ReviewStructure-activity relationship of brassinosteroids and their agricultural practical usages

•Structure and variety of natural/synthetic BRs have been reviewed.•Bioactivity evaluation protocols have been compared.•Structure-activity relationships of BRs have also been summarized.•The review provided a comprehensive insight into how to synthesize effectively derivatives.

Brassinosteroids (BRs) control several important agronomic traits, such as strengthening resistance to diverse adversity, improving the quality, and increasing crop yield. Their chemical structures and varieties, specific methods for the evaluation of bioactivities, structure-activity relationships, potential novel compounds, and practical agricultural uses were summarized. The findings allow the examination of brassinosteroids in two important issues: 1) Do the results of different bioevaluation protocols provide similar activities for BRs? and 2) which bioevaluated compounds would proof to have a greater potential for application in agricultural usages?