• Journal of the Korean Chemical Society
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• v.42 no.3
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• pp.315-322
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• 1998

A series of new dimesogenic compounds were prepared and their thermotropic and liquid crystalline properties were studied by differential scanning calorimetry and on a hot-stage of a polarizing microscope. These compounds, 1,10-bis[2,5-bis(4-substitutedphenoxycarbonyl)phenoxy]decanes, consist of two bis(ρ-substitutedphenoxy)terephthalate units interconnected through a oxydecamethyleneoxy spacer on the central terephthaloyl units resulting in the structure of "H-shaped" dimeric twin compounds. The terminal substitutent groups were changed; X=-F, -H, -I, -Cl, -Br, $-NO_2,\;-CF_3,\;-OC_4H_9,\;-CN\;and\;-C_6H_5.$ The compounds with X=$-OC_4H_9,\;-CN\;and\;-C_6H_5$ were monotropically nematic. In contrast, the compounds with $X=-F, -H, -I, -Cl, -Br, $-NO_2\;and\;-CF_3$ were non-liquid crystals. The nematic group efficiency of these compounds was in the order of -C_6H_5>-CN>-OC_4H_9.$

• YAKHAK HOEJI
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• v.44 no.1
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• pp.9-15
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• 2000

Four 3-alkoxy-6-allylthiopyridazines and 3-chloro-6-allylthiopyridazine were synthesized and their protective effects against oxidative stress and UV-C irradiation were tested. 3-Methoxy-6-allylthiopyridazine and 3-ethoxy-6-allylthiopyridazine did not show protective effect on the oxidative stress but showed the strongest protective effect on UV-C irradiation among the tested compounds. Especially 500 $\mu\textrm{g}$/$m\ell$ of the two compounds was the most effective concentration.

• Archives of Pharmacal Research
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• v.13 no.1
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• pp.78-81
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• 1990

N-Aryl-N'(4-hydroxy-6-methyl-2-pyrimidinyl)guanidines (IIa-c) were prepared by cyclization of N-arybiguanides (Ia-c) with ethyl acetoacetate. Coupling of compounds (IIa-c) with the appropriate diazotized arylamine gave N-aryl-N'-(5-arylhydrazono-6-methyl-4-oxopyrimidin-2-yl) guanidines (IIIa-f). Whereas, their chlorination with phosphorus oxychloride followed by treatment of N-aryl-N'-(4-Chloro-6-methyl-2-pyrimidinyl)guanidimes (IVac) with the appropriate arylamine afforded the corresponding 4-arylamino derivatives (Vaf). Compounds (IIa-f) were also formed when compounds (1a-c) were treated with ethyl 2-arylhydrazono-3-oxobutyrates. The antimircobial testing of some of the prepared compounds against some pathogenic microorganisms revealed that only two have a marked effect against Escherichia coli.

• Korean Journal of Pharmacognosy
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• v.35 no.1 s.136
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• pp.80-87
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• 2004

From the $CHCl_3$ and BuOH soluble fractions of the heartwood of Hemiptelea davidii, eleven compounds have been isolated. On the basis of spectral data, they were identified as ${\beta}-sitosterol$ (1), scopoletin (2), kaempferol (3), 4-hydroxybenzoic acid (4), 2-(4-hydroxyphenyl) ethanol (5), aromadendrin (6), scopolin (7), kaempferol 6-C-glucoside (8), aromadendrin 6-C-glucoside (9), taxifolin 6-C-glucoside (10) and quercetin 6-C-glucoside (11), respectively. Among these compounds, compounds 3, 8, 10, and 11 showed potent DPPH radical scavenging activity with $IC_{50}$ values of 11.9, 14.7, 10.3 and $6.2\;{\mu}g/ml$, respectively.

• Journal of the Korean Chemical Society
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• v.42 no.6
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• pp.679-695
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• 1998

A series of ${\alpha}{\omega}-bis[4-(4'-(S)-(+)-2-methylbutylbiphenyl-4-carboxy)phenoxy]alkanes$, were synthesized, and their thermal and liquid crystalline properties were studied. The chain length of the central polymethylene spacers, x, of the chiral twin compounds was varied from 3 to 12. These compounds were characterized by elemental analysis, IR and NMR spectroscopy, differential thermal analysis (DSC), and crosspolarized microscopy. All compounds were found to be enantiotropic liquid crystalline, and the values of melting $(T_m)$ and isotropization temperature $(T_i)$ as well as ${\delta}H_I$ and ${\delta}S_I$ decreased in a zig-zag fashion, revealing the so called odd-even effect as x increased. Their mesomorphic properties fell into four categories depending upon x; (a) compounds with x=3, 4 and 5 formed only a cholesteric phase on heating, while on cooling they went through two transitions of isotropic (I)-to-cholesteric (Ch) and Ch-to-smectic $A\;(S_A)$ phases before crystallization. (b) compounds with x=6, 8 and 10 exhibited only a cholesteric phase both on heating and on cooling. (c) compounds with x=7 and 9 went through three transitions of crystal $(C)-to-S_A,\;S_A-to-Ch,$ and Ch-to-I phases on heating while on cooling they went through four transitions of I-to-Ch, $Ch-to-S_A,\;S_A-to-Smectic\;C\;(S_C),\;and\;S_c-to-C$ phases in that order, and (d) compounds with x=11 and 12 went reversibly through four transitions of $C-to-S_C,\;S_C-to-S_A,\;S_A-to-Ch,$ and Ch-to-I phases.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.4
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• pp.617-626
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• 1996

Nitrogenous compounds in hydrolysate of skipjack processing by-product(SPB) was increased 6.4 times in amount comparing that of raw SPB. The major compounds in hydrolysate were anserine, histidine, leucine, hydroxyproline, arginine, phenylalanine and taurine, and composed 56.25% of total nitrogenous compounds. In fatty acid composition, the highest amount was saturated fatty acids in both samples. Polyunsaturated fatty acids such as $C_{20:5}$ and $C_{22:6}$ were increased after hydrolysis. A total of 99 volatile compounds was detected in raw and hydrolysate of SPB by vacuum simultaneous steam distillation-solvent extraction/gas chromatography/mass chromatorgraphy. Of these, 75 compounds were identified in raw SPB, while 72 compounds were identified in hydorlysate of SPB. There compounds were composed mainly of 28 aldehydes, 20 ketones, 19 alcohols, 5 nitrogen containing compounds, 5 aromatic hydrocarbons, 4 furans and 12 miscellaneous compounds. Levels of aldehydes and aromatic hydrocarbons decreased after hydrolysis, whereas heterocyclic compounds such as pyrazies, furans increased.

• Journal of Life Science
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• v.18 no.11
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• pp.1570-1577
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• 2008

For useful basic data in developing of Omandungi (Styela plicata) processed products, volatile flavor compounds were analyzed to identify the key reaction flavor compounds induced through heat treatment ($100^{\circ}C$, 10 min) in Omandungi -Doenjang (soybean paste) soups and stew. A total of 128 flavor compounds were identified and composed mainly of esters (16), aromatic compounds (14), N-containing compounds (11), alcohols (34), terpenes (5), carbonyl compounds (23), furans (4), hydrocarbons (13), acids (5) and miscellaneous compounds (3). Three groups including aromatic compounds, alcohols and acids were detected in high amounts in Doenjang. However, the levels of C4-C6 series acids (i.e., pentanoic acid having off-flavor) decreased by cooking ($100^{\circ}C$, 10 min), whereas that of furans (i.e., furfural) as heat induced compounds increased 2 times. Alcohols were detected the major group in Omandungi and followed by hydrocarbons and aromatic compounds in that order. In particular, 3 compounds including decenol, 2,6-dimethylheptanol and octanol were the major alcohols of Omandungi. By cooking, the compounds known heat-induced compound, 2-acetyl-2-thiazoline and benzothiazole, were newly formed in Omandungi-Doenjang stew. The alcohols (i.e., decenol, 2,6-dimethylheptanol), hydrocarbons and aromatic compounds derived from Omandungi were supposed to enhance a seafood-like flavor in Omandungi-Doenjang stew.

• Natural Product Sciences
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• v.19 no.3
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• pp.215-220
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• 2013

Three C-glucosyl flavones (1 - 3), one xanthone (4), and four flavanonols (5 - 8) were isolated by various chromatographic methods from the leaves and stems of Desmodium caudatum (Thunb.) DC. Chemical structures of these compounds were elucidated by 1D and 2D NMR and mass spectroscopy. The compounds were identified as swertisin (1), spinosin (2), 7-methyl-apigenin-6-C-${\beta}$-glucopyranosyl-2"-O-${\beta}$-D-xylopyranoside (3), 1,3,5,6-tetrahydroxyxanthone (4), yokovanol (5), aromadendrin (6), 2'-hydroxy yokovanol (7), and 2'-hydroxy neophellamuretin (8). Compounds 2 - 4 were first isolated from D. caudatum, as well as the spectroscopic data for compound 3.

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.795-800
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• 2002

6,7-Bis-[S-(aryl)thio]-5,8-quinolinediones 4 and 5 were synthesized by the substitution of 6,7-dichloro-5,8-quinolinediones with appropriate arylthiols. Their antifungal activity were tested in vitro for their growth inhibitory activities against pathogenic fungi in comparison with flucytosine. The antifungal activities were significantly improved by S-(aryl)thio moieties of the compounds 4 and 5. The all tested compounds 4 and 5 showed generally good activities against C. albicans and A. niger ranging from 0.8 to 25 $\mu\textrm{g}$/ml. Among them, compounds 4d-4h and 5a-5c exhibited also good activities against C. krusei and C. tropicalis. The activities of compounds 4j and 4I were comparable to those of flucytosine against all tested fungi.