| In this study,the traditional medicine herb Scutellaria Radix was investigated.The method of screening microorganisms for the biotransformation of baicalin and wogonoside from Scutellaria Radix roots was established.With the technology of immobilized microorganisms,the fermentation conditions of biotransformation were optimized based on the biotransformation rate.Then,the antioxidant activity of Scutellaria Radix roots before and after biotransformation was evaluated.These studies provide a scientific basis for rational and efficient use of Scutellaria Radix resources and the modernization of traditional Chinese medicine industry.1.The strains of microorganism for biotransformation of Scutellaria Radix were screened.Four kinds of flavonoids ingredients in Scutellaria Radix were analyzed through HPLC chromatographic.It was observed that baicalin and wogonoside could be transformed to baicalein and wogonin by Aspergillus oryzae and Yeast.After biotransformation,the contents of baicalin,baicalein,wogonoside and wogonin were changed from 134,13,19.16,31'.97 and 7.49 mg/g to 48.54,35.28,15.43 and 15.21 mg/g,respectively.The biotransformation rates of baicalin and wogonoside were 63.83%and 51.83%,respectively.2.The conditions of co-immobilized strains were established as follows:The final concentration of sodium alginate:3%The concentration of Calcium chloride solution:3%The immobilized time:2 hUnder the method of the enzyme activity assay,the enzyme activity of immobilized Aspergillus oryzae was 0.74 ± 0.09 U/g,and the immobilized Yeast was 0.63 ± 0.11 U/g.After co-immobilization of the two strains,the activity of enzyme reached 1.09 ± 0.13 U/g.It showed the immobilized co-strains had higher enzyme activity than the single strain.Then,the results showed that residual activity of immobilized microorganisms was 82.3%of its initial activity after 15 runs.3.The optimum biotransformation conditions of Scutellaria Radix with immobilized co-strains was as follows:The concentration of bacterium:1.5 x 1 07 cells/mLThe wet weight of immobilized co-strains:12 gInitial pH:5.0Liquid/solid ratio:30:1 mL/gIncubation time:48 hIncubation temperature:33 ?Under the optimum conditions,baicalin and wogonoside were transformed into baicalein and wogonin,and the transformation ratio reached 91.62%and 90.02%,respectively.Hence,baicalein and wogonin increased from 19.16 ± 0.92 and 7.49 ± 1.36 mg/g to 66.36 ± 0.59 and 22.75 ± 0.63 mg/g,which were about 3.46-fold and 3.04-fold higher than those of the raw sample without transformation,respectively.4.The antioxidant activity of Scutellaria Radix before and after biotransformation was evaluated.The antioxidant capacities of extracts from Scutellaria Radix were assessed with 2-diphenyl-2-picrylhydrazyI(DPPH)radical-scavenging assay,2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid(ABTS)radical-scavenging assay and ?-Carotene-linoleic acid bleaching test.According to the DPPH radical-scavenging assay results,the extracts from the fermented Scutellaria Radix with an IC50 value of 0.366 mg/mL is superior to that from untreated sample(0.417mg/mL).The ABTS radical-scavenging assay results showed that the extracts sample with an IC50 value of 0.579 mg/mL is superior to that from untreated sample(0.722 mg/mL),at last,in the P-Carotene-linoleic acid bleaching test,we can conclude that the extracts sample with an IC50 value of 0.347 mg/mL is superior to that from untreated sample(0.421 mg/mL).In the present study,the optimum biotransformation conditions of Scutellaria Radix with immobilized co-strains were established.The extracts from the fermented Scutellaria Radix with good antioxidant activity were obtained.These studies provide a solid theoretical basis and technical support for the rational development and utilization of Scutellaria Radix resources,large-scale industrial production. |
PDF Full Text Request