Porphyrins represent a biologically important class of organic molecules which is characterised by the presence of a tetrapyrrole ring{1}. The four nitrogen atoms at the centre of this ring may co-ordinate to a metal atom e.g. iron (II) porphyrin and magnesium porphyrin, which are more commonly known as heme and chlorophyll respectively. In recent years certain tin porphyrins have been shown to
possess beneficial biological properties.

Part 1 outlines the potential pharmaceutical uses of tin-heme (tin protoporphyrin IX){2}, in particular its use in the treatment of jaundice in the new-born.

Part 2 will cover the use of certain other tin porphyrins in the photodynamic therapy of cancer.

Articles from Tin and its Uses, 1990.