• Natural Product Sciences
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• 제14권3호
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• pp.196-201
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• 2008

Five neolignans (1 - 4, 8), two sesquiterpene-lignans (5 - 6), and two phenylpropanoids (7, 9) were isolated from the stem bark of Magnolia obovata Thunberg (Magnoliaceae) by repeated column chromatography. The structures of isolated compounds were identified as 4-methoxyhonokiol (1), obovatol (2), magnolol (3), honokiol (4), eudeshonokiol B (5), eudesobovatol B (6), coumaric acid (7), magnaldehyde B (8), and ${\rho}-coumaric$ acid (9) on the basis of spectroscopic analysis including 2D-NMR and MS data. Compounds 1 - 9 were evaluated for their anti-complement activities against the classical pathway of the complement system. Of them, compound 8 showed significant anti-complement activity on the classical pathway with $IC_{50}$ value of 102.7 ${\mu}M$, whereas compounds 1 - 7 and 9 were inactive. This result indicated that an aldehyde group in the neolignan is important for the anti-complement activity against the classical pathway.

• Journal of Microbiology and Biotechnology
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• 제1권1호
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• pp.70-74
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• 1991

The rheological properties of rifamycin B fermentation broth using Nocardia mediterranei were characterized in concomitance with the chemical changes of the fermentation broth. The data were interpreted with various rheological models. As results, it was found that the rheological behaviour at the early growth phases of the culture was the Newtonian fluid, but it was changed to the non-Newtonian fluid (Casson plastic behaviour) at the later phases of the culture. Rheological parameters viz., apparent viscosity ($\mu_a$), yield shear stress ($\tau_o$), and Casson constant ($K_c$) were changed through the fermentation where cell concentrations were changed and mycelia were greatly branched. Those results indicated that cell concentration and cell morphology played important roles to determine the rheological characters.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.202-204
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• 2008

This paper gives a comparative analysis on lifetime of the fluorescent induction lamp. We have treasured and analysed optical characteristics of circular type fluorescent induction lamps, which has A and B types, to estimate lifetime. In the result of analysis on lifetime, $B_{10}$ lifetime of A and B type lamps are 466 hours and 1,595 hours, respectively.

• Bulletin of the Korean Chemical Society
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• 제31권1호
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• pp.69-74
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• 2010

The new idarubicin analogues (12 and 13) with a glucose or galactoseas as a glycone were synthesized from daunomycin (2). (+)-4-Demethoxydaunomycinone (6) obtained from reaction of 2 with $AlCl_3$ was converted to 4-trifluoromethanesulfonyl daunomycinone (7) through reaction with trifluoromethanesulfonic anhydride. The treatment of 7 with 1,1-bis-(diphenylphospino)ferrocene/$Pd(OAc)_2$ in triethylamine/formic acid/dioxane provided the idarubicinone (5b). Glycosylation of 7-hydroxy group of 5b with two kinds of tetraacetyl pyranosyl halide (8 and 9) by a modified Koenigs-Knorr procedure and then deacetylation using aqueous 0.1 N LiOH solution and amberlite cationic resin gave the objective materials. The in vitro MTT assay of the analogues (12b and 13a) in comparison with idarubicin (5a) on peripheral blood human promyelocytic-leukemia cell line and human breast cancer cell line were also described.

• Bulletin of the Korean Chemical Society
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• 제22권9호
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• pp.963-968
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• 2001

New anthracycline analogues 2-9 as potential anticancer agents have been synthesized from daunomycin (1a) and doxorubicin (1b). Compounds 2 and 6 were prepared by the nucleophilic displacement type esterification of 14-bromodaunomycin (1c) with N-benzoyl-(2R,3S)-phenylisoserine and L-pyroglutamic acid in triethyl-amine, respectively. Compounds 3, 7 and 4, 8 were prepared by the reaction of either daunomycin (1a) or doxorubicin (1b) with one equivalent of the corresponding acids in the presence of EDCI/PP. Compounds 5, 9 were obtained from 1b by reaction with 2.2 equivalents of the corresponding acids in the same manner. The cytotoxic activities of the analogues in comparison with adrimycin on cultured SNU-16 and MCF7 cell were described.

• Bulletin of the Korean Chemical Society
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• 제22권6호
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• pp.581-586
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• 2001

The potential anticancer agents, new anthracycline analogues (2-9) have been synthesized from the glycosides daunomycin (1a) and doxorubicin (1b). Compounds 2 and 6 were prepared by nucleophilic displacement esterification of a 14-bromodauomycin(1c) with sodium or potassium salts of butyric and all trans retinoic acid, respectively. Compounds 3 and 7 were obtained from daunomycin (1a) by direct amidation with a butyric and all trans retinoic acid in the presence of EDCI and PP, respectively. Compounds 4 and 8 were obtained from doxorubicin (1b) by reaction with the corresponding acids in the same manner. Compounds 5 and 9 were prepared from doxorubicin (1b) by acylation with two equivalents of the corresponding acids under the same reaction conditions.

• Bulletin of the Korean Chemical Society
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• 제22권6호
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• pp.587-592
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• 2001

The potential anticancer agents new anthracycline derivatives (2~9) have been synthesized from daunomycin (1a) and doxorubicin (1b) ad starting materials. Compounds 2 and 6 were prepared by the nucleophilic displacement type esterification of a 14-bromodaunomycin (1c) with a acetylsalicylic and palmitic acid in triethylamine, respectively. Compound 3 and 7 were obtained from daunomycin (1a) by direct amidation with the corresponding acids in the presence of EDCI and PP as esterification regents. Whereas 4 and 8 were prepared by reaction of doxorubicin (1b) with one equivalent of acetylsalicylic and palmitic acid using DCC/DMAP, respectively, 5 and 9 were obtained from 1b by acylation with two equivalents of the corresponding acids using EDCI/PP reagents.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.199.1-199.1
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• 2003

In the course of our search for intercellular adhesion molecule-1 (ICAM-1)/leukocyte function-associated antigen-1 (LFA-1) mediated cell adhesion inhibitors from natural sources, new type of cell adhesion inhibitors were isolated from the MeOH extract of Saururus chinensis roots. On the basis of spectral evidence, the structures of the active compounds were identified as manassantin A and B. Manassantin A and B inhibited phorbol 12-myristate 13-acetate (PMA)-induced homotypic aggregation of the human promyelocytic leukemia HL-60 cells without cytotoxicity with MIC value of 1.0 and 5.5 nM, respectively. (omitted)

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제30권3호
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• pp.337-345
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• 2023

Different versions of the boundary Schwarz lemma for the 𝒩 (𝜌) class are discussed in this study. Also, for the function g(z) = z+b₂z²+b₃z³+... defined in the unit disc D such that g ∈ 𝒩 (𝜌), we estimate a modulus of the angular derivative of g(z) function at the boundary point 1 ∈ 𝜕D with g'(1) = 1 + 𝜎 (1 - 𝜌), where ${\rho}={\frac{1}{n}}{\sum\limits_{i=1}^{n}}g(c_i)={\frac{g^{\prime}(c_1)+g^{\prime}(c_2)+{\ldots}+g^{\prime}(c_n)}{n}}{\in}g^{\prime}(D)$ and 𝜌≠1, 𝜎 > 1 and c₁, c₂, ..., c_n ∈ 𝜕D. That is, we shall give an estimate below |g"(1)| according to the first nonzero Taylor coefficient of about two zeros, namely z = 0 and z ≠ 0. Estimating is made by using the arithmetic average of n different derivatives g'(c₁), g'(c₂), ..., g'(c_n).

• 한국자기학회지
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• 제3권1호
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• pp.34-40
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• 1993

급속냉각기술로 제조된 $Nd_{10.5}Fe_{79}Co_{2}Zr_{1.5}B_{7}$ 합금분말을 사용하여 사출성형용 자성 펠렛을 제조하였다. 입도분포가 다른 두 종류의 분말($38~75\;\mu\textrm{m}$ 및 $75~50\;\mu\textrm{m}$)을 사용하여 열가소성(Nylon 6) 펠렛을 제조한 후 자성분말의 임계분율(critical volume fraction) 을 결정하고 수지자석의 성형밀도에 따른 자기특성을 고찰하였다. Nylon 6 수지를 사용한 Nd-Fe-Co-Zr-B계 펠렛은 분말입도가 $38~75\;\mu\textrm{m}$인 경우 임계 부피분율은 70%로 나타났고, 그때의 성형밀도는 이론밀도 의 90%를 상회 했으나 $75~150\;\mu\textrm{m}$ 분말의 경우는 같은 분율에서 이론밀도의 87% 수준에 머물렀다. 최적의 자기특성은 분말에 윤활제로서 silicone oil만을 0.5wt.% 첨가한 경우이며 이때의 자기특성으로, $(BH)_{max}=5.2\;MGOe,\;B_{r}=5.1\;kG$ 그리고 $_{i}H_{c}=8.8\;kOe$의 높은 수준을 보였다. Nylon 6수지자석의 성형밀도를 예측할 수 있는 경험식으로서, ${\rho}(g/cm^{3})=1.1+K.V_{s}$을 얻었으며 K(5.3~5.6)는 자성분말 입도에 따른 기울기 상수이고 $V_{s}$는 분말의 부피분율이다.