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
<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
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<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.
