The main protease (M^pro) of SARS-CoV-2 is an attractive target in anti-COVID-19 therapy for its high conservation and major role in the virus life cycle. The covalent M^pro inhibitor nirmatrelvir (in combination with ritonavir, a pharmacokinetic enhancer) and the non-covalent inhibitor ensitrelvir have shown efficacy in clinical trials and have been approved for therapeutic use. Effective antiviral drugs are needed to fight the pandemic, while non-covalent M^pro inhibitors could be promising alternatives due to their high selectivity and favorable druggability. Numerous non-covalent M^pro inhibitors with desirable properties have been developed based on available crystal structures of M^pro. In this article, we describe medicinal chemistry strategies applied for the discovery and optimization of non-covalent M^pro inhibitors, followed by a general overview and critical analysis of the available information. Prospective viewpoints and insights into current strategies for the development of non-covalent M^pro inhibitors are also discussed.

COVID-19 epidemic continues to spread around the world till these days, and it is urgent to develop more safe and effective new drugs. Due to the limited P3 biosafety laboratories for directly screening inhibitors of virulent viruses with high infectivity, it is necessary to develop rapid and efficient screening methods for viral proteases and other related targets. The main protease (M^pro), which plays a key role in the replication cycle of SARS-CoV-2, is highly conserved and has no homologous proteases in humans, making it an ideal target for drug development. From two different levels, namely, molecular level and cellular level, this paper summarizes the reported screening methods of SARS-CoV-2 M^pro inhibitors through a variety of representative examples, expecting to provide references for further development of SARS-CoV-2 M^pro inhibitors.

As a common protease with high similarity among coronavirus species, the main protease (M^pro) of SARS-CoV-2 is responsible for the catalytic hydrolysis of viral precursor proteins into functional proteins, which is essential for coronavirus replication and is one of the ideal targets for the development of broad-spectrum antiviral drugs. This paper reviews the main protease inhibitors of SARS-CoV-2, including their molecular structures, potencies and drug-like profiles, binding modes and structure-activity relationships, etc.

Objective To investigate effects of human postures on flow characteristics of iliac vein compression syndrome. Methods The numerical model of iliac vein was reconstructed from CT images of a typical patient with pelvic-type iliac vein compression syndrome with collateral veins. Based on the computational fluid dynamics method, the non-Newtonian model and the porous media model were adopted to describe effects of abnormal structures on blood flow and acquire the wall shear stress and pressure of iliac vein. The discrete phase model was used to study the residence conditions of erythrocytes under three human postures. Results The pressure gradient at two ends of the compressive region was lowest under lying state, while the iliac vein showed a high pressure under sitting and walking states. The local maximum wall shear stresses under three postures were found at narrow segment of the collateral vein and convergence region of two flows of right iliac vein. The maximum shear stress was largest under lying state and smallest under sitting state. The blood residence time of 52.2 s in the left iliac vein was the longest under sitting state. The residence time of 14.8 s was shortest under lying state. The blood residence time was 23.8 s under walking state. Conclusions Porous media model used to simulate the effect of abnormal structures was highly consistent with the angiography data. The venous hypertension under sitting and walking states was consistent with the clinical results, and the lying state could relieve the hypertensive condition. In terms of wall shear stress and blood residence time in iliac vein, the continual change between three human postures would cause endothelial damage and blood flow stasis alternately, thus increase the risk of thrombosis.

Indolylarylsulfones (IASs) are classical HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) with a unique scaffold and possess potent antiviral activity. To address the high cytotoxicity and improve safety profiles of IASs, we introduced various sulfonamide groups linked by alkyl diamine chain to explore the entrance channel of non-nucleoside inhibitors binding pocket. 48 compounds were designed and synthesized to evaluate their anti-HIV-1 activities and reverse transcriptase inhibition activities. Especially, compound R₁₀L₄ was endowed with significant inhibitory activity towards wild-type HIV-1 (EC_50(WT) = 0.007 μmol/L, SI = 30,930) as well as a panel of single-mutant strains exemplified by L100I (EC₅₀ = 0.017 μmol/L, SI = 13,055), E138K (EC₅₀ = 0.017 μmol/L, SI = 13,123) and Y181C (EC₅₀ = 0.045 μmol/L, SI = 4753) which were superior to Nevirapine and Etravirine. Notably, R₁₀L₄ was characterized with significantly reduced cytotoxicity (CC₅₀ = 216.51 μmol/L) and showed no remarkable in vivo toxic effects (acute and subacute toxicity). Moreover, the computer-based docking study was also employed to characterize the binding mode between R₁₀L₄ and HIV-1 RT. Additionally, R₁₀L₄ presented an acceptable pharmacokinetic profile. Collectively, these results deliver precious insights for next optimization and indicate that the sulfonamide IAS derivatives are promising NNRTIs for further development.

Novel therapies are urgently needed to improve global treatment of SARS-CoV-2 infection. Herein, we briefly provide a concise report on the medicinal chemistry strategies towards the development of effective SARS-CoV-2 inhibitors with representative examples in different strategies from the medicinal chemistry perspective.

Objective: To investigate the molecular characteristics of ciprofloxacin-cefotaxime-azithromycin co-resistant Salmonella enterica serovar Thompson (S. Thompson) isolates from sporadic cases of foodborne diseases and aquatic foods in Hunan province. Methods: Ciprofloxacin-cefotaxime-azithromycin co-resistant S. Thompson isolates were selected from samples, and broth microdilution method was used to determine the resistance to 11 antibiotics of these isolates in vitro. Whole genome sequencing was used for investigating antimicrobial resistance gene patterns and phylogenetic relationships of strains. Results: Nine ciprofloxacin-cefotaxime-azithromycin co-resistant isolates were recovered from 19 S. Thompson isolates. Among nine ciprofloxacin-cefotaxime-azithromycin co-resistant isolates, eight of them harbored IncC plasmids, simultaneously carrying plasmid-mediated quinolone resistance (PMQR) genes qepA and qnrS1, β-lactamase resistance gene bla_CMY-2, azithromycin resistance gene mph(A), and one isolate harbored IncR plasmid, and carried PMQR genes qnrB4 and aac(6')-Ib-cr, bla_OXA-10 and mph(A). Genetic environment analysis showed that qnrS1, qepA, mph(A) and bla_CMY-2 genes might be integrated on genomes of strains by ISKra4, IS91, IS6100 and ISEcp1, respectively. Phylogenetic core genome comparisons demonstrated that ciprofloxacin-cefotaxime-azithromycin co-resistant isolates from patients and aquatic foods were genetically similar and clustered together. Conclusion: Ciprofloxacin-cefotaxime-azithromycin co-resistant S. Thompson isolates have been isolated from both human and aquatic food samples, suggesting that the spread of multidrug resistant Salmonella between human and aquatic animals.
Animals ; Humans ; Ciprofloxacin ; Cefotaxime ; Azithromycin ; Serogroup ; Phylogeny ; Drug Resistance, Multiple, Bacterial/genetics* ; Anti-Bacterial Agents/pharmacology* ; Salmonella ; Quinolones ; Foodborne Diseases ; Plasmids ; Salmonella enterica ; Microbial Sensitivity Tests

BACKGROUND: Coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has rapidly spread throughout the world. In this study, we aimed to identify the risk factors for severe COVID-19 to improve treatment guidelines. METHODS: A multicenter, cross-sectional study was conducted on 313 patients hospitalized with COVID-19. Patients were classified into two groups based on disease severity (nonsevere and severe) according to initial clinical presentation. Laboratory test results and epidemiological and clinical characteristics were analyzed using descriptive statistics. Univariate and multivariate logistic regression models were used to detect potential risk factors associated with severe COVID-19. RESULTS: A total of 289 patients (197 nonsevere and 92 severe cases) with a median age of 45.0 (33.0, 61.0) years were included in this study, and 53.3% (154/289) were male. Fever (192/286, 67.1%) and cough (170/289, 58.8%) were commonly observed, followed by sore throat (49/289, 17.0%). Multivariate logistic regression analysis suggested that patients who were aged ≥ 65 years (OR: 2.725, 95% confidence interval [CI]: 1.317-5.636; P = 0.007), were male (OR: 1.878, 95% CI: 1.002-3.520, P = 0.049), had comorbid diabetes (OR: 3.314, 95% CI: 1.126-9.758, P = 0.030), cough (OR: 3.427, 95% CI: 1.752-6.706, P < 0.001), and/or diarrhea (OR: 2.629, 95% CI: 1.109-6.231, P = 0.028) on admission had a higher risk of severe disease. Moreover, stratification analysis indicated that male patients with diabetes were more likely to have severe COVID-19 (71.4% vs. 28.6%, χ2 = 8.183, P = 0.004). CONCLUSIONS The clinical characteristics of those with severe and nonsevere COVID-19 were significantly different. The elderly, male patients with COVID-19, diabetes, and presenting with cough and/or diarrhea on admission may require close monitoring to prevent deterioration.
Adult ; COVID-19/pathology* ; China/epidemiology* ; Comorbidity ; Cough ; Cross-Sectional Studies ; Diarrhea ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Risk Factors

【Objective】 To investigate the effect of sample processing at 56℃ for 30 min on routine examination in Department of Blood Transfusion. 【Methods】 A total of 40 cross matched blood samples submitted by clinical departments of our hospital, were collected, and each sample was equally divided into two. Before and after heating at 56℃ for 30 min, the ABO blood group was detected by manual method and card method (gel card and glass beadle card), antibody titer was detected by coagulant method, and cross-matching was conducted by anti-globulin card method. Chi-square test and Wilcoxon signed rank test were used to compare the differences between the two groups (before and after heating treatment). 【Results】 The blood group detection rates of the experimental group were 100% (40/40), 37.5% (15/40) and 80% (32/40) by manual test tube method, gel card and glass beads card, respectively, P<0.01. The geometric mean of blood antibody titers in the control group and the experimental group were anti-A IgM (14.936, 10.556) and IgG(3.563, 4.489), anti-B IgM (9.849, 10.556) and anti-G (5.039, 4.489)(respectively, P>0.05). The matching rate of two groups of samples, cross-matched with corresponding donor samples, was both 100% (40/40) by coagulant method, and 100% (40/40) vs 25% (10/40) respectively by the antiglobulin card method (P<0.01). The other 30 samples in the experimental group presented weak agglutination in the secondary side. 【Conclusion】 The treatment of virus inactivation at 56℃ for 30 min has little effect on blood group identification by test tube method, antibody titer and cross-matching by coagulant method, and reduceds the occupational exposure of staff in Blood Transfusion Department.