Because many natural products of complex topology are biosynthesized by cyclization of modular linear precursors, which are in turn derived from iterative building block assembly, the authors hypothesized that an analogous linear to cyclized strategy could be used to access all fourteen types of structures presented here. (foresight.org)
Rather, you have to design whatever elements of structural information are necessary to get the right structure into your choice of one or more building blocks so that after the linear precursor goes through the final cyclization cascade, the pieces will all be where they should be. (foresight.org)
Polyketide (PK) and nonribosomal peptides (NRP), constructed on multimodular enzymatic assembly lines, often attain the conformations that establish biological activity by cyclization constraints introduced by tailoring enzymes. (science.sciencemag.org)