Recent advances with alkaline phosphatase isoenzymes and their inhibitors

Alkaline phosphatases are found in different living species and play crucial roles in various significant functions, such as hydrolyzing a variable spectrum of phosphate-containing physiological compounds, contributing to DNA synthesis, bone calcification, and attenuation of inflammation. They are homodimeric enzymes; each subunit contains one magnesium ion and two zinc ions crucial for the catalytic activity of the enzyme. Alkaline phosphatases exist in four distinct isoenzymes (placental, intestinal, germ cell, and tissue nonspecific alkaline phosphatases), which are expressed by four different genes; each one of them has distinguished functions. Any disturbance in the gene expression of alkaline phosphatase eventually induces serious disease conditions. Thus, the need to explore new lead inhibitors has increased recently. In this literature review, we aim to investigate the role of alkaline phosphatase in different diseases and physiological conditions and to study the structure-activity relationships of recently reported inhibitors. We focused on the lead compounds reported in the last 5 years (between 2015 and 2019).