Fig. 2.

Structural variation in natural and synthetic strigolactones (SLs). All these SLs have the conserved D‐ring (see strigol). The canonical SLs have the full ABC‐ring system, as in strigol, orobanchol, 5‐deoxystrigol, and 4‐deoxyorobanchol. The noncanonical SLs have an incomplete ABC‐ring system, as illustrated with zealactone and heliolactone (marked with asterisk). 5‐deoxystrigol and 4‐deoxyorobanchol illustrate the differences in orientation of the BC ring junction. Nijmegen‐1 and GR24 are examples of synthetic SLs. Adapted from Wang & Bouwmeester (2018) and Yoshimura et al. (2019).