Bipyrazole-based palladium(II) complexes as DNA intercalator and artificial metallonuclease

Inhibitory activities of bipyrazoles: a patent review

Introduction: Bipyrazole is constituted from two pyrazole units either in their fully aromatic or partially hydrogenated forms. Pyrazoles are widely available in pharmaceutical and agrochemical products. Some pyrazoles are essential parts of commercial drugs in the market. This inspired us to collect the pharmacological activities of bipyrazoles that have potential therapeutic behaviors in several biological aspects but none of them were included in commercial drugs.Areas covered: This review covers all biological and pharmacological potentials of bipyrazole derivatives during 2010-2021. The topics of this review comprised anticancer, antioxidant, anti-inflammatory, antimicrobial, antitubercular, antimalarial, insecticidal activities as well as enzymatic inhibitions.Expert opinion: Bipyrazoles demonstrated a wide array of potent activities against various diseases such as anticancer, antitubercular, anti-inflammatory, and antimicrobial activities. Those are of great benefits for medicinal researchers to develop promising building blocks of bipyrazoles for treatment of diseases. The SAR studies showed that metallated bipyrazoles had better biological activities than bipyrazole ligands. For example, gold(III) and iridium(II) complexes of bipyrazoles were proved to be anticancer agents, and copper(I) as well as silver(I) complexes had excellent antibacterial activities. Several bipyrazoles were reported as antimalarial inhibitors better than chloroquine, the possible COVID-19 drug.

Tetrazolo[1,5-a]quinoline moiety-based Os(IV) complexes: DNA binding/cleavage, bacteriostatic and photocytotoxicity assay

Biological applications of platinum group metal-based complexes have been widely explored in synthetic and inorganic chemistry. The compounds have been subjected to DNA binding, DNA cleavage, In-vivo and In-vitro photocytotoxicity (HCT-116 cell line) and bacteriostatic activities. Binding constant of complexes are 1.42-5.62 × 10⁴ M^-1, whereas that of ligands are 1.12-4.72 × 10⁴ M^-1. K_sv of complexes are about 1.32-5.21 × 10³ M^-1, whereas K_f is about 1.24-6.83 × 10³ M^-1. IC₅₀ of compounds screened using HCT-116 cell line in dark are found to be 121-342 μg/mL. Whereas photocytotoxicity is found in the range of 48-316 μg/mL. Docking energy of molecules have been evaluated to evaluate efficacy of binding. Molecular docking energy of complexes are in the range of -286.00 to -303.11 kJ/mol. Whereas that of ligands are -254.03 to -282.96 kJ/mol. MIC of complexes are 47 ± 2.5 to 77.50 ± 7.5 μM. LC₅₀ values of ligands fall in the range of 4.05-19.72 μg/mL and that of Os(IV) complexes fall in the range of 3.99-15.99 μg/mL. The Os(IV) complexes dominate in proving its potentiality compared to N, N-donor ligands in biological activities. [Formula: see text]Communicated by Ramaswamy H. Sarma.

Synthesis and characterization of new 3,3`-bipyrazole-4,4`-dicarboxylic acid derivatives and some of their palladium(II) complexes as pre-catalyst for Suzuki coupling reaction in water

The 1,3-dipolar cycloaddition reaction of bis-hydrazonyl chlorides with methyl propiolate afforded dimethyl 1,1¢-aryl-3,3`-bipyrazole-4,4`-dicarboxylates (5a,b). Heating the later compound 5a with a mixture of HCl/AcOH gave 3,3`-bipyrazole-5,5`-dicarboxylic acid derivative 6. Treatment of the hydrazonoyl chloride (1a) and 3,3`-bipyrazole-5,5`-dicarboxylic acid (6) with palladium(II) chloride gave the corresponding Pd-complexes 7 and 8, respectively. The catalytic activity of the prepared Pd-complexes was examined in the Suzuki cross-coupling reaction of phenylboronic acid with activated and deactivated aryl(hetaryl) bromides. The catalyst system provides very good to excellent yields, 85-94%. The structures of the obtained products were established from their elemental analysis, spectral data, XPS, EDX, and single crystal X-ray crystallography. Crystal data for C10H7N2O2 (6): triclinic, space group P-1 (no. 2), a = 3.9956(10) Å, b = 9.8917(18) Å, c = 10.810(3) Å, α = 94.167(15)°, β = 94.979(19)°, γ = 98.953(15)°, V = 418.83(16) Å3, Z = 2, T = 296.(2) K, μ(Cu Kα) = 0.887 mm-1, Dcalc = 1.484 g/cm3, 5469 reflections measured (11.72° ≤ 2Θ ≤ 133.24°), 1420 unique (Rint = 0.0633, Rsigma = 7.24%) which were used in all calculations. The final R1 was 0.1055 (>2sigma(I)) and wR2 was 0.3620 (all data).