Aminoguanidine-based bioactive proligand as AIEE probe for anticancer and anticovid studies

The emission features of a novel bioactive compound, 1,3-bis(2-hydroxy-3,5-diiodophenyl-methylideneamino)guanidine is found impressive with aggregation induced emission enhancement. The nitrogen and iodine rich multidentate proligand was characterized physicochemically. SCXRD and Hirshfeld surface investigation have revealed the presence of significant triangular iodine bonding apart from hydrogen bonding, weak C-H⋯π and π⋯π intermolecular interactions. These interactions collectively contribute to the solid-state packing arrangement of the molecules within the crystal lattice. The band gap of the compound was estimated experimentally and is supported with theoretical calculations. The solid-state fluorescence quantum yield of Φ = 0.36 emphasizes the utility of the proligand and the AIEE characteristics is attributed to restricted intramolecular motions as indicated by fluorescence lifetime decay studies. Strong interaction of the compound with calf thymus DNA was explored experimentally and found to align with in silico docking results. Notably, in vitro anticancer assessment on MCF-7 breast cancer cells show an IC50 value of 181.05 μg mL-1 and signifying its potent cytotoxic properties. Also, the compound is found to have lesser cytotoxicity against L929 normal cell line with an IC50 value of 356.54 μg mL-1. Computational studies further underscore the exceptional binding affinity with active sites in the SARS-CoV-2 main protease 3CLpro, surpassing established repurposed drugs. Furthermore, the proligand demonstrates excellent putative affinity towards the SARS-CoV-2 spike glycoprotein, accompanied by its distinctive AIEE attributes, drug likeness and DNA binding capability rendering it a valuable tool for prospective research investigations.

Bis(thio)carbohydrazone Luminogens with AIEE and ACQ Features and Their In Silico Investigations with SARS-CoV-2

Herein, we report two novel multidentate luminogen proligands bis(3,5-diiodosalicylidene) carbohydrazone (H4L1) and bis(3,5-diiodosalicylidene) thiocarbohydrazone (H4L2), which are suitable candidates for biomedical applications. Though the thiocarbohydrazone H4L2 shows aggregation caused quenching (ACQ), the carbohydrazone H4L1 exhibits stronger fluorescence due to aggregation induced emission enhancement (AIEE). Molecular docking studies of H4L1 and H4L2 along with four similar (thio)carbohydrazones with the active sites of SARS-CoV-2 main protease 3CLpro reveals that the thiocarbohydrazones, in general, are showing better propensity compared to their oxygen analogues. Both the thiocarbohydrazones and the carbohydrazones, however, exhibit better binding potential at the active sites than that of some of the repurposed drugs such as chloroquine, hydroxychloroquine, lopinavir, ritonavir, darunavir and remdesivir. Also, the carbohydrazone H4L1 can be a better bioprobe compared to H4L2 as the former is found to have better binding potential with SARS-CoV-2 spike glycoprotein along with AIEE feature.

One-pot and divergent synthesis of polysubstituted quinolin-2(1H)-ones and oxireno[2,3-c]quinolin-2(1aH,3H,7bH)-ones via sequential Ugi/Knoevenagel condensation/hydrolysis and Ugi/Corey–Chaykovsky epoxidation reactions

A new one-pot and divergent synthesis of multisubstituted quinolin-2(1H)-ones and oxireno[2,3-c]quinolin-2(1aH,3H,7bH)-ones was developed.