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1.
Annu Rev Biochem ; 93(1): 447-469, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38603559

RESUMO

Lysosomes catabolize and recycle lipids and other biological molecules to maintain cellular homeostasis in diverse nutrient environments. Lysosomal lipid catabolism relies on the stimulatory activity of bis(monoacylglycero)phosphate (BMP), an enigmatic lipid whose levels are altered across myriad lysosome-associated diseases. Here, we review the discovery of BMP over half a century ago and its structural properties that facilitate the activation of lipid hydrolases and recruitment of their coactivators. We further discuss the current, yet incomplete, understanding of BMP catabolism and anabolism. To conclude, we discuss its role in lysosome-associated diseases and the potential for modulating its levels by pharmacologically activating and inhibiting the BMP synthase to therapeutically target lysosomal storage disorders, drug-induced phospholipidosis, Alzheimer's disease, Parkinson's disease, frontotemporal dementia, cancer, and viral infection.


Assuntos
Lisofosfolipídeos , Doenças por Armazenamento dos Lisossomos , Lisossomos , Monoglicerídeos , Humanos , Lisossomos/metabolismo , Lisofosfolipídeos/metabolismo , Monoglicerídeos/metabolismo , Monoglicerídeos/química , Animais , Doenças por Armazenamento dos Lisossomos/metabolismo , Doenças por Armazenamento dos Lisossomos/patologia , Doenças por Armazenamento dos Lisossomos/genética , Doenças por Armazenamento dos Lisossomos/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Doença de Alzheimer/genética , Metabolismo dos Lipídeos
2.
J Biol Chem ; : 107889, 2024 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-39395801

RESUMO

Niemann-Pick type C (NPC) disease, caused by mutations in the NPC1 or NPC2 genes, leads to abnormal intracellular cholesterol accumulation in late endosomes/lysosomes (LE/LY). Exogenous enrichment with lysobisphosphatidic acid (LBPA), also known as bis-monoacylglycerol phosphate or BMP, either directly or via the LBPA precursor phosphatidylglycerol (PG), has been investigated as a therapeutic intervention to reduce cholesterol accumulation in NPC disease. Here we report the effects of stereoisomer configuration and acyl chain composition of LBPA on cholesterol clearance in NPC1-deficient cells. We find that S,R, S,S, and S,R LBPA stereoisomers behaved similarly, with all 3 compounds leading to comparable reductions in filipin staining in two NPC1-deficient human fibroblast cell lines. Examination of several LBPA molecular species containing one or two mono- or polyunsaturated acyl chains showed that all LBPA species containing one 18:1 chain significantly reduced cholesterol accumulation, whereas the shorter chain species di-14:0 LBPA had little effect on cholesterol clearance in NPC1 deficient cells. Since cholesterol accumulation in NPC1 deficient cells can also be cleared by PG incubation, we used non-hydrolyzable PG analogues to determine whether conversion to LBPA is required for sterol clearance, or whether PG itself is effective. The results showed that non-hydrolyzable PG species were not appreciably converted to LBPA and showed virtually no cholesterol clearance efficacy in NPC1 deficient cells, supporting the notion that LBPA is the active agent promoting LE/LY cholesterol clearance. Overall these studies are helping to define the molecular requirements for potential therapeutic use of LBPA as an option for addressing NPC disease.

3.
Plant J ; 119(1): 176-196, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38575203

RESUMO

4-Coumarate-CoA Ligase (4CL) is an important enzyme in the phenylpropanoid biosynthesis pathway. Multiple 4CLs are identified in Ocimum species; however, their in planta functions remain enigmatic. In this study, we independently overexpressed three Ok4CL isoforms from Ocimum kilimandscharicum (Ok4CL7, -11, and -15) in Nicotiana benthamiana. Interestingly, Ok4CL11 overexpression (OE) caused a rootless or reduced root growth phenotype, whereas overexpression of Ok4CL15 produced normal adventitious root (AR) growth. Ok4CL11 overexpression in N. benthamiana resulted in upregulation of genes involved in flavonoid biosynthesis and associated glycosyltransferases accompanied by accumulation of specific flavonoid-glycosides (kaempferol-3-rhamnoside, kaempferol-3,7-O-bis-alpha-l-rhamnoside [K3,7R], and quercetin-3-O-rutinoside) that possibly reduced auxin levels in plants, and such effects were not seen for Ok4CL7 and -15. Docking analysis suggested that auxin transporters (PINs/LAXs) have higher binding affinity to these specific flavonoid-glycosides, and thus could disrupt auxin transport/signaling, which cumulatively resulted in a rootless phenotype. Reduced auxin levels, increased K3,7R in the middle and basal stem sections, and grafting experiments (intra and inter-species) indicated a disruption of auxin transport by K3,7R and its negative effect on AR development. Supplementation of flavonoids and the specific glycosides accumulated by Ok4CL11-OE to the wild-type N. benthamiana explants delayed the AR emergence and also inhibited AR growth. While overexpression of all three Ok4CLs increased lignin accumulation, flavonoids, and their specific glycosides were accumulated only in Ok4CL11-OE lines. In summary, our study reveals unique indirect function of Ok4CL11 to increase specific flavonoids and their glycosides, which are negative regulators of root growth, likely involved in inhibition of auxin transport and signaling.


Assuntos
Flavonoides , Glicosídeos , Nicotiana , Proteínas de Plantas , Raízes de Plantas , Flavonoides/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Raízes de Plantas/genética , Glicosídeos/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Nicotiana/genética , Nicotiana/crescimento & desenvolvimento , Nicotiana/metabolismo , Regulação da Expressão Gênica de Plantas , Plantas Geneticamente Modificadas , Coenzima A Ligases/metabolismo , Coenzima A Ligases/genética
4.
J Virol ; 98(8): e0032724, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39082785

RESUMO

African swine fever (ASF), caused by the African swine fever virus (ASFV), is a highly infectious disease afflicting domestic pigs and wild boars. It exhibits an alarming acute infection fatality rate of up to 100%. Regrettably, no commercial vaccines or specific drugs for combating this disease are currently available. This study evaluated the anti-ASFV activities in porcine alveolar macrophages, 3D4/21 cells, and PK-15 cells of four bis-benzylisoquinoline alkaloids (BBAs): cepharanthine (CEP), tetrandrine, fangchinoline, and iso-tetrandrine. Furthermore, we demonstrated that CEP, which exhibited the highest selectivity index (SI = 81.31), alkalized late endosomes/lysosomes, hindered ASFV endosomal transport, disrupted virus uncoating signals, and thereby inhibited ASFV internalization. Additionally, CEP disrupted ASFV DNA synthesis, leading to the inhibition of viral replication. Moreover, berbamine was labeled with NBD to synthesize a fluorescent probe to study the cellular location of these BBAs. By co-staining with Lyso-Tracker and lysosome-associated membrane protein 1, we demonstrated that BBAs target the endolysosomal compartments for the first time. Our data together indicated that BBAs are a class of natural products with significant inhibitory effects against ASFV infection. These findings suggest their potential efficacy as agents for the prevention and control of ASF, offering valuable references for the identification of potential drug targets.IMPORTANCEThe urgency and severity of African swine fever (ASF) underscore the critical need for effective interventions against this highly infectious disease, which poses a grave threat to domestic pigs and wild boars. Our study reveals the potent anti-African swine fever virus (ASFV) efficacy of bis-benzylisoquinoline alkaloids (BBAs), particularly evident in the absence of progeny virus production under a 5 µM concentration treatment. The structural similarity among cepharanthine, tetrandrine, fangchinoline, and iso-tetrandrine, coupled with their analogous inhibitory stages and comparable selectivity indexes, strongly suggests a shared antiviral mechanism within this drug category. Further investigation revealed that BBAs localize to lysosomes and inhibit the internalization and replication of ASFV by disrupting the endosomal/lysosomal function. These collective results have profound implications for ASF prevention and control, suggesting the potential of the investigated agents as prophylactic and therapeutic measures. Furthermore, our study offers crucial insights into identifying drug targets and laying the groundwork for innovative interventions.


Assuntos
Vírus da Febre Suína Africana , Antivirais , Benzilisoquinolinas , Endossomos , Lisossomos , Internalização do Vírus , Replicação Viral , Animais , Vírus da Febre Suína Africana/efeitos dos fármacos , Vírus da Febre Suína Africana/fisiologia , Internalização do Vírus/efeitos dos fármacos , Benzilisoquinolinas/farmacologia , Replicação Viral/efeitos dos fármacos , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Lisossomos/virologia , Suínos , Endossomos/metabolismo , Endossomos/efeitos dos fármacos , Endossomos/virologia , Antivirais/farmacologia , Linhagem Celular , Febre Suína Africana/virologia , Febre Suína Africana/tratamento farmacológico , Febre Suína Africana/metabolismo , Guanina/análogos & derivados , Guanina/farmacologia , Alcaloides/farmacologia , Macrófagos Alveolares/virologia , Macrófagos Alveolares/efeitos dos fármacos , Benzodioxóis
5.
Mol Ther ; 32(6): 1917-1933, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38637990

RESUMO

Cancer immunotherapy has greatly improved the prognosis of tumor-bearing patients. Nevertheless, cancer patients exhibit low response rates to current immunotherapy drugs, such as PD1 and PDL1 antibodies. Cyclic dinucleotide analogs are a promising class of immunotherapeutic agents. In this study, in situ autologous tumor vaccines, composed of bis-2'-F-cGSASMP phosphonothioate isomers (FGA-di-pS-2 or FGA-di-pS-4) and cytidinyl/cationic lipids (Mix), were constructed. Intravenous and intratumoral injection of FGA-di-pS-2/Mix or FGA-di-pS-4/Mix enhanced the immunogenic cell death of tumor cells in vivo, leading to the exposure and presentation of whole tumor antigens, inhibiting tumor growth in both LLC and EO771 tumor in situ murine models and increasing their survival rates to 50% and 23%, respectively. Furthermore, the tumor-bearing mice after treatment showed potent immune memory efficacy and exhibited 100% protection against tumor rechallenge. Intravenous administration of FGA-di-pS-2/Mix potently promoted DC maturation, M1 macrophage polarization and CD8+ T cell activation and decreased the proportion of Treg cells in the tumor microenvironment. Notably, two doses of ICD-debris (generated by FGA-di-pS-2 or 4/Mix-treated LLC cells) protected 100% of mice from tumor growth. These tumor vaccines showed promising results and may serve as personalized cancer vaccinations in the future.


Assuntos
Vacinas Anticâncer , Imunoterapia , Animais , Camundongos , Vacinas Anticâncer/imunologia , Vacinas Anticâncer/administração & dosagem , Imunoterapia/métodos , Linhagem Celular Tumoral , Humanos , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/imunologia , Linfócitos T CD8-Positivos/imunologia , Modelos Animais de Doenças , Neoplasias/imunologia , Neoplasias/tratamento farmacológico , Neoplasias/terapia , Células Dendríticas/imunologia , Feminino , Antígenos de Neoplasias/imunologia
6.
J Lipid Res ; 65(7): 100574, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38857781

RESUMO

Bis(monoacylglycerol)phosphate (BMP) is an acidic glycerophospholipid localized to late endosomes and lysosomes. However, the metabolism of BMP is poorly understood. Because many drugs that cause phospholipidosis inhibit lysosomal phospholipase A2 (LPLA2, PLA2G15, LYPLA3) activity, we investigated whether this enzyme has a role in BMPcatabolism. The incubation of recombinant human LPLA2 (hLPLA2) and liposomes containing the naturally occurring BMP (sn-(2-oleoyl-3-hydroxy)-glycerol-1-phospho-sn-1'-(2'-oleoyl-3'-hydroxy)-glycerol (S,S-(2,2',C18:1)-BMP) resulted in the deacylation of this BMP isomer. The deacylation rate was 70 times lower than that of dioleoyl phosphatidylglycerol (DOPG), an isomer and precursor of BMP. The release rates of oleic acid from DOPG and four BMP stereoisomers by LPLA2 differed. The rank order of the rates of hydrolysis were DOPG>S,S-(3,3',C18:1)-BMP>R,S-(3,1',C18:1)-BMP>R,R-(1,1',C18:1)>S,S-(2,2')-BMP. The cationic amphiphilic drug amiodarone (AMD) inhibited the deacylation of DOPG and BMP isomers by hLPLA2 in a concentration-dependent manner. Under these experimental conditions, the IC50s of amiodarone-induced inhibition of the four BMP isomers and DOPG were less than 20 µM and approximately 30 µM, respectively. BMP accumulation was observed in AMD-treated RAW 264.7 cells. The accumulated BMP was significantly reduced by exogenous treatment of cells with active recombinant hLPLA2 but not with diisopropylfluorophosphate-inactivated recombinant hLPLA2. Finally, a series of cationic amphiphilic drugs known to cause phospholipidosis were screened for inhibition of LPLA2 activity as measured by either the transacylation or fatty acid hydrolysis of BMP or phosphatidylcholine as substrates. Fifteen compounds demonstrated significant inhibition with IC50s ranging from 6.8 to 63.3 µM. These results indicate that LPLA2 degrades BMP isomers with different substrate specificities under acidic conditions and may be the key enzyme associated with BMP accumulation in drug-induced phospholipidosis.


Assuntos
Lisofosfolipídeos , Lisossomos , Monoglicerídeos , Humanos , Lisossomos/metabolismo , Lisossomos/enzimologia , Monoglicerídeos/metabolismo , Lisofosfolipídeos/metabolismo , Animais , Camundongos , Fosfolipases A2/metabolismo , Fosfolipídeos/metabolismo , Lipossomos/metabolismo , Lipidoses/metabolismo , Lipidoses/induzido quimicamente , Lipidoses/enzimologia
7.
Small ; : e2406282, 2024 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-39428868

RESUMO

Organosulfides are considered promising cathode materials for zinc batteries due to their merits of high-density active sites and multielectron reactions, but often suffer from sluggish kinetics and limited electrochemical stability. Here organic iodide-catalyzed is reported and stabilized multielectron-redox bis(dimethylthiocarbamyl) sulfide (BS) cathode for superior zinc-organosulfide batteries. Activated by 2e- I-/I3 - conversion in 1-methyl-3-propylimidazolium iodide (MPII)-modulated electrolyte, the electron-deficient structure of BS can stretch the electron cloud of two adjacent C═S bonds to form bipedal C─S bonds, affording high-kinetics and stable 2e- Zn─S storage electrochemistry. This allows high accessibility of zincophilic dual C = S sites with a low activation energy, and stabilizes BS to fulfil anti-dissolution in electrolyte. Consequently, Zn||BS battery with 4e- conversion-coordination harvests high-rate capacities (452 mAh g-1 at 1 A g-1; 255 mAh g-1 at 10 A g-1), high energy density (312 Wh kg-1) and ultralong life (30000 cycles), becoming the state-of-the-art zinc batteries in all-round metrics. This work constitutes a significant advance in developing high-redox-activity organosulfide materials and stand for a good starting point for advanced zinc batteries.

8.
Small ; : e2403336, 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39221547

RESUMO

In the quest for efficient and stable oxygen evolution catalysts (OECs) for photoelectrochemical water splitting, the surface modification of BiVO4 is a crucial step. In this study, a novel and robust OEC, based on 3-(bis(pyridin-2-ylmethyl) amino) propanoic acid bifunctional linker known as dipicolyl alanine acid (DPAA) and cobalt ions, is prepared and fully characterized. The DPAA is anchored to the surface of BiVO4 and utilized to tether cobalt ions. The Co-DPAA/BiVO4 photoanode exhibits remarkable stability and efficiency toward photoelectrochemical water oxidation. Specifically, it showed anodic photocurrent increase of 7.1, 5.0, 3.0, and 1.3-fold at 1.23 VRHE as compared to pristine BiVO4, DPAA/BiVO4, Co-BiVO4, and Co-Pi/BiVO4 photoanodes, respectively. The photoelectrochemical and IMPS studies revealed that the Co-DPAA/BiVO4 photoanode exhibits a longer transient decay time for surface-trapped holes, higher charge transfer kinetics, and charge separation efficiency compared to Co-Pi/BiVO4 and pristine BiVO4 photoelectrodes. This indicates that the Co-DPAA effectively reduces surface recombination and facilitates charge transfer. Moreover, at 1.23 VRHE, the Co-DPAA/BiVO4 photoanode achieved a faradic efficiency of 92% for oxygen evolution reaction and could retain a turnover frequency of 3.65 s-1. The- exhibited effeciency is  higher than most of the efficient molecular oxygen evolution catalyst based on Ru.

9.
Appl Environ Microbiol ; 90(7): e0093324, 2024 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-38953372

RESUMO

Starch utilization system (Sus)D-homologs are well known for their carbohydrate-binding capabilities and are part of the sus operon in microorganisms affiliated with the phylum Bacteroidota. Until now, SusD-like proteins have been characterized regarding their affinity toward natural polymers. In this study, three metagenomic SusD homologs (designated SusD1, SusD38489, and SusD70111) were identified and tested with respect to binding to natural and non-natural polymers. SusD1 and SusD38489 are cellulose-binding modules, while SusD70111 preferentially binds chitin. Employing translational fusion proteins with superfolder GFP (sfGFP), pull-down assays, and surface plasmon resonance (SPR) has provided evidence for binding to polyethylene terephthalate (PET) and other synthetic polymers. Structural analysis suggested that a Trp triad might be involved in protein adsorption. Mutation of these residues to Ala resulted in an impaired adsorption to microcrystalline cellulose (MC), but not so to PET and other synthetic polymers. We believe that the characterized SusDs, alongside the methods and considerations presented in this work, will aid further research regarding bioremediation of plastics. IMPORTANCE: SusD1 and SusD38489 can be considered for further applications regarding their putative adsorption toward fossil-fuel based polymers. This is the first time that SusD homologs from the polysaccharide utilization loci (PUL), largely described for the phylum Bacteroidota, are characterized as synthetic polymer-binding proteins.


Assuntos
Proteínas de Bactérias , Bacteroidetes , Metagenoma , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Bacteroidetes/genética , Bacteroidetes/metabolismo , Celulose/metabolismo , Polímeros/metabolismo , Quitina/metabolismo , Polietilenotereftalatos/metabolismo
10.
Ann Surg Oncol ; 31(11): 7487-7495, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38965099

RESUMO

BACKGROUND: The PREVENT randomized control trial monitored progression to chronic breast cancer-related lymphedema (cBCRL) following intervention for subclinical breast cancer-related lymphedema (sBCRL) assessed by bioimpedance spectroscopy (BIS) versus tape-measure (TM). This multi-institutional trial demonstrated a 92% risk reduction of developing cBCRL. This secondary analysis reviews the timing of sBCRL and cBCRL following breast cancer (BC) treatment. PATIENTS AND METHODS: Women at risk of cBCRL (n = 919) were screened regularly up to 36 months after BC treatment using either BIS or TM. Following diagnosis of sBCRL, patients underwent a 4-week compression sleeve intervention. The time in months from BC treatment to detection was reviewed at 3-month intervals. RESULTS: In total 209 patients developed sBCRL (BIS: n = 89, TM: n = 120) and were eligible for intervention. 30 progressed to cBCRL postintervention (BIS: 7, TM: 23). More than half of patients had measurements consistent with sBCRL within 9 months of BC treatment. Patients continued to have initial detections of sBCRL, regardless of screening method, with rates remaining consistent in years two and three (p > 0.242) post surgery. Additionally, 39 patients progressed to cBCRL without developing sBCRL or receiving intervention across the 3-year period. CONCLUSIONS: The timing of sBCRL detection demonstrates that patients continue to be at risk years after treatment and may continue to progress to cBCRL years after surgery. Early detection of sBCRL allows for early intervention decreasing the likelihood of progression to cBCRL. Patients should continue to be monitored for a minimum of 3 years following completion of cancer treatment. Specifically, careful targeted monitoring over the initial 9-month period is important.


Assuntos
Neoplasias da Mama , Espectroscopia Dielétrica , Humanos , Feminino , Estudos Prospectivos , Espectroscopia Dielétrica/métodos , Neoplasias da Mama/complicações , Neoplasias da Mama/cirurgia , Pessoa de Meia-Idade , Seguimentos , Linfedema Relacionado a Câncer de Mama/diagnóstico , Linfedema Relacionado a Câncer de Mama/etiologia , Linfedema Relacionado a Câncer de Mama/terapia , Fatores de Tempo , Prognóstico , Idoso , Adulto , Progressão da Doença
11.
J Biol Inorg Chem ; 29(3): 315-330, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38722397

RESUMO

Eighteen novel Ti(IV) complexes stabilized by different chelating amino-bis(phenolato) (ONNO, ONON, ONOO) ligands and 2,6-dipicolinic acid as a second chelator were synthesized with isolated yields ranging from 79 to 93%. Complexes were characterized by 1H and 13C-NMR spectroscopy, as well as by HRMS and X-Ray diffraction analysis. The good to excellent aqueous stability of these Ti(IV) complexes can be modulated by the substitutions on the 2-position of the phenolato ligands. Most of the synthesized Ti(IV) complexes demonstrated potent inhibitory activity against Hela S3 and Hep G2 tumor cells. Among them, the naphthalenyl based Salan type 2j, 2-picolylamine based [ONON] type 2n and N-(2-hydroxyethyl) based [ONOO] type 2p demonstrated up to 40 folds enhanced cytotoxicity compared to cisplatin together with a significantly reduced activity against healthy AML12 cells. The three Ti(IV) complexes exhibited fast cellular uptake by Hela S3 cells and induced almost exclusively apoptosis. 2j could trigger higher level of ROS generation than 2p and 2n.


Assuntos
Antineoplásicos , Complexos de Coordenação , Ensaios de Seleção de Medicamentos Antitumorais , Ácidos Picolínicos , Titânio , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Ácidos Picolínicos/química , Ácidos Picolínicos/farmacologia , Ácidos Picolínicos/síntese química , Complexos de Coordenação/química , Complexos de Coordenação/farmacologia , Complexos de Coordenação/síntese química , Relação Estrutura-Atividade , Titânio/química , Titânio/farmacologia , Células HeLa , Apoptose/efeitos dos fármacos , Estrutura Molecular , Proliferação de Células/efeitos dos fármacos
12.
Chemistry ; : e202403432, 2024 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-39365835

RESUMO

The preparation of enantioenriched diarylmethanol derivatives is described using nickel-catalyzed electrochemical cross-couplings between various alkyl/aryl aldehydes and aryl iodides. Performed in an electrochemical cell equipped with an iron anode and a nickel cathode, this electrocatalytic variant led to the scalemic targeted products in the presence of 2,2-bis((4R,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)acetonitrile (L2), as enantiopure cyano-bis(oxazoline) ligand. X-ray structure analysis of a pre-catalyst, for instance the [Ni(II)(L2)2] complex, with L2 as an anionic bisoxazolinate ligand, confirms the chemical formulation of one nickel surrounded by two ligands. The redox behavior of the new Ni complexes generated in situ was first assessed by cyclic voltammetry showing a redox wave at ca. -1.5 V that can be assigned to the two-electron reduction of the Ni(II) center to the Ni(0) state. Oxidative addition between the electrogenerated Ni(0) complex and aryl iodide was evidenced. An intense current was observed in presence of a mixture of the two substrates pertaining an electrocatalytic process. Interestingly, we found that the sacrificial iron anode plays a crucial role in the catalytic mechanism.

13.
Chemistry ; : e202402634, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39078075

RESUMO

BODIPYs have a well-established role in biological sciences as chemosensors and versatile biological markers due to their chemical reactivity, which allows for fine-tuning of their photophysical characteristics. In this work, we combined the unique reactivity of arylazo sulfones with the advantages of a "sunflow" reactor to develop a fast, efficient, and versatile method for the photochemical arylation of BODIPYs and other chromophores. This approach resulted in red-shifted emitting fluorophores due to extended electronic delocalization at the 3- and 5-positions of the BODIPY core. This method represents an advantageous approach for BODIPY functionalization compared to existing strategies.

14.
Chemistry ; 30(42): e202401665, 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-38789388

RESUMO

Gallylene supported by a bis(oxazolinyl)(phenyl)methanide (Boxm) ligand was synthesized and structurally characterized. The reaction of this gallylene with triphenylphosphine sulfide/selenide yielded dimeric gallium sulfide and selenide. These compounds could be converted to monomeric terminal sulfide and selenide by coordination of an external Lewis base such as an N-heterocyclic carbene (NHC or IMe4) and 4-dimethylaminopyridiene (DMAP). These doubly-base-stabilized gallium sulfide/selenide reacted with phenyl isocyanate to give the corresponding cycloadducts by releasing the Lewis base, indicating the formation of a single-base-stabilized gallium sulfide/selenide intermediate.

15.
Chemistry ; 30(19): e202304270, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38285527

RESUMO

With peptides increasingly favored as drugs, natural product motifs, namely the tryptathionine staple, found in amatoxins and phallotoxins, and the 2,2'-bis-indole found in staurosporine represent unexplored staples for unnatural peptide macrocycles. We disclose the efficient condensation of a 5-hydroxypyrroloindoline with either a cysteine-thiol or a tryptophan-indole to form a tryptathionine or 2-2'-bis-indole staple. Judicious use of protecting groups provides for chemoselective stapling using α-MSH, which provides a basis for investigating both chemoselectivity and affinity. Both classes of stapled peptides show nanomolar Ki's, with one showing a sub-nanomolar Ki value.


Assuntos
Peptídeos Cíclicos , alfa-MSH/análogos & derivados , Cisteína , Indóis
16.
Chemistry ; : e202402731, 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39231129

RESUMO

The first examples of bis-squaramide axle containing [2]rotaxanes linked via rigid aryl and flexible alkyl spacers synthesised using copper(I) catalysed active metal template methodology are reported. The halide and oxoanion binding properties of the [2]rotaxanes in aqueous-organic solvent media are examined through extensive 1H-NMR titration experiments to investigate the impact of integrating multiple squaramide motifs on the anion binding capabilities of the interlocked receptors. These studies reveal that the bis-squaramide rotaxane host systems exhibit enhanced halide anion binding capabilities relative to a mono-squaramide axle functionalised rotaxane, demonstrating a rare anti-Hofmeister bias halide anion selectivity trend in aqueous-organic mixtures and highlighting the efficacy of the potent solvent shielded hydrophobic interlocked binding pocket created upon mechanical bond formation. Notably, employing a rigid aryl linker between the two squaramide motifs in the axle component enables the rotaxane host to exhibit strong and selective binding of tetrahedral oxoanions. Conversely, a flexible alkyl spacer facilitates trigonal oxoanion selective recognition by the bis-squaramide [2]rotaxane.

17.
Chemistry ; 30(18): e202303994, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38323675

RESUMO

Immobilization of stimulus-responsive systems on solid surfaces is beneficial for controlled signal transmission and adaptive behavior while allowing the characterization of the functional interface with high sensitivity and high spatial resolution. Positioning of the stimuli-responsive units with nanometer-scale precision across the adaptive surface remains one of the bottlenecks in the extraction of cooperative function. Nanoscale organization, cooperativity, and amplification remain key challenges in bridging the molecular and the macroscopic worlds. Here we report on the design, synthesis, and scanning tunneling microscopy (STM) characterization of overcrowded alkene photoswitches merged in self-assembled networks physisorbed at the solid-liquid interface. A detailed anchoring strategy that ensures appropriate orientation of the switches with respect to the solid surface through the use of bis-urea groups is presented. We implement a co-assembly strategy that enables the merging of the photoswitches within physisorbed monolayers of structurally similar 'spacer' molecules. The self-assembly of the individual components and the co-assemblies was examined in detail using (sub)molecular resolution STM which confirms the robust immobilization and controlled orientation of the photoswitches within the spacer monolayers. The experimental STM data is supported by detailed molecular mechanics (MM) simulations. Different designs of the switches and the spacers were investigated which allowed us to formulate guidelines that enable the precise organization of the photoswitches in crystalline physisorbed self-assembled molecular networks.

18.
Chemistry ; 30(29): e202304291, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38490950

RESUMO

The reaction between bis(1,2,3-triazol-1-yl)methane derivatives and nBuLi and various aldehydes, yielded novel neutral ligand precursors incorporating alcohol functional groups. The resulting compounds exhibited distinct characteristics depending on the steric hindrance of the aldehyde employed. In instances where aromatic aldehydes were utilized, functionalization occurred at the methine group bridging both triazole rings. Conversely, the use of pivalic aldehyde prompted functionalization at the C5 position of the triazole ring. These compounds were subsequently employed as ligand precursors in the synthesis of organometallic aluminum and zinc complexes, yielding dinuclear complexes with high efficiency. The structural elucidation of all compounds was accomplished through spectroscopic methods and validated by X-ray crystallography. Preliminary catalytic investigations into the coupling reaction of cyclohexene oxide and CO2 revealed that aluminum and zinc complexes catalyzed the selective formation of polyether and polycarbonate materials, respectively.

19.
Chemistry ; 30(43): e202401321, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38801410

RESUMO

A sodium bis(fluorosulfonyl)imide (NaFSI)-based multifunctional electrolyte is developed by partially replacing NaPF6 salt in the electrolyte to improve the wide temperature range working capability of NaNi1/3Fe1/3Mn1/3O2/hard carbon (NNFM111/HC) sodium-ion batteries (SIBs). The capacity retention of the SIBs with NaFSI-NaPF6 dual salt electrolyte increases from 47.2 % to 75.5 % after 250 cycles at 25 °C, and from 51.0 % to 82.3 % after 80 cycles at 45 °C, and the 1 C discharge capacity retention at the low temperature of -20 °C also increases 26.8 %. In the single salt system, NaPF6 effectively passivate the aluminum foil and NaFSI passivate the electrode/electrolyte interface. The synergistic effect of NaPF6 and NaFSI greatly improves the battery performance in a wide temperature range. This NaFSI-based dual salt electrolyte also effectively overcomes the flaws when the SIBs using NaFSI or NaPF6 independently, and makes it more suitable for SIBs, indicating promising prospects in the commercial application of NNFM111/HC SIBs.

20.
Chemistry ; 30(47): e202401762, 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-38888454

RESUMO

Force-related discoloration materials are highly valuable because of their characteristics of visualization, easy operation, and environment friendliness. Most force-related discoloration materials focus on polymers and depend on bond scission, which leads to insensitivity and unrecoverable. Small-molecule systems based on well-defined molecular structures and simple composition with high sensitivity would exhibit considerable mechanochromic potential. However, to date, researches about force-related discoloration materials based on small molecule solution remain limited and are rarely reported. In this study, we developed a repeatable and instantaneous discoloration small molecule solution system by simple one-pot synthesis method. It exhibited an instantaneous chromic change from yellowish to dark green under shaking and reverting back to yellow within 1 minute after removal of the shaking. Experimental results confirmed that the discoloration mechanism is attributed to the oscillation accelerating the production of unstable ortho-OH phenoxyl radical. The newly developed shaking-induced discoloration small molecule system (SDSMS) promises in field of mechanical force sensing and optical encryption.

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