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1.
Molecules ; 27(21)2022 Oct 26.
Article in English | MEDLINE | ID: mdl-36364101

ABSTRACT

Tripterygium wilfordii Hook. f. is a well-known traditional Chinese medicine used to treat autoimmune diseases. Sesquiterpene pyridine alkaloids (SPAs) are a major class of components found in this herb that have piqued the interest of researchers due to their complex and diverse structures as well as significant biological activities. In this study, ten new SPAs, wilfordatine A-J (1-10), were isolated from the roots of T. wilfordii, along with ten known analogues (11-20). Their structures were primarily elucidated by extensive 1D and 2D NMR spectroscopic analysis. To search for more immunosuppressive ingredients related to the clinical efficacy of T. wilfordii, the total alkaloids (TA) and compounds 4, 5, and 9-16 were tested for their inhibitory effects on nuclear factor-kappa B (NF-κB) pathway in Lipopolysaccharide (LPS) induced HEK293/NF-κB-Luc cells. Among them, TA, compounds 5, 11, and 16 showed potent immunosuppressive activity, with IC50 values of 7.25 µg/mL, 8.75 µM, 0.74 µM, and 15.66 µM, respectively, and no influence on the cell viability at a concentration of 100 µg/mL (TA) or 100 µM (5, 11, and 16). Accordingly, TA, 5, 11, and 16, especially 11, were identified as promising candidates for further investigation into their potential use as immunosuppressive agents.


Subject(s)
Alkaloids , Drugs, Chinese Herbal , Sesquiterpenes , Humans , Tripterygium/chemistry , NF-kappa B , HEK293 Cells , Sesquiterpenes/pharmacology , Sesquiterpenes/chemistry , Alkaloids/pharmacology , Alkaloids/chemistry , Drugs, Chinese Herbal/pharmacology , Drugs, Chinese Herbal/chemistry , Pyridines/pharmacology , Pyridines/chemistry , Immunosuppressive Agents/pharmacology
2.
Zhongguo Zhong Yao Za Zhi ; 47(16): 4292-4304, 2022 Aug.
Article in Chinese | MEDLINE | ID: mdl-36046855

ABSTRACT

Sesquiterpene pyridine alkaloids are important components in Tripterygium plants, possessing a wide range of pharmacological activities, such as anti-inflammation immunosuppression, anti-tumor, anti-virus, and deinsectization, and are of great research value. They are composed of highly oxidized dihydro-ß-furansquiterpene and pyridine dicarboxylic acid through ester bonds. According to the structural characteristics of pyridine dicarboxylic acid fragments, they can be divided into various structural subtypes. Up to now, more than 110 sesquiterpene pyridine alkaloids have been isolated and identified from Tripterygium plants. This study reviewed the structural features and spectral(i.e., UV, IR, MS, and NMR) characteristics of sesquiterpene pyridine alkaloids and summarized the structural elucidation process in detail to provide references for their further research and development.


Subject(s)
Alkaloids , Drugs, Chinese Herbal , Sesquiterpenes , Alkaloids/pharmacology , Drugs, Chinese Herbal/pharmacology , Molecular Structure , Pyridines/chemistry , Pyridines/pharmacology , Tripterygium/chemistry
3.
Pest Manag Sci ; 78(6): 2657-2666, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35355395

ABSTRACT

BACKGROUND: Fenpicoxamid and florylpicoxamid are picolinamide fungicides targeting the Qi site of the cytochrome bc1 complex, via their primary metabolites UK-2A and CAS-649, respectively. We explore binding interactions and resistance mechanisms for picolinamides, antimycin A and ilicicolin H in yeast by testing effects of cytochrome b amino acid changes on fungicide sensitivity and interpreting results using molecular docking. RESULTS: Effects of amino acid changes on sensitivity to UK-2A and CAS-649 were similar, with highest resistance associated with exchanges involving G37 and substitutions N31K and L198F. These changes, as well as K228M, also affected antimycin A, while ilicicolin H was affected by changes at G37 and L198, as well as Q22E. N31 substitution patterns suggest that a lysine at position 31 introduces an electrostatic interaction with neighbouring D229, causing disruption of a key salt-bridge interaction with picolinamides. Changes involving G37 and L198 imply resistance primarily through steric interference. G37 changes also showed differences between CAS-649 and UK-2A or antimycin A with respect to branched versus unbranched amino acids. N31K and substitution of G37 by large amino acids reduced growth rate substantially while L198 substitutions showed little effect on growth. CONCLUSION: Binding of UK-2A and CAS-649 at the Qi site involves similar interactions such that general cross-resistance between fenpicoxamid and florylpicoxamid is anticipated in target pathogens. Some resistance mutations reduced growth rate and could carry a fitness penalty in pathogens. However, certain changes involving G37 and L198 carry little or no growth penalty and may pose the greatest risk for resistance development in the field. © 2022 Society of Chemical Industry.


Subject(s)
Electron Transport Complex III , Fungicides, Industrial , Picolinic Acids , Amino Acids , Antimycin A/pharmacology , Cytochromes , Electron Transport Complex III/chemistry , Electron Transport Complex III/genetics , Fungicides, Industrial/chemistry , Fungicides, Industrial/pharmacology , Lactones/chemistry , Lactones/metabolism , Molecular Docking Simulation , Mutation , Picolinic Acids/metabolism , Pyridines/chemistry , Pyridines/metabolism , Saccharomyces cerevisiae/genetics
4.
Bioorg Med Chem ; 58: 116656, 2022 03 15.
Article in English | MEDLINE | ID: mdl-35183028

ABSTRACT

We report the synthesis of a range of symmetrical bis-benzimidazoles (BBZ) which possess anticancer and antibacterial activities. One of these BBZs has specific activity against Clostridium difficile and is currently in a phase 3 clinical evaluation as the drug ridinilazole. X-ray and computer modelling studies showed that BBZs typically exhibit high specificity for oligonucleotide sequences that occur in the minor groove of DNA.


Subject(s)
Anti-Bacterial Agents/pharmacology , Antineoplastic Agents/pharmacology , Benzimidazoles/pharmacology , Clostridium Infections/drug therapy , DNA/chemistry , Pyridines/pharmacology , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Benzimidazoles/chemical synthesis , Benzimidazoles/chemistry , Cell Proliferation/drug effects , Cell Survival/drug effects , Crystallography, X-Ray , Drug Screening Assays, Antitumor , Humans , Microbial Sensitivity Tests , Models, Molecular , Molecular Structure , Pyridines/chemistry
5.
Int J Mol Sci ; 23(3)2022 Jan 23.
Article in English | MEDLINE | ID: mdl-35163169

ABSTRACT

The antioxidant/pro-oxidant activity of drugs and dietary molecules and their role in the maintenance of redox homeostasis, as well as the implications in health and different diseases, have not yet been fully evaluated. In particular, the redox activity and other interactions of drugs with essential redox metal ions, such as iron and copper, need further investigation. These metal ions are ubiquitous in human nutrition but also widely found in dietary supplements and appear to exert major effects on redox homeostasis in health, but also on many diseases of free radical pathology. In this context, the redox mechanistic insights of mainly three prototype groups of drugs, namely alpha-ketohydroxypyridines (alpha-hydroxypyridones), e.g., deferiprone, anthraquinones, e.g., doxorubicin and thiosemicarbazones, e.g., triapine and their metal complexes were examined; details of the mechanisms of their redox activity were reviewed, with emphasis on the biological implications and potential clinical applications, including anticancer activity. Furthermore, the redox properties of these three classes of chelators were compared to those of the iron chelating drugs and also to vitamin C, with an emphasis on their potential clinical interactions and future clinical application prospects in cancer, neurodegenerative and other diseases.


Subject(s)
Antioxidants/pharmacology , Chelating Agents/chemistry , Transition Elements/chemistry , Anthraquinones/chemistry , Anthraquinones/pharmacology , Antioxidants/chemistry , Chelating Agents/pharmacology , Coordination Complexes/chemistry , Copper/chemistry , Doxorubicin/chemistry , Doxorubicin/pharmacology , Free Radicals/chemistry , Iron/chemistry , Iron Chelating Agents/chemistry , Iron Chelating Agents/pharmacology , Oxidation-Reduction/drug effects , Pyridines/chemistry , Pyridines/pharmacology , Reactive Oxygen Species/chemistry , Thiosemicarbazones/chemistry , Thiosemicarbazones/pharmacology
6.
Molecules ; 27(3)2022 Feb 07.
Article in English | MEDLINE | ID: mdl-35164367

ABSTRACT

The chemical investigation of the total alkaloid extract (TAE) of the stem bark of Araliopsis soyauxii (Rutaceae) afforded an unreported indolopyridoquinazoline (compound 1) along with nine previously known alkaloids 2-10. In addition, six semi-synthetic derivatives 3a-c, 4b, 5a and 6a were prepared by allylation and acetonidation of soyauxinium nitrate (5), edulinine (3), ribalinine (4) and arborinine (6). The structures and spectroscopic data of five of them are reported herein for the first time. The suggested mechanism for the formation of the new N-allylindolopyridoquinazoline 5a is presented. The structures of natural and derived compounds were determined employing extensive NMR and MS techniques. The absolute configuration of stereogenic centers in compounds 2-4 were determined using NOESY technique and confirmed by the single-crystal X-ray diffraction (SC-XRD) technique. The use of SC-XRD further enabled us to carry out a structural revision of soyauxinium chloride recently isolated from the same plant to soyauxinium nitrate (5). The TAE, fractions, compounds 1-7 and 9, and semi-synthetic derivatives 3a-c, 4b, 5a and 6a were evaluated for their cytotoxic activity towards the cervix carcinoma cell line KB-3-1. No significant activity was recorded for most of the compounds except for 9, which showed moderate activity against the tested cancer cell lines.


Subject(s)
Alkaloids/pharmacology , Antineoplastic Agents, Phytogenic/pharmacology , Plant Bark/chemistry , Plant Extracts/pharmacology , Rutaceae/chemistry , Uterine Cervical Neoplasms/drug therapy , Female , Humans , Indoles/chemistry , Pyridines/chemistry , Quinazolines/chemistry , Tumor Cells, Cultured
7.
Chem Biodivers ; 19(1): e202100500, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34784450

ABSTRACT

In this study, an efficient one-pot procedure for preparing a new series of pyrazolo[3,4-b]pyridine-fused pyrimidines was described. The target hybrids were developed through a three-component reaction of 3-amino-1H-pyrazolo[3,4-b]pyridine, benzaldehydes, and acetophenones (molar ratio 1 : 1 : 1). The best conditions for the previous reaction were 2.5 equivalents of barium hydroxide in DMF at 150 °C for 6 h. New bis(pyrimidines) were synthesized in high yields using a similar one-pot reaction protocol with some modifications. Thus, two equivalents of each of the appropriate acetophenones and 3-aminopyrazolopyridine were reacted with one equivalent of the appropriate bis(aldehydes). The reaction was carried out at 150 °C for 8 h using 4.5 equivalents of barium hydroxide in DMF. Repeating the previous reaction with the appropriate bis(acetyl) derivatives and benzaldehydes resulted in good yields of the target bis(pyrimidines). The in vitro cytotoxic activity of new pyrimidines against the MCF-7, HEPG2, and Caco2 cell lines was evaluated using the reference doxorubicin (IC50 values of 4.34-6.97 µM). Hybrid 6h had the best activity against Caco2 and MCF-7 cell lines, IC50 values of 12.62 and 14.50 µM, respectively. The IC50 values for hybrids 6c, 6e, and 6f against MCF-7 and Caco2 cell lines were 23.99-41.69 and 33.14-43.33 µM, respectively. Furthermore, hybrid 6e displayed IC50 value of 20.06 µM HEPG2 cell lines, while the hybrids 6c, 6f and 6h exhibited IC50 values ranging between 26.29-50.51 µM. Furthermore, hybrid 6e had an IC50 value of 20.06 µM for the HEPG2 cell lines, whereas hybrids 6c, 6f, and 6h had IC50 values ranging from 26.29 to 50.51 µM.


Subject(s)
Antineoplastic Agents/chemical synthesis , Barium Compounds/chemistry , Pyrazoles/chemistry , Pyridines/chemistry , Pyrimidines/chemistry , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Design , Drug Evaluation, Preclinical , Drug Screening Assays, Antitumor , Humans , Pyrazoles/chemical synthesis , Pyrazoles/pharmacology , Pyridines/chemical synthesis , Pyridines/pharmacology , Stereoisomerism , Structure-Activity Relationship
8.
Bioorg Med Chem ; 52: 116500, 2021 12 15.
Article in English | MEDLINE | ID: mdl-34801826

ABSTRACT

The accumulation of epigenetic alterations is one of the major causes of tumorigenesis. Aberrant DNA methylation patterns cause genome instability and silencing of tumor suppressor genes in various types of tumors. Therefore, drugs that target DNA methylation-regulating factors have great potential for cancer therapy. Ubiquitin-like containing PHD and RING finger domain 1 (UHRF1) is an essential factor for DNA methylation maintenance. UHRF1 is overexpressed in various cancer cells and down-regulation of UHRF1 in these cells reactivates the expression of tumor suppressor genes, thus UHRF1 is a promising target for cancer therapy. We have previously shown that interaction between the tandem Tudor domain (TTD) of UHRF1 and DNA ligase 1 (LIG1) di/trimethylated on Lys126 plays a key role in the recruitment of UHRF1 to replication sites and replication-coupled DNA methylation maintenance. An arginine binding cavity (Arg-binding cavity) of the TTD is essential for LIG1 interaction, thus the development of inhibitors that target the Arg-binding cavity could potentially repress UHRF1 function in cancer cells. To develop such an inhibitor, we performed in silico screening using not only static but also dynamic metrics based on all-atom molecular dynamics simulations, resulting in efficient identification of 5-amino-2,4-dimethylpyridine (5A-DMP) as a novel TTD-binding compound. Crystal structure of the TTD in complex with 5A-DMP revealed that the compound stably bound to the Arg-binding cavity of the TTD. Furthermore, 5A-DMP inhibits the full-length UHRF1:LIG1 interaction in Xenopus egg extracts. Our study uncovers a UHRF1 inhibitor which can be the basis of future experiments for cancer therapy.


Subject(s)
CCAAT-Enhancer-Binding Proteins/antagonists & inhibitors , DNA Ligase ATP/antagonists & inhibitors , Enzyme Inhibitors/pharmacology , Molecular Dynamics Simulation , Pyridines/pharmacology , Ubiquitin-Protein Ligases/antagonists & inhibitors , Animals , CCAAT-Enhancer-Binding Proteins/genetics , CCAAT-Enhancer-Binding Proteins/metabolism , Cell Line, Tumor , DNA Ligase ATP/metabolism , Dose-Response Relationship, Drug , Drug Evaluation, Preclinical , Enzyme Inhibitors/chemistry , Humans , Molecular Structure , Pyridines/chemistry , Structure-Activity Relationship , Ubiquitin-Protein Ligases/genetics , Ubiquitin-Protein Ligases/metabolism , Xenopus
9.
Bioorg Med Chem ; 52: 116515, 2021 12 15.
Article in English | MEDLINE | ID: mdl-34839161

ABSTRACT

Hierarchical virtual screening combined with ADME prediction and cluster analysis methods were used to identify influenza virus PB2 inhibitors with high activity, good druggability properties, and diverse structures. The 200,000 molecules in the ChemDiv core library were narrowed down to a final set of 97 molecules, of which six compounds were found to rescue cells from both H1N1 and H3N2 virus-induced CPE with EC50 values ranging from 5.81 µM to 42.77 µM, and could bind to the PB2 CBD of H1N1, with Kd values of 0.11 µM to 6.4 µM. The six compounds have novel structures and low molecular weight and are, thus, suitable serve as lead compounds for development as PB2 inhibitors. A receptor-based pharmacophore model was successfully constructed using key amino acid residues for the binding of inhibitors to PB2, provided by the MD simulations. This pharmacophore model suggested that to improve the activity of our active compounds, we should mainly focus on optimizing their existing structures with the aim of increasing their adaptability to the binding site, rather than adding chemical fragments to increase their binding to adjacent sites. This pharmacophore construction method facilitates the creation of a reasonable pharmacophore model without the need to fully understand the structure-activity relationships, and our descriptions provide a useful reference for similar research.


Subject(s)
Antiviral Agents/pharmacology , Influenza A Virus, H1N1 Subtype/drug effects , Influenza A Virus, H3N2 Subtype/drug effects , Molecular Dynamics Simulation , Pyridines/pharmacology , Pyrimidines/pharmacology , Pyrroles/pharmacology , Viral Proteins/antagonists & inhibitors , Antiviral Agents/chemistry , Dose-Response Relationship, Drug , Drug Evaluation, Preclinical , Microbial Sensitivity Tests , Molecular Structure , Pyridines/chemistry , Pyrimidines/chemistry , Pyrroles/chemistry , Structure-Activity Relationship , Viral Proteins/metabolism
10.
Cancer Lett ; 522: 238-254, 2021 12 01.
Article in English | MEDLINE | ID: mdl-34571084

ABSTRACT

The response rate of anti-PD therapy in most cancer patients remains low. Therapeutic drug and tumor-infiltrating lymphocytes (TILs) are usually obstructed by the stromal region within tumor microenvironment (TME) rather than distributed around tumor cells, thus unable to induce the immune response of cytotoxic T cells. Here, we constructed the cationic thermosensitive lipid nanoparticles IR780/DPPC/BMS by introducing cationic NIR photosensitizer IR-780 iodide (IR780) modified lipid components, thermosensitive lipid DPPC and PD-1/PD-L1 inhibitor BMS202 (BMS). Upon laser irradiation, IR780/DPPC/BMS penetrated into deep tumor, and reduced cancer-associated fibroblasts (CAFs) around tumor cells to remodel the spatial distribution of TILs in TME. Interestingly, the cationic IR780/DPPC/BMS could capture released tumor-associated antigens (TAAs), thereby enhancing the antigen-presenting ability of DCs to activate cytotoxic T lymphocytes. Moreover, IR780/DPPC/BMS initiated gel-liquid crystal phase transition under laser irradiation, accelerating the disintegration of lipid bilayer structure and leading to the responsive release of BMS, which would reverse the tumor immunosuppression state by blocking PD-1/PD-L1 pathway for a long term. This combination treatment can synergistically exert the antitumor immune response and inhibit the tumor growth and metastasis.


Subject(s)
B7-H1 Antigen/immunology , Liposomes/pharmacology , Neoplasms/drug therapy , Programmed Cell Death 1 Receptor/immunology , Acetamides/chemistry , Acetamides/pharmacology , B7-H1 Antigen/antagonists & inhibitors , CD8-Positive T-Lymphocytes/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Humans , Immune Tolerance/drug effects , Immunotherapy/methods , Indoles/chemistry , Indoles/pharmacology , Liposomes/chemistry , Low-Level Light Therapy , Lymphocytes, Tumor-Infiltrating/drug effects , Lymphocytes, Tumor-Infiltrating/radiation effects , Nanoparticles/chemistry , Neoplasms/immunology , Neoplasms/pathology , Neoplasms/radiotherapy , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Pyridines/chemistry , Pyridines/pharmacology , T-Lymphocytes, Cytotoxic/drug effects , T-Lymphocytes, Cytotoxic/radiation effects , Tumor Microenvironment/drug effects
11.
Molecules ; 26(16)2021 Aug 14.
Article in English | MEDLINE | ID: mdl-34443522

ABSTRACT

Five new thiohydantoin derivatives (1-5) were isolated from the rhizomes of Lepidium meyenii Walp. NMR (1H and 13C NMR, 1H-1H COSY, HSQC, and HMBC), HRESIMS, and ECD were employed for the structure elucidation of new compounds. Significantly, the structure of compound 1 was the first example of thiohydantoins with thioxohexahydroimidazo [1,5-a] pyridine moiety. Additionally, compounds 2 and 3 possess rare disulfide bonds. Except for compound 4, all isolates were assessed for neuroprotective activities in corticosterone (CORT)-stimulated PC12 cell damage. Among them, compound (-)-3 exhibited moderate neuroprotective activity (cell viability: 68.63%, 20 µM) compared to the positive control desipramine (DIM) (cell viability: 88.49%, 10 µM).


Subject(s)
Lepidium/chemistry , Neuroprotective Agents/chemistry , Plant Extracts/chemistry , Thiohydantoins/chemistry , Animals , Cell Survival/drug effects , Corticosterone/pharmacology , Desipramine/pharmacology , Humans , Neuroprotective Agents/pharmacology , PC12 Cells , Plant Extracts/pharmacology , Pyridines/chemistry , Rats , Thiohydantoins/isolation & purification
12.
Ecotoxicol Environ Saf ; 220: 112388, 2021 Sep 01.
Article in English | MEDLINE | ID: mdl-34091183

ABSTRACT

Given the key role of bees as indicators for environmental assessment, residues in bees and bee products have attracted great interest. In this regard, an improved, highly sensitive method for quantifying the insecticide pyriproxyfen and its four metabolites (4'-OH-Pyr, DPH-Pyr, 2-OH-PY, 4'-OH-POP) in honeybees, larvae, and bee products (honey, pollen, royal jelly and wax) should be established. For this purpose, we used ultra-performance liquid chromatography coupled with triple-quadrupole mass spectrometry for rapid quantification (≤5 min). Recoveries for various matrices ranged from 73.77% to 114.97%, with satisfactory intra-day and inter-day precision (relative standard deviations of 0.03-8.61% and 0.10-7.25%, respectively). The results demonstrated excellent linearity (R2 > 0.9903) with a limit of quantification of 1 µg/kg for six different matrices. We collected and analyzed 597 samples (honey, bees and wax) from four major beekeeping areas in China. Only 47 of these samples contained residues of pyriproxyfen and two of its metabolites (2-OH-PY, 4'-OH-Pyr), and high levels of contamination were found in bee samples (2-739 µg/kg), with substantive accumulation in wax (levels were 9.49% higher than in other samples). The result demonstrate that the method provides a reliable and convenient means of monitoring pyriproxyfen and its metabolites in bee products for better product quality, human health, and international commercial competition and also lays a foundation for risk assessment of potential pyriproxyfen contamination in China.


Subject(s)
Chromatography, High Pressure Liquid/methods , Honey/analysis , Pesticide Residues/chemistry , Pyridines/chemistry , Tandem Mass Spectrometry/methods , Animals , Bees , China , Chromatography, Liquid/methods , Fatty Acids/chemistry , Insecticides/chemistry , Pollen/chemistry
13.
Chem Asian J ; 16(11): 1324-1364, 2021 Jun 01.
Article in English | MEDLINE | ID: mdl-33844882

ABSTRACT

Corrosion is a phenomenon that devastatingly affects innovative, industrial, and mechanical applications, especially in the oil and gas industries. The corrosion conceivably influences industrial equipment; it deteriorates the environment and lessens the equipment/infrastructure's lifetime. Considering the significant impact of corrosion in our daily lives, this review article aims to briefly discuss the significance of corrosion and different control methods with special attention on corrosion inhibitors. The classification of corrosion inhibitors based on types and their advantage/limitations, and heterocyclic compounds as potential corrosion inhibitors, mainly nitrogen-based compounds (pyridine (1N), pyrimidine (2N), and triazines (3N) fused ring benzimidazole, etc.), and their biological significance has been discussed in detail. The mechanism, challenges, and applications of heterocyclic compounds as corrosion inhibitors in various industrial relevant corrosive environments such as acid pickling, descaling operation in the desalination plant, oil gas industry, etc., have also been highlighted in the review.


Subject(s)
Heterocyclic Compounds/chemistry , Azoles/chemistry , Corrosion , Metals/chemistry , Pyridines/chemistry , Pyrimidines/chemistry , Triazines/chemistry
14.
Nature ; 594(7862): 217-222, 2021 06.
Article in English | MEDLINE | ID: mdl-33910228

ABSTRACT

Fluoroalkyl groups profoundly affect the physical properties of pharmaceuticals and influence almost all metrics associated with their pharmacokinetic and pharmacodynamic profile1-4. Drug candidates increasingly contain trifluoromethyl (CF3) and difluoromethyl (CF2H) groups, and the same trend in agrochemical development shows that the effect of fluoroalkylation translates across human, insect and plant life5,6. New fluoroalkylation reactions have undoubtedly stimulated this shift; however, methods that directly convert C-H bonds into C-CF2X groups (where X is F or H) in complex drug-like molecules are rare7-13. Pyridines are the most common aromatic heterocycles in pharmaceuticals14, but only one approach-via fluoroalkyl radicals-is viable for achieving pyridyl C-H fluoroalkylation in the elaborate structures encountered during drug development15-17. Here we develop a set of bench-stable fluoroalkylphosphines that directly convert the C-H bonds in pyridine building blocks, drug-like fragments and pharmaceuticals into fluoroalkyl derivatives. No preinstalled functional groups or directing groups are required. The reaction tolerates a variety of sterically and electronically distinct pyridines, and is exclusively selective for the 4-position in most cases. The reaction proceeds through initial formation of phosphonium salts followed by sp2-sp3 coupling of phosphorus ligands-an underdeveloped manifold for forming C-C bonds.


Subject(s)
Carbon/chemistry , Fluorine/chemistry , Hydrogen/chemistry , Phosphorus/chemistry , Pyridines/chemistry , Alkylation , Animals , Humans , Ligands , Pharmaceutical Preparations/chemistry , Pharmacokinetics , Phosphines/chemistry
15.
J Med Chem ; 64(9): 5905-5930, 2021 05 13.
Article in English | MEDLINE | ID: mdl-33904304

ABSTRACT

There is an urgent need for new treatments for visceral leishmaniasis (VL), a parasitic infection which impacts heavily large areas of East Africa, Asia, and South America. We previously reported on the discovery of GSK3494245/DDD01305143 (1) as a preclinical candidate for VL and, herein, we report on the medicinal chemistry program that led to its identification. A hit from a phenotypic screen was optimized to give a compound with in vivo efficacy, which was hampered by poor solubility and genotoxicity. The work on the original scaffold failed to lead to developable compounds, so an extensive scaffold-hopping exercise involving medicinal chemistry design, in silico profiling, and subsequent synthesis was utilized, leading to the preclinical candidate. The compound was shown to act via proteasome inhibition, and we report on the modeling of different scaffolds into a cryo-EM structure and the impact this has on our understanding of the series' structure-activity relationships.


Subject(s)
Drug Design , Proteasome Endopeptidase Complex/metabolism , Proteasome Inhibitors/chemistry , Protozoan Proteins/metabolism , Animals , Antiprotozoal Agents/chemistry , Antiprotozoal Agents/metabolism , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/therapeutic use , Binding Sites , Cell Line , Drug Evaluation, Preclinical , Half-Life , Humans , Leishmania donovani/drug effects , Leishmania donovani/metabolism , Leishmaniasis, Visceral/drug therapy , Leishmaniasis, Visceral/parasitology , Mice , Molecular Dynamics Simulation , Proteasome Endopeptidase Complex/chemistry , Proteasome Inhibitors/metabolism , Proteasome Inhibitors/pharmacology , Proteasome Inhibitors/therapeutic use , Protein Subunits/chemistry , Protein Subunits/metabolism , Protozoan Proteins/chemistry , Pyridines/chemistry , Pyridines/metabolism , Pyridines/pharmacology , Pyridines/therapeutic use , Solubility , Structure-Activity Relationship
16.
Eur J Med Chem ; 216: 113270, 2021 Apr 15.
Article in English | MEDLINE | ID: mdl-33765486

ABSTRACT

ß-Site amyloid precursor protein cleaving enzyme 1 (BACE1) has been pursued as a prime target for the treatment of Alzheimer's disease (AD). In this report, we describe the discovery of BACE1 inhibitors with a 1-amino-3,4-dihydro-2,6-naphthyridine scaffold. Leveraging known inhibitors 2a and 2b, we designed the naphthyridine-based compounds by removing a structurally labile moiety and incorporating pyridine rings, which showed increased biochemical and cellular potency, along with reduced basicity on the amidine moiety. Introduction of a fluorine atom on the pyridine culminated in compound 11 which had improved cellular activity as well as further reduced basicity and demonstrated a robust and sustained cerebrospinal fluid (CSF) Aß reduction in dog. The crystal structure of compound 11 bound to BACE1 confirmed van der Waals interactions between the fluorine on the pyridine and Tyr71 in the flap.


Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Amyloid beta-Peptides/metabolism , Aspartic Acid Endopeptidases/antagonists & inhibitors , Naphthyridines/chemistry , Protease Inhibitors/chemistry , Pyridines/chemistry , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Amyloid Precursor Protein Secretases/metabolism , Amyloid beta-Peptides/cerebrospinal fluid , Animals , Aspartic Acid Endopeptidases/metabolism , Binding Sites , Crystallography, X-Ray , Dogs , Drug Evaluation, Preclinical , Half-Life , Humans , Microsomes/metabolism , Molecular Dynamics Simulation , Naphthyridines/metabolism , Naphthyridines/pharmacology , Protease Inhibitors/metabolism , Protease Inhibitors/pharmacology , Rats , Static Electricity , Structure-Activity Relationship
17.
Molecules ; 26(3)2021 Jan 28.
Article in English | MEDLINE | ID: mdl-33525515

ABSTRACT

Polymer templates play an essential role in the robust infiltration-based synthesis of functional multicomponent heterostructures with controlled structure, porosity, and composition. Such heterostructures are be used as hybrid organic-inorganic composites or as all-inorganic systems once the polymer templates are removed. Using iron oxide/alumina heterostructures formed by two-step infiltration of polystyrene-block-polyvinyl pyridine block copolymer with iron and aluminum precursors from the solution and vapor-phases, respectively, we show that the phase and morphology of iron oxide nanoparticles dramatically depend on the approach used to remove the polymer. We demonstrate that thermal and plasma oxidative treatments result in iron oxide nanoparticles with either solid or hollow morphologies, respectively, that lead to different magnetic properties of the resulting materials. Our study extends the boundaries of structure manipulations in multicomponent heterostructures synthesized using polymer infiltration synthesis, and hence their properties.


Subject(s)
Nanoparticles/chemistry , Nanostructures/chemistry , Polymers/chemistry , Aluminum Oxide/chemistry , Ferric Compounds/chemistry , Magnetics/methods , Nanotechnology/methods , Polystyrenes/chemistry , Pyridines/chemistry
18.
Chem Biol Drug Des ; 97(1): 77-86, 2021 01.
Article in English | MEDLINE | ID: mdl-32666679

ABSTRACT

A high-throughput screening assay was developed and applied to a large library of natural product extract samples, in order to identify compounds which preferentially inhibited the in vitro 2D growth of a highly metastatic osteosarcoma cell line (MG63.3) compared to a cognate parental cell line (MG63) with low metastatic potential. Evaluation of differentially active natural product extracts with bioassay-guided fractionation led to the identification of lovastatin (IC50  = 11 µm) and the limonoid toosendanin (IC50  = 26 nm). Other statins and limonoids were then tested, and cerivastatin was identified as a particularly potent (IC50  < 0.1 µm) and selective agent. These compounds potently and selectively induced apoptosis in MG63.3 cells, but not MG63. Assays with other cell pairs were used to examine the generality of these results. Statins and limonoids may represent unexplored opportunities for development of modulators of osteosarcoma metastasis. As cerivastatin was previously approved for clinical use, it could be considered for repurposing in osteosarcoma, pending validation in further models.


Subject(s)
Biological Products/pharmacology , Cell Proliferation/drug effects , High-Throughput Screening Assays/methods , Biological Products/chemistry , Biological Products/isolation & purification , Bone Neoplasms/metabolism , Bone Neoplasms/pathology , Cell Line , Cell Movement/drug effects , Cell Survival/drug effects , Drugs, Chinese Herbal/chemistry , Drugs, Chinese Herbal/isolation & purification , Drugs, Chinese Herbal/pharmacology , Humans , Lovastatin/chemistry , Lovastatin/isolation & purification , Lovastatin/pharmacology , Melia/chemistry , Melia/metabolism , Monascus/chemistry , Monascus/metabolism , Osteosarcoma/metabolism , Osteosarcoma/pathology , Plant Extracts/chemistry , Pyridines/chemistry , Pyridines/isolation & purification , Pyridines/pharmacology , Seeds/chemistry , Seeds/metabolism
19.
J Med Chem ; 63(24): 15564-15590, 2020 12 24.
Article in English | MEDLINE | ID: mdl-33306391

ABSTRACT

A CDK9 inhibitor having short target engagement would enable a reduction of Mcl-1 activity, resulting in apoptosis in cancer cells dependent on Mcl-1 for survival. We report the optimization of a series of amidopyridines (from compound 2), focusing on properties suitable for achieving short target engagement after intravenous administration. By increasing potency and human metabolic clearance, we identified compound 24, a potent and selective CDK9 inhibitor with suitable predicted human pharmacokinetic properties to deliver transient inhibition of CDK9. Furthermore, the solubility of 24 was considered adequate to allow i.v. formulation at the anticipated effective dose. Short-term treatment with compound 24 led to a rapid dose- and time-dependent decrease of pSer2-RNAP2 and Mcl-1, resulting in cell apoptosis in multiple hematological cancer cell lines. Intermittent dosing of compound 24 demonstrated efficacy in xenograft models derived from multiple hematological tumors. Compound 24 is currently in clinical trials for the treatment of hematological malignancies.


Subject(s)
Cyclin-Dependent Kinase 9/antagonists & inhibitors , Protein Kinase Inhibitors/chemistry , Pyridines/chemistry , Animals , Apoptosis/drug effects , Binding Sites , Cell Line, Tumor , Cyclin-Dependent Kinase 9/metabolism , Dogs , Drug Evaluation, Preclinical , Half-Life , Hematologic Neoplasms/drug therapy , Hematologic Neoplasms/pathology , Humans , Mice , Molecular Docking Simulation , Myeloid Cell Leukemia Sequence 1 Protein/metabolism , Protein Kinase Inhibitors/metabolism , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic use , Pyridines/metabolism , Pyridines/pharmacology , Pyridines/therapeutic use , Rats , Solubility , Structure-Activity Relationship , Xenograft Model Antitumor Assays
20.
Bioorg Med Chem ; 28(24): 115828, 2020 12 15.
Article in English | MEDLINE | ID: mdl-33166925

ABSTRACT

Pim-1 kinase targeted recently has proved an essential goal of breast cancer therapy. We report the design, synthesis with full characterization analysis of pyrazolo[3,4-b]pyridine scaffold-based derivatives targeting Pim-1 kinase as anti-breast cancer agents. All the newly synthesized compounds were screened for their in vitro cytotoxic activity against two breast cancer cell lines MCF-7 and MDA-MB-231, and non-cancerous MCF-10A cells. Four derivatives notably, 17 and 19 exhibited a remarkable cytotoxic activity with IC50 values 5.98 and 5.61 µM against MCF-7 (ERα-dependent) cells in a selective way, as they weren't active against MDA-MB-231 (non-ERα-dependent) and safe against MCF-10A. The most active compounds through in vitro screening were subjected to PIM-1 kinase to elucidate the Pim-1 kinase inhibitory activity as the mechanistic mode of action. Among the tested derivatives, Compounds 17 and 19 showed the highest inhibitory activity with IC50 values 43 and 26 nM, respectively, compared to the 5-FU with IC50 value 17 nM. Moreover, apoptotic investigation through flow cytometry and gene expression analysis of the apoptosis-related genes for the most active compound 19 against MCF-7. It was found that compound 19 induced apoptotic MCF-7 cell death by cell cycle arrest at G2/M phase and by elevation the expression of pro-apoptotic genes and inhibition of anti-apoptotic genes expression. Finally, the PIM-1 inhibition activities for compounds 17 and 19 were in accordance with the molecular docking study that revealed good interaction with the Pim-1 kinase active site.


Subject(s)
Drug Design , Protein Kinase Inhibitors/chemistry , Proto-Oncogene Proteins c-pim-1/antagonists & inhibitors , Pyrazoles/chemistry , Pyridines/chemistry , Binding Sites , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Caspase 3/genetics , Caspase 3/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Down-Regulation/drug effects , Drug Evaluation, Preclinical , Female , G2 Phase Cell Cycle Checkpoints/drug effects , Half-Life , Humans , MCF-7 Cells , Molecular Docking Simulation , Protein Kinase Inhibitors/metabolism , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins c-pim-1/metabolism , Pyrazoles/metabolism , Pyrazoles/pharmacology , Pyridines/metabolism , Pyridines/pharmacology , Structure-Activity Relationship , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism
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