Synthesis and in vitro antibacterial activity of quinolone/naphthyridone derivatives containing 3-alkoxyimino-4-(methyl)aminopiperidine scaffolds.

We report herein the synthesis of a series of 7-[3-alkoxyimino-4-(methyl)aminopiperidin-1-yl]quinolone/naphthyridone derivatives. In vitro antibacterial activity of these derivatives was evaluated against representative strains, and compared with ciprofloxacin (CPFX), levofloxacin (LVFX) and gemifloxacin (GMFX). The results reveal that all of the target compounds 19a-c and 20 have considerable Gram-positive activity, although they are generally less active than the reference drugs against the Gram-negative strains with some exceptions. Especially, novel compounds 19a2, 19a4 and 19a5 were found to show strong antibacterial activity (MICs: <0.008-0.5µg/mL) against all of the tested 15 Gram-positive strains including MRSA, LVFX- and GMFX-resistant MRSE, and CPFX-, LVFX- and GMFX-resistant MSSA.

Synthesis, in vitro antimycobacterial and antibacterial evaluation of IMB-070593 derivatives containing a substituted benzyloxime moiety.

A series of novel IMB-070593 derivatives containing a substituted benzyloxime moiety and displaying a remarkable improvement in lipophilicity were synthesized and evaluated for their in vitro antimycobacterial and antibacterial activity. Our results reveal that the target compounds 19a-m have considerable Gram-positive activity (MIC: <0.008-32 µg/mL), although they are generally less active than the reference drugs against the Gram-negative strains. In particular, compounds 19h, 19j, 19k and 19m show good activity (MICs: <0.008-4 µg/mL) against all of the tested Gram-positive strains, including ciprofloxacin (CPFX)- and/or levofloxacin (LVFX)-resistant MSSA, MRSA and MSSE. Moreover, compound 19l (MIC: 0.125 µg/mL) is found to be 2-4 fold more active than the parent IMB070593, CPFX and LVFX against M. tuberculosis H37Rv ATCC 27294.

Optimization and SAR research at the piperazine and phenyl rings of JNJ4796 as new anti-influenza A virus agents, part 1.

JNJ4796, a small molecule fuse inhibitor targeting the conserved stem region of hemagglutinin, effectively neutralized a broad spectrum of group 1 influenza A virus (IAV), and protected mice against lethal and sublethal influenza challenge after oral administration. In this study, we reported the modification and structure-activity relationship (SAR) of C (piperazine ring) and E (phenyl ring) rings of JNJ4796. Compound (R)-2c was identified to show excellent in vitro activity against IAV H1N1 and Oseltamivir-resistant IAV H1N1 stains (IC50: 0.03-0.06 µM), low cytotoxicity (CC50 > 200 µM), accepted oral PK profiles and low inhibition rate of hERG (13.2%, at 10 µM). Evaluation for the in vivo anti-IAV efficacy of (R)-2c will begin soon.

Synthesis and biological evaluation of 1H-benzimidazol-5-ols as potent HBV inhibitors.

A new series of 1-methyl-1H-benzimidazol-5-ol derivatives were synthesized and evaluated for their anti-hepatitis B virus (HBV) activity and cytotoxicity in the HepG2.2.15 cell line. Some of the analogues in this series displayed inhibitory activity superior to lamivudine. Of them, compound 13b was the most potent one, showing an IC(50) value of 7.8 µM and a SI value of 13.0.

Identification of Better Pharmacokinetic Benzothiazinone Derivatives as New Antitubercular Agents.

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 in vitro activity (MIC < 0.15 µM) against the drug susceptive Mycobacterium tuberculosis H37Rv strain and two clinically isolated multidrug-resistant strains. Compounds 11l and 11m 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.

Three dimensional approach to investigating biological effects along energetic ion beam pathways.

Heavy ion beams have many exciting applications, including radiotherapy of deep-seated tumors and simulation tests of space irradiation for astronauts. These beams often use a feature that concentrates the energy deposition largely along the end of the energy pathway, leading to different distributions of biological effects along the axial direction. Currently, there is relatively little information regarding the radial directional difference of biological effects along the heavy ion paths. This study utilized a filter membrane that was quantatively applied with cells to demonstrate a 3D distribution model of irradiation on biological effects in living organisms. Some results have indicated that there is excitatory effect on the non-irradiated regions with energetic ions, which may give new insights into the distribution of biological effects along the paths of heavy ion beams with mid-high energy.

Enhanced efficiency in cell killing at the penetration depths around the Bragg peak of a radioactive 9C-ion beam.

PURPOSE: To evaluate the potential importance of radioactive 9C-ion beam in cancer radiotherapy. METHODS AND MATERIALS: Human salivary gland (HSG) cells were exposed to a double-radiation-source 9C beam at different depths around the Bragg peak. Cell survival fraction was determined by standard clonogenic assay. For comparison, the same experiment was conducted for a therapeutic 12C beam. To determine relative biologic effectiveness (RBE) values, HSG cells were also irradiated with 60Co gamma-rays of fractionation scheme as the reference. RESULTS: The 9C beam was more efficient in cell killing at the depths around its Bragg peak than was the 12C beam, which corresponded to the 9C-ion stopping region and where delayed low-energy particles were emitted. The RBE value at 50% survival level for the 9C beam varied from 1.38 to 4.23. Compared with the 12C beam, the RBE values for the 9C beam were always higher; an increase in RBE by a factor of up to 1.87 has been observed at the depths distal to the Bragg peak. CONCLUSION: The potential advantage of radioactive 9C-ion beam in cancer therapy has been revealed at low dose rate in comparison with a therapeutic 12C beam. This observation, however, remains to be investigated at therapeutic dose rates in the future.

Design, synthesis, and in vitro antibacterial activity of fluoroquinolone derivatives containing a chiral 3-(alkoxyimino)-2-(aminomethyl)azetidine moiety.

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)).

Synthesis and antibacterial activity of naphthyridone derivatives containing mono/difluoro-methyloxime pyrrolidine scaffolds.

A series of novel naphthyridone derivatives containing mono/difluoro-methyloxime pyrrolidine scaffolds were designed and synthesized. These derivatives were initially evaluated for their in vitro antibacterial activity and compounds 13a1, b1 were chosen for further evaluation their in vivo activity against systemic infections in mice. The results indicate that all of the target compounds have considerable in vitro antibacterial activity. In the in vivo experiments, 13b1 was found to be more effective than the parent drug gemifloxacin against the tested five strains, and especially its activity (ED(50):21.27 mg/kg) is 5.2-6.1 times more potent than gemifloxacin and ciprofloxacin against clinically important Gram-negative pathogen Pseudomonas aeruginosa.