A series of new 8-nitro-6-(trifluoromethyl)-1,3-benzothiazin-4-one(BTZ) derivatives containing a C-2 nitrogen spiro-heterocycle moiety based on the structures of BTZ candidates BTZ043 and PBTZ169 were designed and synthesized as new antitubercular agents. Many of them were found to have excellent activity (MIC< 0.15 μM) against the drug susceptive H37Rv strain and two clinically isolated multidrug-resistant strains. Compounds and display acceptable safety, greater aqueous solubility, and better pharmacokinetic profiles than PBTZ169, suggesting their promising potential to be lead compounds for future antitubercular drug discovery.

A series of novel (R)/(S)-7-(3-alkoxyimino-2-aminomethyl-1-azetidinyl)fluoroquinolone derivatives were synthesized and evaluated for their in vitro antibacterial activity against representative strains. Our results reveal that 12 of the target compounds generally show better activity (MIC: <0.008-0.5 μg mL(-1)) against the tested Gram-positive strains including MRSA and MRSE than levofloxacin (LVFX, MIC: 0.125-8 μg mL(-1)). Their activity is similar to that of gemifloxacin (GMFX, MIC: <0.008-4 μg mL(-1)). However, they are generally less active than the two reference drugs against Gram-negative strains. Moreover, against clinical strains of S. aureus including MRSA and S. epidermidis including MRSE, the MIC(50) values (0.06-16 μg mL(-1)) and MIC(90) values (0.5-32 μg mL(-1)) of compounds 16 w, y, and z are 2-8- and 2-16-fold less than LVFX, respectively, and 16 w (MIC(90) range: 0.5-4 μg mL(-1)) was also found to be more active than GMFX (MIC(90) range: 1-8 μg mL(-1)).

No abstract

No abstract

No abstract