• sintesi
• attivatori
• AMPK
• AICAR
• Acadesina

The objective of my thesis is the design and synthesis of novel benzofuran derivatives for the modulation of the AMP-activated protein kinase enzyme, or AMPK for short. This enzyme is central in the regulation of energy homeostasis in the cell and the whole body (1) not only in man but throughout the animal kingdom(2). AMPK is a member of the Serine/Threonine kinase family of transferase enzymes and is comprised of three subunits termed α, β and γ. The α subunit is the kinase portion of the enzyme while the β and γ subunits are the regulatory domains. Crucial to the activation of AMPK are the CBS domains in the γ subunit which bind the three adenosine nucleotides AMP, ADP and ATP and thus sense the energy status of the cell. Binding of ATP signals that the cell is energy replete whilst increased concentrations of AMP and its subsequent binding to the γ subunit signal the depletion of energy reserves and cause the allosteric activation of AMPK. Another method of activation of the enzyme is the phosphorylation of Thr172 in the α subunit which is carried out by LKB1, CaMKK2 and TAK1(3). Once activated the enzyme proceeds to phosphorylate a number of other enzymes with the overall effect of blocking energy consuming pathways and enabling energy producing ones. For example it inhibits the synthesis of new fatty acids (FAs), cholesterol and triglycerides (TGs), and activates FA uptake and β-oxidation (FAO); inhibits protein synthesis(4) and glycogen synthesis while stimulating glycolisis. Interestingly its role applies to whole body energy regulation as well by being expressed in the hypothalamus and subject to hormonal control where in general hormones associated with an overfed state (such as insulin and leptin) inhibit AMPK, whilst those associated with an under-fed state (such as ghrelin and adiponectin) activate it.(5)
For the reasons stated above AMPK makes an interesting target for the treatment of a plethora of diseases including metabolic disorders, cardiovascular disease, cancer and even inflammation, as it appears to be a key element in the activation of the immune systems responses(6). Currently, AMPK is the focus of intensive drug discovery projects which have brought to the identification of several activators, which range from natural plant products to metformin, though the vast majority of these appear to be indirect activators. Among the true activators the 5-aminoimidazole-4-carboxamide riboside, known as AICAR or acadesine, is unique in that it acts by binding with the γ subunit in place of AMP whereas other optimization studies have focused on allosteric activators acting on the β subunit.(7) We focused on the optimization of the nucleosidic structure and chose the 3-aminobenzofuran-2-carboxamide ring as a close structural match as our base structure then proceeded to investigate a series of 5-substituted derivatives. These derivatives were mainly obtained through Heck or Suzuki reactions and subsequent purification via column chromatography or crystallization. Samples of these products will then be tested for their functional activity in vitro to test their ability to activate the AMPK enzyme and in vivo in murine models of inflammatory bowel disease.