PURPOSE: To obtain the subject new derivative, capable of retaining high activities even at a low concentration and effective in suppression, etc., of growth of plants by using a germinated seed of corn.
CONSTITUTION: A compound of formula I [R1 to R3 are each H or a halogen, with the proviso that any thereof is the halogen], preferably 4-chloro-6,7-dimethoxy-2- benzoxazolinone of formula II. This compound is obtained by adding water to a germinated seed of corn, crushing the germinated seed, then allowing the prepared homogenate to stand at ambient temperature for 0.5-1hr, subsequently boiling the homogenate for 0.5-2hr, filtering the prepared extract, recovering the resultant filtrate, providing a crude extract solution, concentrating the prepared crude extract solution so as to provide (1/2) to (1/5) volume ratio, fractionating the concentrate with (A) dichloromethane at 0.8-2 volume ratio based on the concentrate, recovering a layer of the component (A), affording an extract, further adding (B) ethyl acetate and (C) an aqueous solution of sodium carbonate at 0.5-1mol/l concentration thereto, fractionating the extract, regulating the layer of the component (C) to pH4.0-6.5, then fractionating the regulated layer thereof, separating and recovering the derivative from the resultant extract according to the reversed phase high-performance liquid chromatography and silica gel thin-layer chromatography.
HASEGAWA KOJI
TSUBURA HIROKAZU
TANAKA HIROSHI
ISHIGURO YUKIO
