Strigolactone (rac-GR24) is a neutral organic molecule with weak (or moderate) polarity; it is neither non-polar nor strongly polar.

Structure and Polarity

The structural scaffold of strigolactone (rac-GR24) comprises a tricyclic lactone, an enol ether bridge, and an α,β-unsaturated furanone ring. It contains polar oxygen-containing functional groups—such as an ester carbonyl, an ether linkage, and a lactone oxygen—while simultaneously featuring an extensive hydrophobic backbone composed of hydrocarbon rings (alicyclic or aromatic). As the centers of positive and negative charge do not coincide, the molecule is classified as polar; however, the combined influence of the hydrophobic backbone and the polar functional groups results in relatively weak overall polarity.

Solubility and Polarity

Strigolactones are readily soluble in polar organic solvents such as DMSO, DMF, methanol, ethanol, and ethyl acetate, but are virtually insoluble in pure water. This indicates that, overall, they are lipophilic yet possess a certain degree of polarity.