The cyanobacterium Nodularia spumigena often contaminates the drinking water of rural communities in developing countries and accumulates in mussels, flounder, and cod from the northern Baltic Sea. Nodularin is a hepatotoxic monocylic pentapeptide produced by the N. spumigena. It is a potent inhibitor of protein phosphatase types 1 (PP1) and 2A (PP2A), exhibiting IC50 values of 1.8 and 0.026 nM, respectively. PP2B is inhibited to a lesser extent with an IC50 of 1.8 μM. No apparent inhibitory effect is observed with PP2C, alkaline phosphatase, acid phosphatase, insulin receptor tyrosine kinase, protein kinase A, phosphorylase kinase, or protein kinase C.
5-HT7 receptor ligand 1 (Compound 5c) is a potent ligand for the 5-HT7 receptor, with a K i value of 8 nM. The compound demonstrates non-hepatotoxic properties and displays moderate potential for drug-drug interactions with substrates of CYP3A4 or CYP2D6 enzymes [1].
Avarol induces apoptosis in pancreatic ductal adenocarcinoma cells by activating PERK-eIF2α-CHOP signaling. Avarl also acts as a competitive AChE inhibitor which are non-hepatotoxic and neuroprotective agents for Alzheimer's disease.