• YAKHAK HOEJI
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• v.43 no.4
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• pp.516-525
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• 1999

Hedera rhombea (HR) has been used for treatments of hemorrage, chronic catarrh, jaundice, lithisis and convulsion. This study was done to isolate active compounds that have protective effect on liver damage. BuOH and EtOAc fractions of HR recovered serum glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT) and ${\gamma}-glutamyltranspeptidase$ (${\gamma}-GTP$) activities in CCl4 treated rats. We isolated 7 phenolic compounds from BuOH and EtOAc fractions, which were identified as 3-caffeoyl quinic acid, 3,4-di-O-caffeoyl quinic acid, 3,5-di-O-caffeoyl quinic acid, 4,5-di-O-caffeoyl quinic acid, caffeic acid, methyl 3,4-di-O-caffeoyl quinic acid and methyl 3,5-di-O-caffeoyl quinic acid by chemical and spectral analysis. These compounds reduced significantly serum GOT and GPT elevated by CCl4 treatment in rats, and 3-caffeoyl quinic acid, 3,5-di-O-caffeoyl quinic acid and caffeic acid also showed mild inhibitory activity against human immunodeficiency virus.

• Journal of the Korean Chemical Society
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• v.38 no.5
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• pp.372-376
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• 1994

The penicillin-derived 4-mercaptoazetidin-2-one(2a) was unstable in basic media, but it reacted with electrophiles such as acetyl chloride, methyl chloroformate, ethyl iodoacetate, diethyl azodicarboxylate in the presence of triethylamine or pyridine to give the products such as S-acetyl, S-methoxycarbonyl, S-ethoxycarbonylmethyl, and S-diethoxycarbonylhydrazino compounds. However S-methylation could not be done with methyl iodide, but with diazomethane. The reactivity of isomer 3a toward electrophiles was almost the same as that of compound 2a.

• Archives of Pharmacal Research
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• v.21 no.2
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• pp.187-192
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• 1998

The cis- and trans-diastereomers of the 7,8-dihydro-7-deazapurine derivatives were synthesized from the corresponding diastereomers of 4-tran5-cyano-2-methyl-3-phenyl-5-oxopyrrolidine (5), which were reduced from the 2-cis- and 2-tran5-diastereomers of 4-trans-cyano-2-hydroxymethyl-3-phenyl-5-oxopyrrolidine (2) via tosylation, iodination and following elimination respectively. The prepared cis- and ttans-diastereomers of 6-amino-2-mercapto-8-methyl-7-phenyl-7,8-dihydro-7(9H)-deazapurine (8) were transferred to the corresponding 2-methylthio-diastereomers 9 and following desulfurization with Raney-nickel leaded to the cis and trans-diastereomers of 6-amino-8-methyl-7-phenyl-7,8-dihydro-7(9H)-deazapurine (10), respectively. The synthesized 7-deazapurine derivatives were tested for their antibiotic activity by the serial two-fold dilution method.

• Bulletin of the Korean Chemical Society
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• v.14 no.4
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• pp.497-499
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• 1993

Irradiation of 4-biphenylyl-4-methyl-2-cyclohexenone (5) in benzene or methanol produced trans-6-biphenylyl-5-methylbicyclo[3,1,0]hexan-2-o ne (5a) and 3-biphenylyl-4-methylcyclohex-2-enone (5b). Electronic configurations of the excited states for 5a and 5b were assigned as n, ${\pi}^*$ and ${\pi}$, ${\pi}^*$ triplet states respectively. Irradiation of 4-methyl-4(${\beta}$-naphthyl)-2-cyclohexenone in benzene or methanol gave 4-methyl-3-(${\beta}$ -naphthyl)-2-cyclohexenone (6a), which is thought to arise from ${\pi}$, ${\pi}^*$ triplet state.

• Korean journal of applied entomology
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• v.23 no.2 s.59
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• pp.89-95
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• 1984

Sixty isolates of Dendrophoma obscurans isolated from 19 important strawberry growing areas of Korea were tested in vitro for resistance to thiophanate-methyl and iprodione. Naturally-occurring thiophanate-methyl-resistant isolates were about 43 percents of isolates tested, whereas iprodione-resistant isolates were 10 percents. All these resistant isolates except SU 1 and SU 2, which were highly resistant to thiophanate-methyl, showed a week level of resistance. Iprodione-resistant isolates were readily obtained in vitro, when mycelial disk of the fungus was incubated on PDA media containing iprodione at the concentrations of $1{\mu}g/ml\;and\;10{\mu}g/ml$, but no thiophanate-methyl-resistant isolate from the mycelia with or without UV irradiation. All these artificially-obtained iprodione-resistant isolates were showed a high degree of resistance. On the strawberry leaves, thiophanate-methyl and iprodione were no longer effective to all resistant isolates at the recommended concentration, and the protective value to highly resistant isolates was much less than that of weakly resistant isolates. Isolates resistant to thiophanate-methyl were also resistant to benomyl but iprodione-resistant isolates did not show cross-resistance to thiophanate-methyl, benomyl, captan and zineb. Captan controlled both thiophanate methyl-resistant and iprodione-resistant isolates as effectively as sensitive isolates.

• Korean Journal of Pharmacognosy
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• v.26 no.3
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• pp.248-252
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• 1995

Five phenolic compounds were isolated from the MeCOEt extract of Frullania nisquallensis (Jubulaceae), namely methyl 2,4-dihydroxy-3,6-dimethylbenzoate, methyl 2,4-dihydroxy-6-methylbenzoate, acacetin, betuletol, and pectolinaringenin. Revised ${13}^C-NMR$ data of methyl 2,4-dihydroxy-6-methylbenzoate and betuletol are reported.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.309-310
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• 2012

Modeling of biodiesel combustion on compression ignition engine was conducted by using the KIVA3v-Release 2 code coupled with Chemkin chemistry solver2. In order to calculate the chemical kinetics of combustion of biodiesel, a reduced mechanism of methyl decanoate and methyl 9-decanoate was used. It is composed of 123 species and 394 reactions. Also, the experiments were performed on a single-cylinder engine. The simulation results agreed well with experiments results. And soot concentrations of biodiesel were lower than those of diesel.

• Archives of Pharmacal Research
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• v.14 no.2
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• pp.143-146
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• 1991

A new synthetic sequence for the chiral lactone moiety of compactin was developed from $\alpha$-D-glucose in 9 steps via simultaneous reductive detosylation and epoxide-ring opening of 2, 3-epoxy-4-tosylate using NaBH_4$ to afford 2, 4-dideoxy sugar as a key intermediate.

• YAKHAK HOEJI
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• v.41 no.4
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• pp.480-483
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• 1997

The efficient synthesis of p-(acetylamino)phenylacetic acid(7), a antirheumatic agent, is reported. Methyl phenylacetate(3) was prepared from Friedel- Crafts reaction of benzene with methyl ${\alpha}$-chloro-${\alpha}$-(methylthio)acetate(1) followed by reductive desulfurization with zinc dust in acetic acid. Compound(7) was obtained from 3 by a sequence of nitration, reduction, N-acylation, and hydrolysis.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.135.1-135.1
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• 2003

We have previously reported three new oleanene-type glycosides and kudzusaponin $A_3$ methyl ester and subproside II methyl ester from the roots of Echinosophora koreensis. Further study has now led to the isolation of three known oleanen-type glycosides. sophoraflavoside I, azukisaponin V, and kudzusaponin $SA_3$ as their methyl esters. The structures of theses compounds were characterized by spectroscopic and chemical methods.