Carbazole alkaloids from the peels of Clausena lansium

Abstract

A new carbazole alkaloid, claulansine K (1), together with six known carbazole alkaloids (2–7), was isolated from the peels of Clausena lansium (Lour.) Skeels. The new compound was elucidated using a combination of 1D and 2D NMR (HMQC, HMBC, COSY, and ROESY) techniques, and HR-EI-MS analyses. Compound 1 showed in vitro α-glucosidase inhibitory activity with the IC₅₀ value of 0.11 mM. Compound 2 exhibited moderate antibacterial activity against Staphylococcus aureus with the diameter of inhibition zone of 14.2 mm.

Keywords::

• Clausena lansium
• Rutaceae
• carbazole alkaloids
• α-glucosidase inhibitory activity
• antibacterial activity

Acknowledgments

This research was financially supported by Special Fund for Agro-scientific Research in the Public Interest (201303117), National Support Science and Technology Subject (2013BAI11B04), and Major Technology Project of Hainan Province (ZDZX2013008-4, ZDZX2013023-1).