Raphanusol A: a new growth inhibitor of light-grown radish seedlings

A neutral growth inhibitor, for which the name raphanusol Ais proposed, was isolated as a colorless powder (m.p. 137.0–138.0?C)from light-grown radish seedlings and partially characterizedas a phenolic compound which was different from known inhibitors.Raphanusol A inhibited the growth of etiolated radish and lettuceseedlings. Its content, determined by high pressure liquid chromatographyin light-grown radish seedlings, was twice as much as that indark-grown ones. (Received October 18, 1979; )