Recent advances in Synthesis and Biological Applications of Substituted Ureas

: In the last few decades, substituted urea derivatives have got significant importance due to their wide applications in pharmaceutical, polymer, dyes, and agriculture industries. Urea derivatives are the key starting material for the synthesis of novel bioactive heterocyclic molecules. Substituted urea derivatives are known to possess a wide array of biological activities such as herbicidal, antimicrobial, antimalarial, antivirus, anticancer, antioxidants, antiproliferative, antiatherosclerotic, anti-inflammatory, antibiotic, sedatives, anticonvulsants and acting as HIV-1 protease inhibitor. Herein, the synthetic approach and its herbicidal, anticonvulsant, antimicrobial, and antiproliferative activities are reviewed. This review summarizes the current updates regarding the syntheses and biological behavior of substituted urea.

Synthesis of Oligonucleotides Containing 2′-N-alkylaminocarbonyl-2′-amino-LNA (2′-urea-LNA) Moieties Using Post-Synthetic Modification Strategy

The post-synthetic modification of an oligonucleotide is a powerful strategy for the synthesis of various analogs of the oligonucleotide, aiming to achieve the desired functions. In this study, we synthesized the thymidine phosphoramidite of 2′-N-pentafluorophenoxycarbonyl-2′-amino-LNA, which was introduced into oligonucleotides. Oligonucleotides containing a 2′-N-pentafluorophenoxycarbonyl-2′-amino-LNA unit could be isolated under ultra-mild deprotection conditions (50 mM K2CO3 in MeOH at room temperature for 4 h). Moreover, by treatment with various amines as a post-synthetic modification, the oligonucleotides were successfully converted into the corresponding 2′-N-alkylaminocarbonyl-2′-amino-LNA (2′-urea-LNA) derivatives. The duplex- and triplex-forming abilities of the synthesized oligonucleotides were evaluated by UV-melting experiments, which showed that 2′-urea-LNAs could stabilize the nucleic acid complexes, similar to the proto-type, 2′-amino-LNA. Thus, 2′-urea-LNAs could be promising units for the modification of oligonucleotides; the design of a substituent on urea may aid the formation of useful oligonucleotides. In addition, pentafluorophenoxycarbonyl, an amino moiety, acted as a precursor of the substituted urea, which may be applicable to the synthesis of oligonucleotide conjugates.