The present invention relates to compounds represented by the following formula (I) (I) (wherein R1, R2, R3, R4, and R5 independently represent a hydrogen atom or an acetyl or benzyl group, R6 represents a hydrogen atom, a hydroxyl, acetoxy, or benzyloxy group, R7 represents a hydrogen atom, or R6 and R7 together my represent another direct bond, and R8 represents a carboxyl, methoxycarbonyl, hydroxymethyl, or acetoxymethyl group) or salts thereof and a process for the preparation thereof, as well as their utilities in a method for culture, a method for the growth inhibition of moyashi roots, and a method for the growth promotion of moyashi hypocotyls.
