence arises from the notable biological activities as antiviral and antitumor agents. as shown in 4'${\alpha}$-C-methyl-2-deoxythymidine (EC$_{50}$ = 7.2$\mu$M against HIV in MT-4 cell), 4'${\alpha}$-C-fluoromethyl-2-deoxycytidine. 4'${\alpha}$-C-hydroxymethylthymidine and 4'${\alpha}$- -C-azidomethyl-thymidine. (omitted)omitted)