Synthesis of 3,7—Disubstituted 1,4—Benzodiazepin—2—one

A series of 3-methoxycarbonylpropoxy-7-(imidazol-4-ylpropinamide)-1,3-dihydrogen-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2-ones,as farnesyltransferase(Ftase) inhibitors,were synthesized. The preparation of the key intermediate,7-amino-3-methoxycabonylpropoxy-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2-one,was improved.     

Synthesis of 1—（2′—Phenyl）cycloproply1—2,3—epoxypropan—1—ol as the Radical Precursor for the Kinetic Study of Oxiranylcarbinyl Radical

We have successfully synthesized 1-(2′-Phenyl)cycloproply1-2,3-epoxypropan-1-ol 3,which will be applied to the kinetics study of oxiranylcarbinyl radical.     

A Study on Inhibitors for the Prevention of Hydrate Formation in Gas Transmission Pipeline

Gas Hydrate is usually formed during the transportation and treatment of oil and gas, resulting in the plugging of gas pipeline and equipment. Three thermodynamic calculation formulas are analyzed to deal with this problem. The lowering of the freezing point of the inhibitors AT is used to calculate the formation temperature of natural gas hydrates. This is considered to be a good approach because it is not limited by what kind and what concentration of inhibitors one uses. Besides, the rate of lowering of the freezing point could be easily measured. The result of testing methanol and mono-ethylene glycol in a reactor shows that adding 10% inhibitors to the reactor can prevent the hydrates formation. Kinetic inhibitors are favored in the present research. They are divided into two types, polymer and surface-active agents. Their characteristics, mechanisms, and application prospect are separately discussed. Polymer inhibitors exhibit better efficiency. The result of field application of VC-713 inhibiter is also given in this article. In practice, the combination of thermodynamic inhibitors and kinetic inhibitors gives better result.     

Metal Ion Enhanced Phosphorescence of 2,3—Naphtho—10—aza—15—crown—5：A Possible Molecular Photonic Operator

A novel crown ether,2,3-naphtho-10-aza-15-crown-5(NAC) was synthesized.This compound does not show strong fluorescence and phosphorescence due to photoinduced intramolecular electron transfer from the nitrogen lone pair of electrons to the singlet excited state of the naphthalene chromophore.Complexation with heavy-metal ions results in the quenching of the fluorescence and enhancement of the phosphorescence significantly.These observations were interpreted in terms of the binding interactions,between the nitrogen lone pair electrons and the metal cation,which prevent photoinduced intramolecular electron transfer,and the heavy-atom effects which induce quenching of the fluorescence and enhancement of the phosphorescence.These azacrown and heavy-metalbased systems could be useful as potential chemical sensors and molecular photonic devices.     

Synthesis of 5—Aryl—1,2—dihydro—1—pyrrolizinones

In order to search for new potent anti-inflammatory and analgesic agents in pyrrolizinones,the title compounds were designed and synthesized.A series of the compounds were prepared with two different synthetic schemes.Some of the compounds showed remarkable anti-inflammatory and/or analgesic activities on mice.     

Crystal and Molecular Structure of N—Phenyl 1—Methoxycarbonylmethyl—3—benzyl—1,2,3,4—tetrahydro—4—oxo—1,3,2—benzodiazaphosphorin—2—thiocarboxamide 2—Oxide

1 INTRODUCTIONOrganophosphorus compounds are ubiquitous in nature and they have broad applications in the fields of agriculture and medicine. During the past two decades, (-ketophosphonates and their derivatives containing sulfur have attracted considerable attention because these compounds are endowed with special physical, chemical and pharmacological properties due to the proximity of the carbonyl and the phosphoryl groups[1～8]. In the study on new pharmacenticals and agrochemicals, th…     

The Synthesis and Regioselective Hydrolysis of Dialkyl 2—Phenylfuran （an 2—Phenyltetrahydrofuran）—3,4—dicarboxylates

Dialkyl 2-phenylfuran (and 2-phenyltetrahydrofuran)-3,4-dicarboxylates (1,2,5-7), wich are potential precursors of the synthesis of furofuran and tetrahydrofurofuran lignans, can be selectively hydrolyzed to monoacid(3,8) by potassium hydroxide. The regioselective hydrolysis was affected significantly by the 2-phenyl group of the furan or tetrahydrofuran skeleton. The geometric structures of 3,8 and related compounds were elucidated and verified by NMR spectra.     

Investigation of Isomerization of 2—Seleno—1,3,2—diazaphospholidine Derivatives

For the first time the isomerization of 1,3,2-diazaphospholidine-2-sclenide dervatives in refluxing benzene in the presence of trace water was observed. The structures of isomerized products were determined by IR, ^1H NMR,^31P NMR, elemental analysis and X-ray crystallography. The mechanism of isomerization was also proposed.     

Synthesis and Biological Activities of 3—（2—Furyl）—4—aryl—1,2,4—triazole—5—thiones

A series of novel compounds 3-(2-furyl)-4-aryl-1,2,4-triazole-5-thiones have been synthesized.All the compounds were characterized by spectral data and elemental analysis. The preliminary biological test showed that some of them exhibited excellent plant-growth regulative activities.     

SYNTHESIS AND MOLECULAR STRUCTURE OF METHYL 1—BENZYL—6—PHENYLPIPERIDIN—2—ONE—5—CARBOXYLATE

<正> C20H21NO3,Mr=323.39,monoclinic, space group P21, a= 7. 338(2), b=15. 419(3),c=7. 515(1)A,β=95.98(1)°,V= 845. 7(2)A3,Dm(flotation in aq. KL)=1.267,Dx(Z=2)=1.270gcm-3,λ(MoKα)=0.71069A,μ=0.08cm-1,F(000)=344,T=295°K,final RF=0. 042 for 1651 observed reflections. The title compound was synthesized and established as the trans isomer, with the phenyl and carbomethoxy substituents occupying pseudo-axial and axial positions, respectively, of the piperidin-2-one ring in a half-chair conformation.     

Gold Metallodrugs to Target Coronavirus Proteins: Inhibitory Effects on the Spike-ACE2 Interaction and on PLpro Protease Activity by Auranofin and Gold Organometallics**

Gold complexes have a long tradition in medicine and for many examples antirheumatic, anticancer or anti-infective effects have been confirmed. Herein, we evaluated the lead compound Auranofin and five selected gold organometallics as inhibitors of two relevant drug targets of severe acute respiratory syndrome coronaviruses (SARS-CoV). The gold metallodrugs were effective inhibitors of the interaction of the SARS-CoV-2 spike protein with the angiotensin converting enzyme 2 (ACE2) host receptor and might thus interfere with the viral entry process. The gold metallodrugs were also efficient inhibitors of the papain-like protease (PLpro) of SARS-CoV-1 and SARS-CoV-2, which is a key enzyme in the viral replication. Regarding PLpro from SARS-CoV-2, the here reported inhibitors are among the very first experimentally confirmed examples with activity against this target enzyme. Importantly, the activity of the complexes against both PLpro enzymes correlated with the ability of the inhibitors to remove zinc ions from the labile zinc center of the enzyme. Taken together, the results of this pilot study suggest further evaluation of gold complexes as SARS-CoV antiviral drugs.     

Enhancing the Anticancer Potential of Targeting Tumor-Associated Metalloenzymes via VEGFR Inhibition by New Triazolo[4,3-a]pyrimidinone Acyclo C-Nucleosides Multitarget Agents

The role of metalloenzymes in tumor progression had broadened their application in cancer therapy. Of these, MMPs and CAs are validated druggable targets that share some pivotal signaling pathways. The majority of MMPs or CAs inhibitors are designed as single-target agents. Despite their transient efficacy, these agents are often susceptible to resistance. This set the stage to introduce dual inhibitors of correlated MMPs and CAs. The next step is expected to target the common vital signaling nodes as well. In this regard, VEGFR-2 is central to various tumorigenesis events involving both families, especially MMP-2 and CA II. Herein, we report simultaneous inhibition of MMP-2, CA II, and VEGFR-2 via rationally designed hybrid 1,2,4-triazolo[4,3-a]pyrimidinone acyclo C-nucleosides. The promising derivatives were nanomolar inhibitors of VEGFR-2 (8; IC₅₀ = 5.89 nM, 9; IC₅₀ = 10.52 nM) and MMP-2 (8; IC₅₀ = 17.44 nM, 9; IC₅₀ = 30.93 nM) and submicromolar inhibitors of CA II (8; IC₅₀ = 0.21 µM, 9; IC₅₀ = 0.36 µM). Docking studies predicted their binding modes into the enzyme active sites and the structural determinants of activity regarding substitution and regioselectivity. MTT assay demonstrated that both compounds were 12 folds safer than doxorubicin with superior anticancer activities against three human cancers recording single-digit nanomolar IC₅₀, thus echoing their enzymatic activities. Up to our knowledge, this study introduces the first in class triazolopyrimidinone acyclo C-nucleosides VEGFR-2/MMP-2/CA II inhibitors that deserve further investigation.     

新型酪氨酸激酶小分子抑制的三维药效团研究

通过CATALYST软件包得到了两类HER2抑制的三维药效团模型。尽管亚苄基丙二腈化合物和3-取代吲哚啉-2-酮系列化合物具有完全不同的骨架结构,但得到的药效团却具有共同的特性,这表明当这两类抑制剂和受体发生相互作用时,采用了相似的结合模式。共同的药效团模型包括一个氢键受体,一个氢键给体,一个脂肪类疏水团以及一个芳香类疏水团。根据药效团模型,我们还进行了三维构效关系的研究,结果表明得到的药效团模型具有很好的预测能力(线性回归系数R≈0.96)。药效团模型对于研究酪氨酸激酶小分子抑制剂的结构与活性关系,以及评估和预测此类未知化合物活性具人重要的意义。     

Identification of natural compounds targeting SARS-CoV-2 Mpro by virtual screening and molecular dynamics simulations

The SARS-CoV-2 main protease (Mpro) has been chosen as a conserved molecular target to develop broad-spectrum antiviral drugs. Using molecular docking and molecular dynamics (MD) simulations, a total of 5600 natural compounds available for virtual screening were tested to identify potential inhibitors of SARS-CoV-2 Mpro. As a result, three natural compounds (pentagalloylglucose, malonylawobanin and gnetin E dihydride) were found to be potential inhibitors of SARS-CoV-2, which confirms the theoretical and practical significance of this approach for the design of SARS-CoV-2 inhibitors.     

Chemical Proteomic Discovery of Isotype-Selective Covalent Inhibitors of the RNA Methyltransferase NSUN2

5-Methylcytosine (m⁵C) is an RNA modification prevalent on tRNAs, where it can protect tRNAs from endonucleolytic cleavage to maintain protein synthesis. The NSUN family (NSUN1-7 in humans) of RNA methyltransferases are capable of installing the methyl group onto the C⁵ position of cytosines in RNA. NSUNs are implicated in a wide range of (patho)physiological processes, but selective and cell-active inhibitors of these enzymes are lacking. Here, we use cysteine-directed activity-based protein profiling (ABPP) to discover azetidine acrylamides that act as stereoselective covalent inhibitors of human NSUN2. Despite targeting a conserved catalytic cysteine in the NSUN family, the NSUN2 inhibitors show negligible cross-reactivity with other human NSUNs and exhibit good proteome-wide selectivity. We verify that the azetidine acrylamides inhibit the catalytic activity of recombinant NSUN2, but not NSUN6, and demonstrate that these compounds stereoselectively disrupt NSUN2-tRNA interactions in cancer cells, leading to a global reduction in tRNA m⁵C content. Our findings thus highlight the potential to create isotype-selective and cell-active inhibitors of NSUN2 with covalent chemistry targeting a conserved catalytic cysteine.     

Molecular insight into the T798M gatekeeper mutation-caused acquired resistance to tyrosine kinase inhibitors in ErbB2-positive breast cancer

Human epidermal growth factor receptor 2 (ErbB2) is an attractive therapeutic target for metastatic breast cancer. The kinase has been clinically observed to harbor a gatekeeper mutation T798M in its active site, which causes acquired resistance to the first-line targeted breast cancer therapy with small-molecule tyrosine kinase inhibitors. Previously, several theories have been proposed to explain the molecular mechanism of gatekeeper mutation-caused drug resistance, such as blocking of inhibitor binding and increasing of ATP affinity. In the current study, the direct binding of three wild type-selective inhibitors (Lapatinib, AEE788 and TAK-285) and two wild type-sparing inhibitors (Staurosporine and Bosutinib) to the wild-type ErbB2 and its T798M mutant are investigated in detail by using rigorous computational analysis and binding affinity assay. Substitution of the polar threonine with a bulky methionine at residue 798 can impair and improve the direct binding affinity of wild type-selective and wild type-sparing inhibitors, respectively. Hindrance effect is responsible for the affinity decrease of wild type-selective inhibitors, while additional nonbonded interactions contribute to the affinity increase of wild type-sparing inhibitors, thus conferring selectivity to the inhibitors for mutant over wild type. The binding affinity of Staurosporine and Bosutinib to ErbB2 kinase domain is improved by 11.9-fold and 2.1-fold upon T798M mutation, respectively. Structural analysis reveals that a nonbonded network of S–π contact interactions (for Staurosporine) or an S-involving halogen bond (for Bosutinib) forms with the sulfide group of mutant Met798 residue.     

2-巯基苯并噻唑衍生物的合成进展

2-巯基苯并噻唑具有很好的经济价值.为了增强和完善2-巯基苯并噻唑的应用性能,通过将其作为一种中间体,与油溶性基团的活性元素结合在同一分子内,开发和研究了其一系列新型的具有良好性能的衍生物,可用作配体、染料、硫化促进剂、蛋白质酶抑制剂以及杀菌、除草和抗病毒药物.对通过包括苯环、巯基上的S、杂环上的N等3个位置上的取代或加成来合成这些衍生物的简单可行方法进行了综述.     

吡咯烷类胞液型磷脂酶A2抑制剂的比较分子力场分析

胞液型磷脂酶A2能引发关节炎，针对胞液型磷脂酶A2的抑制剂有可能成为治疗关节炎的特效药，因此引起了广泛的关注.文章对于吡咯烷类胞液型磷脂酶A2抑制剂进行了三维定量构效关系研究，利用比较分子力场分析构建了该类分子的定量构效关系，得到三维等值线图，为胞液型磷脂酶A2抑制剂的进一步改造提供了有益的启示.