Fig 2. Structures and synthetic routes of icariin analogs 1–9.

(A) Cellulase, 0.1 M NaOAc, pH = 5.7, 37 °C, overnight. (B) 5% H₂SO₄, 50 °C, 24h. (C) 2-bromoethanol, K₂CO₃, refluxed, 8h. (D) 3-Bromo-1-propanol, K₂CO₃, refluxed, 8h. (E) 1-bromo-2-propanol, K₂CO₃, 75°C, 6h. Glc = glucose, Rha = rhamnose. 5 and 8 are racemic mixtures.