Attachment Of Side Chains Research Articles

Reversed dynamics of bottlebrush polymers with stiff backbone and flexible side chains.

The segmental dynamics of bottlebrush polymers with a stiff backbone and flexible side chains has been studied. The segmental relaxation time of side chains attached to a flexible backbone follows the same trend as linear polymers, an increase with the increasing molecular weight, but is slowed down compared to their linear counterparts. Theoretical work predicts a reversal of the molecular weight dependence of the relaxation time for stiff backbones. As a model for a stiff-g-flexible system, bottlebrushes with poly(norbornene) backbone and poly(propylene oxide) side chains, PNB-g-PPO, at a uniform grafting density have been synthesized and characterized with quasi-elastic neutron scattering. Indeed, the anticipated reversed dynamics was found. Increasing the side chain length decreases the segmental relaxation time. This indicates the importance of the characteristics of the grafting site beyond a simplified picture of an attached side chain. The mean square displacement shows a similar trend with longer side chains exhibiting a larger displacement.

Minimal Peptoid Dynamics Inform Self-Assembly Propensity.

Peptoids are structural isomers of natural peptides, with side chain attachment at the amide nitrogen, conferring this class of compounds with the ability to access both cis and trans ω torsions as well as an increased diversity of ψ/φ states with respect to peptides. Sampling within these dimensions is controlled through side chain selection, and an expansive set of viable peptoid residues exists. It has been shown recently that "minimal" di- and tripeptoids with aromatic side chains can self-assemble into highly ordered structures, with size and morphological definition varying as a function of sequence pattern (e.g., XFF and FXF, where X = a nonaromatic peptoid monomer). Aromatic groups, such as phenylalanine, are regularly used in the design of minimal peptide assemblers. In recognition of this, and to draw parallels between these compounds classes, we have developed a series of descriptors for intramolecular dynamics of aromatic side chains to discern whether these dynamics, in a preassembly condition, can be related to experimentally observed nanoscale assemblies. To do this, we have built on the atomistic peptoid force field reported by Weiser and Santiso (CGenFF-WS) through the rigorous fitting of partial charges and the collation of Charmm General Force Field (CGenFF) parameters relevant to these systems. Our study finds that the intramolecular dynamics of side chains, for a given sequence, is dependent on the specific combination of backbone ω torsions and that homogeneity of sampling across these states correlates well with the experimentally observed ability to assemble into nanomorphologies with long-range order. Sequence patterning is also shown to affect sampling, in a manner consistent for both tripeptoids and tripeptides. Additionally, sampling similarities between the nanofiber forming tripeptoid, Nf-Nke-Nf in the cc state, and the nanotube forming dipeptide FF, highlight a structural motif which may be relevant to the emergence of extended linear assemblies. To assess these properties, a variety of computational approaches have been employed.

Insight into advances for the biosynthetic progress of fermented echinocandins of antifungals.

Invasive fungal infections have increased remarkably, which have become unprecedented concern to human health. However, the effectiveness of current antifungal drugs is limited due to drug resistance and toxic side-effects. It is urgently required to establish the effective biosynthetic strategy for developing novel and safe antifungal molecules economically. Echinocandins become a promising option as a mainstay family of antifungals, due to specifically targeting the fungal specific cell wall. To date, three kinds of echinocandins for caspofungin, anidulafungin, and micafungin, which derived from pneumocandin B0 , echinocandin B, and FR901379, are commercially available in clinic and have shown potential in managing invasive fungal infections in a cost-effective manner. However, current echinocandins-derived precursors all are produced by environmental fungal isolates with long fermentation cycle and low yields, which challenge the production efficacy of these precursors in industry. Therefore, understanding their biosynthetic machinery is of great importance for improving antifungal titres and creating new echinocandins-derived products. With the development of genome-wide sequencing and establishment of gene-editing technology, there are a growing number of reports on echinocandins-derived products and their biosynthetic gene clusters. This review briefly summarizes the discovery and development history of echinocandins, compares their structural characteristics and biosynthetic processes, and sums up existed strategies for improving their production. Moreover, the genomic analysis of related biosynthetic gene clusters of echinocandins is discussed, highlighting the similarities and differences among the clusters. Last, the biosynthetic processes of echinocandins are compared, focusing on the activation and attachment of side-chains and the formation of the hexapeptide core. This review aims to provide insights into the development and production of new echinocandin drugs by modifying the structure of echinocandin-derived precursors and/or optimizing the fermentation processes; and achieve a new microbial chassis for efficient production of echinocandins in heterologous hosts.

Structure of the LarB-Substrate Complex and Identification of a Reaction Intermediate during Nickel-Pincer Nucleotide Cofactor Biosynthesis.

LarB catalyzes the first step of biosynthesis for the nickel-pincer nucleotide cofactor by converting nicotinic acid adenine dinucleotide (NaAD) to AMP and pyridinium-3,5-biscarboxylic acid mononucleotide (P2CMN). Prior studies had shown that LarB uses CO2 for substrate carboxylation and reported the structure of a Lactiplantibacillus plantarum LarB·NAD+ complex, revealing a covalent linkage between Cys221 and C4 of the pyridine ring. This interaction was proposed to promote C5 carboxylation, with C5-carboxylated-NaAD suggested to activate magnesium-bound water, leading to phosphoanhydride hydrolysis. Here, we extended the analysis of wild-type LarB by using ultraviolet-visible spectroscopy to obtain additional evidence for cysteinyl side chain attachment to the ring of NAD+, thus demonstrating that this linkage is not a crystallization artifact. Using the S127A variant of L. plantarum LarB, a form of the enzyme with a reduced rate of NaAD hydrolysis, we examined its interaction with the authentic substrate. The intermediate arising from C5 carboxylation of NaAD, dinicotinic acid adenine dinucleotide (DaAD), was identified by using mass spectrometry. S127A LarB exhibited spectroscopic evidence of a Cys221-NAD+ adduct, but a covalent enzyme-NaAD linkage was not detectable. We determined the S127A LarB·NaAD structure, providing new insights into the enzyme mechanism, and tentatively identified the position and mode of CO2 binding. The crystal structure revealed the location of the side chain for Glu180, which was previously disordered, but showed that it is not well positioned to abstract the C5 proton in the adduct species to restore aromaticity as Cys221 is expelled. Based on these combined results, we propose a revised catalytic mechanism of LarB..

A DFT Study on the Impact of Saturated and Conjugated Side Chains on the Optoelectronic Performance of Y-series Nonfullerene Acceptors

Organic photovoltaic (OPV) consisting of nonfullerene acceptors have been found to be excellent candidates for harnessing solar energy. Extensive studies are being carried out to modify structures in a number of ways to enhance their efficiency. These include modifications in the acceptor part, use of efficient backbones and insertion of pi spacers. One strategy is the attachment of donor side chains for better assembly of molecules. In this work, the effect of theoretically designed side chains on electrochemical and optical properties of OPVs was studied. A series of molecules consisting of saturated (SC1-4) and conjugated donor (CD1-2) were designed and studied computationally for their potential OPV properties. Parameters like Band gap, absorption spectrum, frontier molecular orbital distribution, binding energy, fill factor, open circuit voltage, excitation energies, density of states (DOS) and transition density matrix (TDM) were studied using DFT and TD-DFT methods. Unsaturated side chains although exhibit better performance in terms of open circuit voltage and hole mobility but reduce light harvesting efficiency. All saturated side chain modifications showed improvement in fill factor and open circuit voltage than reference molecule. SC3 modification with red shift and smaller band gap showed the best performance.

Coarse-Grained Molecular Simulation of Bolapolyphiles with a Multident Lateral Chain: Formation and Structural Analysis of Cubic Network Phases.

Bolapolyphiles constitute a versatile class of materials with a demonstrated potential to form a wide variety of complex ordered mesophases. In particular, cubic network phases (like the gyroid, primitive, and diamond phases) have been a target of many studies for their ability to create percolating 3D nanosized channels. In this study, molecular simulations are used to explore the phase behavior of bolapolyphiles containing a rigid rodlike core, associating hydrophilic core ends and a hydrophobic side chain with a multident architecture, i.e., where the branching pattern can vary from bident (two branches) to hexadent (six branches). Upon network phase formation, its skeleton is made up of "nodes" populated by the core ends and "struts" populated by the cores. It is shown that, by varying the side chain length, branching pattern, and attachment point to the core, one can alter the crowding around the cores and hence tune the nodal size and nodal valence (i.e., number of connecting struts) which lead to different types of network morphologies. For example, for a fixed total side chain length, having more branches generates a stronger crowding around the molecular core, driving them to form bundlelike domains with curvier interfaces that result in thinner struts. Also, attaching the lateral chain closer to one core end breaks the symmetry between the environments around the two core ends, leading to networks with bimodal nodal sizes. Importantly, since the characterization of (ordered or partially ordered) network phases is challenging given the potential incompatibilities between the simulation box size with the structure's space group periodic symmetry and the effect of morphological defects, a detailed framework is presented to analyze and fully characterize the unit cell parameters and structure factor of such systems.

Enhanced Organic Electrochemical Transistor Performance of Donor-Acceptor Conjugated Polymers Modified with Hybrid Glycol/Ionic Side Chains by Postpolymerization Modification.

Emergent bioelectronic technologies are underpinned by the organic electrochemical transistor (OECT), which employs an electrolyte medium to modulate the conductivity of its organic semiconductor channel. Here we utilize postpolymerization modification (PPM) on a conjugated polymer backbone to directly introduce glycolated or anionic side chains via fluoride displacement. The resulting polymers demonstrated increased volumetric capacitances, with subdued swelling, compared to their parent polymer in p-type enhancement mode OECTs. This increase in capacitance was attributed to their modified side chain configurations enabling cationic charge compensation for thin film electrochemical oxidation, as deduced from electrochemical quartz crystal microbalance measurements. An overall improvement in OECT performance was recorded for the hybrid glycol/ionic polymer compared to the parent, owing to its low swelling and bimodal crystalline orientation as imaged by grazing-incidence wide-angle X-ray scattering, enabling its high charge mobility at 1.02 cm2·V-1·s-1. Compromised device performance was recorded for the fully glycolated derivative compared to the parent, which was linked to its limited face-on stacking, which hindered OECT charge mobility at 0.26 cm2·V-1·s-1, despite its high capacitance. These results highlight the effectiveness of anionic side chain attachment by PPM as a means of increasing the volumetric capacitance of p-type conjugated polymers for OECTs, while retaining solid-state macromolecular properties that facilitate hole transport.

Ion-Transport Properties of Polydimethylsiloxane-Based Ionomers with Amidinium or Imidazolinium Alkyldithiocarbamate Pendant Groups in Low Dielectric Solvents or as Neat Liquids.

The ion transport properties of ionomers comprised of polydimethylsiloxanes with amidinium or imidazolinium attached side chains and alkyldithiocarbamate anions (where alkyl is hexyl or octadecyl) have been investigated in chloroform solutions principally and as neat liquids. The influence of modifying the molecular weights of the polydimethylsiloxanes, the frequency of their amidininium or imidazolinium side groups, and temperature on the conductivity have been explored. When a solvent more polar than chloroform, syn-tetrachloroethane, was employed, a large increase in the ionic conductivity was found despite there being an increase in the viscosity of the solution. At least in these two solvents, polarity is more important in determining the conductivity than the viscosity. When normalized for ion content, Walden plots of the ionomer solutions at different ionomer concentrations approached values found for 1 M aqueous KCl. As neat liquids, the amidinium and imidazolinium hexyldithiocarbamate ionomers exceeded the values associated with the "superionic" region of the Walden plot (i.e., above the conductivity values for 1 M aqueous KCl). As ion content and polymer molecular weight increased, larger decoupling between bulk viscosity and ionic conductivity was noted, probably as a result of changes in the dynamic fragility of the ionomers.

Highly Emissive Luminogens in Both Solution and Aggregate States

Highly Emissive Luminogens in Both Solution and Aggregate States

Effects of alkyl chain on the liquid crystalline properties of [1]benzothieno[3,2-b][1]benzothiophene-based organic semiconductors

New [1]benzothieno[3,2- b ] [1]benzothiophene (BTBT)-based small molecules with different substituents were synthesized and employed as solution-processable organic semiconductors for organic thin-film transistors (OTFTs). Two types of alkyl side chains (octyl/ethylhexyl) were selected for the solubility enhancement and analysis of material phase transition. Thermal, optical, and electrical properties of new compounds were analyzed and characterized. Synthesized BTBT derivatives exhibited completely different phase transition features depending on the attached side chains; linearly alkylated 2-octyl-7-(5-octylthiophen-2-yl)benzo[ b ]benzo [4,5]thieno[2,3- d ]thiophene (compound 1 ) showed decent carrier mobility up to 0.26 cm 2 /Vs at highly ordered smectic X phase, while 2-(5-(2-ethylhexyl)thiophen-2-yl)-7-octylbenzo[ b ]benzo [4,5]thieno[2,3- d ]thiophene (compound 2 ) with branched alkyl chain showed poor electrical performance. Thin film morphology and microstructure were investigated using atomic force microscopy and X-ray diffraction to reveal the dramatic property difference between the two dialkylated BTBT derivatives. • Solution-processable BTBT-based organic semiconductors were synthesized. • Analysis on alkyl side chain type; linear and branch-like substituents was conducted. • Linearly alkylated compound showed smectic liquid crystalline properties. • Organic transistors with LC phase showed mobility up to 0.26 cm 2 /Vs.

Diastereoselective Functionalization of Chiral N‐Acyl‐1,3‐oxazolidines and Their Applications in the Synthesis of Bioactive Molecules

Abstract1,3‐Oxazolidines, derived from widely available enantiomerically pure 1,2‐aminoalcohols, are versatile chiral auxiliaries for several key transformations, often serving as a platform for inquiries into new and complex reactivity. This Review focuses on the chemistry of N‐acyl‐1,3‐oxazolidines in which the stereoselective transformation is carried out on the N‐acyl attached side chain of the molecule, covering reports from late 1980s to 2020 across several fields of asymmetric synthesis of bioactive molecules, and in particular of natural products.

Solid-phase synthesis of novel antimicrobial peptoids with α- and β-chiral side chains.

Bacterial resistance to conventional antibiotics poses an immense threat to human health and consequently many bacterial infections arise from multi-drug resistant pathogens. It is, therefore, necessary to continue to develop novel antimicrobials. Peptoids are a novel class of antimicrobial agents that mimic the structures of peptides. These N-substituted glycines differ from peptides in the side chain attachment site where in peptoids, the side chain functionality is introduced at the nitrogen rather than the α-carbon in peptides. During the process of design and development of antimicrobial peptoids, several key elements such as charge and amphiphilicity appear to guide peptoid bioactivity against bacterial pathogens. In this study, we report a quick synthesis of three novel cationic antimicrobial peptoids that contain charged, hydrophobic, and chiral monomers. This study is the first to use a monomer that contains both charge and chiral center for the design of the novel peptoid sequences.

Protein Extraction Efficiency and Selectivity of Esterified Styrene-Maleic Acid Copolymers in Thylakoid Membranes.

Amphiphilic styrene-maleic acid copolymers (SMAs) have been shown to effectively extract membrane proteins surrounded by an annulus of native membrane lipids via the formation of nanodiscs. Recent reports have shown that 2-butoxyethanol-functionalized SMA derivatives promote the extraction of membrane proteins from thylakoid membranes, whereas unfunctionalized SMA is essentially ineffective. However, it is unknown how the extent of functionalization and identity of sidechains impact protein solubilization and specificity. Herein, we show that the monoesterification of an SMA polymer with hydrophobic alkoxy ethoxylate sidechains leads to an increased solubilization efficiency (SE) of trimeric photosystem I (PSI) from the membranes of cyanobacterium Thermosynechococcus elongatus. The specific SMA polymer used in this study, PRO 10235, cannot encapsulate single PSI trimers from this cyanobacterium; however, as it is functionalized with alkoxy ethoxylates of increasing alkoxy chain length, a clear increase in the trimeric PSI SE is observed. Furthermore, an exponential increase in the SE is observed when >50% of the maleic acid repeat units are monoesterified with long alkoxy ethoxylates, suggesting that the PSI extraction mechanism is highly dependent on both the number and length of the attached side chains.

Alkyl-Fullerene Materials of Tunable Morphology and Function

Abstract The self-assembly of molecules into complex superstructures underpins the functionality of many biological processes and physical materials. Many such structures stem from amphiphilic monomer units, with attractions and repulsions between their ends determining the structure and state of the assembled system under equilibrium, which affect its function. The photophysical and electronic properties of fullerene (C60) have been extensively studied and proven useful in the fabrication of a variety of devices. The simple attachment of alkyl side chains can convert this highly crystalline solid into an alkyl-C60 hydrophobic amphiphile, in which alkyl-alkyl and C60-C60 interactions determine the state, phase, morphology, or architecture of the substance, while the optoelectronic properties of C60 are retained. In this award article, lipid membranes, crystalline nanostructures, mesophases, and even room-temperature liquid alkyl fullerenes formed through this approach are described. In each case, the effects of chain selection and substitution on morphology and function are explained. The ways in which the inherent properties of C60 can be adapted for particular applications are detailed, such as in superhydrophobic surfaces and photoconductive devices. Thereafter, drawing on these advances, the application of the alkyl chain attachment approach to other functional π-conjugated cores is demonstrated using some examples of functional molecular liquids.

Aromatic Foldamer Helices as α-Helix Extended Surface Mimetics.

Helically folded aromatic oligoamide foldamers have a size and geometrical parameters very distinct from those of α‐helices and are not obvious candidates for α‐helix mimicry. Nevertheless, they offer multiple sites for attaching side chains. It was found that some arrays of side chains at the surface of an aromatic helix make it possible to mimic extended α‐helical surfaces. Synthetic methods were developed to produce quinoline monomers suitably functionalized for solid phase synthesis. A dodecamer was prepared. Its crystal structure validated the initial design and showed helix bundling involving the α‐helix‐like interface. These results open up new uses of aromatic helices to recognize protein surfaces and to program helix bundling in water.

What is Best Strategy for Water Soluble Fluorescence Dyes?-A Case Study Using Long Fluorescence Lifetime DAOTA Dyes*.

The lipophilic nature of organic dyes complicates their effectiveness in aqueous solutions. In this work we investigate three different strategies for achieving water-solubility of the diazaoxatriangulenium (DAOTA+ ) chromophore: hydrophilic counter ions, aromatic sulfonation of the chromophore, and attachment of charged side chains. The long fluorescence lifetime (FLT, τf =20 ns) of DAOTA+ makes it a sensitive probe to analyze solvation and aggregation effects. Direct sulfonation of the chromophore was found to increase solubility drastically, but at the cost of greatly reduced quantum yields (QYs) due to enhanced non-radiative deactivation processes. The introduction of either cationic (4) or zwitterionic side chains (5), however, brings the FLT (τf =18 ns) and QY (ϕf =0.56) of the dye to the same level as the parent chromophore in acetonitrile. Time-resolved fluorescence spectroscopy also reveals a high resistance to aggregation and non-specific binding in a high loading of bovine serum albumin (BSA). The results clearly show that addition of charged flexible side chains is preferable to direct sulfonation of the chromophore core.

Piperidinium-Based Ionic Liquids as an Electrolyte Solvent for Li-Ion Batteries: Effect of Number and Position of Oxygen Atom in Cation Side Chain on Electrolyte Property

In the pursuit of developing reliable Li-ion batteries with high performance and safety, the use of ionic liquids is one of the most promising approaches due to its high thermal stability. There is, however, the critical issue concerning the significantly low Li-ion diffusion in an electrolyte solution, which is directly linked to the degradation of their rapid charge−discharge properties. Ionic liquids with ether-substituted cation have generated much interest as electrolyte solvents for Li-ion batteries because the ether group functions to reduce the coordination number and increase ionic conductivity. In the present study, we synthesized six types of ionic liquids consisting of bis(trifluoromethanesulfonyl)amide (TFSA) anions and piperidinium-based cations in which the attached side chains are 1-((2-methoxyethoxy)methyl)-1-methylpiperidinium (PP1MEM), 1-butoxymethyl-1-methylpiperidinium (PP1BM), 1-methyl-(2-propoxyethyl)piperidinium (PP1PE), 1-(3-ethoxypropyl)-1-methylpiperidinium (PP1EP), 1-(4-methoxybutyl)-1-methylpiperidinium (PP1MB), and 1-hexyl-1-methylpiperidinium (PP16). It was found that the ionic liquid with PP1MEM cations with two oxygen atoms in the side chain exhibited the lowest solvation number of TFSA anions (1.56), whereas PP1BM (1.78), PP1PE (1.86), PP1EP (2.08), and PP1MB-TFSA (2.07) resulted in a larger number, as the oxygen atoms in the alkyl side chain are located far from the positively charged nitrogen atoms. PP1MEM-TFSA with small solvation numbers enhanced the ionic conductivity and thereby achieved high electrode performance.

Mode of hydrophilic and hydrophobic interactions of DL-Tyrosine, DL-Leucine, DL-Isoleucine and DL-Threonine in aqueous binary mixture of dipolar aprotic acetonitrile

The saturated solubilities of DL- Tyrosine, DL-Leucine, DL-Isoleucine and DL-Threonine in binary aqueous dipolar aprotic acetonitrile solvent were estimated by ‘formol titrimetry’ at nine equidistant temperatures under 0.1 MPa pressure. The chemical effects of the standard transfer energetics of these amino acids obtained after elimination of cavity forming, dipole-dipole and dipole-induced dipole interaction effect from the total, are useful to know about chemical stability of it in such system and solvent-solvent interaction therein. Hydrophobic and hydrophilic interactions of standard transfer Gibbs free energies and entropies, as obtained after subtraction of dispersion from chemical interaction are guided by the attached side chains.

Synthesis, Profiling, and Bioactive Conformation of trans‐Cyclopropyl Epothilones

AbstractA series of new 3‐deoxy‐C(12),C(13)‐trans‐cyclopropyl‐epothilones have been prepared, bearing benzothiazole, quinoline, thiazol‐5‐ylvinyl, or isoxazol‐3‐ylvinyl side chains. For analogs with fused aromatic side chains, macrocyclic ring‐closure was based on ring‐closing olefin metathesis (RCM) of a precursor incorporating the fully elaborated heavy atom framework of the target structure (including the side chain moiety), while side chain attachment for the thiazole and isoxazole‐containing 16‐desmethyl analogs was performed only after establishment of the macrolactone core. Two approaches were elaborated for a macrocyclic aldehyde as the common precursor for the latter analogs that involved ring‐closure either by RCM or by macrolactonization. Benzothiazole‐ and quinoline‐based analogs were found to be highly potent antiproliferative agents; the two analogs with a thiazol‐5‐ylvinyl or an isoxazol‐3‐ylvinyl side chain likewise showed good antiproliferative activity but were significantly less potent than the parent epothilone A. Surprisingly, the desaturation of the C(10)−C(11) bond in these analogs was associated with a virtually complete loss in antiproliferative activity, which likely reflects a requirement for a ca. 60 ° C(10)−C(11) torsion angle in the tubulin‐bound conformation of 12,13‐trans‐epothilones.

Structure\u2013activity relationships in a series of antiplasmodial thieno[2,3-b]pyridines

BackgroundMalaria is one of the most prevalent tropical infectious diseases. Since recently cases of artemisinin resistance were reported, novel anti-malarial drugs are required which differ from artemisinins in structure and biological target. The plasmodial glycogen synthase kinase-3 (PfGSK-3) was suggested as a new anti-malarial drug target. 4-Phenylthieno[2,3-b]pyridines were previously identified as selective PfGSK-3 inhibitors with antiplasmodial activity. The present study aims at identifying a molecular position on this scaffold for the attachment of side chains in order to improve solubility and antiplasmodial activity. Furthermore, the role of axial chirality in the compound class for antiplasmodial activity and PfGSK-3 inhibition was investigated.Methods4-Phenylthieno[2,3-b]pyridines with substituents in 4-position of the phenyl ring were docked into the ATP binding site of PfGSK-3. The compounds were synthesized employing a Thorpe reaction as final step. The enantiomers of one congener were separated by chiral HPLC. All derivatives were tested for inhibition of asexual erythrocytic stages of transgenic NF54-luc Plasmodium falciparum. Selected compounds with promising antiplasmodial activity were further evaluated for inhibition of HEK293 cells as well as inhibition of isolated PfGSK-3 and HsGSK-3. The kinetic aqueous solubility was assessed by laser nephelometry.ResultsThe para position at the 4-phenyl ring of the title compounds was identified as a suitable point for the attachment of side chains. While alkoxy substituents in this position led to decreased antiplasmodial activity, alkylamino groups retained antiparasitic potency. The most promising of these congeners (4h) was investigated in detail. This compound is a selective PfGSK-3 inhibitor (versus the human GSK-3 orthologue), and exhibits improved antiplasmodial activity in vitro as well as better solubility in aqueous media than its unsubstituted parent structure. The derivative 4b was separated into the atropisomers, and it was shown that the (+)-enantiomer acts as eutomer.ConclusionsThe attachment of alkylamino side chains leads to the improvement of antiplasmodial activity and aqueous solubility of selective PfGSK-inhibitors belonging to the class of 4-phenylthieno[2,3-b]pyridines. These molecules show axial chirality, a feature of high impact for biological activity. The findings can be exploited for the development of improved selective PfGSK-3 inhibitors.