scholarly journals An Investigation of Structure-Activity Relationships of Azolylacryloyl Derivatives Yielded Potent and Long-Acting Hemoglobin Modulators for Reversing Erythrocyte Sickling

Biomolecules ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1508
Author(s):  
Abdelsattar M. Omar ◽  
Osheiza Abdulmalik ◽  
Mohini S. Ghatge ◽  
Yosra A. Muhammad ◽  
Steven D. Paredes ◽  
...  
Keyword(s):  
Michael Addition ◽  
Oxygen Affinity ◽  
Aromatic Aldehydes ◽  
Structure Activity ◽  
Reactive Center ◽  
Pharmacologic Activity ◽  
Erythrocyte Sickling ◽  
Long Acting ◽  
Covalent Interactions

Aromatic aldehydes that bind to sickle hemoglobin (HbS) to increase the protein oxygen affinity and/or directly inhibit HbS polymer formation to prevent the pathological hypoxia-induced HbS polymerization and the subsequent erythrocyte sickling have for several years been studied for the treatment of sickle cell disease (SCD). With the exception of Voxelotor, which was recently approved by the U.S. Food and Drug Administration (FDA) to treat the disease, several other promising antisickling aromatic aldehydes have not fared well in the clinic because of metabolic instability of the aldehyde moiety, which is critical for the pharmacologic activity of these compounds. Over the years, our group has rationally developed analogs of aromatic aldehydes that incorporate a stable Michael addition reactive center that we hypothesized would form covalent interactions with Hb to increase the protein affinity for oxygen and prevent erythrocyte sickling. Although, these compounds have proven to be metabolically stable, unfortunately they showed weak to no antisickling activity. In this study, through additional targeted modifications of our lead Michael addition compounds, we have discovered other novel antisickling agents. These compounds, designated MMA, bind to the α-globin and/or β-globin to increase Hb affinity for oxygen and concomitantly inhibit erythrocyte sickling with significantly enhanced and sustained pharmacologic activities in vitro.

scholarly journals Quantitative prediction of erythrocyte sickling for the development of advanced sickle cell therapies

2019 ◽  
Vol 5 (8) ◽  
pp. eaax3905 ◽  
Author(s):  
Lu Lu ◽  
Zhen Li ◽  
He Li ◽  
Xuejin Li ◽  
Peter G. Vekilov ◽  
...  
Keyword(s):  
Sickle Cell ◽  
Oxygen Affinity ◽  
Nucleation Theory ◽  
Quantitative Prediction ◽  
Classical Nucleation Theory ◽  
Cell Therapies ◽  
Drug Candidates ◽  
Erythrocyte Sickling

Sickle cell disease is induced by a mutation that converts normal adult hemoglobin to sickle hemoglobin (HbS) and engenders intracellular polymerization of deoxy-HbS and erythrocyte sickling. Development of anti-sickling therapies requires quantitative understanding of HbS polymerization kinetics under organ-specific conditions, which are difficult to assess with existing experimental techniques. Thus, we developed a kinetic model based on the classical nucleation theory to examine the effectiveness of potential anti-sickling drug candidates. We validated this model by comparing its predictability against prior in vivo and in vitro experimental results. We used the model to quantify the efficacy of sickling inhibitors and obtain results consistent with recent screening assays. Global sensitivity analysis on the kinetic parameters in the model revealed that the solubility, nucleation rate prefactor, and oxygen affinity are quantities that dictate HbS polymerization. This finding provides quantitative guidelines for the discovery of intracellular processes to be targeted by sickling inhibitors.

THYROID STIMULATORS AND THYROID STIMULATION

1971 ◽  
Vol 66 (3) ◽  
pp. 558-576 ◽  
Author(s):  
Gerald Burke
Keyword(s):  
Regulatory System ◽  
Control Site ◽  
Thyroid Cell ◽  
Primary Control ◽  
Physico Chemical ◽  
Site Of Action ◽  
Long Acting

ABSTRACT A long-acting thyroid stimulator (LATS), distinct from pituitary thyrotrophin (TSH), is found in the serum of some patients with Graves' disease. Despite the marked physico-chemical and immunologic differences between the two stimulators, both in vivo and in vitro studies indicate that LATS and TSH act on the same thyroidal site(s) and that such stimulation does not require penetration of the thyroid cell. Although resorption of colloid and secretion of thyroid hormone are early responses to both TSH and LATS, available evidence reveals no basic metabolic pathway which must be activated by these hormones in order for iodination reactions to occur. Cyclic 3′, 5′-AMP appears to mediate TSH and LATS effects on iodination reactions but the role of this compound in activating thyroidal intermediary metabolism is less clear. Based on the evidence reviewed herein, it is suggested that the primary site of action of thyroid stimulators is at the cell membrane and that beyond the(se) primary control site(s), there exists a multifaceted regulatory system for thyroid hormonogenesis and cell growth.

Neurotoxicity of Pesticides: The Roadmap for the Cubic Mode of Action

2020 ◽  
Vol 27 (1) ◽  
pp. 54-77 ◽  
Author(s):  
Bogdan Bumbăcilă ◽  
Mihai V. Putz
Keyword(s):  
Biological Activity ◽  
Wiener Index ◽  
Laboratory Animals ◽  
Covalent Bonds ◽  
Organophosphate Compounds ◽  
Sar Studies ◽  
Structure Activity ◽  
Cubic Structure

Pesticides are used today on a planetary-wide scale. The rising need for substances with this biological activity due to an increasing consumption of agricultural and animal products and to the development of urban areas makes the chemical industry to constantly investigate new molecules or to improve the physicochemical characteristics, increase the biological activities and improve the toxicity profiles of the already known ones. Molecular databases are increasingly accessible for in vitro and in vivo bioavailability studies. In this context, structure-activity studies, by their in silico - in cerebro methods, are used to precede in vitro and in vivo studies in plants and experimental animals because they can indicate trends by statistical methods or biological activity models expressed as mathematical equations or graphical correlations, so a direction of study can be developed or another can be abandoned, saving financial resources, time and laboratory animals. Following this line of research the present paper reviews the Structure-Activity Relationship (SAR) studies and proposes a correlation between a topological connectivity index and the biological activity or toxicity made as a result of a study performed on 11 molecules of organophosphate compounds, randomly chosen, with a basic structure including a Phosphorus atom double bounded to an Oxygen atom or to a Sulfur one and having three other simple covalent bonds with two alkoxy (-methoxy or -ethoxy) groups and to another functional group different from the alkoxy groups. The molecules were packed on a cubic structure consisting of three adjacent cubes, respecting a principle of topological efficiency, that of occupying a minimal space in that cubic structure, a method that was called the Clef Method. The central topological index selected for correlation was the Wiener index, since it was possible this way to discuss different adjacencies between the nodes in the graphs corresponding to the organophosphate compounds molecules packed on the cubic structure; accordingly, "three dimensional" variants of these connectivity indices could be considered and further used for studying the qualitative-quantitative relationships for the specific molecule-enzyme interaction complexes, including correlation between the Wiener weights (nodal specific contributions to the total Wiener index of the molecular graph) and the biochemical reactivity of some of the atoms. Finally, when passing from SAR to Q(uantitative)-SAR studies, especially by the present advanced method of the cubic molecule (Clef Method) and its good assessment of the (neuro)toxicity of the studied molecules and of their inhibitory effect on the target enzyme - acetylcholinesterase, it can be seen that a predictability of the toxicity and activity of different analogue compounds can be ensured, facilitating the in vivo experiments or improving the usage of pesticides.

Recent Design and Structure-Activity Relationship Studies on Modifications of DHFR Inhibitors as Anticancer Agents

2019 ◽  
Vol 26 ◽  
Author(s):  
Agnieszka Wróbel ◽  
Danuta Drozdowska
Keyword(s):  
Anticancer Activity ◽  
Anticancer Drugs ◽  
Anticancer Agents ◽  
Physicochemical Characterization ◽  
Structure Activity Relationship ◽  
Activity Relationship ◽  
Biological Research ◽  
Structure Activity ◽  
Dhfr Inhibitors

Background: Dihydrofolate reductase (DHFR) has been known for decades as a molecular target for antibacterial, antifungal and anti-malarial treatments. This enzyme is becoming increasingly important in the design of new anticancer drugs, which is confirmed by numerous studies including modelling, synthesis and in vitro biological research. This review aims to present and discuss some remarkable recent advances on the research of new DHFR inhibitors with potential anticancer activity. Methods: The scientific literature of the last decade on the different types of DHFR inhibitors has been searched. The studies on design, synthesis and investigation structure-activity relationship were summarized and divided into several subsections depending on the leading molecule and its structural modification. Various methods of synthesis, potential anticancer activity and possible practical applications as DHFR inhibitors of new chemical compounds were described and discussed. <p> Results: This review presents the current state of knowledge on the modification of known DHFR inhibitors and the structures and searching for over eighty new molecules, designed as potential anticancer drugs. In addition, DHFR inhibitors acting on thymidylate synthase (TS), carbon anhydrase (CA) and even DNA-binding are presented in this paper. <p> Conclusion: Thorough physicochemical characterization and biological investigations it is possible to understand structure-activity relationship of DHFR inhibitors. This will enable even better design and synthesis of active compounds, which would have the expected mechanism of action and the desired activity.

Enantioselective Michael Addition of Malonates to Enones

2020 ◽  
Vol 24 (7) ◽  
pp. 746-773
Author(s):  
Péter Bakó ◽  
Tamás Nemcsok ◽  
Zsolt Rapi ◽  
György Keglevich
Keyword(s):  
Michael Addition ◽  
Activity Relationship ◽  
Chalcone Derivatives ◽  
Michael Additions ◽  
Michael Reactions ◽  
Structure Activity ◽  
Cyclic Enones ◽  
Michael Acceptors ◽  
Relationship Of ◽  
Enantioselective Catalysts

: Many catalysts were tested in asymmetric Michael additions in order to synthesize enantioenriched products. One of the most common reaction types among the Michael reactions is the conjugated addition of malonates to enones making it possible to investigate the structure–activity relationship of the catalysts. The most commonly used Michael acceptors are chalcone, substituted chalcones, chalcone derivatives, cyclic enones, while typical donors may be dimethyl, diethyl, dipropyl, diisopropyl, dibutyl, di-tert-butyl and dibenzyl malonates. This review summarizes the most important enantioselective catalysts applied in these types of reactions.

Synthesis, Antimalarial Evaluation and SAR Study of Some 1,3,5-Trisubstituted Pyrazoline Derivatives

2019 ◽  
Vol 16 (10) ◽  
pp. 807-817 ◽  
Author(s):  
Shilpy Aggarwal ◽  
Deepika Paliwal ◽  
Dhirender Kaushik ◽  
Girish Kumar Gupta ◽  
Ajay Kumar
Keyword(s):  
Antimalarial Activity ◽  
Analysis Data ◽  
Docking Study ◽  
Maximum Activity ◽  
Elemental Analysis Data ◽  
Mass Spectral ◽  
Structure Activity ◽  
Pharmacokinetic Properties ◽  
Sar Study

The synthesis of a novel series of 1,3,5-trisubstitiuted pyrazoline was achieved by refluxing chalcone derivative with different heteroaryl hydrazines. The newly synthesized compounds were characterized by 1H NMR, 13CNMR, mass spectral and elemental analysis data. The synthetic series of novel pyrazoline hybrids was screened for in vitro schizont maturation assay against chloroquine sensitive 3D7 strain of Plasmodium falciparum. Most of the compounds showed promising in vitro antimalarial activity against CQ sensitive strain. The preliminary structure-activity relationship study showed that quinoline substituted analog at position N-1 showed maximum activity followed by benzothiazole substitution, while phenyl substitution lowers the antimalarial activity. The observed activity was persistent by the docking study on P. falciparum cystein protease falcipain-2. The pharmacokinetic properties were also studied using ADME prediction.

Synthesis and Antitumor Activity Evaluation of New Phenanthrene-Based Tylophorine Derivatives

2019 ◽  
Vol 16 (6) ◽  
pp. 462-467
Author(s):  
Songtao Li ◽  
Hongling Zhao ◽  
Zhifeng Yin ◽  
Shuhua Deng ◽  
Yang Gao ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Cell Lines ◽  
Antitumor Activities ◽  
Human Carcinoma ◽  
Carcinoma Cell Lines ◽  
Structure Activity ◽  
Human Carcinoma Cell ◽  
Ic50 Values ◽  
Relationship Of

A series of new phenanthrene-based tylophorine derivatives (PBTs) were synthesized in good yield and their structures were characterized by 1H-NMR spectroscopy and ESI MS. In vitro antitumor activity of these compounds against five human carcinoma cell lines, including HCT116 (colorectal), BGC-823 (gastric), HepG-2 (hepatic), Hela (cervical) and H460 (lung) cells, was evaluated by MTT assay. Among these PBTs, compound 6b showed the highest antitumor activities against HCT116 and HepG-2 cell lines with IC50 values of 6.1 and 6.4 μM, respectively, which were comparable to that of adriamycin hydrochloride. The structure-activity relationship of these compounds was also discussed based on the results of their antitumor activity.

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