**4.5 Palmirolide A**

A macrocyclic polyketide isolated from the ascidian *Synoicum adareanum.* Palmirolide A displays selective cytotoxicity towards melanoma by inhibiting V-ATPase [35].

### **4.6 Phosphoeleganin**

A novel phosphorylated polyketide isolated from ascidian *Sidnyum elegans* [36]. It has no sufficient cytotoxic activity against human prostate cancer cells and *Antimicrobial Peptides Derived from Ascidians and Associated Cyanobacteria DOI: http://dx.doi.org/10.5772/intechopen.99183*

human breast cancer cell. It subsequently inhibits the activity of Protein tyrosine phosphatase 1B [37].
