Synthesis and in vitro antibacterial activity of 7-(3-alkoxyimino-5-amino/methylaminopiperidin-1-yl)fluoroquinolone derivatives

We report herein the design and synthesis of novel 7-(3-alkoxyimino-5-amino/methylaminopiperidin-1-yl)fluoroquinolone derivatives based on the structures of new fluoroquinolones IMB and DZH. The antibacterial activity of these newly synthesized compounds was also evaluated and compared with gemifloxacin, ciprofloxacin, and levofloxacin. Results revealed that all of the target compounds 10-27 have good potency in inhibiting the growth of Staphylococcus aureus including MSSA (MIC: 0.125-8 μg/mL), Staphylococcus epidermidis including MRSE (MIC: 0.25-16 μg/mL), Streptococcus pneumoniae (MIC: 0.125-4 μg/mL), and Escherichia coli (MIC: 0.25-0.5 μg/mL). In particular, some compounds showed useful activity against several fluoroquinolone-resistant strains, and the most active compound 15 was found to be 16-128, 2-32, and 4-8-fold more potent than the three reference drugs against fluoroquinolone-resistant MSSA, MRSA, and MRSE.     

Design, synthesis and in vitro antibacterial activity of 7-(4-alkoxyimino-3-aminomethylpiperidin-1-yl)fluoroquinolone derivatives

We report herein the design and synthesis of novel 7-(4-alkoxyimino-3-aminomethylpiperidin-1-yl) fluoroquinolone derivatives. The antibacterial activity of the newly synthesized compounds was evaluated and compared with gemifloxacin, levofloxacin and ciprofloxacin. Results reveal that compounds 10, 16, and 17 have good activity against all of the tested Gram-positive organisms including drug-resistance strains (MICs: 0.125-4 μg/mL). In addition, compounds 16 and 17 (MICs: 4 μg/mL) were 2- to 8-fold more potent than the reference drugs against Pseudomonas aeruginosa.     

Synthesis and in vitro antibacterial activity of novel fluoroquinolone derivatives containing substituted piperidines

We report herein the synthesis of novel 7-(4-alkoxyimino-3-aminomethyl-3-methylpiperidin-1-yl) fluoroquinolone derivatives. The antibacterial activity of the newly synthesized compounds was evaluated and correlated with their physicochemical properties. Results reveal that all of the target compounds have good potency in inhibiting the growth of Staphylococcus aureus and Staphylococcus epidermidis including MRSE (MIC: 0.125–4 μg/mL). Compounds 12, 13 are more potent than or comparable to levofloxacin against MRSA, Streptococcus pyogenes, Escherichia coli, Klebsiella pneumoniae, and Shigella sonnei. Compound 17 is more active than or comparable to levofloxacin against S. aureus including MRSA, S. epidermidis and S. pyogenes.     

Synthesis and in vitro antibacterial activity of 3-[N-methyl-N-(3-methyl-1,3-thiazolium-2-yl)aminolmethyl cephalosporin derivatives

The new cephalosporins having N-linked quarternary ammonium salt at C-3 position were prepared from the reaction of 2-methylimino-3-methyl-1,3-thiazoline derivatives with cephalosporins. Also antimicrobial activities of those compounds were determined.     

Synthesis and antibacterial activity of benzyl-[3-(benzylamino-methyl)-cyclohexylmethyl]-amine derivatives

A series of benzyl-[3-(benzylamino-methyl)-cyclohexylmethyl]-amine derivatives with different substitution pattern on the aromatic ring have been prepared and evaluated for their antibacterial activity against Gram-positive and Gram-negative bacterial strains. Most of the compounds exhibit potent activity against Pseudomonas aeruginosa and Staphylococcus epidermidis while compounds 6l and 6m showed antibacterial activity against all the four bacterial strains with MIC values ranging from 0.002 to 0.016 μg/mL and no hemolytic activity up to 512 μg/mL in mammalian erythrocytes was observed.     

Synthesis and antibacterial activity of 4'-O-heteroarylcarbamoyl derivatives of macrolide

A series of novel 4'-position modified macrolide derivatives has been synthesized via a facile procedure. Their in vitro antibacterial activities against constitutively erythromycin-resistant strains were evaluated. Among the derivatives tested, compound 8a which has 11,12-carbamate and 4'-O-heteroarylcarbamoyl groups was found to have potent activity against most resistant bacteria.     

Synthesis and in vitro evaluation of 3-(4-nitrophenyl)coumarin derivatives in tumor cell lines

Coumarins are naturally-occurring compounds that have attracted considerable interest due to their numerous biological activities depending on their pattern of substitution on the coumarin molecule. In this present investigation, we synthesized 3-(4-nitrophenyl)coumarin derivatives (9a–e) and evaluated their in vitro cytotoxic effect on human lung (A549), breast (MDA-MB-231) and prostate (PC3) cancer cell lines for 48 h using crystal violet dye binding assay. Cytotoxic effects of the most active compound on normal human lung (MRC-9) and breast (MCF-10A) cell lines, cell cycle analysis using flow cytometry and mitochondrial membrane potential (MMP) using Tetramethyl Rhodamine Methyl Ester (TMRM; rhodamine-123) fluorescent dye were also examined. Among the compounds that were evaluated, 9c showed cytotoxic effect (active), caused significant cells arrest (p < 0.05) in G₀/G₁ and S phases of cell cycle and loss of MMP in A459, MDA-MB-231 and PC3 cell lines. Additionally, the cytotoxic effect of 9c was compared to reference drugs (Coumarin and Docetaxel) for comparative study. These results further demonstrate that acetoxy group at C-7 and C-8 positions of 9c are responsible for the observed cytotoxic effect in these cancer cell lines.     

Synthesis, antibacterial activity, and quantitative structure-activity relationships of new (Z)-2-(nitroimidazolylmethylene)-3(2H)-benzofuranone derivatives

A new series of (Z)-2-(1-methyl-5-nitroimidazole-2-ylmethylene)-3(2H)-benzofuranones (11a-p) and (Z)-2-(1-methyl-4-nitroimidazole-5-ylmethylene)-3(2H)-benzofuranones (12a-m) were synthesized and assayed for their antibacterial activity against Gram-positive and Gram-negative bacteria. Most of the 5-nitroimidazole analogues (11a-p) showed a remarkable inhibition of a wide spectrum of Gram-positive bacteria (Staphylococcus aureus, Streptococcus epidermidis, MRSA, and Bacillus subtilis) and Gram-negative Klebsiella pneumoniae, whereas 4-nitroimidazole analogues (12a-m) were not effective against selected bacteria. The quantitative structure-activity relationship investigations were applied to find out the correlation between the experimentally evaluated activities with various parameters of the compounds studied. The QSAR models built in this work had reasonable predictive power and could be explained by the observed trends in activities.     

Synthesis and in vitro antitumor activity of 4(3H)-quinazolinone derivatives with dithiocarbamate side chains

A series of 4(3H)-quinazolinone derivatives with dithiocarbamate side chains were synthesized and tested for their in vitro antitumor activity against human myelogenous leukemia K562 cells. Among them, (3,4-dihydro-2-methyl-4-oxoquinazolin-6-yl)methyl 4-(4-fluorophenyl)piperazine-1-carbodithioate 8q exhibited significant inhibitory activity against K562 cells with IC(50) value of 0.5 microM.     

Synthesis and antiplatelet activity of ethyl 4-(1-benzyl-1H-indazol-3-yl)benzoate (YD-3) derivatives

Previously, ethyl 4-(1-benzyl-1H-indazol-3-yl)benzoate (YD-3) was identified by us as the first non-peptide protease-activated receptor 4 (PAR4) antagonist. To continue on our development of novel anti-PAR4 agents, YD-3 was used as a lead compound and a series of its derivatives were synthesized and evaluated for their selective anti-PAR4 activity. Through structure-activity relationship (SAR) study, we identified the important functional groups contributing to anti-PAR4 activity, and these functional groups were kept intact during subsequent structural modification. Several new compounds with anti-PAR4 activity comparable to YD-3 were identified. Among them, ethyl 4-[1-(3-chlorobenzyl)-1H-indazol-3-yl]benzoate (33) showed the most potent inhibitory effect on PAR4-mediated platelet aggregation, ATP release, and P-selectin expression. On the other hand, ethyl 4-(1-phenyl-1H-indazol-3-yl)benzoate (83) exhibited dual inhibitory effects on PAR4 and thromboxane formation from arachidonic acid. The above findings can be used as guidelines for development of novel antiplatelet drug candidates.     

Synthesis of nucleotide derivatives containing 1-(4-(3-(trifluoromethyl)-3H-diazirin-3-yl)benzamido)-2,3-propanediol for photoaffinity modification of proteins and nucleic acid

1-(4-(3-(Trifluoromethyl)-3H-diazirin-3-yl)benzamido)-3-O-(4,4'- dimethoxytrityl)-2,3-propanediol phosphoramidite was synthesized and used as a modified unit in the automatic synthesis of oligodeoxyribonucleotides. Pentadecathymidylates with various numbers of 2,3-propanediol moieties substituted with aryl(trifluoromethyl)diazirinyl (ATFMD) were obtained, and the thermal stability of their duplexes with (dA)15 were studied. One ATFMD-propanediol residue was shown to reduce the thermal stability of the duplex by 8-9 degrees C. The irradiation of the ATFMD-containing duplexes by UV light with the wavelength of 350 nm was found to cause the cross-linking reaction of the ATFMD-containing strand with the complementary strand and the formation of the cross-linked duplexes. The photomodification efficiency was independent of the oligonucleotide sequence, with each ATFMD group providing for 5% cross-linking. The irradiation of an ATFMD-containing duplex, a substrate of the HIV-1 integrase, in the presence of this enzyme resulted in the covalent DNA-protein complex. The oligonucleotides with the 1-(4-(3-(trifluoromethyl)-3H-diazirin-3-yl)benzamido)-2,3-propanediol moiety in their chains can be used for the photoaffinity modification of both nucleic acids and proteins that recognize them. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2002, vol. 28, no. 4; see also http://www.maik.ru.     

Synthesis and anti-inflammatory activity of 3-(4'-geranyloxy-3'-methoxyphenyl)-2-trans propenoic acid and its ester derivatives

Different esters of 3-(4'-geranyloxy-3'-methoxyphenyl)-2-trans propenoic acid (1), an anti-inflammatory principle of Acronychia baueri Schott (Rutaceae), were synthesized. Their topical anti-inflammatory activity was evaluated using the Croton oil ear test in mice as a model of acute inflammation. The activity of the paracetamol, guaiacol and hydroquinone esters of (1) was higher than that of the parent compound, being similar to that exerted by indomethacin, used as reference drug.     

Synthesis,antibacterial and antifungal activities of 3-(1,2,4-triazol-3-yl)-4-thiazolidinones

A new series of 3-(1,2,4-triazol-3-yl)-4-thiazolidinone derivatives has been synthesized by the reaction of Schiff bases of 3-amino-1,2,4-triazoles with mercaptoacetic acid and 2-mercaptopropionic acid. Their antibacterial and antifungal activities were evaluated against S. aureus, S. epidermidis, C. albicans and C. glabrata     

Synthesis and CYP26A1 inhibitory activity of novel methyl 3-[4-(arylamino)phenyl]-3-(azole)-2,2-dimethylpropanoates

The role of all-trans-retinoic acid (ATRA) in the development and maintenance of many epithelial and neural tissues has raised great interest in the potential of ATRA and related compounds (retinoids) as pharmacological agents, particularly for the treatment of cancer, skin, neurodegenerative and autoimmune diseases. The use of ATRA or prodrugs as pharmacological agents is limited by a short half-life in vivo resulting from the activity of specific ATRA hydroxylases, CYP26 enzymes, induced by ATRA in liver and target tissues. For this reason retinoic acid metabolism blocking agents (RAMBAs) have been developed for treating cancer and a wide range of other diseases.The synthesis, CYP26A1 inhibitory activity and molecular modeling studies of novel methyl 3-[4-(arylamino)phenyl]-3-(azole)-2,2-dimethylpropanoates are presented. From this series of compounds clear SAR can be derived for 4-substitution of the phenyl ring with electron-donating groups more favourable for inhibitory activity. Both the methylenedioxyphenyl imidazole (17, IC₅₀ = 8 nM) and triazole (18, IC₅₀ = 6.7 nM) derivatives were potent inhibitors with additional binding interactions between the methylenedioxy moiety and the CYP26 active site likely to be the main factor. The 6-bromo-3-pyridine imidazole 15 (IC₅₀ = 5.7 nM) was the most active from this series compared with the standards liarozole (IC₅₀ = 540 nM) and R116010 (IC₅₀ = 10 nM).     

Synthesis and antibacterial activity of egonol derivatives

Synthesis of egonol derivatives, 5-(3'-chloropropyl)-7-methoxy-2-(3',4'-methylenedioxyphenyl)benzofuran 1, 5-(3'-bromopropyl)-7-methoxy-2-(3',4'-methylenedioxyphenyl)benzofuran 2, 3-[2-(1,3-benzodioxol-5-yl)-7-methoxy-1-benzofuran-5-yl]propanal 3, 5-(3'-iodopropyl)-7-methoxy-2-(3',4'-methylenedioxyphenyl)benzofuran 4, 5-[3-(3'-bromopropyloxy) propyl]-7-methoxy-2-(3',4'-methylenedioxyphenyl)benzofuran 5, 3-[2-(1,3-benzodioxol-5-yl)-7-methoxy-1-benzofuran-5-yl]propylmethanoate 6, 3-[2-(1,3-benzodioxol-5-yl)-7-methoxy-1-benzofuran-5-yl]propyloleate 7, 5-[3'-hydroxypropyl]-6-bromo-7-methoxy-2-(3',4'-methylenedioxyphenyl)benzofuran 8, 4-[2-(1,3-benzodioxol-5-yl)-7-methoxy-1-benzofuran-5-yl]butanenitrile 9, 3-[2-(1,3-benzodioxol-5-yl)-7-methoxy-1-benzofuran-5-yl]propylbenzoate 10, 5-[3'-hydroxypropyl]-7-methoxy-3-nitro-2-(3',4'-methylenedioxyphenyl)benzofuran 11 and their antibacterial activity against Staphylococcus aureus, Bacillus subtilis, Candida albicans and Escherichia coli are reported. The starting material egonol 5-[3'-(hydroxy)propyl]-7-methoxy-2-(3', 4'methylenedioxyphenyl)benzofuran was isolated from seeds of Styrax officinalis L. The structural elucidication of these compounds (1-11) was established using 1D ((1)H, (13)C), 2D NMR (HMBC, HMQC, COSY) and LCMS spectroscopic data. While egonol and some synthesised new compounds show similar antibacterial activity and MIC values against S. aureus, B. subtilis, C. albicans and E. coli, other new derivatives show different activity against S. aureus, B. subtilis, C. albicans and E. coli.     

Synthesis and antibacterial activity of novel (un)substituted benzotriazolyl oxazolidinone derivatives

A series of novel (un)substituted benzotriazolyl oxazolidinone derivatives has been synthesized and tested for in vitro antibacterial activities by MIC determination against a panel of susceptible and resistant Gram-positive and Gram-negative microorganisms, some of which are resistant to methicillin and vancomycin. Compounds 20, 21, 24, 29 and 30 from this series were found to be equipotent or more potent than linezolid in vitro.     

Synthesis and antibacterial activity of novel 3-O-arylalkylcarbamoyl-3-O-descladinosyl-9-O-(2-chlorobenzyl)oxime clarithromycin derivatives

A novel series of 3-O-arylalkylcarbamoyl-3-O-descladinosyl-9-O-(2-chlorobenzyl)oxime clarithromycin derivatives, were designed, synthesized and evaluated for their in vitro antibacterial activity. These derivatives were found to have strong activity against susceptible and resistant bacteria strains. Among them, compounds 7a and 7q showed the most potent activity (0.125?µg/mL) against erythromycin-resistant S. pneumoniae expressing the mefA gene. Moreover, compounds 7f, 7i, 7p and 7z displayed remarkably improved activity (4?µg/mL) against penicillin-resistant S. aureus ATCC31007, and compounds 7a, 7b, 7f, 7p and 7z showed improved activity (8?µg/mL) against erythromycin-resistant S. pyogenes. In particular, compound 7z exhibited potent and balanced activity against the tested drug-susceptible and -resistant bacterial strains.     

Synthesis and antibacterial activity of N-(5-benzylthio-1,3,4-thiadiazol-2-yl) and N-(5-benzylsulfonyl-1,3,4-thiadiazol-2-yl)piperazinyl quinolone derivatives

A series of N-(5-benzylthio-1,3,4-thiadiazol-2-yl) and N-(5-benzylsulfonyl-1,3,4-thiadiazol-2-yl) derivatives of piperazinyl quinolones was synthesized and evaluated for antibacterial activity against Gram-positive and Gram-negative microorganisms. Some of these derivatives exhibit high activity against Gram-positive bacteria; Staphylococcus aureus and Staphylococcus epidermidis, comparable or more potent than their parent N-piperazinyl quinolones norfloxacin and ciprofloxacin as reference drugs. The SAR of this series indicates that both the structure of the benzyl unit and the S or SO(2) linker dramatically impact antibacterial activity.     

Synthesis and in vitro antiproliferative and antibacterial activity of new thiazolidine-2,4-dione derivatives

In our present research, we synthesised new thiazolidine-2,4-diones (12–28). All the newly synthesised compounds were evaluated for antiproliferative and antibacterial activity. Antiproliferative evaluation was carried out using normal human skin fibroblasts and tumour cell lines: A549, HepG2, and MCF-7. The IC₅₀ values were determined for tested compounds revealing antiproliferative activity. Moreover, safety index (SI) was calculated. Among all tested derivatives, the compound 18 revealed the highest antiproliferative activity against human lung, breast, and liver cancer cells. More importantly, the derivative 18 showed meaningfully lower IC₅₀ values when compared to the reference substance, irinotecan, and relatively high SI values. Moreover, newly synthesised compounds were screened for the bacteria growth inhibition in vitro. According to our screening results, most active compound was the derivative 18 against Gram-positive bacteria. Therefore, it may be implied that the novel compound 18 appears to be a very promising agent for anticancer treatment.     

Design, synthesis and anticonvulsant activities of novel 1-(substituted/unsubstituted benzylidene)-4-(4-(6,8-dibromo-2-(methyl/phenyl)-4-oxoquinazolin-3(4H)-yl)phenyl) semicarbazide derivatives

Novel quinazolinone derivatives 5a-5n were designed, synthesized and screened for antiepileptic activity using MES and scPTZ seizures tests. Neurotoxicity study was performed by rotorod test. Compounds 5c, 5d, 5g, 5j and 5k were found active in the preliminary screening in MES model and/or scPTZ model. Further all these five compounds were administered to rats, 5c and 5d showed better activity than Phenytoin in oral route. Among all the title compounds tested, the most active one was 5c that revealed protection in MES at a dose of 30 mg/kg (ip) after 0.5 and 4h. This molecule also provided protection in the scPTZ at a dose of 100mg/kg (0.5h) and 300 mg/kg (4h).