Carbohydrate recognition of C 3-symmetrical tripodal receptor-type 2,4,6-trisubstituted 1,3,5-triazine derivatives with antiviral activities

• Published in: Journal of thermal analysis and calorimetry Vol. 135; no. 5; pp. 2807 - 2811
• Main Authors: Mibu, Nobuko, Ohata, Tomonori, Sano, Marina, Jian-Rong Zhou, Yokomizo, Kazumi, Aki, Hatsumi, Sumoto, Kunihiro
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Nature B.V 15.03.2019
• Subjects: Carbohydrates; Chemical bonds; Chemical synthesis; Compound A; Derivatives; Exothermic reactions; Free energy; Gibbs free energy; Hydrogen bonding; Recognition; Titration calorimetry
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-018-7573-4

In our search for new bioactive compounds that interfere with the sugar recognition process, we have designed and synthesized C3- and Cs-symmetrical tripodal receptor-type molecules. Among the synthesized C3-symmetrical 2,4,6-trisubstituted 1,3,5-triazine (TAZ) derivatives, compounds A [2,4,6-tris(2-propoxy)-TAZ] and B [2,4,6-tris(3,4-dimethoxyphenyl)-TAZ] showed high levels of anti-HSV-1 activity. We carried out isothermal titration calorimetry on compound B·HCl in aqueous 25% 2-PrOH solution with some sugar derivatives including methyl α/β-d-galactopyranoside (MeO-α/β-Gal), methyl α/β-d-mannopyranoside (MeO-α/β-Man) and methyl α/β-d-glucopyranoside (MeO-α/β-Glc). The reactions of compound B·HCl with MeO-β-Gal and MeO-α-Man were exothermic, and the obtained thermodynamic profiles indicated that both reactions are spontaneous and that there is a considerably large enthalpic contribution (ΔH) in total Gibbs free energy change (ΔG), indicating favorable hydrogen bonding interactions. The reaction of compound B·HCl showed a thermodynamic signature different from that of the entropically driven reaction of compound A.