Any lien on real property existing in favor of the state of Missouri, or of such city, at or before the taking effect of such charter, for taxes and special assessments levied by such city, and all right, title and estate acquired by or vested in the state of Missouri or such city, by reason of the forfeiture or sale to the state or such city of any tract of land, town or city lot offered at public sale for taxes or special assessments levied by such city, interest and costs due thereon, and not sold to others for want of bidders, are hereby assigned and transferred to and continued in such city, and all lands, town or city lots forfeited or sold to the state of Missouri or such city on account of taxes or special assessments levied thereon by such city shall, from the taking effect of such charter, be deemed and taken to be forfeited and sold to such city. In all cases where certificates of purchase have, at the time such charter takes effect, been made out in the name of purchasers at any sale for such delinquent taxes or special assessments, the right to redeem from any such sale, or to a deed or deeds, shall not be affected or impaired by anything in this chapter or in such charter contained.