Phenanthrene derivatives from the stems and leaves of Dioscorea nipponica Makino

Abstract

From the CHCl₃-soluble portion of the 70% EtOH extract of the stems and leaves of Dioscorea nipponica Makino, two new phenanthrenes, 7-hydroxy-2,3,5-trimethoxy-9,10-dihydrophenanthrene (1) and 2,2′,7,7′-tetrahydroxy-4,4′,6,6′-tetramethoxy-1,1′-biphenanthrenes (2), as well as three known phenanthrenes, 6-methoxycoelonin (3), 4,7-dihydroxy-2,3,6-trimethoxyphenanthrene (4), and 3,7-dihydroxy-2,4,6-trimethoxyphenanthrene (5), were isolated. The structures were determined by means of HR-MS, ¹H NMR, ¹³C NMR, and HMBC experiments.

Keywords:

• Dioscorea nipponica Makino
• dihydrophenanthrene
• biphenanthrenes

Acknowledgement

We are very grateful to Chun-Yu Wang (Key Laboratory for Supramolecular Structure and Materials of Ministry of Education, Jilin University) for the measurement of NMR.