• 대한화학회지
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• 제45권6호
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• pp.549-554
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• 2001

새로운 COZ-2저해제를 개발하기 위하여 4-hydroxy L-proline의 1-위치에 arylsulfonyl기 2-위치에 arylcarboxamidyl기, 그리고 4-위치의hydroxy에 alkyl기를 도입한 새로운 후보 화합물을 합성하였다. 4-Hydroxy L-proline 1을 출발 물질로 하여 N-tosylation으로 1-위치에 4-methylphenylsulfonyl기를 도입하였고 esterification으로 carboxylic acid를 protection하였다. 4-위치의 O-alkyl-(or aralkyl)ation을 위해서 촉매로 silver oxide를 사용하여 다양한 유도체 4b-d로 전환시키는 데 성공하였다. Carboxylic acid기의 deprotection을 위해서 간편한 base-hydrolysis의 과정을 거쳐 4-alkyloxy-1-tosyl L-prolines 5b-d를 얻었다. 최종 목적 화합물인 1,2,4-치환된 pyrrolidine derivatives, 4-alkyloxy-2-phenylcarboxamidyl-1-tosyl pyrrolidines 6a-d 4종은 DCC를 사용하여 3 및 5b-d와 aniline과의 축합 반응으로 합성하였다.

• Bulletin of the Korean Chemical Society
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• 제7권1호
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• pp.29-35
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• 1986

An empirical formula for semiconductive metal oxides is proposed relating nonstoichiometric value x to a temperature or an oxygen partial pressure such that experimental data can be represented more accurately by the formula than by the well-known Arrhenius-type equation. The proposed empirical formula is log x = A + $B{\cdot}1000/T\;+\;C{\cdot}$exp$(-D{\cdot}1000/T)$ for a temperature dependence and $log\;{\times}\;=a\;+b{\cdot}log\;Po_2\;+\;c{\cdot}$exp$(-d{\cdot}log\;Po_2)$ for an oxygen partial pressure dependence. The A, B, C, D and a, b, c, d are parameters which are evaluated by means of a best-fitting method to experimental data. Subsequently, this empirical formula has been applied to the n-type metal oxides of $Zn_{1+x}O,\; Cd_{1+x}O,\;and\;PrO_{1.8003-x}$, and the p-type metal oxides of $CoO_{1+x},\; FeO_{1+x},\;and\;Cu_2O_{1+x}$. It gives a very good agreement with the experimental data through the best-fitted parameters within 6% of relative error. It is also possible to explain approximately qualitative characters of the parameters A, B, C, D and a, b, c, d from theoretical bases.

• Korean Journal of Mathematics
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• 제25권3호
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• pp.349-358
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• 2017

The cyclic group $C_n={\langle}(12{\cdots}n){\rangle}$ acts on the set $(^{[n]}_k)$ of all k-subsets of [n]. In this action of $C_n$ the number of orbits of size d, for d | n, is $$O^{n,k}_d={\frac{1}{d}}{\sum\limits_{{\frac{n}{d}}{\mid}s{\mid}n}}{\mu}({\frac{ds}{n}})(^{n/s}_{k/s})$$. Stanton and White [6] generalized the above identity to construct the orbit polynomials $$O^{n,k}_d(q)={\frac{1}{[d]_{q^{n/d}}}}{\sum\limits_{{\frac{n}{d}}{\mid}s{\mid}n}}{\mu}({\frac{ds}{n}})[^{n/s}_{k/s}]_{q^s}$$ and conjectured that $O^{n,k}_d(q)$ have non-negative coefficients. In this paper we give a constructive proof for the positivity of coefficients of the orbit polynomial $O^{n,2}_d(q)$.

• 대한화학회지
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• 제34권6호
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• pp.548-554
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• 1990

Eu(III)이온과 간단한 리간드 사이의 착물형성에 대한 온도와 리간드의 영향을 형광방출 스펙트럼을 이용하여 연구하였다. 온도와 리간드에 따라 hypersensitive 전이($^5D0\; {\to}\;^7F_2$)와 nonhypersensitive 전이($^5D0\; {\to}\;^7F_1$)의 상대적 세기는 온도와 리간드의 영향을 크게 받는다. 이러한 상대적 세기변화를 내부권 착물 형성에 의한 평형상수의 변화로 해석하여 $Eu(H_2O)_X^{3+}$ 에서 EuL(H$_2O)_{X-1}^{2+}$로의 내부권 착물 형성시의 열역학적 함수들을 계산하는데 사용하였다. EuCl(H$_2O)_{X-1}^{2+}$의 내부권 착물 형성시의 $\Delta{H}$는 대략 15 kJ/mol이고 온도에 따라 거의 영향을 받지 않는다. 그러나, EuNO$_3(H_2O)_{X-1}^{2+}$의 내부권 착물 형성시의 $\Delta{H}$는 온도에 따라 25$^{\circ}C$에서는 -11 kJ/mol 그리고 250$^{\circ}C$에서는 47 kJ/mol로 증가하였다.

• Bulletin of the Korean Chemical Society
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• 제16권9호
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• pp.805-808
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• 1995

Diacetone-D-glucose was converted into 5-azido-6-O-benzoyl-3-O-benzyl-5-deoxy-1,2-O-isopropylidene-α-D-glucofuranose. After removal of isopropylidene and benzoyl protecting groups, hydrogenation performed reduction of azide and subsequent cyclization by reductive amination to give 3-O-benzyl-1-deoxy nojirimycin in high yield. The second azide group was introduced on 2-carbon by selective substitution reaction, and reduction of azide to amino group gave titled compound.

• 약학회지
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• 제27권2호
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• pp.181-184
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• 1983

DMSO-oxalyl chloride at low temperature in methylene chloride reacted with isolated secondary hydroxyl groups in some monosaccharides to give alkoxysulfonium salts, convertible to carbonyls in high yields upon addition of triethylamine. And 1, 2:5, 6-di-O-isopropylidene-.alpha.- D-allofuranose which is the key intermediate in the synthesis of 3-O-acetyl-5-O-benzoyl- 2-deoxy-2- fluoro-D-arabinofuranosyl bromide, was also obtained by oxidizing 1, 2:5, 6-di-O-isopropylidene-.alpha.- D-glucofuranose with the oxidizing reagent, followed by reduction with sodium borohydride.

• 한국약용작물학회지
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• 제5권2호
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• pp.102-107
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• 1997

명일엽(明日葉)의 부위별 캘러스 유도율을 조사하였고, 배발성(胚發生) 캘러스로부터 식물체 재분화율을 높이고자 에틸렌 작용억제제(作用抑制劑)를 처리한 후, 신초(新梢)의 발생정도 및 소식물체의 길이와 무게를 조사하였던 바 그 결과는 다음과 같다. 1. 2, 4-D의 농도를 달리한 MS배지에 명일엽(明日葉)의 소엽(小葉), 소엽병(小葉柄) 및 엽병(葉柄) 절편(切片)을 배양하였을 때 캘러스 유도는 소엽(小葉)에서 잘 되었으며 2, 4-D의 농도는 2.0 ppm에서 제일 좋았다. 2. 배발성(胚發生) 캘러스로부터 신초의 발생정도와 재분화(再分化)된 소식물체(小植物體)의 신초(新梢) 신장(伸長)에는 $AgNO_3$는 2 ppm, $CoCl_2{\cdot}6H_2O$는 10ppm 첨가가 제일 효과적이었으며, $AgNO_3$나 $CoCl_2{\cdot}6H_2O$를 2, 4-D 1 ppm과 혼용처리하면 신초의 발생정도와 신장은 억제되었다. 3. 재분화된 소식물체(小植物體)의 뿌리 신장(伸長)에는 $AgNO_3$는 1 ppm, $CoCl_2{\cdot}6H_2O$는 5 ppm 첨가가 제일 효과적이었는데, $AgNO_3$나 $CoCl_2{\cdot}6H_2O$를 2, 4-D 1 ppm과 혼용처리 하면 뿌리의 발생은 없었다. 4. 재분화된 소식물체(小植物體)의 생체중은 $AgNO_3$나 $CoCl_2{\cdot}6H_2O$를 단용처리한 경우 각각 2 rpm에서, 2, 4-D 1 ppmr과 혼용처리한 경우 $AgNO_3$는 1 ppm 과 $CoCl_2{\cdot}6H_2O$는 2 ppm에서 제일 무거웠다.

• 대한화학회지
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• 제52권1호
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• pp.47-51
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• 2008

조사 아래 불균일촉매 NaHSO4.SiO2의 존재하에서 5,7-diaryl-4,4-dimethyl-4,5,6,7-tetrahydropyridino [3,4-d]-1,2,3-selenadiazoles의 one-pot.

• Natural Product Sciences
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• 제20권2호
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• pp.95-101
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• 2014

Five lignan glycosides, seven megastigmane glycosides, and seven phenolic compounds were isolated by repeated column chromatography from the MeOH extract of Salsola komarovii. Their structures were determined to be lariciresinol-9-O-${\beta}$-$\small{D}$-glucopyranoside (1), alangilignoside C (2), conicaoside (3), (+)-lyoniresinol 9'-O-${\beta}$-$\small{D}$-glucopyranoside (4), (8S,8'R,7'R)-9'-[(${\beta}$-glucopyranosyl)oxy]lyoniresinol (5), blumenyl B ${\beta}$-$\small{D}$-glucopyranoside (6), blumenyl A ${\beta}$-$\small{D}$-glucopyranoside (7), staphylionoside D (8), icariside $B_2$ (9), (6R,9S)-3-oxo-${\alpha}$-ionol ${\beta}$-$\small{D}$-glucopyranoside (10), 3-oxo-${\alpha}$-ionol 9-O-${\beta}$-$\small{D}$-apiofuranosyl-($1{\rightarrow}6$)-${\beta}$-$\small{D}$-glucopyranoside (11), blumenol B 9-O-${\beta}$-$\small{D}$-apiofuranosyl-($1{\rightarrow}6$)-${\beta}$-$\small{D}$-glucopyranoside (12), benzyl 6-O-${\beta}$-$\small{D}$-apiofuranosyl-${\beta}$-$\small{D}$-glucopyranoside (13), canthoside C (14), tachioside (15), isotachioside (16), biophenol 2 (17), 2-(3,4-dihydroxy)-phenyl-ethyl-${\beta}$-$\small{D}$-glucopyranoside (18), and cuneataside C (19) by spectroscopic methods. All the isolated compounds 1 - 19 were reported from this source for the first time. Compounds 2, 3 and 6 upregulated NGF secretion to $118.8{\pm}3.6%$, $128.2{\pm}9.3%$ and $111.1{\pm}7.1%$ without significant cell toxicity.

• Archives of Pharmacal Research
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• 제25권3호
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• pp.313-319
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• 2002

A total of eight flavonoids (1-8), including a novel $quercetin-7-o-(6"-o-acetyl)-{\beta}-D-glucopyranoside$ (6) and seven known flavonoids, luteolin (1), quercetin (2), luteolin $7-o-{\beta}-D-glucopyranoside$ (3), $luteolin-7-o-(6"-Ο-acetyl)-{\beta}-D-glucopyranoside$ (4) quercetin $7-o-{\beta}-D-glucopyranoside$ (5), acacetin 7-o-{\beta}-D-glucuronide (7) and apigenin-6-C-{\beta}-D-glucopyrano $syl-8-C-{\beta}-D-glucopyranoside$ (8), have been isolated from the leaves of the safflower (Carthamus tinctorius L.) and identified on the basis of spectroscopic and chemical studies. The antioxidative activity of these flavonoids was evaluated against 2-deoxyribose degradation and rat liver microsomal lipid peroxidation induced by hydroxyl radicals generated via a Fenton-type reaction. Among these flavonoids, luteolin-acetyl-glucoside (4) and quercetin-acetyl-glucoside (6) showed potent antioxidative activities against 2-deoxyribose degradation and lipid peroxidation in rat liver microsomes. Luteolin (1), quercetin (2), and their corresponding glycosides (3 & 5) also exhibited strong antioxidative activity, while acacetin glucuronide (7) and apigenin-6,8-di-C-glucoside (8) were relatively less active.