Synthetic access to diverse thiazetidines via a one-pot microwave assisted telescopic approach and their interaction with biomolecules.

A one-pot microwave assisted telescopic approach is reported for the chemo-selective synthesis of substituted 1,3-thiazetidines using readily available 2-aminopyridines/pyrazines/pyrimidine, substituted isothiocyanates and 1,2-dihalomethanes. The procedure involves thiourea formation from 2-aminopyridines/pyrazines/pyrimidine with the substituted isothiocyanates followed by a base catalysed nucleophilic attack of the CS bond on the 1,2-dihalomethane. Subsequently, a cyclization reaction occurs to yield substituted 1,3-thiazetidines. These four membered strained ring systems are reported to possess broad substrate scope with high functional group tolerance. The above synthetic sequence for the formation of four membered heterocycles is proven to be a modular and straightforward approach. Further the mechanistic pathway for the formation of 1,3-thiazetidines was supported by computational evaluations and X-ray crystallography analyses. The relevance of these thiazetidines in biological applications is evaluated by studying their ability to bind bio-macromolecules like proteins and nucleic acids.

Synthesis and in Silico Docking Studies of Ethyl 2-(2-Arylidene-1-alkylhydrazinyl)thiazole-4-carboxylates as Antiglycating Agents.

Ethyl 2-(2-arylidene-1-alkylhydrazinyl)thiazole-4-carboxylates (1a-k) were synthesized by alkylation on HN- of ethyl 2-(2-arylidenehydrazinyl)thiazole-4-carboxylates. The proposed structures (1a-k) are corroborated by spectro-analytical techniques like UV, FT-IR, 1 H-, 13 C-NMR and HR-MS. All synthesized compounds were screened for their antiglycation and antioxidant assays. The in vitro antiglycation results revealed promising activity of compounds 1a, 1b, 1d, 1e, 1f, 1g, 1j and 1k with IC50 values 0.0004±1.097-17.22±0.538 µM when compared to standard, aminoguanidine (IC50 =25.50±0.337 µM). Among all tested compounds 1j and 1k are the best antiglycating agents with IC50 values 1.848±0.646 and 0.0004±1.097 µM, respectively. The in-silico studies also agree with these results where binding energy for 1j and 1k was found to be -9.25 and -8.42 kcal/mol with calculated dissociation constants of 0.16 and 0.67 µM, respectively. The antiglycation results demonstrate the application of these compounds in reducing diabetic complications.

Anti-cancer property and DNA binding interaction of first row transition metal complexes: A decade update.

Metal ions carry out a wide variety of functions, including acid-base/redox catalysis, structural functions, signaling, and electron transport. Understanding the interactions of transition metal complexes with biomacromolecules is essential for biology, medicinal chemistry, and the production of synthetic metalloenzymes. After the coincidental discovery of cisplatin, importance of the metal complexes in biochemistry became a top priority for inquiry. In this review, a decade update on various synthetic strategies to first row transition metal complex and their interaction with DNA through non-covalent binding are explored. Moreover, this effort provides an excellent analysis on the efficacy of theoretical and practical approaches to the systematic generation of new non-platinum based metallodrugs for anti-cancer therapeutics.

Iodoxybenzoic Acid (IBX) in Organic Synthesis: A Septennial Review.

This study reviews the oxidative applications of 2-iodoxybenzoic acid (IBX) in organic synthesis, focusing on C-H functionalization, hetero-hetero bond formations, ring cleavage reactions, dehydrogenation, heterocyclic ring formations, and some miscellaneous reactions in a comprehensive and critical way. It compiles the literature starting from mid-2015 to date.

Synthesis, Characterization, Pharmacogenomics, and Molecular Simulation of Pyridinium Type of Ionic Liquids and Their Applications.

Substituted pyridinium bromides are prepared by conventional and solvent-free greener methods. The solvent-free solid-phase (greener) method is superior to the conventional method because of its nontoxic nature, simple reaction setup procedure, and twenty times less time consumption. Column chromatography and toxic organic solvents are avoided. Substituted pyridinium salts 1-2(a-c) show excellent catalytic response in the preparation of ß-amino carbonyl derivatives using the conventional approach. Pharmacokinetics is very important in target validation and in shifting a lead compound into a drug. The physicochemical properties discussed here can be used effectively in the drug designing candidate, which is a cumbersome process in clinical research. In addition, molecular simulations are demonstrated, and compounds 1-2(a-c) possess the most potent VEGFR-2 kinase protein inhibitory activities, and most interestingly, compound 2a strongly binds and regulates the VEGFR-2 kinase activity in therapeutic approaches and cancer prevention.

Synthesis of potent MDA-MB 231 breast cancer drug molecules from single step.

We have prepared novel potent breast cancer drug molecules from non-toxic and inexpensive method. Column chromatography is not necessary for purification of target molecules. The value of overall atom economy, environmental factor, environmental catalyst and product mass intensity gives additional merits for this synthetic method. Synthesized flexible dimeric imidazolium bromides showed less toxicity and gives excellent anticancer response against normal mammary epithelial cells. Novel dimeric pyridinium bromides showed excellent anticancer response against tested cancer cell lines. In cell cycle, novel flexible dimeric pyridinium bromides showed significant arrest in the G2/M phase by nearly three folds, when compared with control drug. We have studied the targeting epidermal growth factor receptor for all the synthesized flexible amino substituted and methyl substituted dimeric pyridinium bromides.

Metal-Oxides- and Metal-Oxyhydroxides-Based Nanocomposites for Water Splitting: An Overview.

Water electrolysis is an important alternative technology for large-scale hydrogen production to facilitate the development of green energy technology. As such, many efforts have been devoted over the past three decades to producing novel electrocatalysis with strong electrochemical (EC) performance using inexpensive electrocatalysts. Transition metal oxyhydroxide (OxH)-based electrocatalysts have received substantial interest, and prominent results have been achieved for the hydrogen evolution reaction (HER) under alkaline conditions. Herein, the extensive research focusing on the discussion of OxH-based electrocatalysts is comprehensively highlighted. The general forms of the water-splitting mechanism are described to provide a profound understanding of the mechanism, and their scaling relation activities for OxH electrode materials are given. This paper summarizes the current developments on the EC performance of transition metal OxHs, rare metal OxHs, polymers, and MXene-supported OxH-based electrocatalysts. Additionally, an outline of the suggested HER, OER, and water-splitting processes on transition metal OxH-based electrocatalysts, their primary applications, existing problems, and their EC performance prospects are discussed. Furthermore, this review article discusses the production of energy sources from the proton and electron transfer processes. The highlighted electrocatalysts have received substantial interest to boost the synergetic electrochemical effects to improve the economy of the use of hydrogen, which is one of best ways to fulfill the global energy requirements and address environmental crises. This article also provides useful information regarding the development of OxH electrodes with a hierarchical nanostructure for the water-splitting reaction. Finally, the challenges with the reaction and perspectives for the future development of OxH are elaborated.

Discovery of Novel Dimeric Pyridinium Bromide Analogues Inhibits Cancer Cell Growth by Activating Caspases and Downregulating Bcl-2 Protein.

Flexible dimeric substituted pyridinium bromides with primary and tertiary amines are prepared by conventional and solvent-free methods. The formation of compounds 2 and 4 is much easier than that of compounds 1 and 3 because of the benzyl carbon which is more electropositive than the primary alkyl carbon. The newly synthesized dimeric pyridinium compounds are optimized using DFT and B3LYP 6-31 g(d,p). The in vitro antiproliferative activity is studied in lung (A549) and breast cancer cell lines (MDA-MB 231). Among the four compounds, 1,1'-(1,3-phenylene bis(methylene)bis 2-aminopyridinium bromide 4 showed potent anticancer activity when compared to the standard drug 5-fluorouracil. 1,1'-(1,3-Phenylene bis(methylene)bis 2-aminopyridinium bromide 4 is not toxic to normal cell lines 3T3-L1 and MRC-5 cell lines. Also, 1,1'-(1,3-phenylene bis(methylene)bis 2-aminopyridinium bromide 4-induced apoptosis in cancer cell lines is examined using AO/EB and Hoechst staining, which is further supported by cell cycle analysis. Western blot analysis showed that 1,1'-(1,3-phenylene bis(methylene)bis 2-aminopyridinium bromide 4 induces apoptosis through the extrinsic apoptotic pathway by upregulating caspase 3 and caspase 9. This compound also downregulates intrinsic apoptotic proteins, including Bcl-2, Bcl-x, and Bad. From the present study results, it is confirmed that 1,1'-(1,3-phenylene bis(methylene)bis 2-aminopyridinium bromide 4 has potent anticancer activity when compared to other compounds.

Efficient Antibacterial Dimeric Nitro Imidazolium Type of Ionic Liquids from a Simple Synthetic Approach.

Synthesis of dimeric nitro-substituted imidazolium salts under the conventional/solvent-free method is reported. The solvent-free method is more important than the conventional one because of its shorter reaction time, higher yield from easily available starting material, environmental safety, and so forth. Counter anion exchange is carried out using inorganic salt, which is dissolved in deionized water at room temperature. In antibacterial studies, dimeric nitro-substituted imidazolium cations with bromide counter anions showed excellent inhibition against E. coli and P. aeruginosa bacteria. These experimental results were further supported by molecular docking studies. All the compounds (3-6) (a-d) showed excellent antibacterial activity than the standard drugs (gentamycin, nalidixic acid, oflaxacin, ciproflaxacin, and amikacin). Molecular docking studies showed strong hydrogen bonding, polar and hydrophobic interactions between the dimeric imidazolium salts, and Escherichia coli/Pseudomonas aeruginosa/Proteus vulgaris/Staphylococcus aureus receptors.

Exploration of promising optical and electronic properties of (non-polymer) small donor molecules for organic solar cells.

Non-fullerene based organic compounds are considered promising materials for the fabrication of modern photovoltaic materials. Non-fullerene-based organic solar cells comprise of good photochemical and thermal stability along with longer device lifetimes as compared to fullerene-based compounds. Five new non-fullerene donor molecules were designed keeping in view the excellent donor properties of 3-bis(4-(2-ethylhexyl)-thiophen-2-yl)-5,7-bis(2ethylhexyl) benzo[1,2-:4,5-c']-dithiophene-4,8-dione thiophene-alkoxy benzene-thiophene indenedione (BDD-IN) by end-capped modifications. Photovoltaic and electronic characteristics of studied molecules were determined by employing density functional theory (DFT) and time dependent density functional theory (TD-DFT). Subsequently, obtained results were compared with the reference molecule BDD-IN. The designed molecules presented lower energy difference (ΔΕ) in the range of 2.17-2.39 eV in comparison to BDD-IN (= 2.72 eV). Moreover, insight from the frontier molecular orbital (FMO) analysis disclosed that central acceptors are responsible for the charge transformation. The designed molecules were found with higher λmax values and lower transition energies than BDD-IN molecule due to stronger end-capped acceptors. Open circuit voltage (Voc) was observed in the higher range (1.54-1.78 V) in accordance with HOMOdonor-LUMOPC61BM by designed compounds when compared with BDD-IN (1.28 V). Similarly, lower reorganization energy values were exhibited by the designed compounds in the range of λe(0.00285-0.00370 Eh) and λh(0.00847-0.00802 Eh) than BDD-IN [λe(0.00700 Eh) and λh(0.00889 Eh)]. These measurements show that the designed compounds are promising candidates for incorporation into solar cell devices, which would benefit from better hole and electron mobility.

Exploration of efficient electron acceptors for organic solar cells: rational design of indacenodithiophene based non-fullerene compounds.

The global need for renewable sources of energy has compelled researchers to explore new sources and improve the efficiency of the existing technologies. Solar energy is considered to be one of the best options to resolve climate and energy crises because of its long-term stability and pollution free energy production. Herein, we have synthesized a small acceptor compound (TPDR) and have utilized for rational designing of non-fullerene chromophores (TPD1-TPD6) using end-capped manipulation in A2-A1-D-A1-A2 configuration. The quantum chemical study (DFT/TD-DFT) was used to characterize the effect of end group redistribution through frontier molecular orbital (FMO), optical absorption, reorganization energy, open circuit voltage (Voc), photovoltaic properties and intermolecular charge transfer for the designed compounds. FMO data exhibited that TPD5 had the least ΔE (1.71 eV) with highest maximum absorption (λmax) among all compounds due to the four cyano groups as the end-capped acceptor moieties. The reorganization energies of TPD1-TPD6 hinted at credible electron transportation due to the lower values of λe than λh. Furthermore, open circuit voltage (Voc) values showed similar amplitude for all compounds including parent chromophore, except TPD4 and TPD5 compounds. These designed compounds with unique end group acceptors have the potential to be used as novel fabrication materials for energy devices.

Novel quad-rotor-shaped photovoltaic materials: first example of fused-ring non-fullerene acceptors with proficient photovoltaic properties for high-performance solar cells.

Development of novel materials for organic solar cells is a booming area of current research. Fused-ring electron accepters are the potential agents of revolution in organic photovoltaic devices and revealing high efficiency in organic solar cells. This study highlights the novel quad-rotor-shaped molecules as first example of efficient fused-ring non-fullerene acceptor materials with proficient photovoltaic parameters for their utilization in high-performance organic solar cells. First time, eight quad-rotor-shaped fused-ring electron accepters (QRFR-1-QRFR-8) are developed via modulating end-caps of experimentally synthesized (BFTT-TN) molecule (QRFR). Optoelectronic properties of proposed molecules are determined using frontier molecular orbitals (FMO), UV-Visible, density of state (DOS), overlap DOS (ODOS), transition density matrix (TDM) heat maps, open circuit voltage (Voc), binding energies (Eb), reorganization energy of electron (λe), hole (λh), charge transfer analysis, and compared with reference QRFR. All proposed fused-ring electron accepters disclose less energy gap and λmax in near IR region than QRFR after end-capped engineering. Highest Voc with respect to HOMOPM6-LUMOacceptor is found 1.66 V in QRFR-6 than QRFR (1.63 V). Eb values of QRFR-1-QRFR-8 are found better and comparable with QRFR. The λe is found smaller than QRFR in all molecules except QRFR-5. The proposed quad-rotor-shaped molecules exhibit proficient photovoltaic features and can serve as best candidate for organic solar cells when blended with PM6 film. This study not only enlightens the researchers to use end-capped reforms as effective tactic for designing materials, but also provides novel quad-rotor-shaped materials to experimentalist for synthesis and their usage in future application of organic solar cells.

Facile Synthesis of Diversely Functionalized Peptoids, Spectroscopic Characterization, and DFT-Based Nonlinear Optical Exploration.

Compounds having nonlinear optical (NLO) characteristics have been proved to have a significant role in many academic and industrial areas; particularly, their leading role in surface interfaces, solid physics, materials, medicine, chemical dynamics, nuclear science, and biophysics is worth mentioning. In the present study, novel peptoids (1-4) were prepared in good yields via Ugi four-component reaction (Ugi-4CR). In addition to synthetic studies, computational calculations were executed to estimate the molecular electrostatic potential, natural bond orbital (NBO), frontier molecular orbital analysis, and NLO properties. The NBO analysis confirmed the stability of studied systems owing to containing intramolecular hydrogen bonding and hyperconjugative interactions. NLO analysis showed that investigated molecules hold noteworthy NLO response as compared to standard compounds that show potential for technology-related applications.