Hydroxypropyl derivatives from several poly-flavonoids sources were synthesized at room temperature.

A strong structure-properties relationship was established based on functional group analysis and spectroscopic methods.

C → C linkage, and A-ring type affect dramatically the poly-flavonoid reactivity with propylene oxide at 20 °C.

Physicochemical properties of pilot-plant Pinus radiata tannin derivatives highly differ from those obtained for alternative purification processes.