10.1039/c8nj00993g
This study aimed to develop novel 8-hydroxyquinoline (HQ) derivatives with improved pharmacological properties. Three positional isomers of mannose-HQ conjugates (ManHQ2, ManHQ5, and ManHQ7) ??and one glucose-HQ conjugate (GlcHQ7) were synthesized to explore the effects of sugar type and position on biological activity. ManHQ2 was synthesized using 8-hydroxyquinoline-2-carboxylic acid (HQ2) as the starting material. ManHQ5 was synthesized using 8-hydroxyquinoline-5-carboxylic acid (HQ5) as the starting material. ManHQ7 and GlcHQ7 were synthesized using 8-hydroxyquinoline-7-carboxylic acid (HQ7) as the starting material. 8-Hydroxyquinoline-2-carboxamide (CAHQ2) was used as a reference compound for antimicrobial activity testing. These compounds were characterized by nuclear magnetic resonance spectroscopy, electrospray ionization mass spectrometry (ESI-MS), and UV-visible spectroscopy. The study found that these conjugates exhibited significant antioxidant and antibacterial activities, with specific isomers showing significant antibacterial effects against Pseudomonas aeruginosa and Staphylococcus aureus. In addition, ManHQ2 exhibited antiproliferative activity against human tumor cells in the presence of copper (II) ions. The results suggest that these HQ mannose conjugates have the potential to be bioactive molecules and have increased biocompatibility, which can be further explored for their use as antibiotics and cancer treatments.
