• Bulletin of the Korean Chemical Society
• /
• 제24권4호
• /
• pp.484-488
• /
• 2003

Polycarbosilanes containing diacetylene and organosilacyclic groups, such as poly(1,1-diethynyl-1-silacyclopent-3-ene), poly(1,1-diethynyl-3-triethylsilyl-1-silacyclopent-3-ene), and poly(1,1-diethynyl-1- silacyclobutane), were synthesized by the Glaser oxidative coupling polymerization reactions of 1,1-diethynyl-1-silacyclopent-3-ene, 1,1-diethynyl-3-triethylsilyl-1-silacyclopent-3-ene, and 1,1-diethynyl-1-silacyclobutane, respectively. These materials are almost insoluble in usual organic solvents such as $CHCl_3$ and THF. The polymers were characterized by using several spectroscopic methods in solid state. FTIR spectra of all the polymeric materials show that the characteristic C≡C stretching frequencies appear at 2146-2170 $cm^{-1}$, in particular. The polymers in the solid state show that the strong maximum excitation peaks appear at 255-257 nm and the strong maximum fluorescence emission bands at 401-402 nm. About 71-87% of the initial polymer weights remain at 400 ℃ in nitrogen according to thermogravimetric analysis.

• Natural Product Sciences
• /
• 제17권2호
• /
• pp.85-89
• /
• 2011

Bioassay-guided fractionation of the $CHCl_3$-soluble fraction of a MeOH extract of the fruiting bodies of Hygrophorus russula led to the isolation of five ergosterol derivatives (1 - 5). The structures of these compounds were identified as ergosterol peroxide (1), ergosta-4,6,8(14),22-tetraen-3-one (2), ergosta-7,22-diene-3${\beta}$,5${\alpha}$,6${\alpha}$-triol (3), ergosta-7,22-diene-3${\beta}$,5${\alpha}$,6${\beta}$,9${\alpha}$-tetraol (4), and 5${\alpha}$,6${\alpha}$-epoxy-ergosta-8(14),22-diene-3${\beta}$,7${\alpha}$-diol (5) by comparing their physicochemical and spectral data with those in the literature. These compounds were evaluated for in vitro cytotoxicity against A549 and XF498 cancer cell lines. Most of the tested compounds, except for compound 3, exhibited moderate cytotoxicity against both A549 and XF498 cell lines with $IC_{50}$ values ranging from 10.2 to 18.3 ${\mu}g/ml$ and from 11.4 to 24.6 ${\mu}g/ml$, respectively.

• Bulletin of the Korean Chemical Society
• /
• 제21권10호
• /
• pp.959-968
• /
• 2000

Direct reaction of elemental silicon with a mixture of (dichloromethyl)silanes 1 $[Cl_3-nMenSiCHCl_2:$ n = 0 (a), n = 1(b), n = 2(c), n = 3(d)] and hydrogen chloride has been studied in the presence of copper catalyst using a stirred bed reactor equ ipped with a spiral band agitator at various temperatures from $240^{\circ}C$ to $340^{\circ}C.$ Tris(si-lyl) methanes with Si-H bonds, 3a-d $[Cl_3-nMenSiCH(SiHCl_2)_2]$, and 4a-d $[Cl_3-nMenSiCH(SiHCl_2)(SiCl_3)]$, were obtained as the major products and tris(silyl)methanes having no Si-H bond, 5a-d $[Cl_3-nMenSiCH(SiCl_3)_2]$, as the minor product along with byproducts of bis(chlorosilyl)methanes, derived from the reaction of silicon with chloromethylsilane formed by the decomposition of 1. In addition to those products, trichlorosilane and tetra-chlorosilane were produced by the reaction of elemental silicon with hydrogen chloride. The decomposition of 1 was suppressed and the production of polymeric carbosilanes reduced by adding hydrogen chloride to 1. Cad-mium was a good promoter for and the optimum temperature for this direct synthesis was $280^{\circ}C$.

• Journal of the Korean Wood Science and Technology
• /
• 제45권4호
• /
• pp.456-462
• /
• 2017

Japanese anise (Illicium anisatum L.) twigs were collected and ground after drying, then immersed with 50% aqueous acetone for 3 days. After filtration, the extracts were fractionated with n-hexane, chloroform ($CHCl_3$), ethylacetate (EtOAc) and $H_2O$, and then freeze-dried after condensation. A portion of EtOAc soluble fraction (5.7 g) was chromatographed on a Sephadex LH-20 column with various aqueous $MeOH-H_2O$. Compound 2 and compound 3 were isolated from fraction 8 and 5, respectively. Compound 1 and compound 4 were isolated after rechromatography of fraction 7. The isolated compounds were elucidated as (+)-catechin (1), taxifolin (2), taxifolin-3-O-${\beta}$-D-(+)-xylopyranose (3) and quercitrin (4) by spectral and literature data, and by comparison with the authentic samples. Of the isolated compounds, taxifolin (2), taxifolin-3-O-${\beta}$-D-(+)-D-xylopyranose (3) and quercitrin (4) were isolated, for the first time, from the extracts of japanese anise twigs.

• Biomolecules & Therapeutics
• /
• 제7권4호
• /
• pp.371-376
• /
• 1999

By cytotoxicity screening of the 65 Korean medicinal plants against leukemia L1210 and P388D$_{1}$ cell line using the MTT assay in vitro, Albizzia julibrissin was studied. This plant was extracted with MeOH and MeOH extract was solvent-fractionated with CHCl$_{3}$, EtOAc and n-BuOH in sequence. Each fraction by various solvents system was purified by column chromatography and preparative TLC, and four compounds were isolated. The structure of each compound was deduced from UV, IR, $^{1}$H-HMR, $^{13}$ C-NMR and CI-MS spectral data. The cytotoxic activity ($IC_{50}$/_ of the compounds, quercetin-3-rhamnoside, 4',5,7-trihydroxyfla-van-3-glucoside, spinasterol-3-glucoside and acacic acid lactone, were evaluated as 5 $\mu\textrm{g}$/ml, 2$\mu\textrm{g}$/ml, 1 $\mu\textrm{g}$/ml against L1210 and as 9$\mu\textrm{g}$/ml, 10$\mu\textrm{g}$/ml, 1.5 $\mu\textrm{g}$/ml, 1.5 $\mu\textrm{g}$/ml and 0.9 $\mu\textrm{g}$/ml against P388D$_{1}$, respectively.

• Journal of the Korean Society of Combustion
• /
• 제5권1호
• /
• pp.7-18
• /
• 2000

Numerical simulations of counterflow non-premixed $CH_4/C_2HCl_3/Air$ flames added 8%(by volume) C2HCl3 on the fuel side are conducted at atmospheric pressure using a detailed chemical reaction mechanism in order to understand the effect of strain rates. A detailed sensitivity analysis is also performed in order to assess the relative influence of each reaction on the flame established at a strain rate of 200s-1. The structure of flames (i.e., temperature, velocity, and concentration of species) established at both a strain rate of 150s-1 and 300s-1 are investigated. As the strain rate increases, the "flame zone" is restricted to a narrower range and the position of maximum temperature is shifted to the fuel side. The concentrations of major species, H2O, CO, H2, HCl, Cl2, and Cl are decreased with increased strain rate. The reaction involving chlorine, CH4 + Cl $\rightarrow$ CH3 + HCl, instead of the reaction, CH4 + H $\rightarrow$ CH3 + H2 influences the consumption of methane. C2HCl3 + OH $\rightarrow$ CHCl2 + CHOCl and HCl + OH $\rightarrow$ H2O + Cl, are major reactions, through which OH radicals are consumed.

• Bulletin of the Korean Chemical Society
• /
• 제27권6호
• /
• pp.869-874
• /
• 2006

We have carried out the Glaser oxidative coupling polymerizations of diethynyldiphenylsilane, diethynylmethylphenylsilane,diethynylmethyloctylsilane, and 1,2-diethynyl-1,1,2,2-tetramethyldisilane to afford polycarbosilanes containing diethynyl and organosilane groups in the main chain, such as poly(diethynyldiphenylsilane), poly(diethynylmethylphenylsilane), poly(diethynylmethyloctylsilane), and poly(1,2-diethynyl-1,1,2,2-tetramethyldisilane), respectively. These obtained materials are almost insoluble in common organic solvents such as $CHCl_3$ and THF probably due to the presence of a rigid rod diacetylene group along the polymer main chain. Therefore, the polymers were characterized using several spectroscopic methods in solid state. FTIR spectra of all the polymeric materials show that the characteristic $C \equiv C$ stretching frequencies appear at 2147-2154 $cm ^{-1}$, in particular. The polymers in the solid state exhibit that the strong maximum excitation peaks appear at 260-283 nm and the strong maximum fluorescence emission bands at 367-412 nm, especially. Thermogravimetric analysis of the materials shows that about 55-68% of the initial polymer weights remain at 400 ${^{\circ}C}$ in nitrogen.

• Journal of Life Science
• /
• 제9권2호
• /
• pp.207-211
• /
• 1999

Biologically active compounds in Polygonatum sibiricum were extracted using organic solvents as hexane, CHCl$_3$, n-butanol corresponding each component. Compound I was purified from hexane layer and the chemical structure of compound I was characterized using 1H-NMR, 13C-NMR, DEPT135, COSY, HMQC, HMBC spectrum and MS-spectrum. Consequently, the chemical structure of compound I was determined as 9,12-(9E,l2E)-octade cadienoic acid.

• Korean Journal of Pharmacognosy
• /
• 제19권4호
• /
• pp.262-269
• /
• 1988

The Forsythiae fructus is described to be used as an antiinflammatory drug, diuretics, antidotes and antibacterials in oriental literatures. In order to investigate the efficacy of Forsythiae viridissima (Oleaceae), the methanol extract and its fraction have been evaluated for the acute toxicity, antiinflammatory, analgesic and spasmolytic action in animals. The methanol extract of Forsythiae fructus was found to have significant antiinflammatory activity in the acute and subacute antiinflammatory model in rats, but have no analgesic action. Furthermore, through fractionation procedure, it was found that the active compounds were easily soluble in chloroform and butanol. It is also noted that the extracts had spasmolytic activities in the rat fundus and uterus and had low acute toxicity in mice.

• Journal of Applied Biological Chemistry
• /
• 제48권4호
• /
• pp.198-201
• /
• 2005

Two known isoquinoline alkaloids, (+)-chelidonine (1) and (-)-stylopine (2), were isolated from $CHCl_3$-soluble fraction of whole plants of Chelidonium majus L. var. asiaticum, and their structures were identified by spectroscopic methods and X-ray crystallographic analysis. Two isolates (1 and 2) were examined for their in vitro cytotoxic activities against five human cancer cell lines including DU-145 (prostate), MCF (breast), A549 (lung), HePG2 (liver), and HT-29 (colon) by sulphorhodamine B (SRB) assay.