Studien zur Synthese einer Modellverbindung für Tolyporphin A

Tolyporphin A was isolated by Moore and co-workers from the lipophilic extract of the blue green mircoalga Tolypothrix nodosa in 1992. This structurally unique porphyrin was found to reverse mulitidrug resistance (MDR) in a vinblastine resistant population of human ovarian adenocarinoma cells. Subsequently, 10 additional tolyporphins (B-K) were isolated from the same biological source. It was found that these additional structures to possess varying degrees of anti-MDR activity.Aim of this thesis was the total synthesis of a model compound for tolyporphin A. The envisaged model compound reflects the basic structural elements of naturally occurring tolyporphin A including stereochemistry. Only two pyrane moieties of tolyporphin A were replaced in the model structure by simple acetic acid residues.The basic synthetic strategy developed for the model compound should also open an access to tolyporphin A itself.