Advances in Purpurin 18 Research: On Cancer Therapy

How to make cancer treatment more efficient and enhance the patient’s outcome? By multimodal therapy, theranostics, or personalized medicine? These are questions asked by scientists and doctors worldwide. However, finding new unique approaches and options for cancer treatment as well as new selective therapeutics is very challenging. More frequently, researchers “go back in time” and use already known and well-described compounds/drugs, the structure of which further derivatize to “improve” their properties, extend the use of existing drugs to new indications, or even to obtain a completely novel drug. Natural substances, especially marine products, are a great inspiration in the discovery and development of novel anticancer drugs. These can be used in many modern approaches, either as photo- and sonosensitizers in photodynamic and sonodynamic cancer therapy, respectively, or in tumor imaging and diagnosis. This review is focused on a very potent natural product, the chlorophyll metabolite purpurin 18, and its derivatives, which is well suitable for all the mentioned applications. Purpurin 18 can be easily isolated from green plants of all kinds ranging from seaweed to spinach leaves and, thus, it presents an economically feasible source for a very promising anticancer drug.