Infrared spectral analysis and antioxidant activity of Dictamnus dasycarpus Turcz with different growth years

Infrared (IR) spectral analysis via Fourier transform infrared spectroscopy, second derivative infrared spectroscopy, dual-index sequential analysis and antioxidant activity evaluation was conducted to analyze the differences of Dictamnus dasycarpus Turcz (DdT) in different growth years. The position, intensity and shape of the characteristic peaks on IR spectra all differed among different growth years. With the prolonging of growth time, the amount of DdT accumulating in the metabolism substances gradually increased, characteristic peaks appeared at 3420, 2927, 1739, 1670, 1620, 1511, 1230, 989 and 806 cm(-1), and the main chemical components were dictamnine, obacunone and fraxinellone. Antioxidant activity evaluation showed all four samples possessed high scavenging activities against 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH.) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS+), and the activity was strengthened with the increase of growth years. The two-step IR macro-fingerprint identification and bioactivity analysis indicated the potential extension of this technique for identification and discrimination of DdT. This should be beneficial to providing a technical basis for identification and picking of DdT and other natural products in the future. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

In this study, infrared spectral analysis was used to analyze Dictamnus dasycarpus Turcz (DdT) of different growth years, revealing changes in chemical composition and antioxidant activity as growth time increased, providing a technical basis for identification and extraction.