Purification
The culture solution was filtered through Toyo No. 1 filter
paper and evaporated to dryness in vacuo at 350C. The
concentrate was divided into acetone-soluble and -insoluble
fractions. The biological activity of growth promotion of
Amaranthus caudatus L. hypocotyls and growth inhibition of
the roots was detected in the acetone-insoluble fraction. This
fraction was dissolved in 10 mL of H20 and was then
fractionated into three parts, of Mr above 105, from 105 to 5
X 103, and below 5 x 103 by molecular exclusion chromatography
(Mol cut, Millipore Corp.). The biological activity was
detected in the fraction of Mr below 5 x 103, and this was
evaporated to dryness in vacuo at 350C.