New and Convergent Synthesis of Osimertinib

MARK3 kinase: Regulation and physiologic roles

Microtubule affinity-regulating kinase 3 (MARK3), a member of the MARK family, regulates several essential pathways, including the cell cycle, ciliated cell differentiation, and osteoclast differentiation. It is important to understand the control of their activities as MARK3 contains an N-terminal serine/threonine kinase domain, ubiquitin-associated domain, and C-terminal kinase-associated domain, which perform multiple regulatory functions. These functions include post-translational modification (e.g., phosphorylation) and interaction with scaffolding and other proteins. Differences in the amino acid sequence and domain position result in different three-dimensional protein structures and affect the function of MARK3, which distinguish it from the other MARK family members. Recent data indicate a potential role of MARK3 in several pathological conditions, including congenital blepharophimosis syndrome, osteoporosis, and tumorigenesis. The present review focuses on the physiological and pathological role of MARK3, its regulation, and recent developments in the small molecule inhibitors of the MARK3 signalling cascade.

Colorimetric fluoride detection in dimethyl sulfoxide using a heteroleptic ruthenium(ii) complex with amino and amide groups: X-ray crystallographic and spectroscopic analyses

A bis-heteroleptic ruthenium(ii) complex, [Ru(Hdpa)₂(H₂pia)]X₂ (1·X₂; X = Cl, OTf, or F; Hdpa = di-2-pyridylamine; H₂pia = 2-pycolinamide; OTf⁻ = CF₃SO₃⁻), was synthesized and spectroscopically and crystallographically characterized. The crystal structures of 1·Cl₂·2.5H₂O and 1·F₂·2EtOH revealed essentially identical geometries for the 1²⁺ dication; however, the dihedral angle between the two pyridyl groups in the Hdpa ligands, which represented the degree of bending of the bent conformation, was affected by hydrogen-bonding interactions between the NH group and counterions. In 1·F₂·2EtOH, one of the Hdpa ligands had an unusually smaller dihedral angle (15.8°) than the others (29.9°–35.0°). The two NH groups of each Hdpa ligand and the NH₂ group of the H₂pia ligand in 1²⁺ acted as receptors for F⁻ anion recognition via hydrogen-bonding interactions in a dimethyl sulfoxide (DMSO) solution, and the reaction showed an unambiguous color change in the visible region. Upon the addition of tetra-n-butylammonium fluoride to the red DMSO solution of 1·(OTf)₂·H₂O, the solution turned dark brown. ¹H NMR analysis and absorption spectroscopy of the reaction between 1²⁺ and the added F⁻ anions revealed that the F⁻ anions did not distinguish between the two amino groups of Hdpa and the amide group of H₂pia, although they were in different environments in the DMSO solution. A tris-F-adduct with 1²⁺, 1·F₃⁻, was formed when sufficient F⁻ anions were present in the solution, despite the presence of four NH protons in 1²⁺. Time-dependent DFT calculations of 1²⁺ and 1·F₃⁻ were consistent with their absorption spectra.

A bis-heteroleptic ruthenium(ii) complex; [Ru(Hdpa)₂(H₂pia)]X₂ (1·X₂; X = Cl, OTf, or F; Hdpa = di-2-pyridylamine; H₂pia = 2-pycolinamide; OTf^– = CF₃SO₃^–) was synthesized and spectroscopically and crystallographically characterized.

Globally Approved EGFR Inhibitors: Insights into Their Syntheses, Target Kinases, Biological Activities, Receptor Interactions, and Metabolism

Targeting the EGFR with small-molecule inhibitors is a confirmed valid strategy in cancer therapy. Since the FDA approval of the first EGFR-TKI, erlotinib, great efforts have been devoted to the discovery of new potent inhibitors. Until now, fourteen EGFR small-molecule inhibitors have been globally approved for the treatment of different types of cancers. Although these drugs showed high efficacy in cancer therapy, EGFR mutations have emerged as a big challenge for these drugs. In this review, we focus on the EGFR small-molecule inhibitors that have been approved for clinical uses in cancer therapy. These drugs are classified based on their chemical structures, target kinases, and pharmacological uses. The synthetic routes of these drugs are also discussed. The crystal structures of these drugs with their target kinases are also summarized and their bonding modes and interactions are visualized. Based on their binding interactions with the EGFR, these drugs are also classified into reversible and irreversible inhibitors. The cytotoxicity of these drugs against different types of cancer cell lines is also summarized. In addition, the proposed metabolic pathways and metabolites of the fourteen drugs are discussed, with a primary focus on the active and reactive metabolites. Taken together, this review highlights the syntheses, target kinases, crystal structures, binding interactions, cytotoxicity, and metabolism of the fourteen globally approved EGFR inhibitors. These data should greatly help in the design of new EGFR inhibitors.