Current chemical-fuel-driven nanomotors are driven by gas (e.g. H2, O2, NH3) which only provides motion ability, and can produce waste Mg(OH)2, Pt). Here, inspired endogenous biochemical reactions in the human body involving conversion of amino acid L-arginine to nitric oxide (NO) NO synthase (NOS) or reactive oxygen species (ROS), we report on a nanomotor made hyperbranched polyamide/L-arginine (HLA). The utilizes as fuel for production both driving force provide beneficial effects,...

Sulfur and selenium occupy a distinguished position in biology owing to their redox activities, high nucleophilicity, acyl transfer capabilities. Thiolated/selenolated amino acids, including cysteine, selenocysteine, derivatives, play critical roles regulating the conformation function of proteins serve as an important motif for peptide design bioconjugation. Unfortunately, general concise method attain enantiopure β-thiolated/selenolated acids remains unsolved problem. Herein, we present...

Due to their architectural intricacy and biological significance, the synthesis of polycyclic diterpenes biogenetically related alkaloids have been subject considerable interest over last few decades, with progress including impressive several elusive targets. Despite tremendous efforts, conquering unique structural types this large natural product family remains a long-term challenge. The arcutane alkaloids, bearing congested tetracyclo[5.3.3.0(4,9).0(4,12)]tridecane unit, are included in...

A palladium-catalyzed vinylogous C-glycosylation of α,β-unsaturated lactones (including coumarins) is achieved in high yields with exclusive regio- and stereoselectivity. This efficient protocol carried out under mild conditions has an expanded substrate scope (51 examples) as well functional-group tolerance. gram-scale preparation 2,3-unsaturated C-glycosides illustrates the practicality this stereoselective glycosylation approach. The structural feature C-glycoside products enables...

An effective palladium-catalyzed oxidative C-H/C-H cross-coupling of imidazopyridines with azoles using air as the oxidant has been developed. This protocol provides a straightforward and operationally simple method for synthesis 3-azolyl-imidazopyridines in moderate to good yields functional group tolerance. The biological evaluation revealed that newly synthesized compounds 3e 3h exhibit significant vitro antiproliferative activities against human-derived lung cancer cell lines compared...

Abstract Background Deinococcus radiodurans accumulates high levels of manganese ions, and this is believed to be correlated with the radiation resistance ability microorganism. However, maintenance ion homeostasis in D. remains investigated. Results In study, we identified efflux protein (MntE) . The null mutant mntE was more sensitive than wild-type strain growth delayed manganese-supplemented media. Furthermore, there a substantial increase vivo concentration ions. Consistent these...

The synthesis of constrained 12-membered rings is notably difficult. main challenges result from constraints during the linear peptide cyclization. Attempts to overcome through excessive activation frequently cause peptidyl epimerization, while insufficient C-terminus hampers cyclization and promotes intermolecular oligomer formation. We present a β-thiolactone framework that enables cyclo-tetrapeptides via direct aminolysis. This tactic utilizes mechanism restricts C-terminal carbonyl...

A robust metal-organic frameworks (MOFs)-aerogel composite was prepared by a covalent post-assembly method, which shows outstanding catalytic activity and stability in CO₂ cycloaddition excellent adsorption capacity for dyes.

Chemical synthesis offers robust tactics for structural alterations of peptides and proteins. It remains a labor-intensive complex process due to the challenges in selectively modifying diverse amino acid side chains termini. Direct α-peptide ligation without premodification is significant hurdle, especially when aiming include all proteinogenic acids at site. We introduce Native Peptide Cyclization (NPC), chemoselective method enabling intramolecular peptidyl need premodification. NPC...

We present the serendipitous discovery of an unusual dimer formed from anthracene-derived polyarenes. Unlike typical oxidative coupling substituted aromatic scaffolds, reaction yielded a dearomatized enone as sole product. This motif, notably, does not undergo commonly observed rearomatization, and no biaryl products were detected. The anthracene dimers produced in excellent yields. Structural validation via single-crystal X-ray analysis revealed that feature sp3–sp3 carbon–carbon bond...

Abstract Total syntheses of (−)‐isoschizogamine and (−)‐2‐hydroxyisoschizogamine are described. The synthesis employs two asymmetric Michael additions to establish chiral centers at C7 the quaternary carbon C20. Regioselective reduction methylthioiminium cation rather than enamine generates an isoschizogamine‐type pentacyclic skeleton. Acidic hydrolysis intermediate in absence oxygen provides natural (−)‐isoschizogamine. Conducting reaction presence leads a multistep oxidative cascade that...

Peptidyl thioesters or their surrogates with C-terminal β-branched hydrophobic amino acid residues usually exhibit poor reactivities in ligation reactions. Thus, activation using exogenous additives is required to ensure an acceptable reaction efficiency. Herein, we report a traceless at Val-Xaa sites under mild thiol additive-free conditions, whereby the introduction of β-mercaptan on valine residue effectively activates otherwise unreactive N-acyl-benzimidazolinone (Nbz), and enables use...

The ligation of sterically demanding peptidyl sites such as those involving Val-Val and Val-Pro linkages has proven to be extremely challenging with conventional NCL methods that rely on exogenous thiol additives. Herein, we report an efficient β-thiolactone-mediated additive-free protocol enables the establishment these connections in good yield. rapid was followed by situ desulfurization. Reaction rates between β-thiolactones thioesters towards were also investigated, direct aminolysis...

Explanatory sentences are employed to clarify reasons, details, facts, and so on. High quality online product reviews usually include not only positive or negative opinions, but also a variety of explanations why these opinions were given. These can help readers get easily comprehensible information the discussed products aspects. Moreover, explanatory relations benefit sentiment analysis applications. In this work, we focus on task identifying subjective text segments extracting their...

Bisindolylmaleimide derivatives (IMs) were found to be sensitive different anions in various solvents, and utilized construct five logic devices.

A chemoselective primary amine modification strategy that enables the three-component, one-pot bioconjugation is described. The specifically designed, mercaptobenzaldehyde-based bifunctional linker achieves highly selective and robust labeling under biocompatible conditions. This demonstrates wide functional group tolerance simple to prepare, which allowed facile payload incorporation. Finally, our studies have shown introduction of does not impair function modified protein such as insulin.

Abstract Background Researches have shown that chronic inhalation of cigarette smoke (CS) disrupts male reproductive system, but it is unclear about the mechanisms behind damages by tobacco toxicants in rats. This study was designed to explore effects heated products (HTP) aerosols and CS exposure on testicular health Materials Methods Experiments were performed SD rats exposed filtered air, HTP at 10 μg/L, 23 50 μg/L nicotine-equivalent contents, also content for 90 days five groups (coded...

The high-throughput screening of chemically active substances has aroused widespread interest in recent years. drug carriers is usually ignored, although they interact directly with physiological barriers and target cells, determine the fate efficacy drugs vivo. In this work, a series polydiacetylene (PDA) vesicles (ca. 550 nm) that simulate cell membrane are constructed to detect affinity gene vectors. surface potentials adjusted by changing phospholipid composition using different charged...

Native chemical ligation (NCL) represents a cornerstone strategy in accessing synthetic peptides and proteins, remaining one of the most efficacious methodologies this domain. The fundamental requisites for achieving proficient NCL reaction involve chemoselective coupling between C-terminal thioester peptide thiol-bearing N-terminal peptide. However, at sterically congested residues remains challenging. In addition, while NCLs proceed without epimerization, β-branched (e.g., Ile, Thr, Val)...

We present a generic method for screening small molecule kinases their acceptor specificity. The release of the reaction byproduct adenosine diphosphate (ADP) triggers concentration-dependent formation amylose from sucrose, by using combined enzymatic action sucrose synthase and glycogen synthase. Kinase activities could be quantified photometrically after dark-blue amylose-polyiodide complex. demonstrate that this can used to profile both known novel nucleotide- sugar-kinases substrate...