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The Tuberculosis Drug Accelerator, an experiment designed to facilitate collaboration in tuberculosis drug discovery by breaking down barriers among competing labs and institutions, has reached a 10-year landmark. We review the consortium’s achievements, advantages and limitations and advocate for the application of similar models to other diseases.

Nucleotide analogs targeting viral RNA polymerase have been proved to be an effective strategy for antiviral treatment and are promising antiviral drugs to combat the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. In this study, we developed a robust in vitro nonradioactive primer extension assay to quantitatively evaluate the efficiency of incorporation of nucleotide analogs by SARS-CoV-2 RNA-dependent RNA polymerase (RdRp). Our results show that many nucleotide analogs can be incorporated into RNA by SARS-CoV-2 RdRp and that the incorporation of some of them leads to chain termination., Nucleotide analogs targeting viral RNA polymerase have been proved to be an effective strategy for antiviral treatment and are promising antiviral drugs to combat the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. In this study, we developed a robust in vitro nonradioactive primer extension assay to quantitatively evaluate the efficiency of incorporation of nucleotide analogs by SARS-CoV-2 RNA-dependent RNA polymerase (RdRp). Our results show that many nucleotide analogs can be incorporated into RNA by SARS-CoV-2 RdRp and that the incorporation of some of them leads to chain termination. The discrimination values of nucleotide analogs over those of natural nucleotides were measured to evaluate the incorporation efficiency of nucleotide analog by SARS-CoV-2 RdRp. In agreement with the data published in the literature, we found that the incorporation efficiency of remdesivir-TP is higher than that of ATP and incorporation of remdesivir-TP caused delayed chain termination, which can be overcome by higher concentrations of the next nucleotide to be incorporated. Our data also showed that the delayed chain termination pattern caused by remdesivir-TP incorporation is different for different template sequences. Multiple incorporations of remdesivir-TP caused chain termination under our assay conditions. Incorporation of sofosbuvir-TP is very low, suggesting that sofosbuvir may not be very effective in treating SARS-CoV-2 infection. As a comparison, 2′-C-methyl-GTP can be incorporated into RNA efficiently, and the derivative of 2′-C-methyl-GTP may have therapeutic application in treating SARS-CoV-2 infection. This report provides a simple screening method that should be useful for evaluating nucleotide-based drugs targeting SARS-CoV-2 RdRp and for studying the mechanism of action of selected nucleotide analogs.

Nucleotide analogs targeting viral RNA polymerase have been proved to be an effective strategy for antiviral treatment and are promising antiviral drugs to combat the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. In this study, we developed a robust in vitro nonradioactive primer extension assay to quantitatively evaluate the efficiency of incorporation of nucleotide analogs by SARS-CoV-2 RNA-dependent RNA polymerase (RdRp). Our results show that many nucleotide analogs can be incorporated into RNA by SARS-CoV-2 RdRp and that the incorporation of some of them leads to chain termination. The discrimination values of nucleotide analogs over those of natural nucleotides were measured to evaluate the incorporation efficiency of nucleotide analog by SARS-CoV-2 RdRp. In agreement with the data published in the literature, we found that the incorporation efficiency of remdesivir-TP is higher than that of ATP and incorporation of remdesivir-TP caused delayed chain termination, which can be overcome by higher concentrations of the next nucleotide to be incorporated. Our data also showed that the delayed chain termination pattern caused by remdesivir-TP incorporation is different for different template sequences. Multiple incorporations of remdesivir-TP caused chain termination under our assay conditions. Incorporation of sofosbuvir-TP is very low, suggesting that sofosbuvir may not be very effective in treating SARS-CoV-2 infection. As a comparison, 2'-C-methyl-GTP can be incorporated into RNA efficiently, and the derivative of 2'-C-methyl-GTP may have therapeutic application in treating SARS-CoV-2 infection. This report provides a simple screening method that should be useful for evaluating nucleotide-based drugs targeting SARS-CoV-2 RdRp and for studying the mechanism of action of selected nucleotide analogs.

Nucleotide analogs targeting viral RNA polymerase have been proved to be an effective strategy for antiviral treatment and are promising antiviral drugs to combat the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. In this study, we developed a robust

Using the HIV-1 protease binding mode of MK-8718 and PL-100 as inspiration, a novel aspartate binding bicyclic piperazine sulfonamide core was designed and synthesized. The resulting HIV-1 protease inhibitor containing this core showed an 60-fold increase in enzyme binding affinity and a 10-fold increase in antiviral activity relative to MK-8718.

Parasitic filarial nematodes cause debilitating infections in people in resource-limited countries. A clinically validated approach to eliminating worms uses a 4- to 6-week course of doxycycline that targetsWolbachia, a bacterial endosymbiont required for worm viability and reproduction. However, the prolonged length of therapy and contraindication in children and pregnant women have slowed adoption of this treatment. Here, we describe discovery and optimization of quinazolines CBR417 and CBR490 that, with a single dose, achieve >99% elimination ofWolbachiain the in vivoLitomosoides sigmodontisfilarial infection model. The efficacious quinazoline series was identified by pairing a primary cell-based high-content imaging screen with an orthogonal ex vivo validation assay to rapidly quantifyWolbachiaelimination inBrugia pahangifilarial ovaries. We screened 300,368 small molecules in the primary assay and identified 288 potent and selective hits. Of 134 primary hits tested, only 23.9% were active in the worm-based validation assay, 8 of which contained a quinazoline heterocycle core. Medicinal chemistry optimization generated quinazolines with excellent pharmacokinetic profiles in mice. Potent antiwolbachial activity was confirmed inL. sigmodontis,Brugia malayi, andOnchocerca ochengiin vivo preclinical models of filarial disease and in vitro selectivity againstLoa loa(a safety concern in endemic areas). The favorable efficacy and in vitro safety profiles of CBR490 and CBR417 further support these as clinical candidates for treatment of filarial infections.

A novel domino reaction for the preparation of non-racemic β-proline derivatives is reported. The addition of a methyl 2-(oxetan-3-yl)acetate titanium enolate to chiral tert-butanesulfinyl ketimines followed by an intramolecular oxetane ring-opening provides the highly-substituted pyrrolidine ring systems with three contiguous stereogenic centers.

The field of small-molecule inhibitors of protein–protein interactions is rapidly advancing and the specific area of inhibitors of the p53/MDM2 interaction is a prime example. Several groups have published on this topic and multiple compounds are in various stages of clinical development. Building on the strength of the discovery of RG7112, a Nutlin imidazoline-based compound, and RG7388, a pyrrolidine-based compound, we have developed additional scaffolds that provide opportunities for future development. Here, we report the discovery and optimization of a highly potent and selective series of spiroindolinone small-molecule MDM2 inhibitors, culminating in RO8994.

The offshore leakage oil accidents bring great harm to society, economy and ecology. The paper presents a new technology of reclaiming of offshore underwater leakage oil to achieve the aim of emergency treatment, which can improve the emergency speed to win some valuable time for marine casualty treatment, and meanwhile can reduce environmental pollution loss caused by the leakage oil. Designed two groups of physical model test, the test results show that: The technical principle is feasible in theory, and the flexible collection tank in stress has more advantage than the rigid one. It is very significant to promote marine oil spill emergency response ability, and also lays a solid foundation for further forming series of technology and equipments.

The development of 3-D modeling CAD system on production platforms is mainly discussed in this paper. A suitable petroleum platform design by using software is developed according to the design status of domestic production platforms and the principle of structural life cycle method. The research results have been successfully applied to the 3-D graphic design of production platforms. The design level of offshore platform has been remarkably raised and the design quality has been improved. The technology research on developing method, design analysis method, parameterized modeling method, information management method, version management and etc, and can also be applied to other engineering designs and have certain popularization value.

Pollution-free underwater oil storage model is raised, realizing zero-pollution underwater oil storage with oil-water replacement through flexible separation method to prevent crude oil from directly contacting seawater. Experiment on thermal insulation of underwater crude oil with separate replacement of oil and water was made, proving that high pour point crude oil does not change significantly within a time and still possesses a good liquidity. Therefore, it is feasible to apply this underwater oil storage system to the storage of high pour point crude oil.

This paper analyzes the stability and structural optimization of self-elevating platform pile foundation, preliminarily discusses the method of analyzing the bearing capacity of the layer soil foundation, and establishes the numerical computation models for the whole platform, pile, pile shoe, etc. Besides, through these analyses, the pile structure is optimized, and the stress concentration in the joint between pile and pile shoe is reduced. Also, this study is of reference value for the analysis on the self-elevating platform pile foundation design and the platform operation stability.

With the rapid development of offshore oil and gas exploitation and production at marginal oilfields, production facilities of non-pollution oil storage underwater are sorely needed to reduce production costs. The paper gives a general outline of the modes of offshore oil Storage and the status of oil Storage technology underwater. Several modes of oil storage underwater on oil/water separation and replacement are discussed. The scheme on the monitoring system of non-pollution oil storage underwater is put forward. The study is of reference value for the development at offshore marginal oilfields.

The cyclin-dependent protein kinases are key regulators of cell cycle progression. Aberrant expression or altered activity of distinct cyclin-dependent kinase (CDK) complexes results in escape of cells from cell cycle control, leading to unrestricted cell proliferation. CDK inhibitors have the potential to induce cell cycle arrest and apoptosis in cancer cells, and identifying small-molecule CDK inhibitors has been a major focus in cancer research. Several CDK inhibitors are entering the clinic, the most recent being selective CDK2 and CDK4 inhibitors. We have identified a diaminopyrimidine compound, R547, which is a potent and selective ATP-competitive CDK inhibitor. In cell-free assays, R547 effectively inhibited CDK1/cyclin B, CDK2/cyclin E, and CDK4/cyclin D1 (Ki = 1–3 nmol/L) and was inactive (Ki > 5,000 nmol/L) against a panel of >120 unrelated kinases. In vitro, R547 effectively inhibited the proliferation of tumor cell lines independent of multidrug resistant status, histologic type, retinoblastoma protein, or p53 status, with IC50s ≤ 0.60 μmol/L. The growth-inhibitory activity is characterized by a cell cycle block at G1 and G2 phases and induction of apoptosis. R547 reduced phosphorylation of the cellular retinoblastoma protein at specific CDK phosphorylation sites at the same concentrations that induced cell cycle arrest, suggesting a potential pharmacodynamic marker for clinical use. In vivo, R547 showed antitumor activity in all of the models tested to date, including six human tumor xenografts and an orthotopic syngeneic rat model. R547 was efficacious with daily oral dosing as well as with once weekly i.v. dosing in established human tumor models and at the targeted efficacious exposures inhibited phosphorylation of the retinoblastoma protein in the tumors. The selective kinase inhibition profile and the preclinical antitumor activity of R547 suggest that it may be promising for development for use in the treatment of solid tumors. R547 is currently being evaluated in phase I clinical trials. [Mol Cancer Ther 2006;5(11):2644–58]

The cyclin-dependent kinases (CDKs) and their cyclin partners are key regulators of the cell cycle. Since deregulation of CDKs is found with high frequency in many human cancer cells, pharmacological inhibition of CDKs with small molecules has the potential to provide an effective strategy for the treatment of cancer. The 2,4-diamino-5-ketopyrimidines 6 reported here represent a novel class of potent and ATP-competitive inhibitors that selectively target the cyclin-dependent kinase family. This diaminopyrimidine core with a substituted 4-piperidine moiety on the C2-amino position and 2-methoxybenzoyl at the C5 position has been identified as the critical structure responsible for the CDK inhibitory activity. Further optimization has led to a good number of analogues that show potent inhibitory activities against CDK1, CDK2, and CDK4 but are inactive against a large panel of serine/threonine and tyrosine kinases (K(i)10 microM). As one of these representative analogues, compound 39 (R547) has the best CDK inhibitory activities (K(i) = 0.001, 0.003, and 0.001 microM for CDK1, CDK2, and CDK4, respectively) and excellent in vitro cellular potency, inhibiting the growth of various human tumor cell lines including an HCT116 cell line (IC(50) = 0.08 microM). An X-ray crystal structure of 39 bound to CDK2 has been determined in this study, revealing a binding mode that is consistent with our SAR. Compound 39 demonstrates significant in vivo efficacy in the HCT116 human colorectal tumor xenograft model in nude mice with up to 95% tumor growth inhibition. On the basis of its superior overall profile, 39 was chosen for further evaluation and has progressed into Phase I clinical trial for the treatment of cancer.

Using nuclear magnetic resonance (NMR) spectroscopy, we have determined the solution structures for a series of potent agonists for the human melanocortin-4 receptor (hMC4R), based on the cyclic peptide MT-II [Ac-Nle-cyclo-(Asp-Lys) (Asp-His-(D)Phe-Arg-Trp-Lys)-NH 2 ]. Members of this series were designed to improve selectivity for MC4R versus the other melanocortin receptors, and to reduce the flexibility of the side chains. The most selective and rigid analog [penta-cyclo(D-K)-Asp-Apc-(D)Phe-Arg-(2 S ,3 S )-β-methylTrp-Lys-NH 2 ] was found to be a full agonist of hMC4R with an EC 50 of 11 nM against hMC4R, and to exhibit 65-fold selectivity against hMC1R. This compound represents the most constrained hMC4R peptide agonist described to date. A β-turn structure was conserved among all of the cyclic peptides studied. The rigidity of the analogs allowed an exceptionally well-defined pharmacophore model to be derived. This model was used to perform a virtual screen using a library of 1000 drug-like compounds, to which a small set of known potent ligands had been intentionally added. The utility of the model was validated by its ability to identify the known ligands from among this large library.

A series of MT-II related cyclic peptides, based on potent but non-selective hMC4R agonist (Penta-c[Asp-His(6)-DPhe(7)-Arg(8)-Trp(9)-Lys]-NH(2)) was prepared in which His(6) residue was systematically substituted. Two of the most interesting peptides identified in this study are Penta-c[Asp-5-ClAtc-DPhe-Arg-Trp-Lys]-NH(2) and Penta-c[Asp-5-ClAtc-DPhe-Cit-Trp-Lys]-NH(2) which are potent hMC4R agonists and are either inactive or weak partial agonists (not tested for their antagonist activities) in hMC1R, hMC3R and hMC5R agonist assays.

A number of valuable new synthetic strategies, such as the triazene-driven biaryl ether synthesis, have been developed during the total synthesis of vancomycin (1). Modern catalytic asymmetric reactions were employed for the construction of the required amino acid building blocks, which were then assembled to the appropriate peptide fragments, whose cyclization in the order C-O-D→AB/C-O-D→AB/C-O-D-E led to framework of the vancomycin aglycon (2). Sequential attachment of the required sugar moieties onto a suitably protected aglycon derivative, followed by deprotection, allowed the stereoselective total synthesis of the glycopeptide antibiotic vancomycin (1).

Dissection of brevetoxin A at the nine-membered ring site (ring E) formed the basis of the first generation strategy for the total synthesis of this molecule. Unfortuately the planned hydroxy dithioketal cyclization to form the crucial nonacene did not proceed as anticipated and this approach was discontinued.

A first total synthesis and structural revision of chromomoric acid D-I methyl ester 1 were described. Addition of organolithium reagent 13 to epoxy ketone 10 followed by regio- and stereospecific reductive ring opening afforded diol 16 which, after PDC oxidation and aldol condensation, gave rise to dienone 19. Sequential desilylation, oxidation, esterification and thermolysis provided precursor 24 which was then converted to 1, resulting in the revision of the originally postulated structures.

The development of small-molecule MDM2 inhibitors to restore dysfunctional p53 activities represents a novel approach for cancer treatment. In a previous communication, the efforts leading to the identification of a non-imidazoline MDM2 inhibitor, RG7388, was disclosed and revealed the desirable in vitro and in vivo pharmacological properties that this class of pyrrolidine-based inhibitors possesses. Given this richness and the critical need for a wide variety of chemical structures to ensure success in the clinic, research was expanded to evaluate additional derivatives. Here we report two new potent, selective, and orally active p53-MDM2 antagonists, RO5353 and RO2468, as follow-ups with promising potential for clinical development.

Restoration of p53 activity by inhibition of the p53–MDM2 interaction has been considered an attractive approach for cancer treatment. However, the hydrophobic protein–protein interaction surface represents a significant challenge for the development of small-molecule inhibitors with desirable pharmacological profiles. RG7112 was the first small-molecule p53–MDM2 inhibitor in clinical development. Here, we report the discovery and characterization of a second generation clinical MDM2 inhibitor, RG7388, with superior potency and selectivity.

A convenient total synthesis of chromomoric acid B methyl ester 1 and the first synthesis of chromomoric acid F methyl ester 2 have been described. A one-pot Michael addition-enolate trapping sequence afforded ketone 5 which after a few steps was converted to 1 . Retro Diels-Alder reaction of ester 7 afforded enone 9 which was then transformed to the target molecule 2 through hydrogenation and α-hydroxylation.

Stereospecific total synthesis of chromomoric acid C-I and C-II methyl esters and delicate elucidation of their structures have been reported. A stereospecific five-step synthesis, starting from enone 5, with one-pot three-component coupling and retro Diels-Alder reaction as the key reactions provided a target molecule which was proved to be chromomoric acid C-I methyl ester (1), but its physical data were identical with that of the natural product originally assigned to be chromomoric acid C-IV methyl ester (4). Structural elucidation with a lanthanide shift reagent showed the original assignment should be revised to 1. Total synthesis and structural confirmation of chromomoric acid C-II methyl ester (2) was thereafter fulfilled.

A series of pyrimidodiazepines was identified as potent Polo-like kinase 1 (PLK1) inhibitors. The synthesis and SAR are discussed. The lead compound 7 (RO3280) has potent inhibitory activity against PLK1, good selectivity against other kinases, and excellent in vitro cellular potency. It showed strong antitumor activity in xenograft mouse models.

Regio- and stereo-specific reduction of the exo-epoxy alcohol 5 with LiAID4 produced the 4α-D-trans-3,5-diol 7 and the 4β-D-trans-3,5-diol 8 in varying ratios, an indication that in spite of epoxide rearrangement between 5 and 6 direct epoxide ring-opening of 5 to afford the 3,5-diol 4 is the primary pathway.

Regio- and stereo-specific reduction of the exo-epoxy alcohol 5 with LiAID4 produced the 4α-D-trans-3,5-diol 7 and the 4β-D-trans-3,5-diol 8 in varying ratios, an indication that in spite of epoxide rearrangement between 5 and 6 direct epoxide ring-opening of 5 to afford the 3,5-diol 4 is the primary pathway.

Dissection of brevetoxin A at the nine-membered ring site (ring E) formed the basis of the first generation strategy for the total synthesis of this molecule. Unfortuately the planned hydroxy dithioketal cyclization to form the crucial nonacene did not proceed as anticipated and this approach was discontinued.

Two libraries of hMC4R agonists, X-Y-DPhe(7)-Arg(8)-2-Nal(9)-Z-NH(2) and X-Y-DPhe(7)-Arg(8)-Trp(9)-Z-NH(2), totaling 185 peptides were prepared using Irori radiofrequency tagging technology and Argonaut Quest 210 Synthesizer, where X stands for N-caps, Y for His(6) surrogates and Z for Gly(10) surrogates. As a result of this study, His-modified pentapeptides with Trp were found to be more hMC4R potent than the corresponding 2-Nal analogs, novel N-caps and Gly surrogates were identified and 19 new peptides which are potent hMC4R agonists (EC(50) 1-15nM) and selective against hMC1R were discovered.

Linear pentapeptides (Penta-cis-Apc-DPhe-Arg-Trp-Gly-NH2) containing 1-amino-4-phenylcyclohexane-1-carboxylic acid (cis-Apc) and substituted Apc are potent hMC4R agonists and they are inactive or weakly active in hMC1R, hMC3R, and hMC5R agonist assays. This study, together with our earlier report on 5-BrAtc, demonstrated the importance of replacing His6 with phenyl-containing rigid templates in achieving good hMC4R agonist potency and selectivity against hMC1R in linear pentapeptides.

A series of pentapeptides, based on hMC4R pentapeptide agonist (Bu-His(6)-DPhe(7)-Arg(8)-Trp(9)-Gly(10)-NH(2)), was prepared in which either DPhe(7) or Trp(9) residue was systematically substituted. A number of interesting DPhe surrogates (D-Thi, D-3-CF(3)Phe, D-2-Nal and D-3,4-diClPhe) as well as Trp surrogates (2-Nal and Bta) were identified in this study.

Systematic substitution of His(6) residue using non-selective hMC4R pentapeptide agonist (Bu-His(6)-DPhe(7)-Arg(8)-Trp(9)-Gly(10)-NH(2)) as the template led to the identification of Bu-Atc(6)(2-aminotetraline-2-carboxylic acid)-DPhe(7)-Arg(8)-Trp(9)-Gly(10)-NH(2) which showed moderate selectivity towards hMC4R over hMC1R. Further SAR studies resulted in the discovery of Penta-5-BrAtc(6)-DPhe(7)-Arg(8)-Trp(9)-Gly(10)-NH(2) and Penta-5-Me(2)NAtc(6)-DPhe(7)-Arg(8)-Trp(9)-Gly(10)-NH(2) which are potent hMC4R agonists and are inactive in hMC1R, hMC3R and hMC5R agonist assays.

Melanocortin (MC) peptides α-, β-, and γ-MSH and adreno-corticotropic hormone (ACTH) are a group of neuropeptides derived from pro-opiomelanocortin hormone (POMC). The physiological actions of these peptides are mediated through five (MCR-1–5) seven-transmembrane G-protein-coupled receptor subtypes. The MSH peptides have been implicated in numerous biological functions [1] including regulation of skin pigmentation, regulation of steroid production, modulation of the immune response, thermo-regulation and obesity [2]. Clarification of the role of melanocortin receptor subtypes, in particular the recently discovered MC-3, MC-4 and MC-5 receptors, has been hampered by the lack of selective peptide ligands. However, recent studies on MCR knockout animals demonstrated that the MC-4 receptor is involved in regulation of feeding. MCR-4 knockout mice display an obesity phenotype that includes maturity onset obesity, hyperglycemia, and hyperinsulinemia. Moreover, it has been reported that a non-selective cyclic MCR-4 peptide agonist (MT II) inhibits food intake when given icv to mice [3]. Consequently, a potent and selective MC-4R agonist is regarded as potentially useful in therapeutic approaches to obesity management. The goal of this work was to identify a selective MCR-4 cyclic peptide agonist for use as a pharmacological tool in obesity and feeding studies and to develop a pharmacophore model applicable to structure-based drug design.