RESUMO
Six previously undescribed prenylated indole diketopiperazine alkaloids, talaromyines A-F (1-6), were isolated from the marine-derived fungus Talaromyces purpureogenus SCSIO 41517. Their structures including absolute configurations were elucidated on the basis of comprehensive spectroscopic data including NMR, HR-ESI-MS, and electronic circular dichroism calculations, together with chemical analysis of hydrolysates. Compounds 1-5 represent the first example of spirocyclic indole diketopiperazines biosynthesized from the condensation of L-tryptophan and L-alanine. Compounds 2 and 4-5 showed selective inhibitory activities against phosphatases TCPTP and MEG2 with IC50 value of 17.9-29.7 µM, respectively. Compounds 4-5 exhibited mild cytotoxic activities against two human cancer cell lines H1975 and HepG-2.
Assuntos
Dicetopiperazinas , Talaromyces , Talaromyces/química , Dicetopiperazinas/química , Dicetopiperazinas/farmacologia , Dicetopiperazinas/isolamento & purificação , Humanos , Estrutura Molecular , Prenilação , Ensaios de Seleção de Medicamentos Antitumorais , Relação Estrutura-Atividade , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Alcaloides Indólicos/isolamento & purificação , Alcaloides Indólicos/química , Alcaloides Indólicos/farmacologia , Alcaloides/química , Alcaloides/farmacologia , Alcaloides/isolamento & purificação , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Células Hep G2 , Proliferação de Células/efeitos dos fármacos , Monoéster Fosfórico Hidrolases/antagonistas & inibidores , Monoéster Fosfórico Hidrolases/metabolismo , Linhagem Celular TumoralRESUMO
To assess the positive rate of 11 respiratory pathogens in 2023, providing a comprehensive summary and analysis of the respiratory infection patterns after COVID-19 pandemic. The study comprised 7544 inpatients suspected of respiratory infections who underwent respiratory pathogen multiplex polymerase chain reaction tests from July 2022 to December 31, 2023. We analyzed the positive rate of 11 pathogens over 18 months and the characterization of infection patterns among different age groups and immune states. Among 7544 patients (age range 4 months to 104 years, 44.99% female), the incidence of infected by at least one of the 11 pathogens was 26.07%. Children (55.18%, p < 0.05) experienced a significantly higher infection probability than adults (20.88%) and old (20.66%). Influenza A virus (8.63%), Mycoplasma pneumoniae (5.47%), and human rhinovirus (5.12%) were the most common pathogens. In children, M. pneumoniae (35.96%) replaced the predominant role of human respiratory syncytial virus (HRSV) (5.91%) in the pathogen spectrum. Age, immunosuppressed state, and respiratory chronic conditions were associated with a significantly higher risk of mixed infection. Immunosuppressed patients were more vulnerable to human coronavirus (4.64% vs. 1.65%, p < 0.05), human parainfluenza virus (3.46% vs. 1.69%, p < 0.05), and HRSV (2.27% vs. 0.55%, p < 0.05). Patterns in respiratory infections changed following regional epidemic control measures and the COVID-19 pandemic.
Assuntos
COVID-19 , Vírus Sincicial Respiratório Humano , Infecções Respiratórias , Criança , Adulto , Humanos , Feminino , Lactente , Masculino , COVID-19/epidemiologia , Pandemias , China/epidemiologia , Mycoplasma pneumoniaeRESUMO
Eight new decahydrofluorene-class alkaloids, microascones A and B (1 and 2), 2,3-epoxyphomapyrrolidone C (3), 14,16-epiascomylactam B (4), 24-hydroxyphomapyrrolidone A (5), and microascones C-E (6-8), along with five known analogs (9-13) were isolated from the marine-derived fungus Microascus sp. SCSIO 41821. Compounds 1 and 2 have an unprecedented complex macrocyclic alkaloid skeleton with a 6/5/6/5/6/5/13 polycyclic system. Their structures and absolute configurations were determined by spectroscopic analysis, quantum chemical calculations of ECD spectra, and 13C NMR chemical shifts. Compounds 10-13 showed selective enzyme inhibitory activity against PTPSig, PTP1B, and CDC25B, and 4, 9, and 10 exhibited strong antibacterial activity against seven tested pathogens. Their structure-bioactivity relationship was discussed, and a plausible biosynthetic pathway for 1-8 was also proposed.
Assuntos
Alcaloides , Antibacterianos , Testes de Sensibilidade Microbiana , Alcaloides/farmacologia , Alcaloides/química , Alcaloides/isolamento & purificação , Estrutura Molecular , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Relação Estrutura-Atividade , Biologia Marinha , Ascomicetos/química , Fluorenos/farmacologia , Fluorenos/química , Fluorenos/isolamento & purificação , Proteína Tirosina Fosfatase não Receptora Tipo 1/antagonistas & inibidoresRESUMO
Four previously undescribed angucyclinones umezawaones A-D (1-4) were isolated from the liquid cultures of Umezawaea beigongshangensis. Their structures were determined by spectroscopic analyses, single crystal X-ray diffraction, quantum chemical 13C NMR and electronic circular dichroism calculations. All compounds displayed strong inhibitory activities against indoleamine 2,3-dioxygenase and tryptophan-2,3-dioxygenase in enzymatic assay, especially compound 2.
Assuntos
Actinobacteria , Triptofano Oxigenase , Triptofano Oxigenase/química , Triptofano Oxigenase/metabolismo , Anguciclinas e Anguciclinonas , Actinomyces/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenase , Estrutura MolecularRESUMO
Exogenous ethylene is commonly utilized to initiate flower induction in pineapple (Ananas comosus (L.) Merr.). However, the molecular mechanisms and metabolic changes involved are not well understood. In this study, we explored the genetic network and metabolic shifts in the 'Comte de Paris' pineapple variety during ethylene-induced flowering. This was achieved through an integrative analysis of metabolome and transcriptome profiles at vegetative shoot apexes (0 d after ethephon treatment named BL_0d), the stage of bract primordia (8 d after ethephon treatment named BL_8d), stage of flower primordia (18 d after ethephon treatment named BL_18d), and the stage of stopped floret differentiation (34 d after ethephon treatment named BL_34d). We isolated and identified 804 metabolites in the pineapple shoot apex and inflorescence, categorized into 24 classes. Notably, 29, 31, and 46 metabolites showed significant changes from BL_0d to BL_8d, BL_8d to BL_18d, and BL_18d to BL_34d, respectively. A marked decrease in indole was observed, suggesting its role as a characteristic metabolite during flower induction. Transcriptomic analysis revealed 956, 1768, and 4483 differentially expressed genes (DEGs) for BL_0d vs. BL_8d, BL_8d vs. BL_18d, and BL_18d vs. BL_34d, respectively. These DEGs were significantly enriched in carbohydrate metabolism and hormone signaling pathways, indicating their potential involvement in flower induction. Integrating metabolomic and transcriptomic data, we identified several candidate genes, such as Agamous-Like9 (AGL9), Ethylene Insensitive 3-like (ETIL3), Apetala2 (AP2), AP2-like ethylene-responsive transcription factor ANT (ANT), and Sucrose synthase 2 (SS2), that play potentially crucial roles in ethylene-induced flower induction in pineapple. We also established a regulatory network for pineapple flower induction, correlating metabolites and DEGs, based on the Arabidopsis thaliana pathway as a reference. Overall, our findings offer a deeper understanding of the metabolomic and molecular mechanisms driving pineapple flowering.
Assuntos
Ananas , Transcriptoma , Ananas/genética , Ananas/metabolismo , Redes Reguladoras de Genes , Etilenos/metabolismo , Flores/genética , Flores/metabolismo , Metaboloma , Regulação da Expressão Gênica de PlantasRESUMO
A new aromatic polyketide, alternaphenol B2 (1), and four known compounds (2-5) were isolated from the coral-derived fungus Parengyodontium album SCSIO SX7W11. Their structures were elucidated by high-resolution mass spectrometry, 1D and 2D NMR spectroscopy and comparison with reported literatures. Compounds 1 and 2 exhibited selective inhibitory activity against isocitrate dehydrogenase mutant R132H (IDH1m), with IC50 values of 41.9 and 27.7 µM, respectively. Our findings thus provide a fresh incentive for investigation on IDH1m inhibitors as lead compounds for cancer treatment.
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We report the use of l-aspartic acid chiral ionic hydrogen bonds to drive liquid-liquid phase separation (LLPS) and precision two-dimensional electrostatic self-assembly in photo-RAFT aqueous polymerization-induced self-assembly (photo-PISA). Homopolymerization can yield salt-resistant, 3 nm ultrafine fibril-structured 5 nm ultrathin lamellae via LLPS, a left-to-right-handed chirality transition, and a droplets-to-lamellae transition. Like-charge block copolymerization leads to supercharged yet identical fibril-structured ultrathin lamellae, also, via LLPS, the left-to-right chirality transition and the droplets-to-lamellae transition. Ultrafine structures maintain intactness upon the seeded polymerization of the oppositely charged monomer. This work demonstrates that amino acid chiral ionic hydrogen bonds are powerful for the precision synthesis of salt-resistant ultrathin membrane nanomaterials.
RESUMO
Rational design of fast and sensitive determination of nitrite (NO2-) from a complicated actual sample overtakes a crucial role in constructing a high-efficiency sensing platform. Herein, a visual NO2- sensing platform with outstanding selectivity, sensitivity, and stability based on a surface plasmon resonance (SPR)-enhanced oxidase-like activity has been proposed. Benefiting from the intrinsic photocatalytic activity and limited light penetration of ZnS, the oxidase-like activity based on ZnS decorated on Ag nanowires (Ag@ZnS) is determined. It is demonstrated that the electrons are generated efficiently on the surface of ZnS and then transferred into the hot electrons of Ag with the help of localized SPR excitation, thus greatly oxidating the colorless 3,3',5,5'-tetramethylbenzidine (TMB) to produce dark blue oxidized TMB (oxTMB). When nitrite is added into the reaction system, the oxTMB will selectively react with NO2- to generate diazotized oxTMB, leading to a visual color change from dark blue to light green and subsequently to dark yellow. Owing to the specific recognition between nitrite and oxTMB, the recovery of catalytic activity induced an enhanced colorimetric test with a wider linear range for NO2- determination, an ultralow detection limit of 0.1 µM, excellent selectivity, and practicability for application in real samples. This plasmon-enhanced oxidase-like activity not only provides a smart approach to realize a colorimetric assay with high sensitivity and simplicity but also modulates oxidase-like activities.
Assuntos
Nanofios , Oxirredutases , Nitritos , Dióxido de Nitrogênio , Colorimetria , Limite de DetecçãoRESUMO
Single-atom site catalysts (SACs) provide an ideal platform to identify the active centers, explore the catalytic mechanism, and establish the structure-property relationships, and thus have attracted increasing interests for electrocatalytic energy conversion. Substantial endeavors have been devoted to the construction of carbon-supported SACs, and their progress have been comprehensively reviewed. Compared with carbon-supported SACs, transition metal compounds (TMCs)-supported SACs are still in their infancy in the field of electrocatalysis. However, they have also aroused ever-increasing attention for driving electrocatalytic water splitting, and emerged as an indispensable class of SACs in recent years, predominately owing to their inherently structural features, such as rich anchoring sites, surface defects, and lattice vacancy. Herein, in this review, we have systematically summarized the recent advances of a variety of TMC supported SACs toward electrocatalytic water splitting. The advanced characterization techniques and theoretical analyses for identifying and monitoring the atomic structure of SACs are firstly manifested. Subsequently, the anchoring and stabilization mechanisms for TMC supported SACs are also highlighted. Thereafter, the advances of TMC supported SACs for driving water electrolysis are systematically unraveled.
RESUMO
Oxygen evolution reactions (OERs) are regarded as the rate-determining step of electrocatalytic overall water splitting, which endow OER electrocatalysts with the advantages of high activity, low cost, good conductivity, and excellent stability. Herein, a facile H2O2-assisted etching method is proposed for the fabrication of Mo-doped ultrathin Co9Se8@NiSe/NF-X heterojunctions with rich Se vacancies to boost electrocatalytic water oxidation. After step-by-step electronic structure modulation by Mo doping and Se vacancy engineering, the self-standing Mo-Co9Se8@NiSe/NF-60 heterojunctions deliver a current density of 50 mA cm-2 with an overpotential of 343 mV and a cell voltage of only 1.87 V at 50 mA cm-2 for overall water splitting in 1.0 M KOH. Our study opens up the possibility of realizing step-by-step electronic structure modulation of nonprecious OER electrocatalysts via heteroatom doping and vacancy engineering.
RESUMO
Tuning the electronic state of a nanocatalyst is of vital importance for elevating its catalytic performance toward oxygen evolution reaction (OER). Herein, a cation-anion dual doping strategy has been proposed for modifying the electronic structure of CoP via doping Fe and S atoms. Impressively, Fe doping has been demonstrated to be favorable for improving the carrier density of CoP to produce more hydroxyl radicals (â¢OH), while S doping can further modify the electronic structure of CoP to improve the charge-transfer characteristics, thereby synergistically decreasing the energy barrier for the transformation of O* to OOH* and promoting the electrocatalytic OER performance. More importantly, the highly open nanobox structure is also beneficial for the exposure of more accessible catalytically active sites, which can substantially facilitate the electron and mass transport, leading to the superb catalytic OER performance. The successful modulation of OER performance via dual-doping strategy will pose a new strategy for designing more advanced nanocatalysts for energy-related catalysis process.
RESUMO
The photopromoted, Ni-catalyzed acceptorless dehydrogenation esterification of phenols and aromatic aldehydes has been achieved in an oxidant- and external photosensitizer-free manner. This reliable and atom-economical transformation was tolerant to a wide range of functional groups and proceeded efficiently to give various aryl benzoates in moderate to high yields. Additionally, this photocatalytic system displayed high activity for the hydrogen-evolution cross coupling of aliphatic aldehydes and phenols employing dual nickel and aromatic aldehyde catalysis.
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Seven undescribed carotane sesquiterpenoids named fusanoids A-G (1-7), along with one known analog (8) and two known sesterterpenes (9 and 10), were isolated from the fermentation broth of the desert endophytic fungi Fusarium sp. HM166. The structures of the compounds, including their absolute configurations, were determined by spectroscopic data, single-crystal X-ray diffraction analysis, and ECD calculations. Compound 10 showed cytotoxic activities against human hepatoma carcinoma cell line (Huh-7) and human breast cell lines (MCF-7 and MDA-MB-231), and compound 2 showed cytotoxic activity against MCF-7, while compounds 4-9 were inactive against all the tested cell lines. Compounds 4 and 10 showed potent inhibitory activities against the IDH1R132h mutant.
RESUMO
Seven new decahydrofluorene-class alkaloids, pyrrospirones K-Q (1-7), together with six known analogues (8-13) were isolated from the marine-derived fungal strain Penicillium sp. SCSIO 41512. Their structures were determined by extensive spectroscopic analysis, and their absolute configurations were established by single-crystal X-ray diffraction analysis and quantum chemical calculations of electronic circular dichroism spectra. Compounds 1 and 3 possess a novel decahydrofluorene-class alkaloid skeleton with a 6/5/6/8/5/6/13 and a 6/5/6/5/6/13 polycyclic system, respectively. Biologically, 13 displayed significant inhibitory activity against protein tyrosine phosphatases CD45, TCPTP, SHP1, and PTP1B with IC50 values of 8.1-17.8 µM, and 1, 2, 5, 8-10, 12, and 13 showed antibacterial activity against six pathogens. Their structure-activity relationship is also discussed.
Assuntos
Alcaloides , Penicillium , Alcaloides/química , Antibacterianos/química , Dicroísmo Circular , Fungos/química , Estrutura Molecular , Penicillium/químicaRESUMO
Seven undescribed sesquiterpene lactone dimers (SLDs) (carpeabrodilactones A-G), one known SLD, and six known sesquiterpenes were isolated from the fruit of Carpesium abrotanoides L. Carpeabrodilactone A was a dimeric carabrane featuring a rare C-13-C-13' linkage. Carpeabrodilactones B and C are the first two SLDs to be described possessing a carabranolide unit and a guaianolide unit connected by an O-ether linkage. The structures of the SLDs were assigned based on HRESIMS, NMR analysis, 13C NMR calculation, ECD calculation, and modified Mosher's method. Four SLDs showed potent cytotoxicity against K562 and/or A549 cells, with IC50 values below 10 µM, but none inhibited protein tyrosine phosphatases at 40 µM, including PTP1B, SHP1, CD45, and TCPTP.
Assuntos
Asteraceae , Sesquiterpenos , Asteraceae/química , Éteres , Frutas , Lactonas/química , Lactonas/farmacologia , Estrutura Molecular , Compostos Fitoquímicos , Sesquiterpenos/química , Sesquiterpenos/farmacologiaRESUMO
Stability of nitrogen cycle is a key indicator to aquatic health. In recent years, water and sediment inflows to the Three Gorges Reservoir (TGR) have changed significantly. To reveal the effects of such dramatic hydrological changes on aquatic nitrogen cycle, this paper at first analyzed the changing trends of water and suspended sediment discharges of TGR based on dynamic harmonic regression, and found that the intra-year distribution of water flow was significantly homogenized between flood and dry seasons, with the seasonal variations narrowed by 43.5%-69.9% during 2007-2016, while sediment concentration sharply dropped (the non-periodic term decreased by 1.48%-2.07%/month). Modified with the effects of sediment concentration variations on nitrification/denitrification rates, the proposed numerical model surprisingly showed that ammonia nitrogen and total nitrogen concentrations in TGR were insensitive to either water flow homogenization or sediment reduction, implying relative stability of microbial community related to nitrogen cycle, which is a positive sign for aquatic health. However, N2 emission varied more violently. The variation range of nitrogen gas (N2) emitted from TGR enlarged by 30% with the homogenization of water inflow from 2010 to 2016, while the annual total N2 emission decreased by 7% due to the reduction of sediment concentration, indicating quick response and strong adaption of the microbial N2 producing process to the environmental changes of TGR, which is beneficial for maintaining ecological functions related to nitrogen cycling. This work helps understanding nitrogen cycle of reservoirs experiencing dramatic changes in water and sediment inflows.
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Solar-assisted electrocatalytic oxygen evolution reaction (OER) plays a key role in energy conversion and storage technology. Herein, we provide the novel design and synthesis of an advanced category of CeO2/CoS2 heterostructures, which combines the local photothermal effect (LPTE) action of CeO2 and the photoelectric effect CoS2 to boost OER. Interestingly, the hollow framework, rich heterointerface, coupled local photothermal effect and photoelectric effect equip CeO2/CoS2 with remarkably excellent electrocatalytic OER performance. As a result, the optimized CeO2/CoS2-6 only needs an overpotential of 283 mV to reach 10 mA cm-2 as well as a smaller Tafel slop of 33.2 mV dec-1, outperforming the RuO2 catalyst (323 mA @ 10 mA cm-2). Upon combination of experimental data and mechanistic study, it is revealed that the enhanced OER performance is primarily ascribed to the photo-induced local thermal. partly resulting from photoelectric effect, where the photogenerated electron flow from CeO2 to CoS2 can photogenerated holes in CeO2 to boost water oxidation. This work is extremely expected to offer a novel avenue for the rational design and fabrication of outstanding OER electrocatalysts upon LPTE.
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Two glycosylated naphthacemycins (naphthacemycins D1 and D2) were identified in Streptomyces sp. N12W1565. These two compounds not only showed antimicrobial potential against bacteria but also exhibited more aqueous solubility than naphthacemycins. Furthermore, the whole genome of Streptomyces sp. N12W1565 has been sequenced, the natY gene, located outside the biosynthetic gene cluster encoding a D-glucose glycosyltransferase, was identified to mediate glycosylation in the phenolic hydroxyl of the naphthacemycin core scaffold. Glycosyltransferase was elucidated in vitro by using a homologous enzyme, which showed potential as a biocatalyst.
Assuntos
Streptomyces , Antibacterianos/farmacologia , Glicosilação , Glicosiltransferases/genética , Glicosiltransferases/metabolismo , Família MultigênicaRESUMO
We present a template strategy for precision synthesis of "complex coacervates-in-dodecyl atmosphere" ultrathin lamellae possessing exceptional shape-preservation and charge-tolerance properties.
RESUMO
Realizing the simultaneous morphology and electrical conductivity tuning of non-noble metal nanocatalysts is urgently desired for promoting their intrinsic activity toward oxygen evolution reaction (OER), while it is still challenging. Herein, we have demonstrated that the morphology and conductivity of FeNi3 alloy can be finely tailored via introducing the graphene carbon dots (GCDs). Benefitting from the enlarged active areas, significantly improved electrical conductivity, and strong synergistic coupling effect, the optimized FeNi3@GCDs-10 shows extraordinary electrocatalytic performance towards OER by delivering a current density of 10 mA cm-2 with the overpotential of 238 mV, as well as small Tafel slope of 48.7 mV dec-1. Density functional theory (DFT) calculations reveal that Fe is the dominated active sites for boosting water dissociation. In addition, the incorporation of GCDs can also strength the adsorption of *O and lower the energy barrier for the transformation from *OH to *O, thereby optimizing the free energy of *O and greatly promoting the OER activity.