Synthesis, in vitro bioassays, and computational study of heteroaryl nitazoxanide analogs.

Antiprotozoal drug nitazoxanide (NTZ) has shown diverse pharmacological properties and has appeared in several clinical trials. Herein we present the synthesis, characterization, in vitro biological investigation, and in silico study of four hetero aryl amide analogs of NTZ. Among the synthesized molecules, compound 2 and compound 4 exhibited promising antibacterial activity against Escherichia coli (E. coli), superior to that displayed by the parent drug nitazoxanide as revealed from the in vitro antibacterial assay. Compound 2 displayed zone of inhibition of 20 mm, twice as large as the parent drug NTZ (10 mm) in their least concentration (12.5 µg/ml). Compound 1 also showed antibacterial effect similar to that of nitazoxanide. The analogs were also tested for in vitro cytotoxic activity by employing cell counting kit-8 (CCK-8) assay technique in HeLa cell line, and compound 2 was identified as a potential anticancer agent having IC50 value of 172 µg which proves it to be more potent than nitazoxanide (IC50  = 428 µg). Furthermore, the compounds were subjected to molecular docking study against various bacterial and cancer signaling proteins. The in vitro test results corroborated with the in silico docking study as compound 2 and compound 4 had comparatively stronger binding affinity against the proteins and showed a higher docking score than nitazoxanide toward human mitogen-activated protein kinase (MAPK9) and fatty acid biosynthesis enzyme (FabH) of E. coli. Moreover, the docking study demonstrated dihydrofolate reductase (DHFR) and thymidylate synthase (TS) as probable new targets for nitazoxanide and its synthetic analogs. Overall, the study suggests that nitazoxanide and its analogs can be a potential lead compound in the drug development.

The first detection of Pneumocystis jirovecii in asthmatic patients post-COVID-19 in Jordan.

Pneumocystis jirovecii pneumonia (PCP), caused by fungal species named Pneumocystis jirovecii, is a frequent opportunistic infection in those with human immunodeficiency virus (HIV) infection. However, PCP has been documented in immunocompetent patients. This study aims to determine if P. jirovecii detection occurs in asthma patients following coronavirus disease 2019 (COVID-19) in a Jordanian cohort. Also, to evaluate a method of TaqMan quantitative polymerase chain reaction (qPCR) assay to detect P. jirovecii, from sputum samples. The nasopharyngeal swabs were used to detect SARS-CoV-2 and sputum samples were tested for P. jirovecii using real time qPCR assay. Beta-tubulin (BT) and Dihydrofolate reductase (DHFR) genes were the directed targets of P. jirovecii. The results showed that the mean qPCR efficiencies of BT and DHFR were 96.37% and 100.13%, respectively. Three out of 31 included patients (9.7%) had a positive P. jirovecii. All of the three patients had used oral corticosteroids (OCS) in the last two months due asthma exacerbation and were treated with OCS for COVID-19. This is the first study based in Jordan to demonstrate that P. jirovecii and COVID-19 can co-exist and that it is important to maintain a broad differential diagnosis, especially in immunocompromised patients. Chronic lung disease can be a risk factor for the P. jirovecii colonization possibly due to corticosteroid's immunosuppression.

MANORAA: A machine learning platform to guide protein-ligand design by anchors and influential distances.

The MANORAA platform uses structure-based approaches to provide information on drug design originally derived from mapping tens of thousands of amino acids on a grid. In-depth analyses of the pockets, frequently occurring atoms, influential distances, and active-site boundaries are used for the analysis of active sites. The algorithms derived provide model equations that can predict whether changes in distances, such as contraction or expansion, will result in improved binding affinity. The algorithm is confirmed using kinetic studies of dihydrofolate reductase (DHFR), together with two DHFR-TS crystal structures. Empirical analyses of 881 crystal structures involving 180 ligands are used to interpret protein-ligand binding affinities. MANORAA links to major biological databases for web-based analysis of drug design. The frequency of atoms inside the main protease structures, including those from SARS-CoV-2, shows how the rigid part of the ligand can be used as a probe for molecular design (http://manoraa.org).