مهدی خوشنویس زاده

Novel phenanthro-triazine-3-thiol derivatives were designed as potential DNA intercalators and Bcl-2 inhibitors. After being synthesized, the compounds were evaluated for their cytotoxic activity against MOLT-4 (human acute lymphoblastic leukemia) and MCF-7 (human breast adenocarcinoma) cells by MTT assay. P1 (bearing hydrogen substitution) was the most potent derivative against MOLT-4 with an IC50 value of 7.1 ± 1.1 μM, whereas P11 (bearing phenyl substitution) demonstrated considerable cytotoxicity against MCF-7 with an IC50 value of 15.4 ± 2.9 μM. Compounds P7, P8, P14 and P15 exhibited moderate cytotoxic effects. Furthermore, to confirm the potential DNA intercalation and Bcl-2 inhibitory activities of phenanthro-triazine scaffolds, molecular docking analysis was performed. Molecular docking studies indicated that these compounds not only bind to DNA by intercalation mainly through stacking interactions but also are well accommodated in the active site of Bcl-2. Therefore, P1 and P11 having phenanthro-triazine-3-thiol scaffold could be presented as cytotoxic agents with dual DNA intercalation and Bcl-2 inhibitory activities.

Tyrosinase enzyme has a key role in melanin biosynthesis by converting tyrosine into dopaquinone. It also participates in the enzymatic browning of vegetables by polyphenol oxidation. Therefore, tyrosinase inhibitors are useful in the fields of medicine, cosmetics, and agriculture. Many tyrosinase inhibitors having drawbacks have been reported to date; so, finding new inhibitors is a great need.

A variety of 6-hydroxy-3,4-dihydronaphthalenone chalcone-like analogs (C1-C10) have been synthesized by aldol condensation of 6-hydroxy tetralone and differently substituted benzaldehydes. The compounds were evaluated for their inhibitory effect on mushroom tyrosinase by a spectrophotometric method. Moreover, the inhibition manner of the most active compound was determined by Lineweaver-Burk plots. Docking study was done using AutoDock 4.2. The drug-likeness scores and ADME features of the active derivatives were also predicted.

Most of the compounds showed remarkable inhibitory activity against the tyrosinase enzyme. 6-Hydroxy-2-(3,4,5-trimethoxybenzylidene)-3,4-dihydronaphthalen-1(2H)-one (C2) was the most potent derivative amongst the series with an IC50 value of 8.8 μM which was slightly more favorable to that of the reference kojic acid (IC50 = 9.7 μM). Inhibitory kinetic studies revealed that C2 behaves as a competitive inhibitor. According to the docking results, compound C2 formed the most stable enzyme-inhibitor complex, mainly via establishing interactions with the two copper ions in the active site. In silico drug-likeness and pharmacokinetics predictions for the proposed tyrosinase inhibitors revealed that most of the compounds including C2 have proper drug-likeness scores and pharmacokinetic properties.

Therefore, C2 could be suggested as a promising tyrosinase inhibitor that might be a good lead compound in medicine, cosmetics, and the food industry, and further drug development of this compound might be of great interest.

Melanogenesis is a process of melanin synthesize, which is a primary response for the pigmentation of human skin. Tyrosinase is a key enzyme, which catalyzes a rate-limiting step of the melanin formation, natural products have shown potent inhibitors, but some of these possess toxicity. Numerous synthetic inhibitors have been developed in recent years may lead to the potent anti-tyrosinase agents. Therefore its inhibition may be an efficient way for the development of depigmenting agents. A novel series of 2-arylidine-1H-indene-1,3(2H)-dione analogs were designed, synthesized and screened for their in vitro tyrosinase inhibitory activity. 3d derivative bearing nitrothiophene revealed excellent anti-tyrosinase activity with an IC50 value of 3.55 μM comparable to kojic acid as a positive control. 3d as the most potent inhibitor and 3f as the least active derivative were subjected to in silico evaluations considering the 3D conformations, ΔGb of bindings and interactions within the active site of tyrosinase.

Among Recent advances in the identification of anti-inflammation agents, anti-cytokines (like Interleukin-1), related to p38 MAPK families play an important role; Here in we designed new effective and low toxic anti-cytokine agents based on 1-Hydroxy-2,4,5-triaryl imidazole derivatives. The reaction of oximoinoketone intermediate with ten different aromatic aldehyde and ammonium acetate in refluxing acetic acid condition give imidazole derived product, the IL-1β inhibitory assay were performed on Human PBMCs (peripheral blood mononuclear cells) using an enzyme-linked immunosorbent assay (ELISA) kit and then in computational part the binding mode of the best compound was accomplished  by docking in Crystal structure of p38 MAP kinase (PDB ID: 1A9U) compared with SB202190 as standard drug. All compounds were synthesized and evaluated in biological assay showing the inhibitory activity from 28% to 82% compared to SB202190 and binding mode analysis revealed that the hydrogen-bond interactions with residues (Met109, Val30) were key point in inhibitor binding. Compound 5g clearly proved the best inhibitory action and could be further utilized for designing newer anti-cytokine agents and p38α MAP kinase potentially inhibitory action.

Dipeptidyl peptidase IV (DPP-4) is a serine protease that plays a crucial role in glucose metabolism; hence, it is a significant target for type II diabetes mellitus treatment. DPP-4 inhibitors decrease glucose concentrations in such patients by preventing the rapid degradation and thereby lengthening the physiological actions of hypoglycemic incretin hormones. In this study, a structure-based virtual screening strategy was applied to search for novel natural DPP4 inhibitors. From the Supernatural database, 1856 natural structures were picked up and were subjected to molecular docking analysis. Thirteen of them were identified to form more stable complexes than the co-crystallized ligand with the DPP-4 protein. The drug-likeness and pharmacokinetic properties of the top five compounds were also predicted. It was proved that the compounds were compliant with the drug-likeness rules and possess favorable pharmacokinetic properties. The proposed natural compounds can be introduced as potential DPP-4 inhibitors that might be promising leads for further drug development.

Apoptosis is critical for tissue homeostasis and for the physiological removal of abnormal cells. Bcl-2 family proteins are important regulators of apoptosis. It’s observed that antiapototic Bcl-2 family members are generally over expressed in many cancer cells. As a result, it has stimulated a growing interest in the discovery of small molecules targeting such proteins as potential anticancer therapeutics. With the aim of designing and virtual screening of new phenanthrene based Bcl-2 inhibitors, we performed a cross-docking study. This study is done for different available Bcl-2 X-ray crystal structures in order to find the most appropriate PDB code of this enzyme. After analytical analyses, we found a PDB code for the enzyme. Designed library of phenanthrene triazine containing different hydrazone moieties was further screened using selected crystal structure. It identifies the ligand which interacts the target with lower binding energy. As a conclusion, cross docking study could be a validated strategy for finding the most appropriate crystal structure for docking study. Our designed library of phenanthrene triazine-based derivatives containing hydrazone pendant could be served as potential candidates for Bcl-2 inhibition.

Dichloroacetate (DCA) is a pyruvate mimetic compound that stimulates the activity of the enzyme pyruvate dehydrogenase (PDH) through inhibition of the enzyme pyruvate dehydrogenase kinases (PDK1-4). DCA works by turning on the apoptosis which is suppressed in tumor cells, hence let them to die on their own. Here, in this paper a series of DCA analogues were applied to quantitative structure–activity relationship (QSAR) analysis. A collection of chemometrics methods such as multiple linear regression (MLR), factor analysis–based multiple linear regression (FA-MLR), principal component regression (PCR), simple Free-Wilson analysis (FWA) and partial least squared combined with genetic algorithm for variable selection (GA-PLS) were conducted to make relations between structural features and cytotoxic activities of a variety of DCA derivatives. The best multiple linear regression equation obtained from genetic algorithms partial least squares which predict 91% of variances. On the basis of the produced model, an in silico-screening study was also employed and new potent lead compounds based on new structural patterns were suggested. Docking studies of these compounds were also investigated and promising results were obtained. The docking results were also conducted to protein ligand interaction fingerprints (PLIF) studies using self-organizing map (SOM) in order to evaluate the predictive ability in suggesting new potent compounds and some compounds were introduced as a good candidates for synthesis.

Some N-substituted piperidine structures were synthesized and evaluated for cytotoxic activity against four different cell lines using the standard MTT assay method and Doxorubicin was used as the reference drug. The result of cytotoxic activity as a measurement of IC50 values revealed that three of the synthesized compounds were active against breast cancer cell line. Compound 6a bearing hydroxyl at para position of piperidine ring was the most active compound within this series. The N-subtituted piperidine with propene substructure could be considered as a lead structure for further studies of structure activity relationship to develop more potent compounds in future.