The issues, bills, notes, bonds, or certificates of deposit of any bank, corporation, or association of persons formed for banking purposes, or possessing banking privileges, situated within or without the limits of this state, shall not be loaned in this state by any agent, officer or person employed by, or having any interest in or connection with, any such bank, corporation, or association of persons, at a greater rate of discount or interest than is allowed by the laws of this state. All contracts and agreements made in violation of the provisions of this section shall, as to the whole of the discount or interest allowed or paid, or agreed to be allowed or paid, be void, and the discount or interest may be recovered back by the person suffering such discount or paying such interest.