RxnBLAST: RxnBLAST as a web-based tool for analyzing scaffold transformations and reactive chemical environment fea-tures in bioreactions. RxnBLAST extracts chemical features from bioreactions including atom–atom mapping, reaction centers, functional groups, and rules to help understand chemical compositions and reaction patterns. Core-to-Core is proposed, which can be utilized in scaffold networks and for constructing a reac-tion space, as well as provide guidance for subsequent biosynthesis efforts.