Crepis base Product name: Crepis base Other names:HuanYang Alkali;Yang also base CAS NO.: Assay: ≥99 Packing:1kg/foil bags Appearance: White crystalline powder, soluble in water and ethanol, insoluble in lipids, no smell bitter Usage: The strains from the restructuring of Sildenafil by formylation come is phosphodiesterase type 5 inhibitor drugs