Virtual screening can be a helpful approach to propose treatments for COVID-19 by developing inhibitors for blocking the attachment of the virus to human cells. This study uses molecular docking, recovery time and dyn...Virtual screening can be a helpful approach to propose treatments for COVID-19 by developing inhibitors for blocking the attachment of the virus to human cells. This study uses molecular docking, recovery time and dynamics to analyze if potential inhibitors of main protease (M<sup>pro</sup>) of SARS-CoV-2 can interfere in the attachment of nanobodies, specifically Nb20, in the receptor binding domain (RBD) of SARS-CoV-2. The potential inhibitors are four compounds previously identified in a fluorescence resonance energy transfer (FRET)-based enzymatic assay for the SARS-CoV-2 M<sup>pro</sup>: Boceprevir, Calpain Inhibitor II, Calpain Inhibitor XII, and GC376. The findings reveal that Boceprevir has the higher affinity with the RBD/Nb20 complex, followed by Calpain Inhibitor XII, GC376 and Calpain Inhibitor II. The recovery time indicates that the RBD/Nb20 complex needs a relatively short time to return to what it was before the presence of the ligands. For the RMSD the Boceprevir and Calpain Inhibitor II have the shortest interaction times, while Calpain Inhibitor XII shows slightly more interaction, but with significant pose fluctuations. On the other hand, GC376 remains stably bound for a longer duration compared to the other compounds, suggesting that they can potentially interfere with the neutralization process of Nb20.展开更多
目的:荆防颗粒是新型冠状病毒肺炎预防及轻症治疗的推荐用药,本文结合化学成分分析及活性检测,阐明其潜在的活性成分。方法:采用酶学方法测定荆防颗粒提取物对新型冠状病毒3-chymotrypsin-like protease(3CL^(pro))、papain like protea...目的:荆防颗粒是新型冠状病毒肺炎预防及轻症治疗的推荐用药,本文结合化学成分分析及活性检测,阐明其潜在的活性成分。方法:采用酶学方法测定荆防颗粒提取物对新型冠状病毒3-chymotrypsin-like protease(3CL^(pro))、papain like protease(PL^(pro))、spike protein receptor-binding domain(S-RBD)及人cyclooxygenase-2(COX-2)的抑制活性,利用氨水引咳小鼠模型测试其止咳作用;基于liquid chromatography-mass spectrometry(LC/MS)技术对荆防颗粒进行化学成分定性、定量分析,阐明其化学组成;采用酶学实验、分子对接、定点突变等方法测定荆防颗粒中抑制3CL^(pro)、PL^(pro)的主要活性成分并阐明可能的作用机制。结果:荆防颗粒提取物对新型冠状病毒3CL^(pro)、PL^(pro)蛋白酶具有一定的抑制作用,且具有COX-2抑制活性及止咳药效。进一步在荆防颗粒鉴定了56个成分,其中16个成分经与对照品比对,准确鉴定其化学结构,并测定了其含量,总量为2498.8μg/g。16个成分中的主要成分升麻素苷对3CL^(pro)和PL^(pro)均具有显著的抑制活性,8μmol/L的抑制率分别为76.8%和78.2%;新橙皮苷、柚皮苷对PL^(pro)有抑制活性,8μmol/L的抑制率分别为53.5%和46.1%。分子对接结果表明,升麻素苷可与3CL^(pro)、PL^(pro)活性口袋的氨基酸残基形成氢键,结合能分别为-7.7和-7.3 kcal/mol。定点突变结果表明,氨基酸残基K157是升麻素苷与PL^(pro)相互作用的重要活性位点。结论:荆防颗粒的主要成分升麻素苷、新橙皮苷、柚皮苷等具有抑制新型冠状病毒3CL^(pro)及PL^(pro)的活性,为荆防颗粒的临床合理使用提供了依据。展开更多
为了探索除草剂Tiafenacil在防治农业杂草方面的应用前景,以3-氨基-4,4,4-三氟丁烯酸乙酯为原料,经6步反应制备得到Tiafenacil,其结构经1H NMR和ESI-MS确证,并对Tiafenacil进行除草活性测定。结果表明:Tiafenacil在苗前浓度为300 g a.i....为了探索除草剂Tiafenacil在防治农业杂草方面的应用前景,以3-氨基-4,4,4-三氟丁烯酸乙酯为原料,经6步反应制备得到Tiafenacil,其结构经1H NMR和ESI-MS确证,并对Tiafenacil进行除草活性测定。结果表明:Tiafenacil在苗前浓度为300 g a.i.·hm^(-2)条件下,其对稗草、苘麻的除草活性均优于对照药剂97%莠去津原药;在苗前浓度为75 g a.i.·hm^(-2)条件下,其对稗草、苘麻的除草活性均优于对照药剂97%氟磺胺草醚原药。苗后浓度为37.5、75、150、300 g a.i.·hm^(-2)条件下,其对稗草、金色狗尾草、百日草、苘麻的除草活性均可达100%,明显优于对照药剂97%氟磺胺草醚原药和97%莠去津原药。展开更多
SARS CoV 3CL^pro is known to be a promising target for development of therapeutic agents against the severe acute respiratory syndrome （SARS）. A quinolinone compound 1 was selected via virtual screening, and it was ...SARS CoV 3CL^pro is known to be a promising target for development of therapeutic agents against the severe acute respiratory syndrome （SARS）. A quinolinone compound 1 was selected via virtual screening, and it was syn- thetized and tested for enzymatic inhibition in vitro. Compound 1 showed potent inhibitory activity （ICs0= 0.44 μmol/L） toward SARS CoV 3CL^pro. Further work on a series of quinolinone derivatives resulted in the discovery of the most potent compound 23, inhibiting SARS CoV 3CL^pro with an IC50 of 36.86 μmol/L. The structure-activity relationships were also discussed.展开更多
目的比较温阳法、滋阴法、活血法及复合法对肾阳虚型心力衰竭大鼠心室重构(ventricular re-modeling,VR)及心功能的影响。方法采用切除双侧甲状腺组织后持续静脉滴注阿霉素的方法制备心肾阳虚型心力衰竭大鼠模型。随机分为模型组生理盐...目的比较温阳法、滋阴法、活血法及复合法对肾阳虚型心力衰竭大鼠心室重构(ventricular re-modeling,VR)及心功能的影响。方法采用切除双侧甲状腺组织后持续静脉滴注阿霉素的方法制备心肾阳虚型心力衰竭大鼠模型。随机分为模型组生理盐水6mL/(kg·d)灌胃、温阳组温阳健心灵浸膏6mL/(kg·d)灌胃、活血组川芎丹参浸膏6mL/(kg·d)灌胃、滋阴组麦冬知母浸膏6mL/(kg·d)灌胃及复合组阴阳双补健心浸膏6mL/(kg·d)灌胃,每组10只。另选取10只大鼠作为正常对照组(正常组),自由饮食饮水。各组连续干预4周。观察大鼠左心室收缩压(left ventricular systolic pressure,LVSP)、左心室舒张末压(left ventricular end diastolic pressure,LVEDP)、左心室内压最大上升和下降速率maximal rate of left ventricular pressure of development(+dp/dtmax) and maximal rate of left ventricular pressure of decline(-dp/dtmax),测量动脉收缩压(systolic blood pressure,SBP)及舒张压(diastolic blood pressure,DBP),计算平均动脉压(mean arterial pressure,MAP),记录心率(heart rate,HR)。称取心脏质量(heart mass,HM)、左心室(包含室间隔)质量(left ventricular mass,LVM)及右心室质量(right ventricular mass,RVM),计算心脏质量指数(heart mass index,HMI)和左心室质量指数(left ventricular mass index,LVMI)。采用RT-PCR法测定大鼠心肌基质金属蛋白酶9(Matrix metalloproteinase-9,MMP-9)、组织金属蛋白酶抑制剂-1(tissue inhibitors of matrixmetalloproteinase-1,TIMP-1)mRNA表达。采用双抗体夹心ELISA法测定血清MMP-9、TIMP-1、N末端脑钠肽(N-terminal pro-brain natriuretic peptide,NT-proBNP)的含量。结果与正常组比较,模型组HR、LVEDP、HM、LVM、HMI、RVM、LVMI、NT-proBNP、MMP-9含量及MMP-9mRNA升高,SBP、DBP、MAP、LVSP、±dp/dtmax、TIMP-1含量及TIMP-1mRNA降低,差异均有统计学意义(P<0.05)。与模型组比较,温阳组SBP、DBP及±dp/dtmax升高,LVEDP、NT-proBNP、MMP-9降低;活血组HR、LVEDP、HM、LVM、HMI、RVM、LVMI、MMP-9mRNA、NT-proBNP、MMP-9含量均降低,±dp/dtmax、TIMP-1mRNA升高;复合组HR、LVEDP、±dp/dtmax、LVMI、NT-proBNP、MMP-9降低,TIMP-1升高;差异均有统计学意义(P<0.05)。与温阳组比较,滋阴组SBP及+dp/dtmax降低,活血组HR、MMP-9mRNA降低,复合组HR降低,差异均有统计学意义(P<0.05)。其余各指标组间比较,差异无统计学意义(P>0.05)。结论活血法及复合法调节肾阳虚型心力衰竭大鼠MMP-9、TIMP-1表达,有效减轻VR,改善心功能。展开更多
文摘Virtual screening can be a helpful approach to propose treatments for COVID-19 by developing inhibitors for blocking the attachment of the virus to human cells. This study uses molecular docking, recovery time and dynamics to analyze if potential inhibitors of main protease (M<sup>pro</sup>) of SARS-CoV-2 can interfere in the attachment of nanobodies, specifically Nb20, in the receptor binding domain (RBD) of SARS-CoV-2. The potential inhibitors are four compounds previously identified in a fluorescence resonance energy transfer (FRET)-based enzymatic assay for the SARS-CoV-2 M<sup>pro</sup>: Boceprevir, Calpain Inhibitor II, Calpain Inhibitor XII, and GC376. The findings reveal that Boceprevir has the higher affinity with the RBD/Nb20 complex, followed by Calpain Inhibitor XII, GC376 and Calpain Inhibitor II. The recovery time indicates that the RBD/Nb20 complex needs a relatively short time to return to what it was before the presence of the ligands. For the RMSD the Boceprevir and Calpain Inhibitor II have the shortest interaction times, while Calpain Inhibitor XII shows slightly more interaction, but with significant pose fluctuations. On the other hand, GC376 remains stably bound for a longer duration compared to the other compounds, suggesting that they can potentially interfere with the neutralization process of Nb20.
文摘目的:荆防颗粒是新型冠状病毒肺炎预防及轻症治疗的推荐用药,本文结合化学成分分析及活性检测,阐明其潜在的活性成分。方法:采用酶学方法测定荆防颗粒提取物对新型冠状病毒3-chymotrypsin-like protease(3CL^(pro))、papain like protease(PL^(pro))、spike protein receptor-binding domain(S-RBD)及人cyclooxygenase-2(COX-2)的抑制活性,利用氨水引咳小鼠模型测试其止咳作用;基于liquid chromatography-mass spectrometry(LC/MS)技术对荆防颗粒进行化学成分定性、定量分析,阐明其化学组成;采用酶学实验、分子对接、定点突变等方法测定荆防颗粒中抑制3CL^(pro)、PL^(pro)的主要活性成分并阐明可能的作用机制。结果:荆防颗粒提取物对新型冠状病毒3CL^(pro)、PL^(pro)蛋白酶具有一定的抑制作用,且具有COX-2抑制活性及止咳药效。进一步在荆防颗粒鉴定了56个成分,其中16个成分经与对照品比对,准确鉴定其化学结构,并测定了其含量,总量为2498.8μg/g。16个成分中的主要成分升麻素苷对3CL^(pro)和PL^(pro)均具有显著的抑制活性,8μmol/L的抑制率分别为76.8%和78.2%;新橙皮苷、柚皮苷对PL^(pro)有抑制活性,8μmol/L的抑制率分别为53.5%和46.1%。分子对接结果表明,升麻素苷可与3CL^(pro)、PL^(pro)活性口袋的氨基酸残基形成氢键,结合能分别为-7.7和-7.3 kcal/mol。定点突变结果表明,氨基酸残基K157是升麻素苷与PL^(pro)相互作用的重要活性位点。结论:荆防颗粒的主要成分升麻素苷、新橙皮苷、柚皮苷等具有抑制新型冠状病毒3CL^(pro)及PL^(pro)的活性,为荆防颗粒的临床合理使用提供了依据。
文摘为了探索除草剂Tiafenacil在防治农业杂草方面的应用前景,以3-氨基-4,4,4-三氟丁烯酸乙酯为原料,经6步反应制备得到Tiafenacil,其结构经1H NMR和ESI-MS确证,并对Tiafenacil进行除草活性测定。结果表明:Tiafenacil在苗前浓度为300 g a.i.·hm^(-2)条件下,其对稗草、苘麻的除草活性均优于对照药剂97%莠去津原药;在苗前浓度为75 g a.i.·hm^(-2)条件下,其对稗草、苘麻的除草活性均优于对照药剂97%氟磺胺草醚原药。苗后浓度为37.5、75、150、300 g a.i.·hm^(-2)条件下,其对稗草、金色狗尾草、百日草、苘麻的除草活性均可达100%,明显优于对照药剂97%氟磺胺草醚原药和97%莠去津原药。
文摘SARS CoV 3CL^pro is known to be a promising target for development of therapeutic agents against the severe acute respiratory syndrome （SARS）. A quinolinone compound 1 was selected via virtual screening, and it was syn- thetized and tested for enzymatic inhibition in vitro. Compound 1 showed potent inhibitory activity （ICs0= 0.44 μmol/L） toward SARS CoV 3CL^pro. Further work on a series of quinolinone derivatives resulted in the discovery of the most potent compound 23, inhibiting SARS CoV 3CL^pro with an IC50 of 36.86 μmol/L. The structure-activity relationships were also discussed.
文摘目的比较温阳法、滋阴法、活血法及复合法对肾阳虚型心力衰竭大鼠心室重构(ventricular re-modeling,VR)及心功能的影响。方法采用切除双侧甲状腺组织后持续静脉滴注阿霉素的方法制备心肾阳虚型心力衰竭大鼠模型。随机分为模型组生理盐水6mL/(kg·d)灌胃、温阳组温阳健心灵浸膏6mL/(kg·d)灌胃、活血组川芎丹参浸膏6mL/(kg·d)灌胃、滋阴组麦冬知母浸膏6mL/(kg·d)灌胃及复合组阴阳双补健心浸膏6mL/(kg·d)灌胃,每组10只。另选取10只大鼠作为正常对照组(正常组),自由饮食饮水。各组连续干预4周。观察大鼠左心室收缩压(left ventricular systolic pressure,LVSP)、左心室舒张末压(left ventricular end diastolic pressure,LVEDP)、左心室内压最大上升和下降速率maximal rate of left ventricular pressure of development(+dp/dtmax) and maximal rate of left ventricular pressure of decline(-dp/dtmax),测量动脉收缩压(systolic blood pressure,SBP)及舒张压(diastolic blood pressure,DBP),计算平均动脉压(mean arterial pressure,MAP),记录心率(heart rate,HR)。称取心脏质量(heart mass,HM)、左心室(包含室间隔)质量(left ventricular mass,LVM)及右心室质量(right ventricular mass,RVM),计算心脏质量指数(heart mass index,HMI)和左心室质量指数(left ventricular mass index,LVMI)。采用RT-PCR法测定大鼠心肌基质金属蛋白酶9(Matrix metalloproteinase-9,MMP-9)、组织金属蛋白酶抑制剂-1(tissue inhibitors of matrixmetalloproteinase-1,TIMP-1)mRNA表达。采用双抗体夹心ELISA法测定血清MMP-9、TIMP-1、N末端脑钠肽(N-terminal pro-brain natriuretic peptide,NT-proBNP)的含量。结果与正常组比较,模型组HR、LVEDP、HM、LVM、HMI、RVM、LVMI、NT-proBNP、MMP-9含量及MMP-9mRNA升高,SBP、DBP、MAP、LVSP、±dp/dtmax、TIMP-1含量及TIMP-1mRNA降低,差异均有统计学意义(P<0.05)。与模型组比较,温阳组SBP、DBP及±dp/dtmax升高,LVEDP、NT-proBNP、MMP-9降低;活血组HR、LVEDP、HM、LVM、HMI、RVM、LVMI、MMP-9mRNA、NT-proBNP、MMP-9含量均降低,±dp/dtmax、TIMP-1mRNA升高;复合组HR、LVEDP、±dp/dtmax、LVMI、NT-proBNP、MMP-9降低,TIMP-1升高;差异均有统计学意义(P<0.05)。与温阳组比较,滋阴组SBP及+dp/dtmax降低,活血组HR、MMP-9mRNA降低,复合组HR降低,差异均有统计学意义(P<0.05)。其余各指标组间比较,差异无统计学意义(P>0.05)。结论活血法及复合法调节肾阳虚型心力衰竭大鼠MMP-9、TIMP-1表达,有效减轻VR,改善心功能。
