IM To study the relationship between βglucuronidase and the invasiveness of human colorectal carcinoma cell lines.METHODS Six colorectal carcinoma cell lines including three welldifferentiated (CX1, CCL 187, CCL 22...IM To study the relationship between βglucuronidase and the invasiveness of human colorectal carcinoma cell lines.METHODS Six colorectal carcinoma cell lines including three welldifferentiated (CX1, CCL 187, CCL 229) and three poorlydifferentiated ones (CCL 227, CCL 228, Clone A) were analyzed for βglucuronidase in the medium by Fischman′s method.RESULTS Low levels of βglucuronidase (activity range, 129 to 196μg/106 cells·h) were associated with the poorly invasive cells. This was in contrast to the elevated levels of the enzyme (246337μg/106·h) present in the medium derived from the more aggressive cells (CCL 227, CCL 228, Clone A, CCL 229).CONCLUSION The highly invasive colorectal carcinoma cells secreted higher levels of βglucuronidase than the poorly invasive ones, and the determination of secreted βglucuronidase might provide a useful in vitro measurement of the invasiveness of colorectal carcinoma.展开更多
PeniciUium purpurogenum Li-3, a fungus producing β-glucuronidase （PGUS）, can con- vert glycyrrhizin （GL） to glycyrrhetinic acid monoglucuronide （GAMG） when grown in medium with GL as the sole carbon source. In ...PeniciUium purpurogenum Li-3, a fungus producing β-glucuronidase （PGUS）, can con- vert glycyrrhizin （GL） to glycyrrhetinic acid monoglucuronide （GAMG） when grown in medium with GL as the sole carbon source. In order to improve the conversion rate of GL and the yield of GAMG, licorice extract （LE） was added as an inducer to enhance the production of GAMG by the PGUS. In this work, the influence of LE on the conversion rate of GL to GAMG was studied. When the Penicil- lium purpurogenum Li-3 was grown in the medium containing LE and GL （ concentration ratio of LE to GL was 2： 3）, the conversion rate of GL was 84. 12% with 38. 18% increase and the yield of GAMG was 80. 47% with 37. 18% increase, comparing with to the medium only containing GL at 48 h. The enzyme activity of ^-glucuronidase was also enhanced from 22. 4 U/mL to 82.3 U/mL, which in- creased up to about 3. 67 fold. The results showed that LE could significantly improve the induced expression level of PGUS.展开更多
The conversion of acetone derived from biomass to isobutene has attracted extensive attentions.In comparison with Brønsted acidic catalyst,Lewis acidic catalyst could exhibit a better catalytic performance with a...The conversion of acetone derived from biomass to isobutene has attracted extensive attentions.In comparison with Brønsted acidic catalyst,Lewis acidic catalyst could exhibit a better catalytic performance with a higher isobutene selectivity.However,the catalyst stability remains a key problem for the long-running acetone conversion and the reasons for catalyst deactivation are poorly understood up to now.Herein,the deactivation mechanism of Lewis acidic Y/Beta catalyst during the acetone to isobutene conversion was investigated by various characterization techniques,including acetone-temperature-programmed surface reaction,gas chromatography-mass spectrometry,in situ ultraviolet-visible,and ^(13)C cross polarization magic angle spinning nuclear magnetic resonance spectroscopy.A successive aldol condensation and cyclization were observed as the main side-reactions during the acetone conversion at Lewis acidic Y sites.In comparison with the low reaction temperature,a rapid formation and accumulation of the larger cyclic unsaturated aldehydes/ketones and aromatics could be observed,and which could strongly adsorb on the Lewis acidic sites,and thus cause the catalyst deactivation eventually.After a simple calcination,the coke deposits could be easily removed and the catalytic activity could be well restored.展开更多
Ce-encapsulated Beta zeolite was synthesized by a one-pot hydrothermal method with citric acid complexing Ce in the absence of Na species.Additional citric acid can effectively prevent the deposition of Ce species dur...Ce-encapsulated Beta zeolite was synthesized by a one-pot hydrothermal method with citric acid complexing Ce in the absence of Na species.Additional citric acid can effectively prevent the deposition of Ce species during the hydrothermal synthesis of zeolites,leading to uniform distribution of Ce cluster in the framework of Beta zeolites.Moreover,the sodium-free synthesis system resulted that the Brønsted acid sites were mainly located on the straight channels and external surface of Beta zeolites,improving the utilization of Brønsted acid sites.In addition,Ce encapsulated Beta zeolites showed enhanced activity and robust stability in the alkylation of benzene with 1-dodecene based on the synergistic effect between Ce species and Brønsted acid sites,which pave the way for its practical application in the production of alkylbenzene.展开更多
<strong>Background:</strong> Hydrolysis improves the sensitivity of drug detection for drug classes such as opiates/opioids and benzodiazepines, which are highly metabolized by glucuronidation and sulfatio...<strong>Background:</strong> Hydrolysis improves the sensitivity of drug detection for drug classes such as opiates/opioids and benzodiazepines, which are highly metabolized by glucuronidation and sulfation and should be implemented in analytical procedures to convert conjugated metabolites into the free or unbound form. This study was aimed to compare different enzymes to make an informed decision. <strong>Methods:</strong> In this study, the CEDIA Benzodiazepine assay was compared with the LC-MS-MS method using 150 positive urine samples and 50 negative urine samples. The samples were analysed without adding any enzyme and then by adding different enzymes to compare their performance.<strong> Results: </strong>The Kura <em>Escherichia coli</em> enzyme performed better than the Roche <em>Escherichia coli </em>enzyme which had 20% false-positive results. Kura BG-100 enzyme performed well but Kura B-One enzyme performed better The Kura B-One enzyme had only 11.5% false-positive results. When double the volume of Kura B-One enzyme was used to test to see if it will have any impact on reducing the number of false negatives, it performed worse. Kura Turbo enzyme behaved similarly to Kura BG-100. <strong>Conclusions: </strong>The <em>β</em>-glucuronidase enzymes comparison allowed us to identify the Kura B-One enzyme as the enzyme of choice for our operation because it reduces the false positives from 20% to 11.5% when compared with the Roche enzyme. It also improved the detection of oxazepam. The Kura B-One enzyme has a short incubation time for hydrolysis when used with the LC-MS-MS method. As a result, we improved the overall turn-around time and reduced the number of false positives that needed confirmation.展开更多
文摘IM To study the relationship between βglucuronidase and the invasiveness of human colorectal carcinoma cell lines.METHODS Six colorectal carcinoma cell lines including three welldifferentiated (CX1, CCL 187, CCL 229) and three poorlydifferentiated ones (CCL 227, CCL 228, Clone A) were analyzed for βglucuronidase in the medium by Fischman′s method.RESULTS Low levels of βglucuronidase (activity range, 129 to 196μg/106 cells·h) were associated with the poorly invasive cells. This was in contrast to the elevated levels of the enzyme (246337μg/106·h) present in the medium derived from the more aggressive cells (CCL 227, CCL 228, Clone A, CCL 229).CONCLUSION The highly invasive colorectal carcinoma cells secreted higher levels of βglucuronidase than the poorly invasive ones, and the determination of secreted βglucuronidase might provide a useful in vitro measurement of the invasiveness of colorectal carcinoma.
基金Supported by the National Science Foundation of China(21276024,21276025)National High-Tech Research and Development Program of China("863"Program)(2012AA02A704)
文摘PeniciUium purpurogenum Li-3, a fungus producing β-glucuronidase （PGUS）, can con- vert glycyrrhizin （GL） to glycyrrhetinic acid monoglucuronide （GAMG） when grown in medium with GL as the sole carbon source. In order to improve the conversion rate of GL and the yield of GAMG, licorice extract （LE） was added as an inducer to enhance the production of GAMG by the PGUS. In this work, the influence of LE on the conversion rate of GL to GAMG was studied. When the Penicil- lium purpurogenum Li-3 was grown in the medium containing LE and GL （ concentration ratio of LE to GL was 2： 3）, the conversion rate of GL was 84. 12% with 38. 18% increase and the yield of GAMG was 80. 47% with 37. 18% increase, comparing with to the medium only containing GL at 48 h. The enzyme activity of ^-glucuronidase was also enhanced from 22. 4 U/mL to 82.3 U/mL, which in- creased up to about 3. 67 fold. The results showed that LE could significantly improve the induced expression level of PGUS.
文摘The conversion of acetone derived from biomass to isobutene has attracted extensive attentions.In comparison with Brønsted acidic catalyst,Lewis acidic catalyst could exhibit a better catalytic performance with a higher isobutene selectivity.However,the catalyst stability remains a key problem for the long-running acetone conversion and the reasons for catalyst deactivation are poorly understood up to now.Herein,the deactivation mechanism of Lewis acidic Y/Beta catalyst during the acetone to isobutene conversion was investigated by various characterization techniques,including acetone-temperature-programmed surface reaction,gas chromatography-mass spectrometry,in situ ultraviolet-visible,and ^(13)C cross polarization magic angle spinning nuclear magnetic resonance spectroscopy.A successive aldol condensation and cyclization were observed as the main side-reactions during the acetone conversion at Lewis acidic Y sites.In comparison with the low reaction temperature,a rapid formation and accumulation of the larger cyclic unsaturated aldehydes/ketones and aromatics could be observed,and which could strongly adsorb on the Lewis acidic sites,and thus cause the catalyst deactivation eventually.After a simple calcination,the coke deposits could be easily removed and the catalytic activity could be well restored.
基金supported by the National Natural Science Foundation of China(22278090,21978055)Natural Science Foundation of Guangdong Province,China(2022A1515012088)the Science and Technology Planning Project of Guangdong Province,China(2022A0505030073,2022A0505030013).
文摘Ce-encapsulated Beta zeolite was synthesized by a one-pot hydrothermal method with citric acid complexing Ce in the absence of Na species.Additional citric acid can effectively prevent the deposition of Ce species during the hydrothermal synthesis of zeolites,leading to uniform distribution of Ce cluster in the framework of Beta zeolites.Moreover,the sodium-free synthesis system resulted that the Brønsted acid sites were mainly located on the straight channels and external surface of Beta zeolites,improving the utilization of Brønsted acid sites.In addition,Ce encapsulated Beta zeolites showed enhanced activity and robust stability in the alkylation of benzene with 1-dodecene based on the synergistic effect between Ce species and Brønsted acid sites,which pave the way for its practical application in the production of alkylbenzene.
文摘<strong>Background:</strong> Hydrolysis improves the sensitivity of drug detection for drug classes such as opiates/opioids and benzodiazepines, which are highly metabolized by glucuronidation and sulfation and should be implemented in analytical procedures to convert conjugated metabolites into the free or unbound form. This study was aimed to compare different enzymes to make an informed decision. <strong>Methods:</strong> In this study, the CEDIA Benzodiazepine assay was compared with the LC-MS-MS method using 150 positive urine samples and 50 negative urine samples. The samples were analysed without adding any enzyme and then by adding different enzymes to compare their performance.<strong> Results: </strong>The Kura <em>Escherichia coli</em> enzyme performed better than the Roche <em>Escherichia coli </em>enzyme which had 20% false-positive results. Kura BG-100 enzyme performed well but Kura B-One enzyme performed better The Kura B-One enzyme had only 11.5% false-positive results. When double the volume of Kura B-One enzyme was used to test to see if it will have any impact on reducing the number of false negatives, it performed worse. Kura Turbo enzyme behaved similarly to Kura BG-100. <strong>Conclusions: </strong>The <em>β</em>-glucuronidase enzymes comparison allowed us to identify the Kura B-One enzyme as the enzyme of choice for our operation because it reduces the false positives from 20% to 11.5% when compared with the Roche enzyme. It also improved the detection of oxazepam. The Kura B-One enzyme has a short incubation time for hydrolysis when used with the LC-MS-MS method. As a result, we improved the overall turn-around time and reduced the number of false positives that needed confirmation.
