Design, synthesis and biological evaluation of novel trimethylangelicin analogues targeting nuclear factor kB (NF-kB).

A series of trimethylangelicin (TMA) derivatives were designed and synthesized to overcome the unwanted effects of TMA, promising agent for treatment of inflammation-related diseases and other pathologies, such as cystic fibrosis. The new generation TMA analogues bore hindered substituents at the 4 position in order to minimize or avoid the photoreactions with DNA. Among them, the 4-isopropyl-6-ethyl derivative 23 exhibited TMA-like inhibitory activity on NF-κB/DNA interactions but it proved unable to photoreact with pyrimidine bases of DNA, nor to induce any other DNA damage. The isopropyl analogue 23 was proven to lack mutagenicity when assayed through Ames test and exhibited no anti-proliferative activity on cystic fibrosis IB3-1 cells, displaying at the same time inhibition of the TNF-α induced release of the NF-κB regulated PDGF-B chain, IL-10, IL-15, IL-17 and IFN-γ. Therefore compound 23 deserves further assay to determine its anti-inflammatory properties, since it lacks photoreaction properties and mutagenicity-related side effects.