Lupan-3beta,20-diol synthase  Lupan-3beta,20-diol synthase (, "LUP1 (gene)") is an enzyme with systematic name "(3S)-2,3-epoxy-2,3-dihydrosqualene hydro-lyase (lupan-3beta,20-diol forming)". This enzyme catalyses the following chemical reaction  The reaction occurs in the reverse direction.