Abstract
Aqueous 70% methanol extract of rice (Oryza saliva, var. Hadsaduri) hulls was found to contain an effective plant growth regulator, which was located at Rf 0.7 on a histogram on silica gel (Kieselgel GF254) TLC (iso-PrOH: 14% NH4OH, 10:2). After preliminary purification by ion exchange, the crude extract was repeatedly purified by column chromatography. The active substance thus obtained as colorless crystals was identical with authentic nicotinamide. The growth promotive effect of nicotinamide in co-operation with ammonium ion on the intact plant at low concentration was observed.
