The Biological Actions of Deoxypodophyllotoxin (Anthricin). I. Physiological Activities and Conformational Analysis of Deoxypodophyllotoxin

Deoxypodophyllotoxin (I), which was isolated from Anthriscus sylvestris HOFFM., has strong toxic activity towards killifish (Oryzias latipes) (TLm48 : 0.058ppm) and shrimp (Altemia salina) (TLm48 : 0.15 ppm). Furthermore, I exhibited the phytogrowth-inhibitory activity against two kinds of plant roots. On the other hand, deoxypicropodophyllin (II), a stereoisomer of I, showed none of these activities. From these results it can be assumed that the difference of activity between I and II is due to a difference in their conformations. Through analysis of the proton nuclear magnetic resonance spectra it was clarified that 1) the conformation at the 5a position of I is quasi-equatorial, whereas that of II is quasi-axial, and 2) the B-ring of I takes a half-chair form, whereas that of II takes a half-boat form.