Synthesis and evaluation of photophysical, electrochemical, and ROS generation properties of new chalcogen-naphthoquinones-1,2,3-triazole hybrids

This study presents a comprehensive analysis encompassing the synthesis, structural elucidation, photophysical behavior, and electrochemical properties of a novel series of chalcogen-naphthoquinone-1,2,3-triazole hybrids. Employing a meticulously designed protocol, the synthesis of these hybrids, denoted as 11a-j, was achieved with remarkable efficiency (yielding up to 81%). This synthesis used a regioselective copper-catalyzed azide-alkyne cycloaddition reaction (CuAAC). Furthermore, a detailed investigation into the photophysical characteristics, TDDFT calculations, electrochemical profiles, and photobiological attributes of compounds 11a-j was conducted. This exploration aimed to unravel insights into the excited state behaviors of these molecules, as well as their redox properties. Such insights are crucial for future applications of these derivatives in diverse biological assays.

Synthesis of Spiro[5.5]trienones- and Spiro[4.5]trienones-Fused Selenocyanates via Electrophilic Selenocyanogen Cyclization and Dearomative Spirocyclization

A practical strategy for the synthesis of spiro[5.5]trienones-fused selenocyanates and spiro[4.5]trienones-fused selenocyanates through electrophilic selenocyanogen cyclization and dearomative spirocyclization is reported. This approach was conducted under mild conditions with broad substrate scope and good functional group tolerance. The utility of this procedure is exhibited in the late-stage functionalization of nature product and drug molecules.

Absolute Quantitation of N-Nitrosamines by Coulometric Mass Spectrometry without Using Standards

Carcinogenic N-nitrosamines were recently found in the sartan family of drugs and caused many drug recalls. Both of their detection and quantification are therefore important. Methods reported for N-nitrosamine quantitation rely on the use of standards and are just applicable to simple N-nitrosamines. There is an urgent need to quantify N-nitrosamines derived from drugs with a complicated structure that lack standards. To tackle the issue, this study describes a novel absolute quantitation strategy for N-nitrosamines using coulometric mass spectrometry (CMS) without standards. In our approach, N-nitrosamine is first converted into electrochemically active hydrazine via zinc reduction under acidic condition and the resulting hydrazine can then be easily quantified using CMS. To validate our method, six simple N-nitrosamines, N-nitrosodiethylamine (NDEA), N-nitroso-4-phenylpiperidine (NPhPIP), N-nitrosodiphenylamine (NDPhA), N-nitrosodibutylamine (NDBA), N-nitrosodipropylamine (NDPA), and N-nitrosopiperidine (NPIP), were chosen as test samples, and they all were quantified with excellent measurement accuracy (quantitation error ≤1.1%). Taking this one step further, as a demonstration of the method utility, a drug-like N-nitrosamine, (R)-N-(2-(6-chloro-5-methyl-1'-nitroso-2,3-dihydrospiro[indene-1,4'-piperidin]-3-yl)propan-2-yl)acetamide (VII), was also synthesized and successfully quantified using our method at 15 ppb level in a complex formulation matrix, following solvent extraction, N-nitrosamine isolation, and reductive conversion. Because of the feature of requiring no standards, CMS provides a simple and powerful approach for N-nitrosamine absolute quantitation and has great potential for analysis of other drug impurities or metabolites.

The crystal structure of 5-bromo-2-(2-methyl-2H-tetrazol-5-yl)pyridine, C7H6BrN5

C7H6BrN5, triclinic, P1̄ (no. 2), a = 8.3319(4) Å, b = 10.0666(5) Å, c = 11.4042(6) Å, α = 107.213(5)°, β = 99.394(4)°, γ = 95.540(4)°, V = 890.71(8) Å3, Z = 4, R gt(F) = 0.0452, wR ref(F 2) = 0.0972, T = 293(2) K.

Synthesis, cytotoxicity, and molecular docking of substituted 3-(2-methylbenzofuran-3-yl)-5-(phenoxymethyl)-1,2,4-oxadiazoles

A series of new benzofuran/oxadiazole hybrids (8a-n) was synthesized from 2H-chromene-3-carbonitriles (3a-c) through the multistep synthetic methodology, and these hybrids are known to exhibit anticancer activities. All the compounds were evaluated for their in vitro cytotoxicity against the HCT116 and MIA PaCa2 cell lines. Compounds 6a (IC₅₀ : 9.71 ± 1.9 μM), 6b (IC₅₀ : 7.48 ± 0.6 μM), and 6c (IC₅₀ : 3.27 ± 1.1 μM) displayed a significant cytotoxic activity, whereas compounds 8d and 8e exhibited good activity against both cell lines. The depletion of glycogen synthase kinase-3β (GSK3β) induces apoptosis through the inhibition of basal NF-κB activity in HCT116 colon cancer cells and MIA PaCa2 pancreatic cancer cells. Molecular docking of compounds 6a, 6b, 6c, 8d, and 8e with GSK3β demonstrated the best binding affinity, correlating with the biological activity assay. Furthermore, the structure-activity relationship of these novel compounds reveals promising features for their use in anticancer therapy.

A Straightforward and High-Yielding Synthesis of 1,2,4-Oxadiazoles from Chiral N-Protected α-Amino Acids and Amidoximes in Acetone-Water: An Eco-Friendly Approach

A straightforward and high-yielding methodology for the synthesis of a high structural diversity of 1,2,4-oxadiazoles from different chiral N-protected α-amino acids and amidoximes under microwave (MW) irradiation is described herein. This greener approach gives the desired products using acetone/water as solvent in very short reaction times.

‘One-pot’ synthesis and redox evaluations of chiral chalcogenocysteinol and β-bis-chalcogenoamine derivatives from l-serine methyl ester

The synthesis of a new class of potential antioxidant chiral chalcogenocysteinols and bis-chalcogenoamines is described in this study.