Two new benzophenone glycosides from the aerial parts of Hypericum przewalskii

Abstract

Plants of the genus Hypericum contain various types of secondary metabolites that exhibited extensive biological activities. In the ongoing efforts to discover natural neuroinflammatory inhibitors with the potential to develop into therapeutic agents for neurodegenerative diseases, two new benzophenone glycosides, hyperewalones A and B (1 and 2), along with eight known compounds (3–10), were isolated from the aerial parts of Hypericum przewalskii. Their structures were elucidated by comprehensive analysis of IR, HRESIMS, 1D and 2D NMR spectra, and chemical derivatization. The anti-neuroinflammatory activity of compounds 1–10 was evaluated by determining their ability to inhibit the production of nitric oxide (NO) in lipopolysaccharide (LPS)-activated BV-2 microglial cells. Compounds 2, 4, 6–8 exhibited significant anti-neuroinflammatory activity with IC₅₀ values of 0.61–4.90 μM. These findings suggest that the benzophenone, ionone, and flavonoid glycosides isolated from H. przewalskii are promising anti-neuroinflammatory compounds worthy of further investigations.

Graphical Abstract

Keywords:

• Hypericaceae
• Hypericum przewalskii
• benzophenone glycoside
• anti-neuroinflammatory activity
• antimicrobial activity

Acknowledgements

The authors thank the Xi'an Institute for Food and Drug Control for kind help in our experiments.

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

This study was supported by the National Natural Science Foundation of China (No. 31800291), Natural Science Basic Research plan in Shaanxi Province (No. 2018JQ3032), the Fundamental Research Funds for the Central Universities (No. 2452017173).