1-CYANO-2-HYDROXY-3-BUTENE, A PHYTOTOXIN FROM CRAMBE (CRAMBE ABYSSINICA) SEEDMEAL

Crambe (Crambe abyssinica) seedmeal was found to suppress seedling eme rgence and biomass accumulation when added to a sandy loam soil contai ning wheat (Triticum aestivum Cardinal) and hemp sesbania (Sesbania ex altara) seeds. Hexane, CH2Cl2, MeOH, and water extracts of the seedmea l were prepared and bioassayed against wheat and velvetleaf (Abutilon theophrasti) radicle elongation. The CH2Cl2 extract was the most inhib itory, while the other extracts inhibited the bioassay species only sl ightly (MeOH) or not at all (hexane, water). Fractionation of the CH2C l2 extract identified the major phytotoxin as 1-cyano-2-hydroxy-3-bute ne (CHB), comprising 96.1% of the active CH2Cl2, fraction. Radicle elo ngation of wheat and velvetleaf were inhibited by CHB with I-50 values of 2.1 x 10(-4) M for wheat and 2.7 x 10(-3) M for velvetleaf.