Synthesis and Antioxidant Studies of 2,4-Dioxothiazolidine-5-acetic Acid Based Organic Salts: SC-XRD and DFT Approach.

In the current study, two organic salts (1 and 2) are synthesized, and then crystalline structures are characterized by FTIR, UV spectroscopy, and X-ray crystallographic studies. The organic salts 1 and 2 are optimized at the M06/6-311G(d,p)level of theory and further utilized for analysis of natural bond orbitals (NBOs), natural population, frontier molecular orbitals (FMOs), and global reactivity parameters, which confirmed the stability of the studied compounds and charge transfer phenomenon in the studied compounds. The studies further revealed that 1 and 2 are more stable than 3. The lowest energy merged monomer-coformer conformations were docked as flexible ligands with rigid fungal proteins and DNA receptors. The stagnant binding of the monomer through two H bonds with protein was observed for ligands 1 and 3 while different pattern was found with 2. The coformers formed a single H bond with the active site in 2 and 3 and a single pi-arene H interaction in 1. The two-point ligand-receptor interactions hooked the monomer between DNA base pairs for partial intercalation; pi stacking with additive hydrogen bonding with the base pair led to a strong benzimidazole interaction in 1 and 2, whereas ethylene diamine formed weak H bonding. Thus, the molecular docking predicted that the coformer exhibited DNA intercalation reinforced by its salt formation with benzimidazole 1 and methyl benzimidazole 2. Antioxidant studies depicted that 3 has a higher IC50 value than that of 2,4-D and also the largest value among the studied compounds, whereas 2 showed the lowest value among the studied compounds.

Ferrocene-Based Terpolyamides and Their PDMS-Containing Block Copolymers: Synthesis and Physical Properties.

Aromatic polyamides are well-known as high-performance materials due to their outstanding properties making them useful in a wide range of applications. However, their limited solubility in common organic solvents restricts their processability and becomes a hurdle in their applicability. This study is focused on the synthesis of processable ferrocene-based terpolyamides and their polydimethylsiloxane (PDMS)-containing block copolymers, using low-temperature solution polycondensation methodology. All the synthesized materials were structurally characterized using FTIR and 1H NMR spectroscopic techniques. The ferrocene-based terpolymers and block copolymers were soluble in common organic solvents, while the organic analogs were found only soluble in sulfuric acid. WXRD analysis showed the amorphous nature of the materials, while the SEM analysis exposed the modified surface of the ferrocene-based block copolymers. The structure-property relationship of the materials was further elucidated by their water absorption and thermal behavior. These materials showed low to no water absorption along with their high limiting oxygen index (LOI) values depicting their good flame-retardant behavior. DFT studies also supported the role of various monomers in the polycondensation reaction where the electron pair donation from HOMO of diamine monomer to the LUMO of acyl chloride was predicted, along with the calculation of various other parameters of the representative terpolymers and block copolymers.

The Development of Highly Fluorescent Hemicyanine and Dicyanoisophorone Dyes for Applications in Dye-Sensitized Solar Cells.

Ruthenium-based metal complex dyes have been employed extensively in dye-sensitized solar cells (DSSCs) as photosensitizers, but the cost and toxicity of metal complexes have promoted the development of metal-free organic dyes. The present investigation deals with the synthesis of hemicyanine and Dicyanoisophorone (DCI) based dyes adopting the D-π-A strategy, and their application on sensitization of nano-crystalline ZnO electrodes by appending the carboxyl (COOH) anchoring group as a pendant on the primary skeleton of dyes. Dyes have been characterized by UV, FTIR, and NMR spectroscopic studies. Absorption maxima (λmax) were found in the region 416-551 nm while emission wavelength (λem) was observed in the range 575-685 nm. Cyclic voltammetry and DFT calculations were used to estimate redox potential and band gap energies of dyes.

Investigation of redox mechanism and DNA binding of novel 2-(x-nitrophenyl)-5-nitrobenzimidazole (x = 2, 3 and 4).

The present study describes the investigation of the binding modes of potential anti-cancerous nitrophenyl derivatives of 2-(x-nitrophenyl)-5-nitrobenzimidazole with calf thymus DNA. The -2-(x-nitrophenyl)-5-nitrobenzimidazoles under investigation differ only in position x of nitro group in nitrophenyl substituent relative to benzimidazole moiety leading to 1-NPNB (x = 2), 2-NPNB (x = 3) and 3-NPNB (x = 4). The DFT calculations predicted that derivatives were electrochemically reducible which was then confirmed by cyclic voltammetry. In cyclic voltammetry, the second reversible peak was dependent on first irreversible reduction. This revealed that electrochemical irreversible process was governed by some other process which was then followed by reversible second electron transfer. Thus, ECE (electron transfer leading to coupled chemical reaction followed by another electron transfer process) mechanism was attributed for electrochemical reduction. Experimental results based on UV-Vis spectroscopy vaguely showed intercalation of 1-NPNB, 2-NPNB and 3-NPNB into DNA which was assisted by cyclic voltammetry. However, thermal melting and florescence spectroscopy unambiguously established intercalation for all three compounds. Molecular docking analysis ascertained in pocket stacking of 5-nitrobenzimidazole moiety in 1-NPNB and 2-NPNB while nitro phenyl substitution in 3-NPNB stacks between DNA base pair during intercalation which was in agreement with DFT computed molecular geometry. Therefore, the relative positions of nitro group and 5-nitrobenzimidazole moieties in 2-(x-nitrophenyl)- 5-nitrobenzimidazole influenced the DNA binding pattern of compounds during intercalation. The cytotoxicity of these compounds was comparable to standard drug doxorubicin against both cancerous (MCF-7) and normal (MCF-10A) breast cells which depicts their anti-cancerous potential.

Substituted phenyl[(5-benzyl-1,3,4-oxadiazol-2-yl)sulfanyl]acetates/acetamides as alkaline phosphatase inhibitors: Synthesis, computational studies, enzyme inhibitory kinetics and DNA binding studies.

Substituted phenyl[(5-benzyl-1,3,4-oxadiazol-2-yl)sulfanyl]acetates/acetamides 9a-j were synthesized as alkaline phosphatase inhibitors. Phenyl acetic acid 1 through a series of reactions was converted into 5-benzyl-1,3,4-oxadiazole-2-thione 4. The intermediate oxadiazole 4 was then reacted with chloroacetyl derivatives of phenols 6a-f and anilines derivatives 8a-d to afford the title oxadiazole derivatives 9a-j. All of the title compounds 9a-j were evaluated for their inhibitory activity against human alkaline phosphatise (ALP). It was found that compounds 9a-j exhibited good to excellent alkaline phosphatase inhibitory activity especially 9h displayed potent activity with IC50 value 0.420 ±â€¯0.012 µM while IC50 value of standard (KH2PO4) was 2.80 µM. The enzyme inhibitory kinetics of most potent inhibitor 9h was determined by Line-weaever Burk plots showing non-competitive mode of binding with enzyme. Molecular docking studies were performed against alkaline phosphatase enzyme (1EW2) to check the binding affinity of the synthesized compounds 9a-j against target protein. The compound 9h exhibited excellent binding affinity having binding energy value (-7.90 kcal/mol) compared to other derivatives. The brine shrimp viability assay results proved that derivative 9h was non-toxic at concentration used for enzyme assay. The lead compound 9h showed LD50 106.71 µM while the standard potassium dichromate showed LD50 0.891 µM. The DNA binding interactions of the synthesized compound 9h was also determined experimentally by spectrophotometric and electrochemical methods. The compound 9h was found to bind with grooves of DNA as depicted by both UV-Vis spectroscopy and cyclic voltammetry with binding constant values 7.83 × 103 and 7.95 × 103 M-1 respectively revealing significant strength of 9h-DNA complex. As dry lab and wet lab results concise each other it was concluded that synthesized compounds, especially compound 9h may serve as lead compound to design most potent inhibitors of human ALP.

Radical scavenging propensity of Cu2+, Fe3+ complexes of flavonoids and in-vivo radical scavenging by Fe3+-primuletin.

Cu2+ and Fe3+ complexes of three flavonoids (morin or mo, quercetin or quer and primuletin or prim) were synthesized with the objective of improving antioxidant capacities of flavonoids. The radical scavenging activities of pure flavonoids and their metal complexes were assayed to monitor their tendencies towards sequestering of radicals at physiological conditions. The scavenger potencies of metal-flavonoid complexes were significantly higher than those of the parent flavonoids. Further, influence of the solvent polarity on the radical capturing by flavonoids and their metal complexes was in favor for the polar solvent. Fe3+-prim displayed its radical scavenging ability via up gradation of CAT and SOD activities in in-vivo antioxidant assays.

ß-Cyclodextrin assisted solubilization of Cu and Cr complexes of flavonoids in aqueous medium: a DNA-interaction study.

Cu and Cr complexes of three flavonoids (morin, quercetin and 6-hydroxyflavone) were synthesized and included in beta-cyclodextrin (ßCD) with the objective of improving their pharmacokinetic profiles. Then binding with ds.DNA was studied to monitor their interactive tendencies at physiological conditions. The binding constants and other thermodynamic data from UV-vis spectroscopy and cyclic voltammetry revealed Cr-flavonoid-ßCD to interact with ds.DNA at pH-7.4 through electrostatic mode of binding while Cu-flavonoid-ßCD can intercalate into DNA. The strong binding propensity of Cu-flavonoid-ßCD with ds.DNA encourages their application as anticancerous agent.

Interaction of antihypertensive acetazolamide with nonsteroidal anti-inflammatory drugs.

The binding of antihypertensive acetazolamide with eleven nonsteroidal anti-inflammatory drugs (NSAIDs) was investigated at pH 3, 7 and 9.5 with the objective of monitoring their interactive pharmacokinetics during digestion and absorption in human body. The results of UV-Vis spectroscopy and cyclic voltammetry revealed two NSAIDs (acetaminophen and dichlofenic sodium) to interact with acetazolamide in stomach fluid conditions forming complexes of 1:1 and 1:2 stoichiometry. The complexation ratio was also verified by computational methods. The strong binding propensity of acetaminophen and dichlofenic sodium with acetazolamide prohibited their combined therapy. However, the poor binding affinity of aspirin and mefinamic acid suggested these drugs as preferred NSAIDs to be prescribed with acetazolamide.