This invention provides 2-, 6, and 9-substituted purine derivatives, particularly 2(1-R hydroxymethylpropylamino)-6-benzylamino-9-isopropyl purine, having, in particular, antiproliferative properties, and suitable for use as pharmaceutical compositions and herbicidal compositions. Also provided are pharmaceutical compositions and herbicidal compositions comprising the 2-, 6, and 9-substituted purine derivatives, and methods of treatment using the 2-, 6, and 9-substituted purine derivatives.