Two new naphthoquinones from the stem of Diospyros maritima

Abstract

Two new naphthoquinones, 2-ethoxy-8′-hydroxyisodiospyrin (1) and 3-ethoxy-8′-hydroxyisodiospyrin (2), together with two known naphthoquinones, 6-hydroxy-5-methoxy-2-methyl-1,4-naphthoquinone and bisisodiospyrin were isolated from the stems of Diospyros maritima. The structures of 1 and 2 were established on the basis of spectroscopic data.

Keywords:

• Diospyros maritima
• Ebenaceae
• Naphthoquinones

Acknowledgements

This research was supported by the National Science Council, Taiwan. We thank Ms Shou-Ling Huang and Shu-Yun Sun for the NMR data acquisition and HREI-MS measurement in the Instrumentation Center of the College of Science, National Taiwan University.