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DTO 반응에서 촉매수명과 경질 올레핀 선택도에 미치는 SAPO-34의 산 처리 효과
최기환 ( Ki Hwan Choi ),이동희 ( Dong Hee Lee ),김효섭 ( Hyo Sub Kim ),박주식 ( Chu Sik Park ),김영호 ( Young Ho Kim ) 한국공업화학회 2015 공업화학 Vol.26 No.2
Effects of the post-acid treatment of SAPO-34 sample by hydrochloric acid were investigated to enhance the catalytic performance in DTO reaction. Uniformly sized SAPO-34 samples with cubic-like morphology were prepared by hydrothermal method using TEAOH and DEA as the structure directing agents. It was modified in terms of the HCl concentration and treating time. As a result, the total surface area and micropore volume for the well modified samples increased and the total acid site was somewhat decreased along with the erosion of the external surface. Especially, the catalytic lifetime and light olefins selectivity for acid treated SAPO-0.2 M (3 h) samples were considerably enhanced compared with those of untreated SAPO-34 samples. It indicates that the deactivation by coke formation proceeds mainly at the pore entrance on the external surface. Therefore, the acid treatment was confirmed to be a simple method which can significantly improve the catalytic performance by modifying the external surface of SAPO-34 catalyst.
적출관류 간에서 대황, 마황 및 황금이 7-에톡시쿠마린의 대사에 미치는 영향
최기환(Ki Hwan Choi),김순선(Soon Sun Kim),박윤주(Youn Joo Park),정혜주(Hye Joo Chung),안미령(Mee Ryung Ahn),서수경(Soo Kyung Suh),신윤용(Yhun Yhong Sheen),김동섭(Dong Sup Kim),장영섭(Young Sup Chang) 대한약학회 1998 약학회지 Vol.42 No.4
In order to study the effects of Rhei rhizoma, Ephedrae herba and Scutellariae radix on hepatic metabolism, we examined the pretreatment effect of those on the metabolism of 7-ethoxycoumarin (EC). Water extracts (1g/kg) of Rhei rhizoma, Ephedrae herba and Scutellariae radix were administered orally to rats for 7 days, respectively. Livers were then isolated and perfused with 100mcM EC for 2 hours. The metabolites of EC, 7-hydroxycoumarin, sulfate conjugate and glucuronide conjugate were measured in the perfusates. The amount of glucuronide conjugates was decreased in Rhei rhizoma pretreated rats (p<0.01), however. 7-hydroxycoumarin was increased in Ephedrae herba pretxeated rats (p<O.OD. We examined whether the change of enzyme activity is related to the change of cytochrome P4501A1 a n d P4502B1 mRNA level in the perfused rat liver, which are responsible for EC metabolism. CYPlAl a n d CYP2B1 mRNA level was increased, which was not statistically significant with rhei rhizoma nor ephedrae herba pretreatment. We also assessed the hepatotoxicity of Rhei rhizoma. Ephedrae herba a n d Scutellariae radix. The activities of ALT and AST were assayed at 24 hours after 7 days administration. Only the ratio of ALT over AST was increased in ephedrae herba pre treated rats (p<0.05). Lipid peroxidation was increased in Rhei rhizoma treatment (p<0.05). while histopathological examination performed after liver perfusion did not show a n y difference compared with vehicle treatment. These results suggest that Ephedrae herba pretreatment increases the o-deethy-lation of 7-ethoxycoumarin in rats, which may be mediated b y CYPlAl mRNA induction.