Design,synthesis, and biological evaluation of new ALDH2 activators

Mitochondrial aldehyde dehydrogenase 2 (ALDH2) is an important enzyme response for the metabolism or detoxification of toxic aldehydes, in particular acetaldehyde and 4-hydroxynonenal (4-HNE), which were important risk factors for acute alcoholism and stroke respectively. A special variant ALDH212 with reduced enzymatic activity was carried by a high percentage of East Asians, especially Han Chinese, and that could increase the risk of these diseases further. Therefore, ALDH2 activators had important potential clinical values. N-benzylbenzamide compounds represented by Alda-1 were the only ALDH2-specific activators that have been reported so far. In this study, three new classes of compounds were modified from Alda-1 to improve their water-solubility and then drug-like properties. The results showed that all compounds had increased water solubility and two classes of compounds exhibited good activation activity. Among them, compound I-6 showed the best activity.     

Design,synthesis and biological evaluation of novel non-azole derivatives as potential antifungal agents

A series of 3-substituted quinazolinones, 2-substituted quinoxalines and 2-substituted benzopyrans were synthesized and evaluated for their antifungal activity in vitro. The new compounds revealed excellent in vitro antifungal activity with broad spectrum. The structure-activity relationships (SARs) of the derivatives were analyzed. Compound 9A2 exhibits better antifungal activity against 5 tested fungi in vitro than fluconazole, especially against Trichophyton rubrum and Microsporum gypseum. This study provides a series of novel lead compounds for the development of non-azole antifungal agents.     

Conception, synthesis, and biological evaluation of original discodermolide analogues

Due to its intriguing biological activity profile and potential chemotherapeutic application discodermolide (DDM) proved to be an attractive target. Therefore, notable efforts have been carried out directed toward its total synthesis and toward the production and evaluation of synthetic analogues. Recently, we achieved the total synthesis of DDM. At the present, guided by the knowledge gained during our DDM total synthesis and by the requirement of keeping the bioactive "U" shape conformation, we report the convergent preparation of five original analogues. Three types of changes were realized through modification of the terminal (Z)-diene moiety, of the methyl group at the C14-position, and the lactone region. All analogues were active in the nanomolar range and two of them turned out to be equipotent to DDM.     

Design,synthesis, characterization of zirconium (IV), cadmium (II) and iron (III) complexes derived from Schiff base 2-aminomethylbenzimidazole, 2-hydroxynaphtadehyde and evaluation of their biological activity

(E)-1-((((1H-benzo[d]imidazol-2-yl)methyl)imino)methyl)naphthalen-2-ol, ligand was synthesized by condensation of (1H-benzo[d]imidazol-2-yl) methanamine, with 2-hydroxynaphthaldehyde. The ligand and the metal complexes were characterized by various spectroscopic techniques. Interpretation of spectra confirmed that the ligand adopted either a neutral tridentate or a monobasic tridentate mode, bonded to the metal ions through the nitrogen atom of the heterocyclic benzimidazole, azomethine nitrogen atom and deprotonated phenolic oxygen atom forming either a square planer geometry. X-ray powder diffraction analysis of complexes indicated that the complexes were crystalline in nature with triclinic structures. The antibacterial and the antifungal activities of the ligand and its complexes were examined against Escherichia coli, Bacillus subtilis and Aspergillus niger by well- diffusion method. The results showed that Cd (II) complex exhibits the highest antifungal and antibacterial activities among the tested complexes. The in vitro antitumor activityies of the different complexes were tested and the results revealed an important cytotoxicity of cadmium complex against MCF-7, Hep G2 and HCT 116 cell. Iron complex showed also a strong toxicity towards Hep G2 and HCT cell whereas moderate activity against MCF-7. The bioassay study of different complexes against mosquito larvae demonstrated strong activity of zirconium complex with 0.172 values of LC50.     

Design,synthesis and biological evaluation of indole derivatives as novel inhibitors targeting B-Raf kinase

A series of novel indole derivatives were designed and synthesized and their inhibitory activity against B-Raf and HepG2 cell were also described. Among them, compounds 7a and 7b exhibited excellent potency, which showed the potential for further research as lead compounds.     

Stereoselective synthesis of 3-alkylidene/alkylazetidin-2-ones from azetidin-2,3-diones

Azetidin-2,3-diones have been used as synthons for the synthesis of C-3 alkylidene/alkylazetidin-2-ones. Some of the 3-alkylazetidin-2-ones are well known for their cholesterol absorption inhibitor activity. A regio and stereoselective Grignard reaction on a keto group followed by dehydration using PPh₃/CCl₄ reagent is a key step in this synthesis. Hydrogenation of the 3-alkylideneazetidin-2-ones provided stereoselectively cis-3-alkylazetidin-2-ones in very good yields.     

Design,synthesis and biological evaluation of isoxazole-naphthalene derivatives as anti-tubulin agents

In this study, a novel series of isoxazole-naphthalene derivatives as tubulin polymerization inhibitors were designed, synthesized and evaluated for their anti-proliferative activities against human breast cancer cell line MCF-7. Most of the synthesized compounds exhibited moderate to potent antiproliferative activity (IC₅₀ < 10.0 μM), as compared to cisplatin (15.24 ± 1.27 μM). Among them, compound 5j containing 4-ethoxy substitution at phenyl ring was found to be the most active compound with IC₅₀ value of 1.23 ± 0.16 μM. Mechanistic studies revealed that compound 5j arrested cell cycle at G2/M phase and induces apoptosis. Furthermore, in vitro tubulin polymerization assay showed that compound 5j displayed better inhibition activity on tubulin polymerization (IC₅₀ = 3.4 μM) than colchicine (IC₅₀ = 7.5 μM). Molecular docking study also revealed that compound 5j binds to the colchicine binding site of tubulin.     

Design,synthesis, biological evaluation and in silico studies of N-(pyridin-2-yl)-benzamides derivatives as quorum sensing inhibitors

The emergence of bacterial resistance against chemical treatment is a big threat to the efficacy of bacterial infection treatment. One of the major reasons for resistance to antimicrobial agents is growth of microorganisms in biofilm. An alternative treatment by developing novel anti-biofilm agents had led to the concept of quorum sensing (QS) inhibition, which primarily targets QS signaling system by disrupting cell-cell communication. Therefore, this study focuses to develop novel antimicrobial agents which work by QS inhibition and act as anti-biofilm agents against Bacillus Subtilis and Pseudomonas Aeruginosa. In this work, a natural product-like scaffolds from Asinex library were screened and N-pyridin-2-yl-benzamide moiety was chosen to design and synthesize. Synthesized compounds were evaluated for potential anti-biofilm activity for the aforesaid microorganisms and also checked for cell viability assay, where two potent compounds 3a and 3c showed their static biofilm activity to ∼59% and ∼58% at 100 μM, respectively against Bacillus subtilis. These synthesized compounds were investigated for physicochemical parameters and binding mode prediction through molecular modelling tools. The interactions and stability of these compounds showed better affinity towards TasA and LasR proteins from Bacillus subtilis and Pseudomonas aeruginosa, respectively. Furthermore, molecular dynamic simulation for 100 ns was executed in order to appreciate the stability of the protein and ligand complex. The overall results promised that N-pyridin-2-yl-benzamide derivatives can be discovered as a lead in developing potent anti-quorum sensing agents against various bacteria.     

Design,synthesis and biological evaluation of substituted 2-amino-1,3-thiazine derivatives as antituberculosis and anti-cancer agents

A series of substituted 2-amino-1,3-thiazines were synthesized as amides (9a–9i), carbamates (9j–9m), sulfonamides (9n–9o) and urea derivatives (9p–9q) by treating the compound 7 with acid chlorides (8a–8i), chloroformates (8j–8m), sulfonyl chlorides (8n–8o) and isocyanates (8p–8q) respectively. The synthesized compounds (9a–9q) were screened for antituberculosis activity against Mycobacterium tuberculosis H₃₇Rv ATCC 27294 and the results show that some of these derivatives possess good activity against Mycobacterium tuberculosis H₃₇Rv ATCC 27294. A few also display promising cytotoxic activity against human breast cancer MCF-7 and human esophageal cancer EC-9706 cell lines. Regarding both biological profiles 9b, 9m and 9h are the most active for anti-cancer, anti-TB activity.     

Design synthesis and biological evaluation of 3-substituted triazole derivatives

Based on the active site of lanosterol 14α-demethylase of azole antifungal agents,sixteen 1-(1H-1,2,4-triazole-1-yl)- 2-(2,4- difluorophenyl)-3-(N-n-butyl-N-1-substitutedbenzyl-4-methylene-1H-1,2,3-triazole)-2-propanols have been designed,synthesized and evaluated as antifungal agents.Results of preliminary antifungal tests against eight human pathogenic fungi in vitro showed that some of the compounds exhibited excellent activities with broad spectrum.     

Copper-catalyzed synthesis of 2-sulfenylindoles from indoline-2-thiones and aryl iodides

A novel and efficient method for synthesis of 2-sulfenylindole via copper-catalyzed coupling reaction of indoline-2-thiones with aryl iodides has been developed. A series of N-substituted and N-free 2-sulfenylindole were obtained in high yields. Furthermore, the method was employed to synthesis of benzothieno[2,3-b]indoles from indoline-2-thiones with 1,2-diiodobenzene in the presence of CuI and Pd(OAc)₂ as catalysts.     

Design,synthesis, and anticancer activity evaluation of novel aziridine-1,2,3-triazole hybrid derivatives

Some new 1-aryl-4-[(aziridine-1-yl)diaryl-methyl]-5-methyl-1H-1,2,3-triazole derivatives 7j–s were synthesized by the one-pot reaction of diaryl-(1-aryl-5-methyl-1H-1,2,3-triazol-4-yl)methanol compounds 6j–s formed from 1-aryl-5-methyl-1H-1,2,3-triazole-4-carboxylic acid derivatives. The new compounds 7j–s and 6j–s are investigated by ¹H and ¹³C NMR, MS, and IR. The anticancer activity of the synthesis target compounds was evaluated against human leukemia (HL-60) cells and human hepatoma G2 cells. Some of the compounds were highly efficient. The ¹H-NMR signals of the aziridine-ring cis-H/trans-H protons were found to be two group peaks at 1.800–1.884 and 1.183–1.327?ppm.     

Design, synthesis, and biological evaluation of somatostatin-based radiopeptides

The prototypes for tumor targeting with radiolabeled peptides are derivatives of somatostatin. Usually, they primarily have high affinity for somatostatin receptor subtype 2 (sst2), and they have moderate affinity for sst5. We aimed at developing analogs that recognize different somatostatin receptor subtypes for internal radiotherapy in order to extend the present range of accessible tumors. We synthesized DOTA-octapeptides based on octreotide by replacing Phe3 mainly with unnatural amino acids. The affinity profile was determined by using cell lines transfected with sst1-5. Internalization was determined by using AR42J, HEK-sst3, and HEK-sst5 cell lines, and biodistribution was studied in rat tumor models. Two of the derivatives thus obtained showed an improved binding affinity profile, enhanced internalization into cells expressing sst2 and sst3, respectively, and better tumor:kidney ratios in animals.     

Design and synthesis of fluorescent symmetric bis-triazolylated-1,4-dihydropyridines as potent antibreast cancer agents

Herein, we report the synthesis of fluorescent 1,4-dihydropyridine-linked bis-triazoles (2a–2n) through Hantzsch synthesis by the condensation of o/m-chloro-substituted benzaldehyde, ethyl 3-oxo-4(prop-2-yn-1-yloxy)butanoate, and ammonium acetate in the presence of Ba(NO₃)₂ as a catalyst followed by the click reaction of resultant Hantzsch product (1) with various aromatic as well as aliphatic azides. All the synthesized compounds were well characterized by ¹H-NMR, ¹³C-NMR, FTIR, and HRMS spectral techniques. Antibreast cancer evaluation of all the synthesized derivatives revealed that the compounds 2f (IC₅₀?=?7?±?0.02?µM) and 2g (IC₅₀?=?5?±?0.03?µM) showed better anticancer activity (lower IC₅₀) than the standard drug tamoxifen (IC₅₀?=?11.2?±?0.01?µM) against breast carcinoma (MDA-MB-231) cell line. The synthesized compounds were also screened against normal human embryonic kidney (HEK-293) cell line and found to be nontoxic. The fluorescent nature and cytotoxicity assay of these newly synthesized hybrids recommend their utility in tumor cell imaging.     

Design,synthesis and biological evaluation of acylhydrazone derivatives as PI3K inhibitors

Since the PI3K signaling pathway is the most commonly activated in human cancers,inhibition of PI3K is a promising approach to cancer therapy.In this study,a series of 2-methyl-5-nitrobenzeneacylhydrazones were designed and synthesized.All the new derivatives were tested by p110α enzymatic and Rh30 cellular assays.Further enzyme selectivity profiling proved that 6e and 7 were potential selective PI3K inhibitors.     

Design,synthesis and biological evaluation of novel isoniazid hybrids

We herein report the design and synthesis of novel isoniazid derivatives. Isoniazid derived Schiff bases (3 a-d) were subjected to cyclization with acetic anhydride and sulphuric acid to yield the 5′-substituted-3′-acetyl-5-(pyridin-4-yl)-3H-spiro[indole-3, 2-[1′, 3′, 4’]oxadiazol]-2′-yl acetates (4 a-d) and 8′-substituted-3’-(pyridin-4-yl)[1′,3′,4’]oxadiazino [6,5-b]indoles (5 a-d) respectively. The advantages of spectral methods were used for the confirmation of the structure of all the newly synthesized hybrid molecules. Further, these compounds were evaluated for their antibacterial activity against B. Subtilis, S. aureus, E. coli & S. typhi, antifungal activity against C. albicans, C. oxysporum, A. Flavus & A. niger, and antimycobacterial activity against M. tuberculosis. Amongst, the compounds 4b, 4c and 5c showed excellent inhibitory activity against tested microorganisms. Also, the DNA cleavage activity of selected compounds was carried out by the AGE method.     

Design, synthesis, and biological evaluation of novel fluorinated ethanolamines

The preparation of novel fluorinated allylamines and their use as key fragments for the stereoselective synthesis of hydroxyethyl secondary amine (HEA)-type peptidomimetics is described. Our strategy employs chiral sulfinyl imines as synthesis intermediates, by treatment of hemiaminal precursors with two equivalents of vinylmagnesium bromide. The subsequent oxidation of the allylic amines to the corresponding epoxides was achieved by treatment with methyl(trifluoromethyl)dioxirane. Finally, epoxide ring opening with a range of nitrogen nucleophiles provided a library of HEA-derived peptidomimetics with a phenyldifluoromethylene moiety. The biological evaluation of these derivatives revealed compounds with remarkable BACE1 inhibitory activity. Docking studies revealed the influence of the fluorine atoms in the binding mode of the synthesized ligands. Furthermore, the biological evaluation of our final products and synthesis intermediates led to the discovery of compounds with antimicrobial activity against Mycobacterium and Nocardia species.     

Design, synthesis and biological evaluation of novel glucokinase activators

A new series of benzamide derivatives as glucokinase activators(GKAs) were designed and synthesized,and their activation for glucokinase were evaluated by the preliminary glucokinase activity assay.The structure-activity relationship(SAR) is discussed. The result shows that compound 12d and 12h have potent activity reference drug RO-28-1675.