The non-covalent immobilization ofβ-glucuronidase enzyme obtained from Rhizopus oryzae was carried out by entrapment in natural fiber(papaya and coconut).The bioconversion capability of immobilized enzyme was analyze...The non-covalent immobilization ofβ-glucuronidase enzyme obtained from Rhizopus oryzae was carried out by entrapment in natural fiber(papaya and coconut).The bioconversion capability of immobilized enzyme was analyzed based on conversion of glycyrrhizin to 18β-glycyrrhetinic acid under different conditions.The hydrolytic activity of theβ-glucuronidase enzyme was highly depended on the microbial source and matrix,in which enzyme was immobilized.R.oryzaeβ-glucuronidase immobilized in papaya fibers produced the highest GA content(13.170μg/mL)at 10 h of reaction.However R.oryzaeβ-glucuronidase immobilized in coconut fibers produced the highest GA content(21.425μg/mL)at 15 h of reaction.Online Molinspiration software was used to predict drug like molecular properties of the 18β-glycyrrhetinic acid,and software suggested that the compounds had potential of becoming the orally active molecules.Therefore,in silico studies were conducted on proposed 18β-glycyrrhetinic acid to select the best possible drug candidates based on drug properties and bioactivity score of the compounds.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
Glycyrrhetinic acid 3-0-mono-β-D-glucuronide (GAMG), an important pharmaceutical intermediate and functional sweetener, has broad applications in the food and medical industries. A green and cost-effective method for...Glycyrrhetinic acid 3-0-mono-β-D-glucuronide (GAMG), an important pharmaceutical intermediate and functional sweetener, has broad applications in the food and medical industries. A green and cost-effective method for its preparation is highly desired. Using sitedirected mutagenesis, we previously obtained a variant of β-glucuronidase from Aspergillus oryzae Li-3 (PGUS1), which can specifically transform glycyrrhizin (GL) into GAMG. In this study, a facile method was established to prepare a CaHP04-PGUSl hybrid nanoflower for enzyme immobilization, based on protein-inorganic hybrid selfassembly. Under optimal conditions, 1.2 mg of a CaHP04- PGUS1 hybrid nanoflower precipitate with 71.2% immobilization efficiency, 35.60 mg·g^-1 loading capacity, and 118% relative activity was obtained. Confocal laser scanning microscope and scanning electron microscope results showed that the enzyme was encapsulated in the CaHP04-PGUSl hybrid nanoflower. Moreover, the thermostability of the CaHP04-PGUSl hybrid nanoflower at 55°C was improved, and its half-life increased by 1.3 folds. Additionally, the CaHP04-PGUSl hybrid nanoflower was used for the preparation of GAMG through GL hydrolysis, with the conversion rate of 92% in 8 h, and after eight consecutive runs, it had 60% of its original activity.展开更多
Started from the liver targeting compounds（glycyrrhizin,glycyrrhetinicacid,bile acid）,six（amine-terminated） compounds were prepared via two-step reactions.The NMR experiments provided the direct evidence of the ex...Started from the liver targeting compounds（glycyrrhizin,glycyrrhetinicacid,bile acid）,six（amine-terminated） compounds were prepared via two-step reactions.The NMR experiments provided the direct evidence of the existence of amide.The polymers were synthesized by polymerizing of BLG-NCA initiated by each of six amine-terminated compounds.The liver targeting group was introduced to the main chain of the polymer.The molecular weight of the resultant polymers was adjusted by changing the molar ratio of monomer BLG-NCA to initiator.The product structure was characterized by GPC,FTIR and（）1H NMR.The results demonstrate that amine-terminated compounds containing liver targeting group could initiate the polymerization of BLG-NCA.展开更多
文摘The non-covalent immobilization ofβ-glucuronidase enzyme obtained from Rhizopus oryzae was carried out by entrapment in natural fiber(papaya and coconut).The bioconversion capability of immobilized enzyme was analyzed based on conversion of glycyrrhizin to 18β-glycyrrhetinic acid under different conditions.The hydrolytic activity of theβ-glucuronidase enzyme was highly depended on the microbial source and matrix,in which enzyme was immobilized.R.oryzaeβ-glucuronidase immobilized in papaya fibers produced the highest GA content(13.170μg/mL)at 10 h of reaction.However R.oryzaeβ-glucuronidase immobilized in coconut fibers produced the highest GA content(21.425μg/mL)at 15 h of reaction.Online Molinspiration software was used to predict drug like molecular properties of the 18β-glycyrrhetinic acid,and software suggested that the compounds had potential of becoming the orally active molecules.Therefore,in silico studies were conducted on proposed 18β-glycyrrhetinic acid to select the best possible drug candidates based on drug properties and bioactivity score of the compounds.
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.
基金the National Natural Science Foundation of China (Grant Nos.21425624, 21878021, and 21506011).
文摘Glycyrrhetinic acid 3-0-mono-β-D-glucuronide (GAMG), an important pharmaceutical intermediate and functional sweetener, has broad applications in the food and medical industries. A green and cost-effective method for its preparation is highly desired. Using sitedirected mutagenesis, we previously obtained a variant of β-glucuronidase from Aspergillus oryzae Li-3 (PGUS1), which can specifically transform glycyrrhizin (GL) into GAMG. In this study, a facile method was established to prepare a CaHP04-PGUSl hybrid nanoflower for enzyme immobilization, based on protein-inorganic hybrid selfassembly. Under optimal conditions, 1.2 mg of a CaHP04- PGUS1 hybrid nanoflower precipitate with 71.2% immobilization efficiency, 35.60 mg·g^-1 loading capacity, and 118% relative activity was obtained. Confocal laser scanning microscope and scanning electron microscope results showed that the enzyme was encapsulated in the CaHP04-PGUSl hybrid nanoflower. Moreover, the thermostability of the CaHP04-PGUSl hybrid nanoflower at 55°C was improved, and its half-life increased by 1.3 folds. Additionally, the CaHP04-PGUSl hybrid nanoflower was used for the preparation of GAMG through GL hydrolysis, with the conversion rate of 92% in 8 h, and after eight consecutive runs, it had 60% of its original activity.
文摘Started from the liver targeting compounds（glycyrrhizin,glycyrrhetinicacid,bile acid）,six（amine-terminated） compounds were prepared via two-step reactions.The NMR experiments provided the direct evidence of the existence of amide.The polymers were synthesized by polymerizing of BLG-NCA initiated by each of six amine-terminated compounds.The liver targeting group was introduced to the main chain of the polymer.The molecular weight of the resultant polymers was adjusted by changing the molar ratio of monomer BLG-NCA to initiator.The product structure was characterized by GPC,FTIR and（）1H NMR.The results demonstrate that amine-terminated compounds containing liver targeting group could initiate the polymerization of BLG-NCA.
