Background: Diabetes mellitus type 2 (DMT2) is an endocrine disease of global proportions which is currently affecting 1 in 12 adults in the world, with still increasing prevalence. World Health Organization (WHO) declared this worldwide health problem, as an epidemic disease, to be the only non-infectious disease with such categorization. People with DMT2 are at increased risk of various complications and have shorter life expectancy. The main classes of oral antidiabetic drugs accessible today for DMT2 vary in their chemical composition, modes of action, safety profiles and tolerability. Methods: A systematic search of peer-reviewed scientific literature and public databases has been conducted. We included the most recent relevant research papers and data in respect to the focus of the present review. The quality of retrieved papers was assessed using standard tools. Results: The review highlights the chemical structural diversity of the molecules that have the common target-DMT2. So-called traditional antidiabetics as well as the newest and the least explored drugs include polypeptides and amino acid derivatives (insulin, glucagon-like peptide 1, dipeptidyl peptidase-IV inhibitors, amylin), sulfonylurea derivatives, benzylthiazolidine- 2,4-diones (peroxisome proliferator activated receptor-γ agonists/glitazones), condensed guanido core (metformin) and sugar-like molecules (α-glucosidase and sodium/ glucose co-transporter 2 inhibitors). Conclusion: As diabetes becomes a more common disease, interest in new pharmacological targets is on the rise.

The inhibitory activities of selected cyclic urea and carbamate derivatives (1–13) toward α-glucosidase (α-Gls) in in vitro assay were examined in this study. All examined compounds showed higher inhibitory activity (IC₅₀) against α-Gls compared to standard antidiabetic drug acarbose. The most potent was benzyl (3,4,5-trimethoxyphenyl)carbamate (12) with IC₅₀ = 49.85 ± 0.10 µM. In vitro cytotoxicity of the investigated compounds was tested on three human cancer cell lines HeLa, A549 and MDA-MB-453 using MTT assay. The best antitumour activity was achieved with compound 2 (trans-5-phenethyl-1-phenylhexahydro-1H-imidazo[4,5-c]pyridin-2(3H)-one) against MDA-MB-453 human breast cancer cell line (IC₅₀ = 83.41 ± 1.60 µM). Cyclic ureas and carbamates showed promising anti-α-glucosidase activity and should be further tested as potential antidiabetic drugs. The PLS model of preliminary QSAR study indicated that, in planing the future synthesis of more potent compounds, the newly designed should have the substituents capable of polar interactions with receptor sites in various positions, while avoiding the increase of their lipophilicity.

An efficient, one-pot procedure for the Hofmann rearrangement of aromatic and aliphatic amides has been developed. Methyl and benzyl carbamates are produced with N-bromoacetamide in the presence of lithium hydroxide or lithium methoxide, in high yields. β-Phenylamino amides gave five-membered cyclic ureas stereospecifically. Side products of aryl or benzyl bromination were minimized. This procedure offers an easy access to various protected amines or diamines, which represent important synthetic precursors.