Separation of antioxidant and α-glucosidase inhibitory flavonoids from the aerial parts of Asterothamnus centrali-asiaticus

Abstract

A new flavonoid, along with 16 known ones, was separated from the aerial parts of Asterothamnus centrali-asiaticus. Their structures were elucidated by extensive spectroscopic methods, including 1D and 2D NMR techniques and HRESIMS. To confirm the structure of the new compound, computational prediction of its ¹³C chemical shifts was performed. All of the 17 flavonoids were reported from A. centrali-asiaticus for the first time. In addition, all flavonoids were evaluated for their antioxidant and α-glucosidase inhibitory activities. The results showed that 10 of them exhibited antioxidant activity. Meanwhile, four flavonoids displayed α-glucosidase inhibitory effect with IC₅₀ values ranging from 38.9 to 299.7 μM.

Keywords:

• Asterothamnus centrali-asiaticus
• flavonoids
• antioxidants
• α-glucosidase inhibitors

Acknowledgements

We appreciate Dr. Yong Cong (Analysis and testing centre of Lanzhou University) for his suggestions about NMR computational calculation.