Synthesis and biological activities of three-molecule conjugates with para-aminosalicylic acid as parent nucleus / 药学学报

Based on the idea of multi-target drug design, taking p-aminosalicylic acid (PAS) as the parent nucleus, the unreported target molecules TM1 and TM2 were designed with PAS, isonicotinic acid and fluoroquinolone as three structural units conjugated by different linkers. Sixteen target molecules were synthesized by multi-step reaction, and their activities against Mycobacterium tuberculosis and human pathogenic bacteria were evaluated. The results showed that the anti-tuberculosis activity of TM2a was stronger than those of the assayed fluoroquinolones, while TM1a was comparable to that of clinafloxacin, the most active compound of the positive control fluoroquinolones; TM1a showed the strongest inhibitory activity to all almost tested strains, TM1b and TM2a showed very strong inhibitory activity to most strains, and TM1h/2h had strong inhibitory activity to some strains; The inhibitory activities of TM1a/1h on Staphylococcus aureus ATCC14125 are much stronger than those of fluoroquinolones, which eminently deserves further study. The hemolysis test results showed that the highly active molecules TM1a and TM2a exhibited relative safety below the concentrations of 8 and 32 μg·mL-1, respectively. In this study, a new hybrid molecule of three molecular pharmacophores with PAS as the parent nucleus was synthesized for the first time, and some of which have highly strong antibacterial activity, which provides a new idea for the research and development of antibiotics.

Synthesis and antibacterial activity of synephrine sulfonamide derivatives containing tetrazole and sulfuryl groups / 药学学报

Synephrine is a natural small-molecule alkaloid found in Aurantii fructus immaturus with versatile biological activities, but its derivatives have been rarely studied so far. Based on the multi-target drug design strategy, the phenolic hydroxyl and secondary amino group of synephrine were modified structurally by the molecular splicing method in this study and thus five intermediates and fifteen target molecules were designed and synthesized. These compounds were evaluated with certain human pathogenic bacteria and fungi, and found that the inhibitory activities of IM4 and IM5 against E.coli are comparable to those of eight fluoroquinolones; TM1n showed stronger inhibitory activity against drug-resistant C. trobicans and drug-resistant C. albicans than the positive control drug fluconazole. TM1d and TM1f against C. albicans ATCC90023, TM1o and TM1f against drug-resistant C. albicans, and TM1f against C. parapsilosis ATCC22019 are all comparable to fluconazole, all of which have the potential for in-depth research. In this study, synephrine derivatives with strong inhibitory activities against human pathogenic fungi were discovered for the first time, which provided a new idea for the further study of synephrine.

Synthesis and antibacterial activity of C-7 haloacyl cephalosporins / 药学学报

Cephalosporins are widely used in the treatment of infectious diseases. The structural differences in cephalosporin drugs mainly lie in the C-7 amino side chain and the C-3 substituent. In this study, twenty-five haloacylated cephalosporins of five series were designed by using a strategy of introducing simple substituents at the C-7 amino group in four cephalosporin parent nucleus with different C-3 substituents and efficiently synthesized under optimized conditions. Their activities against human pathogenic bacteria, Pichia pastoris, citrus canker and citrus pathogenic fungi were evaluated. The results showed that most of the molecules had activity against human pathogenic bacteria, of which seven compounds including TM1f had stronger or equivalent inhibitory activities against eight human pathogens than the marketed drugs cefalotin, cefoxitin sodium and ceftizoxime sodium. The inhibitory activity of TM1s against Alternaria alternate Al.6 was stronger than that of cephalosporins and comparable to that of the positive control prochloraz. TM1f and TM1s are worthy of further study.