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1.
J Cell Sci ; 135(5)2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-33912962

RESUMEN

Membrane contact sites (MCSs) between the endoplasmic reticulum (ER) and late endosomes/lysosomes (LE/lys) are emerging as critical hubs for diverse cellular events, and changes in their extents are linked to severe neurological diseases. While recent studies show that the synaptotagmin-like mitochondrial-lipid-binding (SMP) domain-containing protein PDZD8 may mediate the formation of ER-LE/lys MCSs, the cellular functions of PDZD8 remain largely elusive. Here, we attempt to investigate the lipid transfer activities of PDZD8 and the extent to which its cellular functions depend on its lipid transfer activities. In accordance with recent studies, we demonstrate that PDZD8 is a protrudin (ZFYVE27)-interacting protein and that PDZD8 acts as a tether at ER-LE/lys MCSs. Furthermore, we discover that the SMP domain of PDZD8 binds glycerophospholipids and ceramides both in vivo and in vitro, and that the SMP domain can transport lipids between membranes in vitro. Functionally, PDZD8 is required for LE/lys positioning and neurite outgrowth, which is dependent on the lipid transfer activity of the SMP domain.


Asunto(s)
Retículo Endoplásmico , Endosomas , Lípidos , Lisosomas , Proyección Neuronal
2.
Environ Sci Technol ; 58(26): 11748-11759, 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38912726

RESUMEN

Despite extensive study, geochemical modeling often fails to accurately predict lead (Pb) immobilization in environmental samples. This study employs the Charge Distribution MUlti-SIte Complexation (CD-MUSIC) model, X-ray absorption fine structure (XAFS), and density functional theory (DFT) to investigate mechanisms of phosphate (PO4) induced Pb immobilization on metal (hydr)oxides. The results reveal that PO4 mainly enhances bidentate-adsorbed Pb on goethite via electrostatic synergy at low PO4 concentrations. At relatively low pH (below 5.5) and elevated PO4 concentrations, the formation of the monodentate-O-sharing Pb-PO4 ternary structure on goethite becomes important. Precipitation of hydropyromorphite (Pb5(PO4)3OH) occurs at high pH and high concentrations of Pb and PO4, with an optimized log Ksp value of -82.02. The adjustment of log Ksp compared to that in the bulk solution allows for quantification of the overall Pb-PO4 precipitation enhanced by goethite. The CD-MUSIC model parameters for both the bidentate Pb complex and the monodentate-O-sharing Pb-PO4 ternary complex were optimized. The modeling results and parameters are further validated and specified with XAFS analysis and DFT calculations. This study provides quantitative molecular-level insights into the contributions of electrostatic enhancement, ternary complexation, and precipitation to phosphate-induced Pb immobilization on oxides, which will be helpful in resolving controversies regarding Pb distribution in environmental samples.


Asunto(s)
Plomo , Fosfatos , Plomo/química , Fosfatos/química , Compuestos de Hierro/química , Minerales/química , Concentración de Iones de Hidrógeno , Adsorción
3.
Bioorg Chem ; 143: 107103, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38211549

RESUMEN

Three undescribed (1-3) and nine known (4-12) platanosides were isolated and characterized from a bioactive extract of the May leaves of Platanus × acerifolia that initially showed inhibition against Staphylococcus aureus. Targeted compound mining was guided by an LC-MS/MS-based molecular ion networking (MoIN) strategy combined with conventional isolation procedures from a unique geographic location. The novel structures were mainly determined by 2D NMR and computational (NMR/ECD calculations) methods. Compound 1 is a rare acylated kaempferol rhamnoside possessing a truxinate unit. 6 (Z,E-platanoside) and 7 (E,E-platanoside) were confirmed to have remarkable inhibitory effects against both methicillin-resistant S. aureus (MIC: ≤ 16 µg/mL) and glycopeptide-resistant Enterococcus faecium (MIC: ≤ 1 µg/mL). These platanosides were subjected to docking analyses against FabI (enoyl-ACP reductase) and PBP1/2 (penicillin binding protein), both of which are pivotal enzymes governing bacterial growth but not found in the human host. The results showed that 6 and 7 displayed superior binding affinities towards FabI and PBP2. Moreover, surface plasmon resonance studies on the interaction of 1/7 and FabI revealed that 7 has a higher affinity (KD = 1.72 µM), which further supports the above in vitro data and is thus expected to be a novel anti-antibacterial drug lead.


Asunto(s)
Glicósidos , Staphylococcus aureus Resistente a Meticilina , Fenoles , Sepsis , Infecciones Estafilocócicas , Humanos , Antibacterianos/química , Cromatografía Liquida , Enoil-ACP Reductasa (NADH) , Pruebas de Sensibilidad Microbiana , Espectrometría de Masas en Tándem , Relación Estructura-Actividad
4.
Environ Res ; 252(Pt 2): 118935, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38621630

RESUMEN

Hematite nanoparticles commonly undergoes isomorphic substitution of Al3+ in nature, while how the Al-substitution-induced morphological change, defective structure and newly generated Al-OH sites affect the adsorption behavior of hematite for contaminants remains poorly understood. Herein, the interfacial reactions between Al-substituted hematite and Pb2+ was investigated via CD-MUSIC modeling and DFT calculations. As the Al content increased from 0% to 9.4%, Al-substitution promoted the proportion of (001) facets and caused Fe vacancies on hematite, which increased the total active site density of hematite from 5.60 to 17.60 sites/nm2. The surface positive charge of hematite significantly increased from 0.096 to 0.418 C/m2 at pH 5.0 due to the increases in site density and proton affinity (logKH) of hematite under Al-substitution. The adsorption amount of hematite for Pb2+ increased from 3.92 to 9.74 mmol/kg at pH 5.0 and 20 µmol/L initial Pb2+ concentration with increasing Al content. More Fe vacancies may lead to a weaker adsorption energy (Ead) of hematite for Pb2+, while the Ead was enhanced at higher Al content. The adsorption affinity (logKPb) of bidentate Pb complexes slightly increased while that of tridentate Pb complexes decreased with increasing Al content due to the presence of ≡ AlOH-0.5 and ≡ Fe2AlO-0.5 sites. Tridentate Pb complexes were dominant species on the surface of pure hematite, while bidentate ones became more dominant with increasing Al content. The obtained model parameters and molecular scale information are of great importance for better describing and predicting the environmental fate of toxic heavy metals in terrestrial and aquatic environments.


Asunto(s)
Aluminio , Compuestos Férricos , Plomo , Modelos Químicos , Plomo/química , Compuestos Férricos/química , Adsorción , Aluminio/química , Aluminio/análisis
5.
FASEB J ; 36(10): e22554, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36111973

RESUMEN

Mesial temporal lobe epilepsy (MTLE) is one of the most common refractory epilepsies and is usually accompanied by a range of brain pathological changes, such as neuronal injury and astrocytosis. Naïve astrocytes are readily converted to cytotoxic reactive astrocytes (A1) in response to inflammatory stimulation, suppressing the polarization of A1 protects against neuronal death in early central nervous system injury. Our previous study found that pro-inflammatory cytokines and miR-132-3p (hereinafter referred to as "miR-132") expression were upregulated, but how miR-132 affected reactive astrocyte polarization and neuronal damage during epilepsy is not fully understood. Here, we aimed to explore the effect and mechanism of miR-132 on A1 polarization. Our results confirmed that A1 markers were significantly elevated in the hippocampus of MTLE rats and IL-1ß-treated primary astrocytes. In vivo, knockdown of miR-132 by lateral ventricular injection reduced A1 astrocytes, neuronal loss, mossy fiber sprouting, and remitted the severity of status epilepticus and the recurrence of spontaneous recurrent seizures. In vitro, the neuronal cell viability and axon length were reduced by additional treatment with A1 astrocyte conditioned media (ACM), and downregulation of astrocyte miR-132 rescued the inhibition of cell activity by A1 ACM, while the length of axons was further inhibited. The regulation of miR-132 on A1 astrocytes may be related to its target gene expression. Our results show that interfering with astrocyte polarization may be a breakthrough in the treatment of refractory epilepsy, which may extend to the research of other astrocyte polarization-mediated brain injuries.


Asunto(s)
Epilepsia del Lóbulo Temporal , MicroARNs , Estado Epiléptico , Animales , Ratas , Astrocitos/metabolismo , Medios de Cultivo Condicionados/farmacología , Epilepsia del Lóbulo Temporal/inducido químicamente , Epilepsia del Lóbulo Temporal/genética , Epilepsia del Lóbulo Temporal/metabolismo , Hipocampo/metabolismo , Interleucina-1beta/metabolismo , Interleucina-1beta/farmacología , MicroARNs/genética , MicroARNs/metabolismo , Convulsiones/genética , Convulsiones/metabolismo , Estado Epiléptico/inducido químicamente , Estado Epiléptico/genética , Estado Epiléptico/metabolismo
6.
BMC Infect Dis ; 23(1): 834, 2023 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-38012543

RESUMEN

INTRODUCTION: The urgent need for new treatments for multidrug-resistant tuberculosis (MDR-TB) and pre-extensively drug-resistant tuberculosis (pre-XDR-TB) is evident. However, the classic randomized controlled trial (RCT) approach faces ethical and practical constraints, making alternative research designs and treatment strategies necessary, such as single-arm trials and host-directed therapies (HDTs). METHODS: Our study adopts a randomized withdrawal trial design for MDR-TB to maximize resource allocation and better mimic real-world conditions. Patients' treatment regimens are initially based on drug resistance profiles and patient's preference, and later, treatment-responsive cases are randomized to different treatment durations. Alongside, a single-arm trial is being conducted to evaluate the potential of sulfasalazine (SASP) as an HDT for pre-XDR-TB, as well as another short-course regimen without HDT for pre-XDR-TB. Both approaches account for the limitations in second-line anti-TB drug resistance testing in various regions. DISCUSSION: Although our study designs may lack the internal validity commonly associated with RCTs, they offer advantages in external validity, feasibility, and ethical appropriateness. These designs align with real-world clinical settings and also open doors for exploring alternative treatments like SASP for tackling drug-resistant TB forms. Ultimately, our research aims to strike a balance between scientific rigor and practical utility, offering valuable insights into treating MDR-TB and pre-XDR-TB in a challenging global health landscape. In summary, our study employs innovative trial designs and treatment strategies to address the complexities of treating drug-resistant TB, fulfilling a critical gap between ideal clinical trials and the reality of constrained resources and ethical considerations. TRAIL REGISTRATION: Chictr.org.cn, ChiCTR2100045930. Registered on April 29, 2021.


Asunto(s)
Tuberculosis Extensivamente Resistente a Drogas , Mycobacterium tuberculosis , Tuberculosis Resistente a Múltiples Medicamentos , Humanos , Antituberculosos/efectos adversos , Tuberculosis Extensivamente Resistente a Drogas/tratamiento farmacológico , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Protocolos Clínicos , Ensayos Clínicos Controlados Aleatorios como Asunto , Estudios Multicéntricos como Asunto
7.
J Nat Prod ; 86(6): 1487-1499, 2023 06 23.
Artículo en Inglés | MEDLINE | ID: mdl-37291059

RESUMEN

A preliminary phytochemical investigation on the 90% MeOH extract from the twigs and needles of the vulnerable conifer Keteleeria fortunei led to the isolation and characterization of 17 structurally diverse triterpen-26-oic acids, including nine previously undescribed ones (fortunefuroic acids A-I, 1-9) featuring a rare furoic acid moiety in the lateral chain. Among them, 1-5 are uncommon 9ßH-lanostane-type triterpenoic acids. Friedo-rearranged triterpenoids 6 and 7 feature a unique 17,14-friedo-lanostane skeleton, whereas 9 possesses a rare 17,13-friedo-cycloartane-type framework. Their structures and absolute configurations were elucidated by extensive spectroscopic (e.g., detailed 2D NMR) and computational (NMR/ECD) calculations and the modified Mosher's method. In addition, the absolute structure of compound 1 was ascertained by single-crystal X-ray diffraction analyses. Fortunefuroic acids B (2), G (7), and I (9), along with isomangiferolic acid (12) and 3α,27-dihydroxycycloart-24E-en-26-oic acid (14), exhibited dual inhibitory effects against the adenosine triphosphate (ATP)-citrate lyase (ACL, IC50s: 5.7-11.4 µM) and acetyl-CoA carboxylase 1 (ACC1, IC50s: 7.5-10.5 µM), both of which are key enzymes for glycolipid metabolism. The interactions of the bioactive triterpenoids with both enzymes were examined by molecular docking studies. The above findings reveal the important role of protecting plant species diversity in support of chemical diversity and potential sources of new therapeutics for ACL-/ACC1-associated diseases.


Asunto(s)
Abies , Tracheophyta , Triterpenos , Simulación del Acoplamiento Molecular , Triterpenos/química , Abies/química , Espectroscopía de Resonancia Magnética , Estructura Molecular
8.
J Nat Prod ; 86(5): 1251-1260, 2023 05 26.
Artículo en Inglés | MEDLINE | ID: mdl-37196240

RESUMEN

Seven [4 + 2]-type triterpene-diterpene hybrids derived from a rearranged or a normal lanostane unit (dienophile) and an abietane moiety (diene), forrestiacids E-K (1-7, respectively), were further isolated and characterized from Pseudotsuga forrestii (a vulnerable conifer endemic to China). The intriguing molecules were revealed with the guidance of an LC-MS/MS-based molecular ion networking strategy combined with conventional phytochemical procedures. Their chemical structures with absolute configurations were established by spectroscopic data, chemical transformation, electronic circular dichroism calculations, and single-crystal X-ray diffraction analysis. They all contain a rare bicyclo[2.2.2]octene motif. Both forrestiacids J (6) and K (7) represent the first examples of this unique class of [4 + 2]-type hybrids that arose from a normal lanostane-type dienophile. Some isolates remarkably inhibited ATP-citrate lyase (ACL), with IC50 values ranging from 1.8 to 11 µM. Docking studies corroborated the findings by highlighting the interactions between the bioactive compounds and the ACL enzyme (binding affinities: -9.9 to -10.7 kcal/mol). The above findings reveal the important role of protecting plant species diversity in support of chemical diversity and potential sources of new therapeutics.


Asunto(s)
Diterpenos , Pseudotsuga , Tracheophyta , Triterpenos , Triterpenos/química , Cromatografía Liquida , Espectrometría de Masas en Tándem , Diterpenos/química , Estructura Molecular
9.
BMC Public Health ; 23(1): 2174, 2023 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-37932777

RESUMEN

BACKGROUND: The association between body fat percentage (BFP) and kidney stone disease (KSD) among bus drivers has not been explored in the existing literature. Thus, this study was conducted to explore the influence of BFP on the risk of KSD as well as KSD development for bus drivers to fill the research gap. METHODS: A cross-sectional and longitudinal cohort study was designed. In total, 3433 bus drivers were included in the cross-sectional analyses, and 1864 bus drivers without KSD at baseline and with regular follow-up were included in the longitudinal cohort study. RESULTS: During a median follow-up of 2.9 years, KSD occurred in 15.0% of bus drivers. Multivariate logistic analysis found that each 5% higher BFP was not only significantly related with higher odds of KSD (odds ratio [OR] = 1.48), but also associated with higher odds of developing KSD (OR = 1.27). The risk of prevalent KSD in obesity group based on BFP was 2.47 times of the normal group; and the corresponding risk of developing KSD was 1.61 times. For obesity bus drives with age < 40, the corresponding risk increased to 4.54 times. CONCLUSION: Bus drivers were reported to have a high prevalence of KSD as well as development of KSD. As a significant predictive factor for KSD, BFP can be used to monitor and prevent bus drivers from kidney stone formation. Bus drivers in obesity group based on BFP, especially with age < 40 years should become priority subjects for targeted prevention.


Asunto(s)
Cálculos Renales , Humanos , Adulto , Estudios Longitudinales , Estudios Transversales , Obesidad/epidemiología , Tejido Adiposo
10.
Ecotoxicol Environ Saf ; 252: 114622, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36764069

RESUMEN

Combined pollution of cadmium (Cd) and lead (Pb) occurs frequently in agriculture lands, which has received increasing research attention. However, little is known about the interaction behaviors of Cd and Pb at various concentrations in the mixture. This study evaluated the single and combined effects of Cd and Pb on rice (Oryza sativa L.) root elongation through acute exposure test. The combined pollution was analyzed with the concentration addition (CA) model, independent action (IA) model and mathematical statistical methods. The dose-response results revealed that the interaction could weaken the toxicity of both Pb and Cd, and Cd had a more significant inhibitory effect on Pb toxicity. The predicted values of CA and IA models were consistently lower than the observed values in the relative root elongation range of 0-60%. Further, combining the CA or IA model with mathematical statistical methods, the interaction of Pb and Cd at similar concentrations showed a significant antagonistic effect on rice root elongation. At low Pb concentrations (Cd > 0.0195, Pb < 0.015 mg/L), there was a synergistic effect of the mixture on rice root; at high Pb concentrations (Cd < 0.225, Pb ≥ 1.25 mg/L), Pb dominated the toxicity on rice root. This is the first report of a systematic method for assessing heavy metal interaction at different concentration levels, which may facilitate the formulation of control standards of heavy metal combined pollution in agricultural land.


Asunto(s)
Metales Pesados , Oryza , Contaminantes del Suelo , Cadmio/toxicidad , Cadmio/análisis , Plomo/toxicidad , Plomo/análisis , Contaminantes del Suelo/toxicidad , Contaminantes del Suelo/análisis , Metales Pesados/análisis , Suelo
11.
Sensors (Basel) ; 23(3)2023 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-36772175

RESUMEN

Fundamental theory and methods are investigated of inspecting tubing and casing simultaneously using pulsed eddy current testing by numerical simulations and experiments. The distribution and variation of eddy current field are given in the finite element simulation for the inspection of undamaged and corroded casing and tubing combinations, with tubing outer diameter 73.8 mm, wall thickness 5.7 mm, corrosion depth 1.25 mm, 2.5 mm, 3.75 mm, and casing outer diameter 141.5 mm, wall thickness 7.7 mm, corrosion depth 1.25 mm, 2.5 mm, and 3.75 mm, respectively. The results show that eddy current field propagates around and to the depth after the direct section of the exciting current is cut off and the intensity center of eddy current field shifts gradually from the inner side of the tubing to the casing, which forms the basis of analyzing inspection mechanism. Corrosion at a particular depth is related to a particular optimum time slice of the induced voltage (namely with deepest concave) and a highest sensitivity is obtained at this slice. The time associated with this slice is in accordance with the time when the intensity center of eddy current reaches the corrosion. Corrosion at different depths has different voltage time slices starting to show signal of defect, which can be used to estimate the depth of the defect in order to judge the defect coming from tubing or casing. Furthermore, sinking degree of the time slice reflects the size of the defect. All machined defects can be recognized in the experiments and the optimum time slice appears at 0.01 s and 0.008 s after the excitation current is cut off for the tubing corrosion of 1.25 mm and 2.5 mm, respectively. The optimum time slice appears at the last moment of cut-off period, 0.625, for the casing corrosion. Experimental results agree well with the simulations and show the existence of the optimum correspondence between depth of corrosion and starting time of the defect signal of time slice, relations between sinking degree of the time slice, and corrosion size.

12.
Environ Monit Assess ; 195(8): 970, 2023 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-37466699

RESUMEN

River sediment is vital in containing water pollution and strengthening water remediation. This paper has conducted a study on the microecological health assessment of the sediment and water body of Guixi River in Dianjiang, Chongqing, China, using metagenomics sequencing and microbial biological integrity index (M-IBI) technology. The analysis of physical and chemical characteristics shows that the concentration of TN varies from 2.62 to 9.76 mg/L in each sampling section, and the eutrophication of the water body is relatively severe. The proportion of Cyanobacteria in the sampling section at the sink entrance is higher than that of other sites, where there are outbreaks of water blooms and potential hazards to human health. The dominant functions of each site include carbon metabolism, TCA cycle, and pyruvate metabolism. In addition, the main virulence factors and antibiotic resistance genes in sediment are Type IV pili (VF0082), LOS (CVF494), MymA operon (CVF649), and macrolide resistance genes macB, tetracyclic tetA (58), and novA. Correlation analysis of environmental factors and microorganisms was also performed, and it was discovered that Thiothrix and Acidovorax had obvious gene expression in the nitrogen metabolism pathway, and the Guixi River Basin had a self-purification capacity. Finally, based on the microecological composition of sediment and physical and chemical characteristics of the water body, the health assessment was carried out, indicating that the main pollution area was Dianjiang Middle School and the watershed near the sewage treatment plant. The findings should theoretically support an in-depth assessment of the water environment's microecological health.


Asunto(s)
Monitoreo del Ambiente , Metagenómica , Ríos , Contaminantes Químicos del Agua , China , Contaminantes Químicos del Agua/análisis , Farmacorresistencia Bacteriana , Genes Bacterianos , Humanos
13.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 48(2): 294-301, 2023 Feb 28.
Artículo en Inglés, Zh | MEDLINE | ID: mdl-36999477

RESUMEN

Börjeson-Forssman-Lehmann syndrome (BFLS) is a rare X-linked intellectual disability. The main features of the patients include intellectual disability/global developmental delay, characteristic face, anomalies of fingers and toes, hypogonadism, linear skin hyperpigmentation, and tooth abnormalities in female patients, and obesity in male patients. A case of BFLS caused by a novel mutation of PHF6 gene who was treated in the Department of Pediatrics, Xiangya Hospital, Central South University was reported. The 11 months old girl presented the following symptons: Global developmental delay, characteristic face, sparse hair, ocular hypertelorism, flat nasal bridge, hairy anterior to the tragus, thin upper lip, dental anomalies, ankyloglossia, simian line, tapering fingers, camptodactylia, and linear skin hyperpigmentation. The gene results of the second-generation sequencing technology showed that there was a novel heterozygous mutation site c.346C>T (p.Arg116*) of the PHF6 (NM032458.3), variation rating as pathogenic variation. During the follow-up, the patient developed astigmatism, strabismus, awake bruxism, and stereotyped behavior, and the linear skin hyperpigmentation became gradually more evident. The disease is lack of effective therapy so far.


Asunto(s)
Hipogonadismo , Discapacidad Intelectual , Discapacidad Intelectual Ligada al Cromosoma X , Humanos , Masculino , Femenino , Niño , Lactante , Discapacidad Intelectual/genética , Discapacidad Intelectual Ligada al Cromosoma X/complicaciones , Discapacidad Intelectual Ligada al Cromosoma X/genética , Discapacidad Intelectual Ligada al Cromosoma X/patología , Obesidad/complicaciones , Hipogonadismo/genética , Hipogonadismo/patología
14.
J Am Chem Soc ; 144(4): 1622-1633, 2022 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-35060699

RESUMEN

Naturally occurring hydrazones are rare despite the ubiquitous usage of synthetic hydrazones in the preparation of organic compounds and functional materials. In this study, we discovered a family of novel microbial metabolites (tasikamides) that share a unique cyclic pentapeptide scaffold. Surprisingly, tasikamides A-C (1-3) contain a hydrazone group (C═N─N) that joins the cyclic peptide scaffold to an alkyl 5-hydroxylanthranilate (AHA) moiety. We discovered that the biosynthesis of 1-3 requires two discrete gene clusters, with one encoding a nonribosomal peptide synthetase (NRPS) pathway for assembling the cyclic peptide scaffold and another encoding the AHA-synthesizing pathway. The AHA gene cluster encodes three ancillary enzymes that catalyze the diazotization of AHA to yield an aryl diazonium species (diazo-AHA). The electrophilic diazo-AHA undergoes nonenzymatic Japp-Klingemann coupling with a ß-keto aldehyde-containing cyclic peptide precursor to furnish the hydrazone group and yield 1-3. The studies together unraveled a novel mechanism whereby specialized metabolites are formed by the coupling of two biosynthetic pathways via an unprecedented in vivo Japp-Klingemann reaction. The findings raise the prospect of exploiting the arylamine-diazotizing enzymes (AAD) for the in vivo synthesis of aryl compounds and modification of biological macromolecules.


Asunto(s)
Compuestos de Diazonio/química , Hidrazonas/química , Oligopéptidos/biosíntesis , Vías Biosintéticas/genética , Hidrazonas/síntesis química , Familia de Multigenes , Oligopéptidos/química , Péptido Sintasas/genética , Péptido Sintasas/metabolismo , Péptidos Cíclicos/biosíntesis , Péptidos Cíclicos/química , Streptomyces/metabolismo
15.
Small ; 18(13): e2108072, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35128776

RESUMEN

Designing a synthesis of ultra-small Ni-based nanomaterials with high intrinsic activity and stability in alkaline hydrogen evolution reaction (HER) is a major challenge. Herein, a series of noble metal doped ultra-small size (4 nm) M-Ni/NiO nanoparticles supported on CNT are rationally designed by a solvent-free microwave reduction method that is fast (60 s), simple, includes no surfactants, extensive (>1 g), and has high yield (82.7%). The Ir-Ni/NiO@CNT has superior performance with a low overpotential of 24.6 mV at 10 mA cm-2 . In addition, the turnover frequency (TOF) value up to 2.51 s-1 and the exchange current density reaches 4.34 mA cm-2 , indicating that the catalyst has better intrinsic catalytic activity. It is further proved by density functional theory (DFT) that the NiO surface is conducive to the adsorption of OH* in the Volmer step while the Ni is inclined to adsorb H*, which synergistically promotes the water-splitting reaction, thereby increasing the catalytic rate of HER. It is believed that this work will provide valuable contributions and inspirations toward the large-scale production of high-performance Ni-based electrocatalysts for HER.

16.
J Org Chem ; 87(10): 6927-6933, 2022 05 20.
Artículo en Inglés | MEDLINE | ID: mdl-35512323

RESUMEN

Liriogerphines A-D (1-4, respectively), an unprecedented class of hybrids of germacranolide-type sesquiterpenoids and aporphine-type alkaloids, were isolated from the rare medicinal plant Liriodendron chinense. Their structures were elucidated by comprehensive spectroscopic analyses combined with electronic circular dichroism calculations and X-ray crystallographic data. Biosynthetically, an aza-Michael addition reaction is proposed to be involved in the assemblies of this class of hybrids. Compound 4 exhibited cytotoxicity against leukemia cells via inducing apoptosis and inhibiting Bcl-2 expression.


Asunto(s)
Alcaloides , Antineoplásicos , Liriodendron , Sesquiterpenos , Alcaloides/química , Alcaloides/farmacología , China , Estructura Molecular , Sesquiterpenos/química , Sesquiterpenos/farmacología , Árboles
17.
Phys Chem Chem Phys ; 24(2): 704-714, 2022 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-34933324

RESUMEN

Proton binding to "carboxylic" and "phenolic" sites of humic nano particles (HNPs) is determined by the total proton affinity that is due to a specific and an electrostatic affinity. Both affinities are accounted for in the bi-modal Langmuir-Freundlich (bi-LF)-equation extended with a Boltzmann factor that includes the electrostatic site potential(s), y. For y → 0 the equation reduces to the bi-LF Master Curve (MC). Commonly, an electrical double layer model is used to obtain y, e.g., the bi-LF-Donnan-Vapp (monocomponent NICA-Donnan) model and bi-LF-soft-particle-Poison-Boltzmann-Theory (SPBT). A new method is presented that combines the "condensation approximation" (CA) with the MC concept (CA-MC). With the CA, the proton binding curve and MC can be transformed in, respectively, the total and specific affinity distribution. The difference at a given charge density provides the electrostatic affinity and CA-potentials vs. charge density. The MC can be obtained theoretically or by using the convention that the electrostatic interaction is negligible at 1 M salt concentration. For five HNPs CA-potentials corresponding with the bi-LF-SPBT are compared with results of the bi-LF-Donnan-Vapp model using the MC(SPBT). The bi-LF-Donnan-Vapp model fails when the Debye length > hydrated particle radius. The CA-MC(1M) method does not require characteristics of the HNPs. Combination of the bi-LF-eq. with the CA-MC(1 M) method gives the bi-LF-CA-MC(1 M) model. The CA-MC(1 M) differs from the MC(SPBT); therefore, resulting parameters can only be compared when the same method is used.

18.
Bioorg Chem ; 124: 105825, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35489273

RESUMEN

A preliminary phytochemical investigation on the MeOH extract of the twigs and needles of Pseudotsuga gaussenii (a 'vulnerable' plant endemic to China) led to the isolation and characterization of 25 structurally diverse mono- and dimeric triterpenoids. 19 of them are previously undescribed, including eight cucurbitane-type triterpenoids (gaussenols A-H, 1-8, resp.), one serratene-type triterpene (gaussenol I, 9), and 10 triterpenic dimers (gaussenols J-S, 10-19, resp.). Their chemical structures were elucidated by means of spectroscopic data, some chemical transformations, the modified Mosher's method, and single crystal X-ray diffraction analyses. Compound 9 is the first 13R diastereoisomeric serratene-type triterpenoid derivative from nature. The unprecedented dimeric triterpenoids are constructed either through ester linkage (10-18) or via ether bond (19) among the side chains of same or different types of triterpenoid skeletons (e.g., cucurbitane-type, lanostane-type, and/or cycloartane-type). Compounds 9, 15, 21, and 25 exhibited inhibitory effects against the human protein tyrosine phosphatase 1B (PTP1B, a potential drug target for the treatment of type-II diabetes and obesity), with IC50 values of 3.1, 8.6, 9.0, and 5.6 µM, respectively. The interactions of the bioactive compounds with PTP1B were thereafter performed by employing molecular docking studies, with binding affinities ranging from - 6.9 to - 7.3 kcal/mol. The above findings could reveal the important role of protecting plant species diversity in support of chemical diversity and potential sources of new therapeutics.


Asunto(s)
Pseudotsuga , Tracheophyta , Triterpenos , Humanos , Simulación del Acoplamiento Molecular , Estructura Molecular , Proteína Tirosina Fosfatasa no Receptora Tipo 1 , Triterpenos/química
19.
Bioorg Chem ; 120: 105630, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35091291

RESUMEN

The ethanolic extracts of the dried flower buds of two Caprifoliaceae plants, Lonicera japonica and Abelia × grandiflora, showed considerable inhibitory activities against adenosine triphosphate (ATP)-citrate lyase (ACL), a new promising drug target for the treatment of metabolic disorders. Bioassay-guided purification in conjunction with HPLC-PDA profiling led to the isolation and characterization of thirty-five (1-35) and fourteen (1'-14') structurally diverse compounds from the above two plant extracts, respectively. Compounds 1-9 and 1'-6' are previously undescribed glycosides. Their structures were elucidated on the basis of spectroscopic data, electronic circular dichroism (ECD), and single crystal X-ray diffraction analyses. In particular, lonicejaposide A (1) has an unprecedented skeleton generated through the coupling of C-7 in secologanin with C-2'' in phenylacetaldehyde via an aldol condensation. Abeliflorosides A (1') and B (2') are hitherto unknown glycosides of triterpene and bisiridoid conjugates constructed through the formation of a 1,3-dioxane moiety. All the isolates were evaluated for their inhibitory activities against ACL. Compounds 9, 25-28, 31, 1', 2', and 14' displayed significant inhibitory effects, with IC50 values ranging from 0.1 to 14.2 µM. The interactions of selected compounds possessing different structure features (e.g., 9, 25, 31, and 2') with ACL were thereafter performed by employing molecular docking studies. In addition, compound 2', the most complex triterpene-bisiridoid conjugate glycoside reported herein, also inhibited acetyl-CoA carboxylase 1 (ACC1), with an IC50 value of 7.9 µM. The dried material of the flower buds of L. japonica (honeysuckle) is a well-known traditional oriental medicine (i.e., Flos Lonicerae Japonicae, FLJ) and has long been used in large quantities. The above findings not only provide new insights for the development of multipurpose utilization of FLJ in healthcare community, but also provide profitable clues indicating that the flower buds of A. × grandiflora might be a potential alternative to FLJ in the traditional Chinese medicine market.


Asunto(s)
Caprifoliaceae , Lonicera , Triterpenos , Adenosina Trifosfato , Flores/química , Glicósidos/química , Lonicera/química , Simulación del Acoplamiento Molecular , Complejos Multienzimáticos , Oxo-Ácido-Liasas
20.
Int Arch Occup Environ Health ; 95(10): 1995-2003, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35792921

RESUMEN

PURPOSE: To explore the transition patterns among different levels of blood pressure for bus drivers. METHODS: A follow-up study was conducted to investigate the transition probabilities of three blood pressure states, the sojourn time in each state, the survival probabilities, and the risk factors affecting hypertension progression. Based on 5618 blood pressure measurements of 1883 Chinese bus drivers from 2017 to 2021, a multi-state Markov model was established. RESULTS: The mean age of participants was 41.43 ± 6.71 years, and 82.37% were male. The probabilities from normal state to hypertension within 1-year follow-up were 4.60% (male) and 2.13% (female); however, the corresponding changes over a 3-year follow-up had a significant increase to 20.27% (male) and 7.98% (female). The sojourn time of normal state and elevated state was 1.82 ± 0.09 years and 1.98 ± 0.08 years, respectively. The male participants, the increasing age, BMI, CHOL and TG were risk factors for progression from normal state to elevated state, and/or from elevated state to hypertensive state (HR: 1.04-2.53). CONCLUSIONS: Early preventive measures on the progression of hypertension should be taken for Chinese bus drivers, and at least one physical examination per year is strongly recommended. The government and bus companies should pay more attention to these kinds of bus drivers with high probabilities of hypertension: male, older than 40 years, with the higher values of BMI and blood lipid. The derived findings of sojourn time, transition probabilities and survival probabilities can provide reference for health professionals to make targeted intervention to reduce bus drivers' hypertension occurrence.


Asunto(s)
Conducción de Automóvil , Hipertensión , Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Presión Sanguínea , Estudios de Seguimiento , Hipertensión/epidemiología , Factores de Riesgo
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