New antifungal pyranoisoflavone from Ficus tikoua Bur

To establish the UHPLC fingerprint of Miao Medicine Ficus tikoua Bur., study its spectrum-effect relationship with antioxidant activity, and screen the antioxidant active components. UHPLC was used to establish the fingerprint of Ficus tikoua Bur.. Evaluation System for Similarity of Chromatographic Fingerprint of Chinese Herbal Medicine (Version 2012) was used to evaluate the similarity and identify the common peaks. SPSS 16.0 and SIMCA 14.1 software were used for hierarchical cluster analysis(HCA) and principal component analysis(PCA). The 1,1-diphenyl-2-picrylhydrazyl(DPPH) free radical scavenging method, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt(ABTS) free radical scavenging method and total antioxidant capacity method were used to evaluate the antioxidant activity of 16 batches of ethanol extracts from Ficus tikoua Bur. Three methods including grey relational analysis(GRA), bivariate correlation analysis and partial least squares regression(PLSR) were used to study the spectrum-effect relationship. The UHPLC fingerprints of 16 batches of Ficus tikoua Bur. were established and 13 common peaks were identified. The similarities were 0.613−0.996. At the same time, it was identified that peak 9 was rutin, peak 10 was isoquercetin, and peak 12 was narcissin. The results of HCA showed that the samples were clustered into two categories, which was consistent with the PCA results. Sixteen batches of Ficus tikoua Bur. had different degrees of antioxidant activity. The results of GRA showed that the correlation between 13 common peaks and antioxidant activity was >0.8, and all of them had high correlation. The results of bivariate correlation analysis and PLSR analysis showed that the correlation coefficient and regression coefficient of peak 5, peak 9(rutin), peak 10(isoquercetin), peak 11 and peak 12(narcissin) were positively correlated with antioxidant activity, and the contribution rate was larger(variable importance in projection>1), which were the main active components of antioxidant activity. All the 16 batches of Ficus tikoua Bur. have good antioxidant activity, and its antioxidant effect is the result of the synergistic action of the internal antioxidant component group. The components corresponding to the common peaks 5, 9, 10, 11, 12 are closely related to their antioxidant activity, revealing the pharmacodynamic material basis of the antioxidant activity of Ficus tikoua Bur.