| In this paper,the physical and chemical properties,preparation technology and biological activity of glycyrrhizic acid and related desaccharide derivatives are analyzed and studied,and the current research status of glycyrrhizic acid biotransformation is sorted out,with a view to the selective desugarization and fermentation of this research to produce mono-glucose.Aldehydic acid glycyrrhetinic acid provides research ideas and references.At the same time,it analyzes the status quo of the industrialization of glycyrrhizic acid fermentation products,and puts forward existing problems and difficulties in order to provide some thoughts for the realization of industrialization.A selective medium was used to screen out the strains that can achieve the selective desugaring of glycyrrhizic acid to produce mono-glucuronic acid glycyrrhetinic acid from the soil of the Gansu grassland.Combining the morphological observation with 18S rDNA identification,it was determined to be Aspergillus terreus and named TMZ05.After single-factor investigation and orthogonal experiment to verify the optimization method,the optimal technology for selective desugar fermentation of Aspergillus terreus TMZ05 strain was obtained,which achieved a breakthrough in the substrate concentration limit in the test of Aspergillus terreus transforming glycyrrhizic acid.The fermentation medium is:yeast extract 2.5 g/L,glucose 0.5 g/L,and CaCO30.5 g/L.Fermentation conditions are:inoculation amount of 30 mycelium,initial pH of fermentation broth is 6,glycyrrhizic acid concentration 5g/L,180r/min shake flask fermentation at 30℃ for 4 days,the molar yield of monoglucuronic acid glycyrrhetinic acid is the highest,Up to 62.34%,compared with the screening stage,its molar yield is increased to 3 times.Combining the physicochemical properties of monoglucuronic acid glycyrrhetinic acid,a reversed-phase chromatographic separation packing column is selected,and the macroporous resin is used for preliminary separation,and MCI and high-pressure preparation and purification are continued to obtain monoglucuronic acid glycyrrhetinic acid.At the same time,the TMZ05 strain was induced and domesticated to obtain the TMZ05-2 strain which can produce glycyrrhetinic acid derivatives in large quantities.Optimize the fermentation process of strains.The optimal fermentation medium is potato broth.Fermentation conditions are:inoculation amount 30-40 mycelium,initial pH of fermentation broth 6.0,glycyrrhizic acid concentration 5g/L,180r at 35℃/min shake flask fermentation for 6 days,the molar yield of glycyrrhetinic acid derivatives is the highest,up to 90%,realizing high-efficiency biotransformation of this substance.The silica gel column chromatography elution system of glycyrrhetinic acid derivatives was investigated by thin layer chromatography.The silica gel column chromatography was used for preliminary separation,MCI and high-pressure preparation and purification were used to obtain the pure product,combined with UPLC-Q-TOF-MS/MS and NMR technology.This substance is identified as chryseno[2,1,c]oxepin-12-carboxylic acid.Based on DPPH free radical scavenging method,bacteriostatic zone determination method,broth micro-dilution method,hyaluronidase inhibition method,the antioxidant activity,antibacterial and anti-allergic properties of glycyrrhizic acid and monoglucuronic acid glycyrrhetinic acid were evaluated.Studies have shown that the two have no obvious antioxidant activity;they have a significant inhibitory effect on Escherichia coli and Staphylococcus aureus in the bacteriostatic test,and at the same time have a good inhibitory effect on the hyaluronidase in type I allergies in the anti-allergic test.In addition,the antibacterial and anti-allergic properties of monoglucuronic acid glycyrrhetinic acid are better than glycyrrhizic acid.It provides a scientific basis for the application of monoglucuronic acid glycyrrhetinic acid in the food,drug and cosmetics industry. |
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