Valacyclovir-associated neurotoxicity (VAN) is a recognized adverse effect in elderly patients with renal impairment but remains underdiagnosed due to its nonspecific presentation and overlap with acute neurologic emergencies. We report a 78-year-old Filipino female with end-stage renal disease on maintenance hemodialysis who developed acute disorientation, agitation, vivid visual hallucinations and generalized weakness shortly after initiation of valacyclovir for herpes zoster. Given the abrupt onset of neuropsychiatric symptoms, viral encephalitis was initially considered. Magnetic resonance imaging of the brain showed no evidence of acute infarction or encephalitis, while electroencephalography demonstrated diffuse generalized slowing consistent with an encephalopathic process. Review of the medication history revealed valacyclovir dosing that exceeded recommendations for patients with end-stage renal disease. Valacyclovir was discontinued and emergent hemodialysis was initiated resulting in marked improvement in sensorium after the second session and complete resolution of symptoms after the third. This case shows VAN as an important diagnostic mimic of acute encephalopathy in elderly patients with renal failure and emphasizes the critical role of early medication review in preventing unnecessary investigations and enabling prompt, reversible management.

Amoenucles A-F (1-6), six previously undescribed nucleoside derivatives, and two known analogs (7 and 8) were isolated from the culture of Aspergillus amoenus TJ507. Their structures were elucidated through spectroscopic analysis, single-crystal X-ray crystallography, and chemical reactions. Notably, 3 and 4 represent the first reported instances of nucleosides with an attached pyrrole moiety. Of particular significance, the absolute configuration of the sugar moiety of 1-4 was determined using nuclear magnetic resonance (NMR), electric circular dichroism (ECD) calculations, and a hydrolysis reaction, presenting a potentially valuable method for confirming nucleoside structures. Furthermore, 1, 2, and 5-8 exhibited potential tumor necrosis factor α (TNF-α) inhibitory activities, which may provide a novel chemical template for the development of agents targeting autoimmune and inflammatory diseases.
Aspergillus/chemistry* ; Tumor Necrosis Factor-alpha/antagonists & inhibitors* ; Molecular Structure ; Nucleosides/isolation & purification* ; Crystallography, X-Ray ; Animals ; Humans ; Mice ; Magnetic Resonance Spectroscopy

In this study, we employed a combination of genome mining and heteronuclear single quantum coherence (HSQC)-based small molecule accurate recognition technology (SMART) technology to search for fernane-type triterpenoids. Initially, potential endophytic fungi were identified through genome mining. Subsequently, fine fractions containing various fernane-type triterpenoids were selected using HSQC data collection and SMART prediction. These triterpenoids were then obtained through targeted isolation and identification. Finally, their antifungal activity was evaluated. As a result, three fernane-type triterpenoids, including two novel compounds, along with two new sesquiterpenes and four known compounds were isolated from one potential strain, Diaporthe discoidispora. Their structures were elucidated through analysis of high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) and nuclear magnetic resonance (NMR) spectroscopic data. The absolute configurations were determined using single-crystal X-ray diffraction analysis and electron capture detector (ECD) analysis. Compound 3 exhibited moderate antifungal activity against Candida albicans CMCC 98001 and Aspergillus niger.
Triterpenes/isolation & purification* ; Antifungal Agents/isolation & purification* ; Molecular Structure ; Candida albicans/drug effects* ; Ascomycota/genetics* ; Magnetic Resonance Spectroscopy ; Aspergillus niger/drug effects* ; Genome, Fungal ; Microbial Sensitivity Tests

Nine novel compounds, comprising seven tetrahydroanthraquinones (auxarthrolones A-G, 1-7), a γ-butenolide glycoside (malfilamentoside E, 26), and a γ-butenolide (auxarthrolide A, 27), together with eighteen known compounds (8-25) were isolated from rice-based solid culture of Auxarthron umbrinum (A. umbrinum) DSM3193 using the one strain many compounds (OSMAC) approach. The structural elucidation of these compounds was accomplished through nuclear magnetic resonance (NMR), mass spectrometry (MS), and NMR calculation combined with DP4+ analysis or MAEΔΔδ parameter, while the absolute configurations of new compounds were established through single-crystal X-ray diffraction, electronic circular dichroism (ECD) spectroscopic data analysis and/or chemical derivatization. Austrocortilutein (10) and auxarthrol H (14) demonstrated moderate cytotoxicity against U87 and U251 [half maximal inhibitory concentration (IC₅₀) 3.5-12.1 μmol·L^-1]. Additionally, auxarthrolone A (1), auxarthrol H (14), eupolyphagin B (15), and 7-hydroxy-2-(2-hydroxypropyl)-5-methylchromone (17) exhibited torsional effects on fibroblast proliferation challenges induced by oleic acid, thus demonstrating fibroblast proliferation-promoting activity.
4-Butyrolactone/pharmacology* ; Molecular Structure ; Anthraquinones/pharmacology* ; Humans ; Animals ; Mice ; Cell Line, Tumor ; Magnetic Resonance Spectroscopy

(±)-Penicithrones A-D (1a/1b-4a/4b), four novel pairs of anthrone-cyclopentenone heterodimers characterized by a distinctive bridged 6/6/6-5 tetracyclic core skeleton, together with three previously identified compounds (5-7), were isolated from the crude extract of the mangrove-derived fungus Penicillium sp., guided by heteronuclear single quantum correlation (HSQC)-based small molecule accurate recognition technology (SMART 2.0) and liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based molecular networking. The structural elucidation of new compounds was accomplished through comprehensive spectroscopic analysis, and their absolute configurations were determined using DP4+ ¹³C nuclear magnetic resonance (NMR) calculations and electronic circular dichroism (ECD) calculations. Compounds 1a/1b-4a/4b demonstrated moderate cytotoxicity against three human cancer cell lines HeLa, HCT116 and MCF-7 with half maximal inhibitory concentration (IC₅₀) values ranging from 15.95 ± 1.64 to 28.56 ± 2.59 μmol·L^-1.
Humans ; Penicillium/chemistry* ; Molecular Structure ; Cyclopentanes/isolation & purification* ; Cell Line, Tumor ; Antineoplastic Agents/pharmacology* ; Tandem Mass Spectrometry ; Dimerization ; HeLa Cells ; Magnetic Resonance Spectroscopy

The chemical constituents of the chloroform extract of the 90% methanol extract obtained from the dried branches and leaves of Croton lauioides were investigated. By using silica gel column chromatography, C_(18 )column chromatography, MCI column chromatography, and semi-preparative high-performance liquid chromatography(HPLC), six compounds were isolated. Their structures were identified as lauioidine(1), 2α-methoxy-8α-hydroxy-6-oxogermacra-1(10),7(11)-dien-8,12-olide(2), myrrhanolide B(3), gossweilone(4), 6β,7β-epox-4α-hydroxyguaian-10-ene(5), and 4(15)-eudesmane-1β,5α-diol(6) by analyzing the HR-ESI-MS, IR, ECD, 1D NMR and 2D NMR data, as well as their physicochemical properties. All compounds were isolated from C. lauioides for the first time, among which compound 1 is a new nor-clerodane diterpenoid.
Croton/chemistry* ; Diterpenes, Clerodane/isolation & purification* ; Molecular Structure ; Drugs, Chinese Herbal/isolation & purification* ; Magnetic Resonance Spectroscopy ; Chromatography, High Pressure Liquid

The chemical constituents from Cephalotaxus lanceolata were isolated and purified by using multiple chromatographic techniques, including octadecylsilane(ODS), silica gel, Sephadex LH-20 column chromatography, and semi-preparative high-performance liquid chromatography(HPLC). A total of 17 compounds obtained were identified by using spectroscopic methods such as nuclear magnetic resonance(NMR), mass spectrometry(MS), and ultraviolet(UV) combined with literature data. Compound 1 was a new alkaloid dimer, named cephalancetine E. The known compounds were determined as cephalancetine A(2), 11-hydroxycephalotaxine(3), 4-hydroxycephalotaxine(4), cephalotaxine(5), epicephalotaxine(6), cephalotaxine β-N-oxide(7), acetylcephalotaxine(8), cephalotine A(9), cephalotine B(10), 11-hydroxycephalotaxine hemiketal(11), 3-deoxy-3,11-epoxy-cephalotaxine(12), cephalotaxinone(13), isocephalotaxinone(14), 2,11-epoxy-1,2-dihydro-8-oxo-cephalotaxine(15), cephalotaxamide(16), and drupacine(17), respectively. Compounds 11, 12, and 15 were isolated from the Cephalotaxus genus for the first time. The biological activity was tested for compounds 1-17. The results reveal that compound 17 displays potent inhibitory activities against three human cancer cell lines(HepG-2, MCF-7, and SH-SY5Y).
Cephalotaxus/chemistry* ; Humans ; Cell Line, Tumor ; Drugs, Chinese Herbal/pharmacology* ; Harringtonines/pharmacology* ; Molecular Structure ; Dimerization ; Alkaloids/isolation & purification* ; Magnetic Resonance Spectroscopy

The nuclear magnetic resonance (NMR) thermal control subsystem described in this paper is a newly developed platform-based thermal management solution. It presents critical challenges in system architecture design and core component selection. Therefore, it is necessary to carry out sufficient reliability design and verification work in the design and development stage to ensure its high quality and high reliability. Firstly, based on the statistical and analytical calculation of the client installation data of the benchmark product, the reliability metric of the new research subsystem is determined, and its usage and environmental profile are defined. Secondly, for the reliability metric to be verified, the test based on reliability growth and reliability demonstration is planned and implemented. A customized test platform is built, relevant reliability test parameters are designed, and a long-term test monitoring and recording mechanism is established to ensure the high-quality implementation of reliability tests. Finally, a detailed analysis is carried out on the design defects and failure modes exposed during the reliability test, and corresponding control measures are proposed to achieve the engineering goal of improving product robustness throughout its life cycle.
Equipment Design ; Magnetic Resonance Spectroscopy/instrumentation* ; Reproducibility of Results

OBJECTIVES: To investigate the associations between Tau protein deposition and brain biochemical metabolites detected by proton magnetic resonance spectroscopy (¹H-MRS) in patients with advanced Alzheimer's disease (AD). METHODS: From April, 2022 to December, 2024, 64 Tau-positive AD patients and 29 healthy individuals underwent ¹⁸F-APN-1607 PET/MR and simultaneously acquired multi-voxel ¹H-MRS in the Department of Nuclear Medicine, Nanjing First Hospital. Visual analysis and voxel-based analysis of PET/MR data were performed to investigate the Tau protein deposition patterns in AD patients. Valid voxels within the ¹H-MRS field of view were selected, and their standardized uptake value ratio (SUVr) in PET and metabolite levels of N-acetylaspartate (NAA), choline (Cho), creatine (Cr), NAA/Cr, and Cho/Cr were recorded. The Tau-positive (Tau⁺) voxels and Tau-negative (Tau^-) voxels of the AD patients were compared for PET and ¹H-MRS parameters, and the correlations between the metabolites and Tau PET SUVr within Tau⁺ voxels were analyzed. RESULTS: Significant Tau protein deposition were observed in the AD patients, involving mainly the bilateral frontal lobes (30.07%), parietal lobes (29.96%), temporal lobes (21.07%), and occipital lobes (15.89%). A total of 1422 valid voxels in AD group (including 994 Tau⁺ and 428 Tau^- voxels) and 814 voxels in the control group were selected. The AD patients showed significantly decreased NAA level and increased SUVr compared with the control group (P<0.05). Subgroup analyses revealed that Tau⁺ voxels had higher SUVr and lower Cr and Cho/Cr than Tau^- voxels (P<0.05). Compared with the control group, Tau⁺ voxels exhibited higher SUVr and lower Cr (P<0.05), while Tau^- voxels showed lower NAA (P=0.004). No significant differences were found in Cho or NAA/Cr among the subgroups (P>0.05). Within Tau⁺ voxels, NAA, Cho, and Cr were negatively correlated with SUVr (P<0.001). CONCLUSIONS The patients with progressive AD have significant Tau protein deposition in the brain, which is correlated with alterations in metabolite levels. Decreased NAA is more prominent in early or pre-tau deposition stages, while Cr changes is more significant in the regions with Tau protein deposition, suggesting the potential of NAA and Cr as biomarkers for Tau protein deposition in AD for disease monitoring and treatment evaluation.
Humans ; Alzheimer Disease/diagnostic imaging* ; Aspartic Acid/metabolism* ; tau Proteins/metabolism* ; Creatine/metabolism* ; Brain/metabolism* ; Biomarkers/metabolism* ; Positron-Emission Tomography ; Male ; Female ; Proton Magnetic Resonance Spectroscopy ; Choline/metabolism* ; Aged ; Middle Aged

In this study, we systematically tested the hypothesis that during the critical developmental period of adolescence, on a macro scale, the concentrations of major excitatory and inhibitory neurotransmitters (glutamate/glutamine and γ‑aminobutyric acid [GABA]) in the dorsal and ventral lateral prefrontal cortex are associated with the brain's functional connectivity and an individual's psychopathology. Neurotransmitters were measured via magnetic resonance spectroscopy while functional connectivity was measured with resting-state fMRI (n = 121). Seed-based and network-based analyses revealed associations of neurotransmitter concentrations and functional connectivities between regions/networks that are connected to prefrontal cortices via structural connections that are thought to be under dynamic development during adolescence. These regions tend to be boundary areas between functional networks. Furthermore, several connectivities were found to be associated with individual's levels of internalizing psychopathology. These findings provide insights into specific neurochemical mechanisms underlying the brain's macroscale functional organization, its development during adolescence, and its potential associations with symptoms associated with internalizing psychopathology.
Humans ; Adolescent ; Glutamic Acid/metabolism* ; Prefrontal Cortex/diagnostic imaging* ; Male ; Glutamine/metabolism* ; Female ; gamma-Aminobutyric Acid/metabolism* ; Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy ; Nerve Net/metabolism* ; Neural Pathways ; Connectome