Synthesis and evaluation of Novel Benzimidazole derivative [Bz-Im] and its radio/biological studies

Biology-oriented Drug Synthesis (BIODS), Structural Characterization and Bioactivities of Novel Albendazole Derivatives

Background:

Albendazole is a drug, belongs to the family of benzimidazole, and used as an anthelmintic agent in both human and veterinary medicine. It is marketed as Albenza which is used for the treatment of a variety of parasitic worm infestations such as roundworms, tapeworms, and flukes. In recent past, we have reported various classes of compounds as anti-glycating agents, in continuation of Biology-oriented Drug Synthesis (BIODS), seventeen albendazole derivatives 2-18 were synthesized evaluated for yeast glucose uptake activity.

Methods:

In the present study, Albendazole (2 g, 7.5 mmol), potassium hydroxide (3 g) were dissolved in ethanol (50 mL) into a 250 mL round-bottomed flask and refluxed for 48 h. TLC (ethyl acetate: hexane, 6:4) was monitored in order to check the reaction progress. After completion, the reaction mixture was dried under air and washed with an excess of distilled water. Precipitates were dried and crystallized from ethanol. The product was characterized by EI-MS and 1H-NMR.

Results:

Our present study showed that all compounds showed a varying degree of yeast glucose uptake activity ranging between IC50 = 51.41-258.40 µM, compared with standard metronidazole (IC50 = 41.86 ± 0.09 µM). This study has identified a series of potential leads for anti-glycating agents.

Conclusion:

Biology-oriented drug synthesis and in vitro yeast glucose uptake activity of albendazole derivatives gave rise to a number of lead molecule such as 3 (IC50 = 59.37 ± 0.26 µM), 5 (IC50 = 59.70 ± 0.32 µM), 6 (IC50 = 60.78 ± 0.54 µM), 8 (IC50 = 54.61 ± 0.20 µM), 16 (IC50 = 56.57 ± 0.04 µM) and 14 (IC50 = 51.41 ± 1.25 µM).

Synthesis of Pyridinyl-benzo[d]imidazole/Pyridinyl-benzo[d]thiazole Derivatives and their Yeast Glucose Uptake Activity In Vitro

Background:

Diabetes is the primary cause of fatality and disability all over the world, in recent past, we have reported various classes of compounds as anti-glycating agents and we have also reported benzimidazole and benzothiazole derivatives as a potential class of anti-glycating agents. This encouraged us to evaluate the pyridinyl benzimidazole/pyridinyl benzothiazole derivatives 1-27 for yeast glucose uptake activity.

Methods:

In the present study, an equimolar mixture of pyridine carboxaldehyde derivatives (1 mmol) and sodium metabisulphite (1 mmol) in DMF (10 mL) was stirred for 10 to 15 min, followed by addition of o-phenylene diamine/2-aminothiophenol (1 mmol) into it and refluxed for 3 h. The progress of the reaction was monitored by TLC. After completion, the reaction mixture was poured into crushed ice. Precipitates were formed which were collected by filtration to produce compounds 1-27 in good yields. Recrystallization from methanol yielded pure crystals.

Results:

Our present study showed that all compounds showed a varying degree of yeast glucose uptake activity in the range IC50 = 36.43-272.20 µM, compared to standard metronidazole (IC50 = 41.86 ± 0.09 µM). Compounds 5 (IC50 = 38.14 ± 0.17 µM), 6 (IC50 = 40.23 ± 0.20 µM), and 7 (IC50 = 36.43 ± 0.02 µM) showed an excellent yeast glucose uptake activity better than the standard.

Conclusion:

Pyridinyl benzimidazole/pyridinyl benzothiazole derivatives 1-27 were synthesized, structurally characterized, and evaluated for in vitro yeast glucose uptake activity. Compounds 5 (IC50 = 38.14 ± 0.17 µM), 6 (IC50 = 40.23 ± 0.20 µM), and 7 (IC50 = 36.43 ± 0.02 µM) demonstrated potent yeast glucose uptake activity as compared to standard metronidazole (IC50 = 41.86 ± 0.09 µM). This study identified a number of potential lead molecules which can be helpful in lowering the blood glucose level in hyperglycemia.

Antimicrobial potential of 1H-benzo[d]imidazole scaffold: a review

Background

Benzimidazole is a heterocyclic moiety whose derivatives are present in many of the bioactive compounds and posses diverse biological and clinical applications. Benzimidazole agents are the vital pharmacophore and privileged sub-structures in chemistry of medicine. They have received much interest in drug discovery because benzimidazoles exhibited enormous significance. So attempts have been made to create repository of molecules and evaluate them for prospective inherent activity. They are extremely effective both with respect to their inhibitory activity and favorable selectivity ratio.

Conclusion

Benzimidazole is most promising category of bioactive heterocyclic compound that exhibit a wide variety of biological activities in medicinal field. The present review only focus on antimicrobial activity of reported benzimidazole derivatives may serve as valuable source of information for researchers who wish to synthesize new molecules of benzimidazole nucleus which have immense potential to be investigated for newer therapeutic possibilities.

Crystal structure of {bis-[(1H-benzimid-azol-2-yl-κN (3))meth-yl]sulfane}dichloridomercury(II)

In the asymmetric unit of the title compound, [HgCl2(C16H14N4S)], the Hg(II) cation is linked to two Cl atoms and two imidazole N atoms of the chelating bis-[(1H-benzimidazol-2-yl)meth-yl]sulfane ligand, forming a slightly distorted tetra-hedral environment. The substitued imidazole rings of the ligand are almost perfectly planar [with maximum deviations of 0.017 (3) and 0.012 (3) Å] and form a dihedral angle of 42.51 (5)°. The crystal packing can be described as alternating layers parallel to (010). In this arrangement, N-H⋯Cl hydrogen bonds between the N-H groups of the benzimidazole moieties and chloride ligands are responsible for the formation of the chain-like packing pattern along [010] exhibiting a C(6) graph-set motif.

Design, synthesis, and biological evaluation of pyridoquinazoline derivatives as potent epidermal growth factor receptor inhibitors

Pyridoquinazolines have been synthesized, characterized, and tested for their in vitro epidermal growth factor receptor (EGFR) tyrosine kinase inhibitory activity. The compounds were prepared from alkylideno/arylideno-bis-ureas. Their structures were elucidated on the basis of elemental analyses and spectral studies (infrared, nuclear magnetic resonance [1H NMR], fourier transform infrared spectroscopy [FTIR], and electron ionization mass spectrometry [EI-MS]). Three of the new compounds had IC50 values in the range of 4.5-11.0 nM. The cellular EGFR internalization response of selected compounds was evaluated using HeLa cells. Three halogenated derivatives had a pronounced effect in inhibiting EGFR internalization.

2-(4-Chloro-phen-yl)-1-phenyl-1H-benz-imidazole

In the title compound, C₁₉H₁₃ClN₂, the dihedral angle formed by the imidazole core with the chloro­phenyl and phenyl rings are 24.07 (4) and 67.24 (4)°, respectively.

6-Nitrobenzimidazole derivatives: potential phosphodiesterase inhibitors: synthesis and structure-activity relationship

6-Nitrobenzimidazole derivatives (1-30) synthesized and their phosphodiesterase inhibitory activities determined. Out of thirty tested compounds, ten showed a varying degrees of phosphodiesterase inhibition with IC(50) values between 1.5±0.043 and 294.0±16.7 μM. Compounds 30 (IC(50)=1.5±0.043 μM), 1 (IC(50)=2.4±0.049 μM), 11 (IC(50)=5.7±0.113 μM), 13 (IC(50)=6.4±0.148 μM), 14 (IC(50)=10.5±0.51 μM), 9 (IC(50)=11.49±0.08 μM), 3 (IC(50)=63.1±1.48 μM), 10 (IC(50)=120.0±4.47 μM), and 6 (IC(50)=153.2±5.6 μM) showed excellent phosphodiesterase inhibitory activity, much superior to the standard EDTA (IC(50)=274±0.007 μM), and thus are potential molecules for the development of a new class of phosphodiesterase inhibitors. A structure-activity relationship is evaluated. All compounds are characterized by spectroscopic parameters.

Kinetics of formation for lanthanide (III) complexes of DTPA-(Me-Trp)2 used as imaging agent

Diethlenetriamine-N,N,N'N''N''-pentaacetic acid (DTPA)-bis (amide) analogs have been synthesized and evaluated as a potential biomedical imaging agents. Imaging and biodistribution studies were performed in mice that showed a significant accumulation of DTPA analogs in brain. The stability and protonation constants of the complexes formed between the ligand [DTPA-(Me-Trp)(2)] and Gd(3+), Eu(3+), and Cu(2+) have been determined by pH potentiometry (Gd(3+), Eu(3+)) and spectrophotometry (Cu(2+)) at 25 °C and at constant ionic strength maintained by 0.10 M KCl. The kinetic inertness of Gd [DTPA-(Me-Trp)(2)] was characterized by the rates of exchange reactions with Zn(2+) and Eu(3+). In the Eu(3+) exchange, a second-order [H(+)] dependence was found for the pseudo-first-order rate constant [k(0) = (4.5 ± 1.2) × 10(-6)/s; k(1) = 0.58 ± 0.1 /M/s, k(2) = (6.6 ± 0.2) × 10(4) /M(2)/s, k(3) = (4.8 ± 0.8) × 10(-4) /M/s]. In the Eu(3+) exchange, at pH <5.0, the rate decreases with increasing concentration of the exchanging ion. At physiological pH, the kinetic inertness of [DTPA-(Me-Trp)(2)] is more inert than GdDTPA(2-), the most commonly used MRI contrast agent (t(1/2) = 127 h). High kinetic stability is an important requirement for the Gd complexes used as contrast enhancement agents in magnetic resonance imaging.