Efficient click chemistry towards novel 1H-1,2,3-triazole-tethered 4H-chromene-d-glucose conjugates: Design, synthesis and evaluation of in vitro antibacterial, MRSA and antifungal activities.
Thanh ND, Hai DS, Ngoc Bich VT, Thu Hien PT, Ky Duyen NT, Mai NT, Dung TT, Toan VN, Kim Van HT, Dang LH, Toan DN, Thanh Van TT.
The series of 2-amino-7-propargyloxy-4H-chromene-3-carbonitriles 5a-t were synthesized from corresponding 2-amino-7-phydroxy-4H-chromene-3-carbonitriles 4a-t and propargyl bromide. Two procedures were used in these syntheses: K<sub>2</sub>CO<sub>3</sub>/acetone and NaH/DMF procedures with yields of 65-89% and 80-96%, respectively. 1H-1,2,3-Triazole-tethered 4H-chromene-d-glucose conjugates 7a-t were synthesized using click chemistry of propargyl ethers 5a-t and tetra-O-acetyl-β-d-glucopyranosyl azide. Cu@MOF-5 was the optimal catalyst for this chemistry. The yields of 1H-1,2,3-triazoles were 80-97.8%. All triazoles 7a-t were evaluated in vitro for anti-microorganism activities. Among tested compounds with MIC values of 1.56-6.25 μM, there were four compounds against B. subtilis, four compounds against S. aureus, and four compounds against S. epidermidis; five compounds against E. coli, four compounds against K. pneumoniae, five compounds against P. aeruginosa, and six compounds against S. typhimurium. Compounds 7c,7d,7f,7h, and 7r had MIC values of 1.56-6.25 μM for three clinical MRSA isolates. Some compounds had inhibitory activities against four fungi, including A. niger, A. flavus, C. albicans, and S. cerevisiae, with MIC values of 1.56-6.25 μM. Some 1H-1,2,3-triazoles had comparatively low toxicity against RAW 264.7 cells.