Figure 2.From: Q&A: What are strigolactones and why are they important to plants and soil microbes?Strigolactone structures. Strigol and orobanchol are naturally occurring, and their stereochemical structures are shown. GR24 is a synthetic analogue and shown without stereochemical configuration because it is synthesized as a racemic mixture. The lettering convention for ring structures is shown on the strigol molecule, where C and D are both lactones.Back to article page