New dibenz[b, f]oxepins from Cercis chinensis Bunge

Abstract

Three new dibenz[b,f]oxepins: 6-methoxy-7-methyl-8-hydroxydibenz[b, f]oxepin (1), 1,8-dimethoxy-6-hydroxy-7-methyldibenz[b, f]oxepin (2), and 1-hydroxy-6,8-dimethoxy-7-methyldibenz[b,f]oxepin (3), along with two known dibenz[b,f]oxepins pacharin (4) and bauhiniastatin 4 (5), were isolated from Cercis chinensis Bunge (Leguminosae). Their structures were elucidated on the basis of spectroscopic evidence (EI-MS, UV, IR, ¹H, ¹³C and 2D NMR). Compounds 1–5 were isolated from the Cercis genus for the first time.

Keywords:

• Cercis chinensis Bunge
• Leguminosae
• Dibenz[b, f]oxepins

Acknowledgements

We are grateful to the department of the instrumental analysis in Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College for all spectra measurements. This work was supported by the National Natural Science Foundation of China (No. 20432030).