Design and synthesis of trans 2-(furan-2-yl)vinyl heteroaromatic iodides with antitumour activity

A new molecular modelling approach based on physico-chemical and pharmacokinetic properties, called Volsurf plus, was used to design new heterocyclic compounds with antiproliferative activity. The synthesis and in vitro antitumour tests on a breast carcinoma cell line (MCF7) confirmed VOLSURF predicted activity values.     

In vitro antitumor activities of 2,6-di-[2-(heteroaryl)vinyl]pyridines and pyridiniums

The in vitro antitumor activities of 2,6-di-[2-(heteroaryl)vinyl]pyridines versus the standard National Cancer Institute 60 cell lines panel and of 2,6-di-[2-(heteroaryl)vinyl] pyridinium cations versus MCF7 (human mammary carcinoma) and LNCap (prostate carcinoma) cell lines are reported. Antiproliferative effects in both series are particularly evident for MCF7 mammary adenocarcinoma cells. Multivariate analysis of DNA microarray data for responsive tumor cell lines suggest a mechanistic pathway involving polyamine biosynthesis and prolactin signal transduction.     

Design,synthesis and biological evaluation of trans 2-(thiophen-2-yl)vinyl heteroaromatic iodides

A modeling approach based on physico-chemical and pharmacokinetic properties, called Volsurf+, was used to design new trans 2-(thiophen-2-yl)vinyl heteroaromatic iodides with antiproliferative activity. The synthesis and in vitro antitumor tests on two cell lines (MCF-7 and LNCap) confirmed Volsurf predicted activity values. An Almond model, derived to have an overall structural insight on the above compounds, supported the validity of Volsurf and provided guidelines for the synthesis of new compounds.     

Synthesis, cytostatic, and antiviral activity of novel 6-[2-(dialkylamino)ethyl]-, 6-(2-alkoxyethyl)-, 6-[2-(alkylsulfanyl)ethyl]-, and 6-[2-(dialkylamino)vinyl]purine nucleosides

An efficient and facile synthesis of a large series of diverse 6-[2-(dialkylamino)vinyl]-, 6-[2-(dialkylamino)ethyl]-, 6-(2-alkoxyethyl)-, and 6-[2-(alkylsulfanyl)ethyl]purine nucleosides (35 examples of both ribo- and 2'-deoxyribonucleosides) was developed. The key transformations involved conjugate nucleophilic additions of amines, alcoholates, or thiolates to Tol-protected 6-alkylylpurine or 6-vinylpurine nucleosides. 6-[(2-Dialkylamino)vinyl]- and some 6-[(2-dialkylamino)ethyl]purine ribonucleosides exerted significant cytostatic effects and some anti-HCV activity with low selectivity.     

Design, synthesis, and in vitro antitumor activity of new 1,4-diarylimidazole-2-ones and their 2-thione analogues

A series of new 1,4-diarylimidazol-2(3H)-one derivatives and their 2-thione analogues has been prepared and evaluated in vitro for antitumor activity against the NCI human cancer cell panel. Compounds bearing a 3,4,5-trimethoxyphenyl ring linked to either N-1 or C-4 position of the imidazole core demonstrated an interesting profile of cytotoxicity with preferential activity against leukemic cell lines. Compound 13 exhibited a potent antitumor activity against MOLT-4 (GI(50)=20 nM) and SR (GI(50)=32 nM) cell lines.     

Enhanced antitumor activity [correction for activitiy] of trans(+/-)-1,2-diaminocyclo- hexaneglutamatoplatinum(II) formulated with stealth liposome

The antitumor platinum(II) compound, [Pt(dach)(Glu)] (dach=trans(+/-)-1,2-diaminocyclohexane, Glu=glutamate) was formulated with a stealth liposome to improve its biological activity. Liposomes were composed of PC/PEG2000-PE/CH (PC=1,2-diacyl-glycero-3-phosphocholine; PEG2000-PE=poly(ethylene glycol)2000-1,2-diacyl-glycero-3-phosphoethanolamine; CH=cholesterol) involving different acyl moieties of phospholipids such as DO (dioleoyl), DM (dimyristoyl) or DS (distearoyl) group. Among the different acyl groups in the stealth liposomes, the DM formulation was optimal for the preparation of the liposomal [Pt(dach)(Glu)] at the mole ratio of DMPC/PEG2000-DMPE/CH=50/5/45 and at the weight ratio of drug/lipid=1/20, which is represented as L-[Pt(dach)(Glu)]. In vitro cytotoxicity was examined in sensitive A2780 and ME180 and their cisplatin-resistant A2780/PDD and ME180/PDD cancer cells. L-[Pt(dach)(Glu)] was 2 approximately 3 times more cytotoxic than the free complex [Pt(dach)(Glu)] and cisplatin in sensitive cells, and 4 approximately 8 times more cytotoxic in resistant cells. Thus, the resistance index of L-[Pt(dach)(Glu)] was 1.3 approximately 2 while those of the free complex and cisplatin were 5 approximately 6, which indicates that L-[Pt(dach)(Glu)] overcome the cisplatin resistance in both resistant cells. In vivo antitumor activity was assayed against the L1210/S leukemia. The optimal activities (% T/C) of the free complex and L-[Pt(dach)(Glu)] were >459/20 and >442/200 mg/kg, respectively. Considering the amount of the platinum complex in L-[Pt(dach)(Glu)], the liposomal [Pt(dach)(Glu)] displayed 2-fold higher drug potency than the free complex. The biodistribution experiment using LE52 tumor-bearing mouse showed excellent lung targeting property of L-[Pt(dach)(Glu)].     

Design, synthesis, and antitumor activity of new bis-aminomethylnaphthalenes

A new series of bis-aminomethylnaphthalenes were synthesized in satisfactory overall yield, through a simple synthetic strategy using reductive amination. The DNA binding properties of these compounds have been examined and compared to those of reference drugs using an UV spectroscopy method. The compounds were evaluated for their in vitro anticancer activity and some of them were studied in vivo. Compound 15 exhibited remarkable antitumor activity and represents a novel template for anticancer chemotherapy and can serve as a new lead compound.     

Synthesis and antibacterial activity of N-[2-[5-(methylthio)thiophen-2-yl]-2-oxoethyl] and N-[2-[5-(methylthio)thiophen-2-yl]-2-(oxyimino)ethyl]piperazinylquinolone derivatives

A number of N-substituted piperazinylquinolone derivatives were synthesized and evaluated for antibacterial activity against Gram-positive and Gram-negative bacteria. Preliminary results indicated that most compounds tested in this study demonstrated comparable or better activity against Staphylococcus aureus and Staphylococcus epidermidis than their parent piperazinylquinolones as reference drugs. Among these derivatives, ciprofloxacin derivative 5a, containing N-[2-[5-(methylthio)thiophen-2-yl]-2-oxoethyl] residue, showed significant improvement of potency against staphylococci, maintaining Gram-negative coverage.     

Synthesis and anti-rhinovirus activity of novel 3-[2-(pyridinyl)vinyl]substituted -2H-chromenes and -4H-chromen-4-ones

Human rhinoviruses (HRVs) are the most common cause of viral respiratory infections and their complications. So far, no anti-viral agent has been approved for prevention or treatment of HRV infections. Pursuing our researches on small molecules with anti-rhinovirus activity, in this paper we describe the synthesis and in vitro anti-HRV 1B and 14 properties of new [2-(2H-chromen-3-yl)vinyl]pyridines and 3-[2-(pyridinyl)vinyl]-4H-chromen-4-ones. Generally, the synthesized compounds interfered with the replication of both serotypes at the micromolar or submicromolar concentrations. Preliminary results on their mechanism of action, performed on selected (E)-2-[2-(2H-chromen-3-yl)vinyl]pyridine, indicate an interference with the early step(s) of HRV 1B and 14 replication, probably at the uncoating level.     

Design,synthesis and antitumor activity of novel pyrazolo[3,4-d]pyrimidine derivatives as EGFR-TK inhibitors

A novel series of 2-(3,6-dimethyl-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-yloxy)-N-(4-substitutedbenzylidene)acetohydrazide (12a–g) was prepared and their structures were confirmed by spectral and elemental analyses. The cytotoxic activity of the newly synthesized compounds was evaluated against breast carcinoma (MCF-7), non-small cell lung cancer (A549) and human colorectal adenocarcinoma (HT-29) cell lines using MTT and colony formation assays. The tested compounds showed a marked anticancer activity against all the tested cell lines, especially compound 12g, which was the most potent anticancer agent with half maximal inhibitory concentrations (IC₅₀) between 5.36 and 9.09 μM. Docking studies into ATP binding site of EGFR protein tyrosine kinase were performed to predict their scores and mode of binding to amino acids, In addition, the inhibitory activity of the target compounds against epidermal growth factor receptor tyrosine kinase (EGFR-TK) was evaluated. Results indicated the ability of the target compounds to inhibit EGFR-TK with half maximal inhibitory concentrations (IC₅₀) in the range of 4.18–35.88 μM. Furthermore, The most active compounds 12g, 12c and 12d were assayed against Fibroblast Growth Factor Receptor (FGFR), Insulin Receptor (IR) and Vascular Endothelial Growth Factor Receptor (VEGFR). The activity of the reported compounds warrants further optimization as novel members in cancer treatment protocols.     

Optically active antifungal azoles: synthesis and antifungal activity of (2R,3S)-2-(2,4-difluorophenyl)-3-(5-[2-[4-aryl-piperazin-1-yl]-ethyl]-tetrazol-2-yl/1-yl)-1-[1,2,4]-triazol-1-yl-butan-2-ol

A series of (2R,3S)-2-(2,4-difluorophenyl)-3-(5-[2-[4-aryl-piperazin-1-yl]-ethyl]-tetrazol-2-yl)-1-[1,2,4]-triazol-1-yl-butan-2-ol (11a-n) and (2R,3S)-2-(2,4-difluorophenyl)-3-(5-[2-[4-aryl-piperazin-1-yl]-ethyl]-tetrazole-1-yl)-1-[1,2,4]-triazol-1-yl-butan-2-ol (12a-n) has been synthesized. The antifungal activity of compounds was evaluated by in vitro agar diffusion and broth dilution assay. Compounds 11d and its positional isomer 12d having 3-trifluoromethyl substitution on the phenyl ring of piperazine demonstrated significant antifungal activity against variety of fungal cultures (Candida spp. C. neoformans and Aspergillus spp.). The compound 12d showed MIC value of 0.12 microg/mL for C. albicans, C. albicans V-01-191A-261 (resistant strain); 0.25 microg/mL for C. tropicalis, C. parapsilosis ATCC 22019 and C. krusei and MIC value of 0.5 microg/mL for C. glabrata, C. krusei ATCC 6258, which is comparable to itraconazole and better than fluconazole. Further, compound 11d showed significant activity (MIC; 0.25-0.5 microg/mL) against Candida spp. and strong anticryptococcal activity (MIC; 0.25 microg/mL) against C. neoformans.     

Synthesis of new 1-[2-Azido-2-(2,4-dichlorophenyl)ethyl]-1H/-imidazoles and in vitro evaluation of their antifungal activity

New 1-[2-azido-2-(2,4-dichlorophenyl)ethyl]-1H/-imidazole were synthesized by nucleophilic substitution of various tertiary alcohols with azide anion in presence of boron trifluoride-diethyl etherate. Their antifungal activity was evaluated against Candida albicans, Candida glabrata, Aspergillus fumigatus and an azole-resistant petite mutant of C. glabrata. Preliminary SAR results are discussed.     

Substituted E-3-(2-Chloro-3-indolylmethylene)1,3-dihydroindol-2-ones with antitumor activity

The synthesis and antitumor activity of a new series of E-3-(2-chloro-3-indolylmethylene)1,3-dihydroindol-2-ones is described. Several compounds were active on the primary test (three human cell lines) and entered the second level (60 human cell lines). All of them were potent growth inhibitors with GI(50) ranging from -5.32 to -7.27. Four are now under review by BEC (Biological Evaluation Committee of the NCI). The most potent antitumor derivatives were also evaluated as cardiotonic agents (in view of a possible coanthracyclinic activity). In order to find a possible mechanism of action their effects on cell cycle progression in an adenocarcinoma cell line (HT29) were tested, evidencing that these molecules are able to block HT29 in mitosis. The introduction of new substituents in the indolinone moiety while maintaining the same chloroindole portion generated interesting derivatives. 3-(2-Chloro-5-methoxy-6-methyl-3-indolylmethylene)5-hydroxy-1,3-dihydroindol-2-one was the most active of the whole series. It was more potent than vincristine against seven of the nine tumors considered. Moreover it was selective towards some cell lines such as MDA-MB-435 (breast), OVCAR-3 (ovarian) and SK-MEL-28 (melanoma). Even the introduction of a benzyl ring at the nitrogen of the chloroindole portion, gave rise to potent compounds.     

Design, synthesis and antiproliferative activity of two new heteroannelated (-)-muricatacin mimics

Two new (-)-muricatacin mimics bearing a furano-furanone ring and an oxygen isostere in the side chain have been designed and synthesized and their in vitro antiproliferative activity was evaluated against several human tumour cell lines. Both analogues showed an increased activity against HL-60 cells with 17- and 185-fold higher potency than (-)-muricatacin. A straightforward synthesis of (-)-muricatacin is also disclosed.     

Synthesis of new 1-[2-Azido-2-(2,4-dichlorophenyl)ethyl]-1H/-imidazoles and in vitro evaluation of their antifungal activity

New 1-[2-azido-2-(2,4-dichlorophenyl)ethyl]-1H/-imidazole were synthesized by nucleophilic substitution of various tertiary alcohols with azide anion in presence of boron trifluoride-diethyl etherate. Their antifungal activity was evaluated against Candida albicans, Candida glabrata, Aspergillus fumigatus and an azole-resistant petite mutant of C. glabrata. Preliminary SAR results are discussed.     

Design and synthesis of a novel family of triazine-based inhibitors of sorbitol dehydrogenase with oral activity: 1-[4-[3R,5S-dimethyl-4-(4-methyl-[1,3,5]triazin-2-yl)-piperazin-1-yl]-[1,3,5]triazin-2-yl]-(R) ethanol

Two new templates, (R) 2-hydroxyethyl-pyridine and (R) 2-hydroxyethyl-triazine, were used to design novel sorbitol dehydrogenase inhibitors (SDIs). The design concept included spawning of these templates to function as effective ligands to the catalytic zinc within the enzyme through incorporation of optimally substituted piperazino-triazine side chains so as to accommodate the active site in the enzyme for efficient binding. This strategy resulted in orally active SDIs, which penetrate key tissues, for example, sciatic nerve of chronically diabetic rats. The latter template led to the design of the title inhibitor, 33, which normalized the elevated sciatic nerve fructose by 96% at an oral dose of 10mg/kg.     

Design,synthesis and in vitro anti-tuberculosis activity of benzo[6,7]cyclohepta[1,2-b]pyridine-1,2,3-triazole derivatives

A series of novel benzo[6,7]cyclohepta[1,2-b]pyridine-1,2,3-triazole hybrids (7a–j & 8a–j) have been designed and synthesized in excellent yields by Huisgen’s [3+2] cyclo addition reaction of 3-(azidomethyl)-2-methyl-6,7-dihydro-5H-benzo[6,7]cyclohepta[1,2-b]pyridine (5) with various alkynes 6 in presence of copper sulphate and sodium ascorbate and their structures were confirmed by IR, ¹H NMR, ¹³C NMR and HRMS. The newly synthesized compounds 7a–j & 8a–j were evaluated for their in vitro anti-mycobacterial activity against Mycobacterium tuberculosis H37Rv (ATCC 27294). Among the compounds tested, the compounds 7i and 8g displayed most potent activity with MIC value of 1.56?µg/mL with low cytotoxicity.     

Design, synthesis, SAR, and biological evaluation of new 4-(phenylamino)thieno[2,3-b]pyridine derivatives

In this work, we performed the design, synthesis, and the structure-activity relationship studies of 13 new derivatives of thieno[2,3-b]pyridine. These derivatives were prepared in high yields (96-70%) and their structures were elucidated by IR, (1)H, (13)C NMR, and MS. The biological results showed some derivatives as antiparasitic agents against Giardia lamblia. Computational analysis of HOMO and LUMO energy, HOMO orbital coefficient distribution, electrostatic potential map, dipole moment, and density HOMO was performed to gain insight into the SAR aspects. This study pointed the p-methoxy substituted derivative as a leading compound for the development of new microbicidal medicines based on thieno[2,3-b]pyridine analogs.     

Synthesis and evaluation of in vitro antimicrobial activity of novel 2-[2-(aroyl)aroyloxy]methyl-1,3,4-oxadiazoles

Synthetic pathway of the ten novel 2-[2-(aroyl)aroyloxy]methyl-1,3,4-oxadiazoles as new potential antimicrobial agents is illustrated. Intramolecular cyclization of 2-(2-aroylaryloxy) aceto hydrazides to 2-[2-(aroyl)aroyloxy]methyl-1,3,4-oxadiazoles was achieved with triethyl orthoformate in good yields. The compounds were characterized by IR, ¹H NMR, mass spectra and by means of CHN analysis. The target compounds were tested for their in vitro antimicrobial activity against representative strains by disc diffusion method and micro dilution methods. Several compounds showed antimicrobial activity comparable with or higher than the standard drugs.     

Design and synthesis of a new [18F]fluoropyridine-based haloacetamide reagent for the labeling of oligonucleotides: 2-bromo-N-[3-(2-[18F]fluoropyridin-3-yloxy)propyl]acetamide

Based on the recently highlighted potential of nucleophilic heteroaromatic ortho-radiofluorinations in the preparation of fluorine-18-labeled radiotracers and radiopharmaceuticals for PET, a [(18)F]fluoropyridine-based bromoacetamide reagent has been prepared and used in prosthetic group introduction for the labeling of oligonucleotides. [(18)F]FPyBrA (2-bromo-N-[3-(2-[(18)F]fluoropyridin-3-yloxy)propyl]acetamide) was designed as a radiochemically feasible reagent, its pyridinyl moiety both carrying the radioactive halogen (fluorine-18) and allowing its efficient incorporation via a nucleophilic heteroaromatic substitution, and its 2-bromoacetamide function, ensuring the efficient alkylation of a phosphorothioate monoester group born at the 3'- or 5'-end of single-stranded oligonucleotides. [(18)F]FPyBrA (HPLC-purified) was efficiently prepared in 18-20% non-decay-corrected yield (based on starting [(18)F]fluoride) using a three-step radiochemical pathway in 80-85 min. The developed procedure involves (1) a high-yield nucleophilic heteroaromatic ortho-radiofluorination as the fluorine-18 incorporation-step (70-85% radiochemical yield) and uses [3-(3-tert-butoxycarbonylaminopropoxy)pyridin-2-yl]trimethylammonium trifluoromethanesulfonate as precursor for labeling, followed by (2) rapid and quantitative TFA-removal of the N-Boc-protective group and (3) condensation with 2-bromoacetyl bromide (45-65% radiochemical yield). Typically, 3.3-3.7 GBq (90-100 mCi) of HPLC-purified [(18)F]FPyBrA could be obtained in 80-85 min, starting from 18.5 GBq (500 mCi) of a cyclotron production batch of [(18)F]fluoride. [(18)F]FPyBrA was regioselectively conjugated with 9-mer and 18-mer single-stranded oligonucleotides, provided with a phosphorothioate monoester group at their 3'-end. Both natural phosphodiester DNAs and in vivo-stable 2'-methoxy and -fluoro-modified RNAs were used. Conjugation uses optimized, short-time reaction conditions (MeOH/0.1 M PBS pH 7.4, 15 min, 120 degrees C), both compatible with the chemical stability of the oligonucleotides (ONs) and the half-life of fluorine-18. Conjugated [(18)F]ONs were finally purified by RP-HPLC and desalted using a Sephadex NAP-10 column. The whole radiosynthetic procedure, including the preparation of the fluorine-18-labeled reagent, the conjugation with the oligonucleotide, and the HPLC purification and formulation lasted 140-160 min. [(18)F]FPyBrA represents a valuable alternative to the already reported N-(4-[(18)F]fluorobenzyl)-2-bromoacetamide for the design and development of oligonucleotide-based radiopharmaceuticals for PET.