• Applied Chemistry for Engineering
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• v.21 no.5
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• pp.548-552
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• 2010

This study focused on the development of effective adsorbent to remove acetylenes for the purification of isoprene. The adsorbents with various pore sizes from $4{\AA}$ to $5{\AA}$ were prepared to investigate the effect of pore size on selective adsorption of acetylene as an impurity. The pore size of zeolite A was adjusted by ion-exchange between Na and Ca ions. The pore size of adsorbents has affected the removal of acetylenes selectively because of the kinetic diameter of acetylenes, such as 2-methyl-1-butyne-3-yen (IPA) and 2-butyne. In a batch adsorption experiment, 5A zeolite with pore size of $5{\AA}$ showed the highest removal capacity of 2-butyne. However, IPA was hardly removed from isoprene by the A-type zeolites. For the adsorption isotherm, modified Langmuir model was well fitted with 2-butyne adsorption. Moreover, the regeneration of adsorbent was carried out to determine optimum method. The adsorbent heated for 12 h at $300^{\circ}C$ was regenerated significantly.

• Journal of the Korean Chemical Society
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• v.56 no.3
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• pp.316-321
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• 2012

Poly(ethylene glycol) (PEG) has been used as a sustainable, non-volatile, and environmentally friendly reaction solvent for the synthesis of functionalized benzene/biaryl and fluoren-9-one derivatives from activated acetylenes and 1,3-diones at $100^{\circ}C$. No additional solvent and catalyst are required.

• Bulletin of the Korean Chemical Society
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• v.26 no.4
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• pp.665-667
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• 2005

• Korean Journal of Pharmacognosy
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• v.21 no.4
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• pp.290-299
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• 1990

Taxonomic relationships between some inulin containing plants such as Platycodon and Codonopsis have been investigated comparing their contents of inulin crystals, resin, as well as TLC patterns of saponins and acetylenes. Although Platycodon and Codonopsis have been known to be close in anatomic characters, the present results showed that there were significant differences between not only in the genus but also in the species.

• Bulletin of the Korean Chemical Society
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• v.29 no.8
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• pp.1561-1564
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• 2008

Although the use of Cu(II) salts as catalysts without reductants is limited in the cycloaddition of acetylenes with azides, the catalytic system employing average 10 nm CuO(II) nanoparticles in the absence of reductants shows good catalytic activity to form 1,4-disubstituted 1,2,3-triazoles even in wet THF as well as water. It is also noticeable that CuO(II) nanoparticle catalysts can be recycled with consistent activity. A range of alkynes and azides were subject to the optimized CuO(II) nanoparticle-catalyzed cycloaddition reaction conditions to afford the desired products in good yields.

• The Journal of Natural Sciences
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• v.5 no.2
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• pp.63-73
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• 1992

There are many methods of obtaining butadiene described in the literature. In the america it is produced largely from petroleum gases, i.e., by catalytic dehydrogenation of butene of butene-butane mixtures. Butadiene can be recovered from the $C_4$ residue of an olefin plant by distilling off a fraction containing most of the butadiene, catalytically hydrogenating the higher acetylenes to olefins and separating the product from other olefins and isobutane by extraction. Also it can be obtained by cracking naphtha and light oil. Among the individual dienes of commercial importance, 1, 3-butadiene is of first importance. It is used primarily for the production of polymers.In the present paper, it was investigated for a effect of the formation and the growth inhibition of popped corn polymer in butadiene extraction unit. As a result of study, inhibitors, $NaNO_2$ and TBC were good effective for inhibition of the formation and growth in popcorn polymer. The rational formula of popcorn polymer obtained was $(C_4H_6)_x$.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.37-38
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• 2001

The cytochrome P450 (P450) 1 family (1A1, 1A2, 1B1) is involved in the activation of many pro-carcinogens. Previously we characterized a number of synthetic bi- and polycyclic hydrocarbon acetylenes as selective-mechanism-based inhibitors of recombinent P450s 1A1, 1A2, 1B1 (Shimada et al., Chem. Res. Toxicol., 11, 1048-1056, 1998). We reported that the drug oltipraz is a mechanism-based indicator of P450 1A2 (Lagouet et al. Chem. Res. Toxicol., 13, 245-252, 2000).(omitted)

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.107.1-107.1
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• 2001

• Natural Product Sciences
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• v.12 no.4
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• pp.175-192
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• 2006

Screening for the cytotoxicity from plant origin is the first stage for anti-cancer drug development. A variety of terpenoids with exomethylene, epoxide, allyl, $\alpha,\beta-unsaturated$ carbonyl, acetylenes, and $\alpha-methylene-\gamma-lactone$ induces apoptosis and/or differentiation as well as cytotoxicity through the ROS signal transduction pathways. These are found among monoterpenes, sesquiterpenes, triterpenes, flavonoids, coumarins, diarylheptanoids, and even organosulfuric compounds. The most essential characteristics of natural cytotoxic substances is to possess the strong electrophilicity that is susceptible to nucleophilic biomolecules in the cell. Thiol-reductants and superoxide dismutase can block or delay apoptosis. Thus, ROS and the resulting cellular redox-potential changes can be parts of the signal transduction pathway during apoptosis. Disturbance of the balance of oxireduction by the pigment of natural quinones also caused the induction of the differentiation and apoptosis. Saponins with the cytotoxicity are restricted to their monodesmosides, rather than to bisdesmosides. Those saponins exhibited calcium ion-mediated apoptosis in addition to cytotoxicity whereas they showed also differentiation without extracellular calcium ion. The properties on cytotoxicity, apoptosis, and differentiation were assumed to depend on resultant oxidative stress to the cells. In this review, we describe a spectrum of cytotoxic compounds with various action mechanisms.