Glycyrrhiza glabra L. Extracts and Other Therapeutics against SARS-CoV-2 in Central Eurasia: Available but Overlooked.

In Central Eurasia, the availability of drugs that are inhibitors of the SARS-CoV-2 virus and have proven clinical efficacy is still limited. The aim of this study was to evaluate the activity of drugs that were available in Kazakhstan during the acute phase of the epidemic against SARS-CoV-2. Antiviral activity is reported for Favipiravir, Tilorone, and Cridanimod, which are registered drugs used for the treatment of respiratory viral infections in Kazakhstan. A licorice (Glycyrrhiza glabra) extract was also incorporated into this study because it offered an opportunity to develop plant-derived antivirals. The Favipiravir drug, which had been advertised in local markets as an anti-COVID cure, showed no activity against SARS-CoV-2 in cell cultures. On the contrary, Cridanimod showed impressive high activity (median inhibitory concentration 66 µg/mL) against SARS-CoV-2, justifying further studies of Cridanimod in clinical trials. Tilorone, despite being in the same pharmacological group as Cridanimod, stimulated SARS-CoV-2 replication in cultures. The licorice extract inhibited SARS-CoV-2 replication in cultures, with a high median effective concentration of 16.86 mg/mL. Conclusions: The synthetic, low-molecular-weight compound Cridanimod suppresses SARS-CoV-2 replication at notably low concentrations, and this drug is not toxic to cells at therapeutic concentrations. In contrast to its role as an inducer of interferons, Cridanimod is active in cells that have a genetic defect in interferon production, suggesting a different mechanism of action. Cridanimod is an attractive drug for inclusion in clinical trials against SARS-CoV-2 and, presumably, other coronaviruses. The extract from licorice shows low activity against SARS-CoV-2. At the same time, high doses of 2 g/kg of this plant extract show little or no acute toxicity in animal studies; for this reason, licorice products can still be considered for further development as a safe, orally administered adjunctive therapy.

Design, synthesis, spectroscopic characterization, computational analysis, and in vitro α-amylase and α-glucosidase evaluation of 3-aminopyridin-2(1H)-one based novel monothiooxamides and 1,3,4-thiadiazoles.

Due to the growth in the incidence of diabetes mellitus throughout the world, the urgency in the search for new safe and effective inhibitors of α-amylase and α-glucosidase is increasing. In this work, we attempted to carry out studies on the synthesis, modification and comprehensive computer and biological research of new derivatives of monothiooxamides. It was shown that monothiooxamides based on 3-aminopyridin-2(1H)-ones enter into transamidation reactions with hydrazine hydrate to form the corresponding thiohydrazides. Furthermore, under the action of chloroacetyl chloride and succinic anhydride, these thiohydrazides are cyclized into conjugated 1,3,4-thiadiazole derivatives. The possible biological activity of the obtained products was evaluated by molecular docking using the AutoDock Vina program. Compounds 7a and 8b showed higher binding affinities for selected target proteins compared to the known anti-diabetic drugs acarbose and TAK-875. The obtained new derivatives of 1,3,4-thiadiazole showed sufficiently high values of inhibitory activity in the in vitro test against the enzymes α-amylase and α-glucosidase as well as sufficiently low IC50 values (for 8b 122.2 µM), which is 8 times less than the value for the reference drug acarbose (998.3 µM). All synthesized derivatives of monothiooxamides 5-8(a-c) showed no cytotoxic properties at physiological concentrations in the MTT test in human neonatal dermal fibroblasts. Moreover, some compounds (6a-c, 7a-c, 8b,c) showed pronounced cytoprotective activity. Thus, the compounds 5-8(a-c) synthesized by us, both according to the results of computer calculations and in vitro biological screening, showed their potential antidiabetic activity and high prospects for further in-depth studies, including in vivo studies.

Crystal structure and antidiabetic activity of 2-aminospiropyrazolinium tosylates and the product of O-tosylation of ß-(benzimidazol-1-yl)propioamidoxime.

2-Amino-1,5-diazaspiro[4.5]dec-1-en-5-ium salts possess bioactivity tuned by the nature of the heteroatoms in the six-membered ring and the counter-ion. The molecular environment of these cations in solids provides an opportunity to establish the conformations and hydrogen-bonding patterns typical for this family. ß-Aminopropioamidoxime tosylation products [2-amino-1,5-diazaspiro[4.5]dec-1-en-5-ium tosylates and the product of the O-tosylation of ß-(benzimidazol-1-yl)propioamidoxime, namely, 2-amino-1,5-diazaspiro[4.5]dec-1-en-5-ium tosylate, C8H16N3+·C7H7O3S- (6), 2-amino-8-oxa-1,5-diazaspiro[4.5]dec-1-en-5-ium tosylate, C7H14N3O+·C7H7O3S- (7), the monohydrate of 7, C7H14N3O+·C7H7O3S-·H2O (7a), 2-amino-8-thia-1,5-diazaspiro[4.5]dec-1-en-5-ium tosylate, C7H14N3S+·C7H7O3S- (8), 2-amino-8-phenyl-1,5,8-triazaspiro[4.5]dec-1-en-5-ium tosylate, C13H19N4+·C7H7O3S- (9), and 3-(1H-benzimidazol-1-yl)-N'-(tosyloxy)propanimidamide, C17H18N4O3S (10)] were investigated using X-ray diffraction to study peculiarities of their molecular geometry and intermolecular interactions. In vitro antitubercular and antidiabetic screening of the ß-aminopropioamidoxime tosylation products was also carried out. It was revealed that this series of compounds does not have activity against drug-sensitive and multidrug-resistant M. tuberculosis strains, and exhibits high and moderate antidiabetic α-amylase and α-glucosidase activity. Using the hydrogen-bond propensity tool, we found that the inclination of counter-ions and atoms to act as acceptors of hydrogen bonds for the amino group decreases passing from tosylate O atoms to water molecules and the N atoms of five-membered rings. This fact is probably the reason for the formation in the solids of hydrogen-bonded tetramers consisting of two anions and two cations, and the rare occurrence of 2-aminospiropyrazolinium salt hydrates.

Synthesis and Antiviral Properties against SARS-CoV-2 of Epoxybenzooxocino[4,3-b]Pyridine Derivatives.

The COVID-19 pandemic is ongoing as of mid-2022 and requires the development of new therapeutic drugs, because the existing clinically approved drugs are limited. In this work, seven derivatives of epoxybenzooxocinopyridine were synthesized and tested for the ability to inhibit the replication of the SARS-CoV-2 virus in cell cultures. Among the described compounds, six were not able to suppress the SARS-CoV-2 virus' replication. One compound, which is a derivative of epoxybenzooxocinopyridine with an attached side group of 3,4-dihydroquinoxalin-2-one, demonstrated antiviral activity comparable to that of one pharmaceutical drug. The described compound is a prospective lead substance, because the half-maximal effective concentration is 2.23 µg/µL, which is within a pharmacologically achievable range.