• The Korean Journal of Pesticide Science
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• v.9 no.2
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• pp.153-158
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• 2005

Safening activities of optically active ${\alpha}$-methylbenzylphenylureas on crop injury of rice (Oryza sativa L., cv. Tsukinohikari, japonica) caused by bensulfuron-methyl (methyl 2-[[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]methyl]benzoate) and pyribenzoxim (benzophenone o-[2,6-bis[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzoyl]oxime) were investigated. Some derivatives of the optically active compounds exhibited strong safening activity against growth inhibition of rice by bensulfuron-methyl. Out of the derivatives tested, (S)-2,3-diCl and (S)-2-F-4-Me derivatives showed greater relieving activity than that of dymuron. In addition, the stress relieving activity was also obtained when they were applied at 4 days after bensulfuron-methyl treatment. On the other hand, crop injury caused by pyribenzoxim was relieved by about 95% with (S)-2-F-4-Me derivative in shoots and roots of rice seedlings.

• Journal of the Korean Chemical Society
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• v.19 no.3
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• pp.174-178
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• 1975

The intermediate, 17${\alpha}$-methyl-4-aza-5${\alpha}$-androstan-17${\beta}$-ol(Ⅸ) required for the synthesis of 4-(${\beta}$-guanidinoethyl)-17${\alpha}$-methyl-4-aza-5${\alpha}$-androstan-17${\beta}$-ol(V) was obtained through a reaction of 17${\alpha}$-methyl-3,5-seco-4-norandrostan-17${\beta}$-ol-5-on-3-oic acid(VI) with ammonium hydroxide followed by two reductions(platinum dioxide with hydrogen and lithium aluminium hydride). Condensation of Ⅸ with chloroacetonitrile under anhydrous condition, followed by reduction of the nitrile with lithium aluminium hydride gave 4-(${\beta}$-aminoethyl)-17${\alpha}$-methyl-4-aza-5${\alpha}$-androstan-17${\beta}$-ol(XI). The reaction of XI with 2-methyl-2-thiopseudourea or 3,5-dimethylpyrazole-1-carboxamidine, or cyanamide provided the title compound, V. Relaxation of the nictitating membrane, in the absence of mydriasis, is considered to be evidence of adrenergic neurone blockade. Thus the test compound(V) resembles that of the classical adrenergic neurone blocking agents.

• Bulletin of the Korean Chemical Society
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• v.14 no.1
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• pp.79-81
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• 1993

Synthetic routes are described for the introduction of hydroxyalkyl groups to the upper rim of calix[4]arene. Treatment of p-bromocalix[4]arene methyl ether 3 with n-BuLi followed by para-formaldehyde produced p-hydroxymethylcalix[4]arene methyl ether 4 in 60% yield. p-Acetylcalix[4]arene methyl ether 7, obtained by Friedel-Crafts acetylation of calix[4]arene methyl ether 6, was reduced with NaBH4 to produce p-(1-hydroxy ethyl)calix[4]arene methyl ether 8 in 67% yield.

• Journal of the Korean Chemical Society
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• v.40 no.11
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• pp.692-698
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• 1996

A synthesis of the oxazole skeleton of discokiolide B, represented by discokiic acid 1, is described. Aldol condensation of 2[2'-(4-phenyl-3-butenyl)]-1,3-oxazole 4-carboxaldehyde(4a) with lithium enolate of methyl propionate provided the discokiic acid methyl ester. The key intermediate 2[2'-(4-phenyl-3-butenyl)]-1,3-oxazole-4-carboxaldehyde (4a) has been synthesized from the rhodium-catalyzed cycloaddition of diazomalonaldehyde with nitrile. The relative stereochemistry of the 3-hydroxy-2-methylpropanoate unit of discokiic acid was assigned on the basis of $^1H$ and $^{13}C$ NMR data.

• Biomolecules & Therapeutics
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• v.15 no.1
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• pp.46-51
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• 2007

Bioassay-directed chromatographic fractionation of an ethyl acetate extract from leaves of sweet potato (Ipomoea batatas L.) afforded six quinic acid derivatives: 3,5-epi-dicaffeoylquinic acid (1), 3,5-dicaffeoylquinic acid (2), methyl 3,5-O-dicaffeoylquinate (3), methyl 3,4-dicaffeoylquinate (4), methyl 4,5-dicaffeoylquinic acid (5),4,5-dicaffeoylquinate (6), and two phenolic compounds: caffeic acid (7) and caffeic acid methyl ester (8) together with three flavonoids: quercetin 3-O-${\beta}$-D-glucopyranoside (9), quercetin 3-O-${\beta}$-D-glucopyranoside, isoquercitrin (10) and kaempferol 3-O-${\beta}$-D-glucopyranoside (11). The structures of these compounds were elucidated by the aid of spectroscopic methods. These compounds were assessed for antioxidant activities using three different cell-free bioassay systems. All isolates except 11 showed potent DPPH and superoxide anion radicals scavenging, and lipid peroxidation inhibitory activities. 3,5-epi-DCQA (1) and methyl quinates (3-5) along with flavonoide 9 were isolated for the first time from this plant.

• Preventive Nutrition and Food Science
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• v.4 no.2
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• pp.88-91
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• 1999

Aroma components of tea processed from Korean chicory roots were isolated and identified. The model system of amino-carbonyl reaction was carried out to study the formation mechanism of aroma compounds of chicory tea during manufacturing process. The concentration extracts from chicory tea and model system were analyzed and identified by gas chromatography(GC) and GC-mass spectrometry. Twenty-nine compounds, including pyrazines, furans, acids, alcohols, pyrroles and lactones were isolated and identified in chicory tea. The main compounds were pyrazines including methyl pyrazine, 2,5-dimethyl pyrazine, 2, 6-dimethyl pyrazine, 2-ethyl-6-methyl pyrazine, 2-ethyl-3-methyl pyrazine, thrimethyl pyrazine, 3-ethyl-2-5-dimenthyl pyrazine, 5-ethyl-2-3-dimenthyl pyrazine, and 2-acetyl-3-methy pyrazine and pyrroles including acethl pyrrole and formlyl pyrrole ; and furans including furfural , acetyl furan, 5-methyl furan, 5-methyl furfuralm, and furfuryl alcohol. These pyrazine compounds of a roasted and nutty aroma may be important contributors to the flavor of chicory tea. The aroma concentrate of model system also had a roasted and nutty aroma and the main compounds were methyl pyrazine, 2, 5-dimetyl pyrazine, 2, 6-dimethyl pyrazine and trimethyl pyrazine.

• Journal of Food Hygiene and Safety
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• v.12 no.3
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• pp.195-199
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• 1997

For the purpose of isolation and screening of tyrosinase inhibitory activity from edible mushrooms, Pleurotus ostreatus, Auricularia auricula-Judae, Umbilicaria esculenta, Agaricus bisporus, Flammuline velutipes, Lentinus edodes, Ganoderma lucidum, and Coriouls versicolor were examined by tracing inhibitory activities against tyrosinase, utilizing L-3,4-dihydroxyphenylalanine (L-DOPA) as a substrate. Among the eight edible mushrooms tested, Umbilicaria esculenta showed potent enzyme inhibitory activities above 7804% against tyrosinase in ethylacetate (EtOAc) extracts. Ganoderma lucidum and Agaricus bisporus showed inhibitory activities of 67.3% and 51.5% in water extracts. EtOAc extracts of Umbilicaria esculenta was fractionated from silicagel column chromatography and one fraction showed the most inhibitory activity of 60.9%. The three bands (Rf=0.38, 0.27, 0.19) were isolated from preparative TLC of the fraction for purification and identified as mixtures of orsellinate, methyl orsellinate, methyl lecanorate, and methyl gyrophorate by high pressure liquid chromatography (HPLC), ultravisible spectrophotometer (UV), mass spectrophotometer (Mass), nuclear magnetic resonance spectrometer (NMR).

• Korean Journal of Environmental Agriculture
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• v.16 no.3
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• pp.269-273
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• 1997

This research aims at developing a new plant growth inhibitors related to abscisic acid by means of esterification of (S)-(+)-ABA with p-hydroxy methyl cinnamate and umbelliferone, and testing its biological activity on growth of rice seedlings. The over-all yield of ABA-methyl cinnamate(AC) and ABA-umbelliferone(AC) ester compounds were 83% and 78%, respectively. The growth inhibition activity of these synthetic compounds were shown about 3 to 10 times(AC) and 10 to 30 times(AU) higher than (S)-(+)-ABA.

• Journal of Applied Biological Chemistry
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• v.43 no.1
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• pp.44-48
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• 2000

Burkholderia cepacia strain G4 (pHG-2) containing toluene 2-monooxygenase and toluene dioxygenase, was able to grow on toluene and accumulate cis-3-methyl-3,5-cyclohexadien-1,2-diol (cis-toluene dihydrodiol) in the liquid culture. The cis-toluene dihydrodiol produced was identical to the authentic compound, as judged through mass spectrometry and nuclear magnetic resonance analysis. Our results indicate that pHG-2 provides an economical means to produce chemically-important chiral synthons while growing on toluene.

• YAKHAK HOEJI
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• v.52 no.6
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• pp.514-519
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• 2008

We developed a convenient synthetic route to 3-alkylated 2-phenyl-4-quinolone derivatives (4a-h and 5a-c), which were expected to retain antitumor activity. A series of 2,3-dihydro-2-hydroxy-2-phenyl-4-quinolones (3a-h) was synthesized through dehydration, dealcoholation and hydration using acid-catalyzed one-pot reaction from anilines and ethyl benzoylacetates. 3-Methyl (or 3,3-dimethyl)-2-phenyl-4-quinolone derivatives 4 and 5 were synthesized from 3a-h through the methylation using methyl iodide. Formation of quinolone nucleus was undertaken with p-toluenesulfonic acid (p-TSA) at $90{\sim}110^{\circ}C$ in toluene for 3${\sim}$7.5 hr over the Dean-Stark apparatus. The key intermediates in these preparations are ${\beta}$-ketoesters 2a-h, which can be readily obtained from the corresponding anilines 1a-e by reaction with ethyl bezoylacetates.