The basic chemical substances of total alkaloids of Uncaria rhynchophylla and their anti-neuroinflammatory activities

Abstract

To clarify the chemical basis of the total alkaloids of Uncaria rhynchophylla, HPLC-VWD chromatogram of total alkaloids was established. Under its guidance, modern chromatographic and spectroscopic techniques were used to track, isolate and identify the representative principal components. As a result, one new monoterpenoid indole alkaloid, 3S,15S-N4-methoxymethyl-geissoschizine methyl ether (1), together with 20 known alkaloids (2-21), and 5 other known compounds (22-26) were obtained. Meanwhile, sixteen characteristic peaks were identified from the total alkaloids using HPLC analysis. Then, the anti-neuroinflammatory effect of compounds 1-21 was assessed through inhibiting nitric ­­­oxide (NO) production in lipopolysaccharide (LPS)-induced BV-2 microglial cells. Among them, compounds 1, 3, 7, 8, 11, 12, 19 and 21 showed potent inhibitory activities with IC₅₀ values of 5.87–76.78 μM.

Keywords:

• Uncaria rhynchophylla
• total alkaloids
• traceability separation
• basic chemical substances
• anti-neuroinflammatory activity

Acknowledgments

This work was financially supported by the Expenditure Budget Program of Shanghai University of Traditional Chinese Medicine (Grant No. 2021LK002).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Expenditure Budget Program of Shanghai University of Traditional Chinese Medicine (Grant No. 2021LK002).