One-Pot Parallel Synthesis of 5-(Dialkylamino)tetrazoles

Nanomagnetic tetraaza (N4 donor) macrocyclic Schiff base complex of copper(ii): synthesis, characterizations, and its catalytic application in Click reactions

In this research, a novel nanomagnetic tetra-azamacrocyclic Schiff base complex of copper(ii) was produced via a post-synthetic surface modification of an Fe3O4 surface by a silane-coupling agent that contains acetylacetone functionalities at the end of its chain. Moreover, the target Cu complex that involves a tetradentate Schiff base ligand was obtained from a template reaction with o-phenylenediamine and Cu(NO3)2·3H2O. Furthermore, the prepared complex was nominated as [Fe3O4@TAM-Schiff-base-Cu(II)]. The Fourier-transform infrared (FT-IR) analysis indicates the presence of a Schiff-base-Cu complex in the catalyst. X-ray spectroscopy (EDS) and TGA analysis reveal that approximately 6-7% of the target catalyst comprises hydrocarbon moieties. The scanning electron microscope (SEM) and transmission electron microscopy (TEM) images demonstrate the presence of uniformly shaped particles, nearly spherical in nature, with sizes ranging from 9 to 18 nm. [Fe3O4@TAM-Schiff-base-Cu(II)] was applied as a catalyst for the click synthesis of a diverse range of 5-substituted-1H-tetrazoles in PEG-400 as a green medium. Regarding the electrical properties of the Cu(ii) complex, the presence of a tetra-aza (N4 donor) macrocyclic Schiff base as an N-rich ligand was reasonable - leading to its excellent capacity to catalyze these organic transformations. Finally, the high magnetization value (44.92 emu g-1) of [Fe3O4@TAM-Schiff-base-Cu(II)] enables its recycling at least four times without compromising the catalytic efficiency.

Creation of targeted compound libraries based on 3D shape recognition

In the emerging field of drug discovery, rapid virtual screening methods become extremely valuable, especially when dealing with ultra-large databases of organic small bioactive molecules. In this work, we present a fast, computationally resource-efficient, and simple workflow for screening targeted compound libraries generated from ultra-large virtual chemical space. This workflow aims to find compounds with similar molecular 3D shapes with reference ones, and at the same time to expand chemical diversity and to identify new and potentially active scaffolds. This pipeline ensures the enrichment of the generated libraries with novel chemotypes. Also, it was shown that delicate tailoring of the physicochemical parameters of the search set ensures that all library compounds will possess desired property distributions. A visual inspection has shown that found structures bind to the receptor in the same way as the reference ones. Using our screening workflow, we have created a number of conventional protein-targeted libraries: the GPCRs Targeted Library (531 K compounds) and the Protein Kinases Targeted Library (113 K compounds). The described pipeline and scripts are freely accessible at: https://github.com/ChemSpace-LLC/usrcat_sim .

Novel hybrid isoindole-1,3(2H)-dione compounds containing a 1H-tetrazole moiety: Synthesis, biological evaluation, and molecular docking studies

In this study, novel hybrid isoindole-1,3(2H)-dione compounds (10 and 11) carrying a 1H-tetrazole moiety were synthesized, characterized and their inhibitory properties against xanthine oxidase (XO) and carbonic anhydrase isoenzymes (hCA I and hCA II) were investigated. Allopurinol for XO and acetazolamide for carbonic anhydrase isoenzymes were used as positive standards in inhibition studies. In addition, compounds 8 and 9, which were obtained in the intermediate step, were also investigated for their inhibition effects against the three enzymes. According to the enzyme inhibition results, hybrid isoindole-1,3(2H)-dione derivatives 10 and 11 showed significant inhibitory effects against all three enzymes. Surprisingly, compound 8, containing a SCN functional group, exhibited a greater inhibitory effect than the other compounds against hCA I and hCA II. The IC₅₀ values of compound 8 against hCA I and hCA II were found to be 3.698 ± 0.079 and 3.147 ± 0.083 µM, respectively. Compound 8 (IC₅₀  = 4.261 ± 0.034 μM) showed higher activity than allopurinol (IC₅₀  = 4.678 ± 0.029 μM) and the other compounds against XO, as well. These results clearly show the effect of the SCN group on the inhibition. In addition, in silico molecular docking studies were performed to understand the molecular interactions between each compound and enzymes, and the results were evaluated.

Synthon-based ligand discovery in virtual libraries of over 11 billion compounds

Structure-based virtual ligand screening is emerging as a key paradigm for early drug discovery owing to the availability of high-resolution target structures^1-4 and ultra-large libraries of virtual compounds^5,6. However, to keep pace with the rapid growth of virtual libraries, such as readily available for synthesis (REAL) combinatorial libraries⁷, new approaches to compound screening are needed^8,9. Here we introduce a modular synthon-based approach-V-SYNTHES-to perform hierarchical structure-based screening of a REAL Space library of more than 11 billion compounds. V-SYNTHES first identifies the best scaffold-synthon combinations as seeds suitable for further growth, and then iteratively elaborates these seeds to select complete molecules with the best docking scores. This hierarchical combinatorial approach enables the rapid detection of the best-scoring compounds in the gigascale chemical space while performing docking of only a small fraction (<0.1%) of the library compounds. Chemical synthesis and experimental testing of novel cannabinoid antagonists predicted by V-SYNTHES demonstrated a 33% hit rate, including 14 submicromolar ligands, substantially improving over a standard virtual screening of the Enamine REAL diversity subset, which required approximately 100 times more computational resources. Synthesis of selected analogues of the best hits further improved potencies and affinities (best inhibitory constant (K_i) = 0.9 nM) and CB₂/CB₁ selectivity (50-200-fold). V-SYNTHES was also tested on a kinase target, ROCK1, further supporting its use for lead discovery. The approach is easily scalable for the rapid growth of combinatorial libraries and potentially adaptable to any docking algorithm.