(E)-1-(2-Hy­droxy­phen­yl)-3-(2,4,5-trimeth­oxy­phen­yl)prop-2-en-1-one

In the title chalcone derivative, C(18)H(18)O(5), the dihedral angle between the hy­droxy-substituted benzene ring and the trimeth­oxy-substituted benzene ring is 16.3 (1)°. The three meth­oxy groups are essentially coplanar with the benzene ring to which they are attached, with an r.m.s. deviation of 0.0208 Å. An intra­molecular O—H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, weak C—H⋯O inter­actions link mol­ecules into helical chains along the b axis. These chains are connected into sheets parallel to the bc plane by further weak C—H⋯O inter­actions.