ABSTRACT
The global COVID-19 coronavirus pandemic has infected over 109 million people, leading to over 2 million deaths up to date and still lacking of effective drugs for patient treatment. Here, we screened about 1.8 million small molecules against the main protease (Mpro) and papain like protease (PLpro), two major proteases in severe acute respiratory syndrome-coronavirus 2 genome, and identified 1851Mpro inhibitors and 205 PLpro inhibitors with low nmol/l activity of the best hits. Among these inhibitors, eight small molecules showed dual inhibition effects on both Mpro and PLpro, exhibiting potential as better candidates for COVID-19 treatment. The best inhibitors of each protease were tested in antiviral assay, with over 40% of Mpro inhibitors and over 20% of PLpro inhibitors showing high potency in viral inhibition with low cytotoxicity. The X-ray crystal structure of SARS-CoV-2 Mpro in complex with its potent inhibitor 4a was determined at 1.8 Å resolution. Together with docking assays, our results provide a comprehensive resource for future research on anti-SARS-CoV-2 drug development.
Subject(s)
Humans , Antiviral Agents/chemistry , COVID-19 , COVID-19 Drug Treatment , High-Throughput Screening Assays , Molecular Docking Simulation , Protease Inhibitors/chemistry , SARS-CoV-2/enzymology , Viral Nonstructural ProteinsABSTRACT
OBJECTIVE:To establish a method for the simultaneous determination of 6 kinds of residual organic solvents in Omeprazole magnesium,such as methanol,isopropanol,acetonitrile,dichloromethane,ethyl acetate and toluenein. METHODS:Headspace GC was adopted. The determination was performed on the column of DB-624 column by temperature programming. The inlet temperature was 200 ℃,and hydrogen flame ionization detector was adopted with the temperature of 250 ℃;nitrogen gas was used as carrier gas with flow rate of 2.0 mL/min;the splitting-radio was 5 : 1,and sample size was 1 mL;the headspace tem-perature was 80 ℃ and the equilibrium time was 20 min. RESULTS:The linear range were 12.56-628.00 μg/mL for methanol(r=0.9997),20.22-1011.20 μg/mL for isopropanol(r=0.9999),1.96-97.76 μg/mL for acetonitrile(r=0.9997),3.10-154.88 μg/mL for dichloromethane(r=0.9998),20.69-1034.56 μg/mL for ethyl acetate(r=0.9998),and 3.53-176.72 μg/mL for toluene(r=0.9998);the limits of quantitation were 1.00,0.91,0.47,0.93,0.41 and 0.35 μg/mL respectively;the limits of detection were 0.31,0.30,0.14,0.31,0.12 and 0.11 μg/mL respectively;RSDs of precision,stability and reproducibility tests were lower than 3%;the recoveries were 94.53%-101.29%(RSD=2.15%,n=9),97.78%-103.42%(RSD=1.77%,n=9),96.99%-105.76%(RSD=2.59%,n=9),96.83%-102.05%(RSD=1.86%,n=9),97.98%-101.13%(RSD=0.88%,n=9)and 97.80%-102.40%(RSD=1.41%,n=9). CONCLUSIONS:The method is sensitive and accurate,can be used for the simultaneous determination of 6 kinds of residual organic solvents in Omeprazole magnesium,such as methanol,isopropanol,acetonitrile,dichloromethane,eth-yl acetate and toluenein.
ABSTRACT
Objective:To establish a method for the content determination of magnesium in esomeprazole magnesium. Methods:The content of magnesium in esomeprazole magnesium was determined by inductive coupled plasma atomic emission spectrometry. Re-sults:The linear range was 10.0-80.0 μg·ml-1(r=0.999 8). The average recovery was 99.55% with RSD of 1.35% (n=9). The detection limit was 0. 000 75 μg·ml-1 and the quantitative limit was 0. 002 5 μg·ml-1 . Conclusion:The method is accurate, sensitive and reproducible, which can be used for the content determination of magnesium in esomeprazole magnesium.
ABSTRACT
Objective:To establish a headspace capillary gas chromatography method for the determination of residual solvents in erlotinib hydrochloride .Methods:A DB-624 capillary column (30 m ×0.53 mm, 3.0 μm) was used and the carrier gas was nitro-gen.The flow rate was 2.0 ml· min-1 and the inlet temperature was 190℃.The FID detector temperature was 230 ℃.The column temperature program was with the initial temperature of 35℃( maitaining 8 min) , risen to 170℃with the rate of 28℃· min-1 ( main-taining 8 min) , and then risen to 200℃with the rate of 32℃· min-1 ( maintaining 7 min) .The headspace vial temperature was 100℃and the time was 30 min.Results:Ethanol, isopropanol, methylene chloride and n-butanol had a good linear relationship within the range of 0.68-409.14 μg· ml-1 (r=0.999 8),0.67-404.88 μg· ml-1 (r=0.999 8),1.71-51.31μg· ml-1 (r=0.999 7) and 0.72-431.12 μg· ml-1(r=0.999 8), respectively.The average recovery was 99.0% (RSD=0.41%, n=9), 100.2%(RSD=0.52%, n=9),97.1%(RSD=1.75%, n =9) and 102.5% (RSD=1.08%, n=9), respectively.Conclusion: The method is simple and accurate , which can be used for the determination of four residual organic solvents in erlotinib hydrochloride .
