Synthesis, Biological, Immunological and Anticancer Properties of a New Brassinosteroid Ligand

We have developed polyclonal antibodies against the brassinosteroid, 24-epicastasterone. Antiserum against this substance was produced by immunizing rabbits and mice with 24-epicastasterone O-(carboxymethyl)oxime (24-epiCS-CMO) conjugated with bovine-serum albumin (BSA). The conjugates were prepared by a mixed anhydride procedure. The antibodies obtained were tested in enzyme-linked immunosorbent assay (ELISA) using 24-epiCS-CMO-peroxidase conjugate. The use of the ELISAallowed detection over the range of 0.01 to 500 pmoles. Natural brassinosteroids (BRs) like brassinolide, and 24-epibrassinolide exhibited relatively high cross-reactivities but many other natural BRs were inactive. The 24-epiCS-CMO ligand was also slightly active in second bean internode bioasaay and on cancer cell lines of different histopathological origin.