Design, Synthesis and Evaluation of Linear and Cyclic Peptide Analogues of Carnosine as Anticancer Agents

Aim Carnosine (β-alanyl-L-histidine) is a naturally occurring dipeptide widely and abundantly distributed in the muscle and nervous tissues of animal species. Carnosine contains several beneficial biological properties such as antiglycating and antioxidant activities. It also contains antineoplastic effects in human cell culture as well as in animal experiments, however, the clear molecular basis of this activity has not been known yet. In the present study, in order to further examine structural basis of Carnosine for the anticancer activity, some linear and cyclic Carnosine peptide analogues were synthesized and their cytotoxicity were examined. Material and Methods  Linear and cyclic Carnosine peptide analogues were synthesized with appropriate protected amino acids and reagents using solid-phase peptide synthesis strategy, and anti-neoplastic activity of the synthesized compounds were examined on cancer cell lines of HepG2 (Human Liver Cancer Cell Line) and HT-29 (Human Colorectal Adenocarcinoma Cell Line) using MTT assay and flow cytometry analysis. Safety profile of the synthesized Carnosine analogues was also examined using skin fibroblast cells. Results  Our results showed that Carnosine analogues were toxic against HepG2 and HT-29 cell lines with a mean IC50 value 12.7 µg/mL. Flow cytometry analysis showed that such toxic activity could be, at least partly, through apoptosis induction. Conclusion  According to our experiments, in overall, compound 3b can be a good candidate for the further development of safe anticancer agents. On the other hand, cyclic peptides analogues of Carnosine, 1c and 2c, considering the properties of toxicity activities good enough on cancerous cell lines along with high safety profiles on normal skin cells, could be candidates for further works on finding anticancer agents with peptide structure giving better physicochemical properties for oral administration.   &nbsp

Nano-Silica Phosphoric Acid: An Efficient Catalyst for One-Pot Synthesis of Tetrahydrobenzo[a]xanthenes-11-one Under Solvent- Free or Sonication Conditions

Two simple protocols for the synthesis of tetrahydrobenzo[a]xanthenes-11-ones using nano silica phosphoric acid are reported. Short reaction times, high yields, reusability of catalyst and easy workup are some advantages of these protocols

Solvent-free Preparation of 1,1-Diacetates from Aldehydes Mediated by Zirconium Hydrogen Sulfate at Room Temperature

A mild and efficient method has been developed for the preparation of acylals in good yields through a reaction of aldehydes with acetic anhydride using Zr(HSO 4 ) 4 as catalyst at room temperature and under solvent-free conditions

SnCl₄-functionalized nano-Fe₃O₄encapsulated-silica particles as a novel heterogeneous solid acid for the synthesis of 1,4-dihydropyridine derivatives

A simple and general synthetic method for the synthesis of 1,4-dihydropyridines under ultrasonic irradiation was developed using Fe3O4@SiO2–SnCl4as an efficient catalyst.</p