AN EVALUATION OF THE HERBICIDAL AND PLANT-GROWTH REGULATORY ACTIVITY OF A NOVEL CLASS OF CARBOHYDRATE-DERIVED 6,8-DIOXABICYCLO[3.2.1]OCTANES

Thirty‐five carbohydrate‐derived dioxabicyclo[3.2.l]octane derivatives have been tested for herbicidal and plant growth regulatory (PGR) activity in an Arabidopsis thaliana assay. Nine of these were herbicidal at concentrations of ⩽ 16 μg ml−1 in the growth medium. Three compounds, viz, 1,6‐anhydro‐3‐deoxy‐4‐O‐(2,6‐dichlorobenzyl)‐2‐O‐methyl‐β‐D‐ribo‐hexopyranose(I), its 4‐O‐benzyl analogue (II), and l,6‐anhydro‐2‐azido‐4‐O‐benzyl‐2,3‐dideoxy‐β‐D‐ribo‐hexopyranose (III) were very active herbicides, killing plants by the rosette stage at 1 μg ml−1 or less. At lower rates, the herbicides acted as growth regulators, reducing growth rates of shoots and roots as well as flowering and seed‐pod development. A further 14 compounds exerted PGR effects only, while 12 compounds were virtually inactive at 16 μg ml−1, the highest rate tested. The ability of the active compounds to reduce seed viability on mature plants at sublethal concentrations was demonstrated in four cases. Copyright © 1990 John Wiley & Sons, Ltd