1.The Application of Spatial Resolved Metabolomics in Neurodegenerative Diseases
Lu-Tao XU ; Qian LI ; Shu-Lei HAN ; Huan CHEN ; Hong-Wei HOU ; Qing-Yuan HU
Progress in Biochemistry and Biophysics 2025;52(9):2346-2359
The pathogenesis of neurodegenerative diseases (NDDs) is fundamentally linked to complex and profound alterations in metabolic networks within the brain, which exhibit marked spatial heterogeneity. While conventional bulk metabolomics is powerful for detecting global metabolic shifts, it inherently lacks spatial resolution. This methodological limitation hampers the ability to interrogate critical metabolic dysregulation within discrete anatomical brain regions and specific cellular microenvironments, thereby constraining a deeper understanding of the core pathological mechanisms that initiate and drive NDDs. To address this critical gap, spatial metabolomics, with mass spectrometry imaging (MSI) at its core, has emerged as a transformative approach. It uniquely overcomes the limitations of bulk methods by enabling high-resolution, simultaneous detection and precise localization of hundreds to thousands of endogenous molecules—including primary metabolites, complex lipids, neurotransmitters, neuropeptides, and essential metal ions—directly in situ from tissue sections. This powerful capability offers an unprecedented spatial perspective for investigating the intricate and heterogeneous chemical landscape of NDD pathology, opening new avenues for discovery. Accordingly, this review provides a comprehensive overview of the field, beginning with a discussion of the technical features, optimal application scenarios, and current limitations of major MSI platforms. These include the widely adopted matrix-assisted laser desorption/ionization (MALDI)-MSI, the ultra-high-resolution technique of secondary ion mass spectrometry (SIMS)-MSI, and the ambient ionization method of desorption electrospray ionization (DESI)-MSI, along with other emerging technologies. We then highlight the pivotal applications of spatial metabolomics in NDD research, particularly its role in elucidating the profound chemical heterogeneity within distinct pathological microenvironments. These applications include mapping unique molecular signatures around amyloid β‑protein (Aβ) plaques, uncovering the metabolic consequences of neurofibrillary tangles composed of hyperphosphorylated tau protein, and characterizing the lipid and metabolite composition of Lewy bodies. Moreover, we examine how spatial metabolomics contributes to constructing detailed metabolic vulnerability maps across the brain, shedding light on the biochemical factors that render certain neuronal populations and anatomical regions selectively susceptible to degeneration while others remain resilient. Looking beyond current applications, we explore the immense potential of integrating spatial metabolomics with other advanced research methodologies. This includes its combination with three-dimensional brain organoid models to recapitulate disease-relevant metabolic processes, its linkage with multi-organ axis studies to investigate how systemic metabolic health influences neurodegeneration, and its convergence with single-cell and subcellular analyses to achieve unprecedented molecular resolution. In conclusion, this review not only summarizes the current state and critical role of spatial metabolomics in NDD research but also offers a forward-looking perspective on its transformative potential. We envision its continued impact in advancing our fundamental understanding of NDDs and accelerating translation into clinical practice—from the discovery of novel biomarkers for early diagnosis to the development of high-throughput drug screening platforms and the realization of precision medicine for individuals affected by these devastating disorders.
2.Synergistic neuroprotective effects of main components of salvianolic acids for injection based on key pathological modules of cerebral ischemia.
Si-Yu TAN ; Ya-Xu WU ; Zi-Shu YAN ; Ai-Chun JU ; De-Kun LI ; Peng-Wei ZHUANG ; Yan-Jun ZHANG ; Hong GUO
China Journal of Chinese Materia Medica 2025;50(3):693-701
This study aims to explore the synergistic effects of the main components in salvianolic acids for Injection(SAFI) on key pathological events in cerebral ischemia, elucidating the pharmacological characteristics of SAFI in neuroprotection. Two major pathological gene modules related to endothelial injury and neuroinflammation in cerebral ischemia were mined from single-cell data. According to the topological distance calculated in network medicine, potential synergistic component combinations of SAFI were screened out. The results showed that the combination of caffeic acid and salvianolic acid B scored the highest in addressing both endothelial injury and neuroinflammation, demonstrating potential synergistic effects. The cell experiments confirmed that the combination of these two components at a ratio of 1∶1 significantly protected brain microvascular endothelial cells(bEnd.3) from oxygen-glucose deprivation/reoxygenation(OGD/R)-induced reperfusion injury and effectively suppressed lipopolysaccharide(LPS)-induced neuroinflammatory responses in microglial cells(BV-2). This study provides a new method for uncovering synergistic effects among active components in traditional Chinese medicine(TCM) and offers novel insights into the multi-component, multi-target acting mechanisms of TCM.
Brain Ischemia/metabolism*
;
Neuroprotective Agents/pharmacology*
;
Animals
;
Drugs, Chinese Herbal/administration & dosage*
;
Benzofurans/pharmacology*
;
Mice
;
Drug Synergism
;
Caffeic Acids/pharmacology*
;
Polyphenols/pharmacology*
;
Humans
;
Alkenes/pharmacology*
;
Endothelial Cells/drug effects*
;
Depsides
3.The Molecular Mechanism of HCQ Reversing Immune Mediators Dysregulation in Severe Infection after Chemotherapy in Acute Myeloid Leukemia and Inducing Programmed Death of Leukemia Cells.
Qing-Lin XU ; Yan-Quan LIU ; He-Hui ZHANG ; Fen WANG ; Zuo-Tao LI ; Zhi-Min YAN ; Shu-Juan CHEN ; Hong-Quan ZHU
Journal of Experimental Hematology 2025;33(4):931-938
OBJECTIVE:
To explore the effects of hydroxychloroquine (HCQ) on immune mediators dysregulation in severe infection after chemotherapy in acute myeloid leukemia (AML) and its molecular mechanism.
METHODS:
Bone marrow or peripheral blood samples of 36 AML patients with severe infection (AML-SI) and 29 AML patients without infection (AML-NI) after chemotherapy were collected from the First Affiliated Hospital of Gannan Medical University from August 2022 to June 2023. In addition, the peripheral blood of 21 healthy subjects from the same period in our hospital was selected as the control group. The mRNA expressions of CXCL12, CXCR4 and CXCR7 were detected by RT-qPCR technology, and the levels of IL-6, IL-8 and TNF-α were detected by ELISA. Leukemia-derived THP-1 cells were selected and constructed as AML disease model. At the same time, bone marrow mesenchymal stem cells (BM-MSCs) from AML-SI patients were co-cultured with THP-1 cells and divided into Mono group and Co-culture group. THP-1 cells were treated with different concentration gradients of HCQ. The cell proliferation activity was subsequently detected by CCK-8 method and apoptosis was detected by Annexin V/PI double staining flow cytometry. ELISA was used to detect the changes of IL-6, IL-8 and TNF-α levels in the supernatant of the cell co-culture system, RT-qPCR was used to detect the mRNA expression changes of the core members of the CXCL12-CXCR4/7 regulatory axis, and Western blot was used to detect the expressions of apoptosis regulatory molecules and related signaling pathway proteins.
RESULTS:
CXCL12, CXCR4, CXCR7, as well as IL-6, IL-8, and TNF-α were all abnormally increased in AML patients, and the increases were more significant in AML-SI patients (P <0.01). Furthermore, there were statistically significant differences between AML-NI patients and AML-SI patients (all P <0.05). HCQ could inhibit the proliferation and induce the apoptosis of THP-1 cells, but the low concentration of HCQ had no significant effect on the killing of THP-1 cells. When THP-1 cells were co-cultured with BM-MSCs of AML patients, the levels of IL-6, IL-8 and TNF-α in the supernatance of Co-culture group were significantly higher than those of Mono group (all P <0.01). After HCQ intervention, the levels of IL-6, IL-8 and TNF-α in cell culture supernatant of Mono group were significantly decreased compared with those before intervention (all P <0.01). Similarly, those of Co-culture group were also significantly decreased (all P <0.001). However, the expression of the core members of the CXCL12-CXCR4/7 regulatory axis was weakly affected by HCQ. HCQ could up-regulate the expression of pro-apoptotic protein Bax, down-regulate the expression of anti-apoptotic protein Bcl-2, as well as simultaneously promote the hydrolytic activation of Caspase-3 when inhibiting the activation level of TLR4/NF-κB pathway, then induce the programmed death of THP-1 cells after intervention.
CONCLUSION
The core members of CXCL12-CXCR4/7 axis and related cytokines may be important mediators of severe infectious immune disorders in AML patients. HCQ can inhibit cytokine levels to reverse immune mediators dysregulation and suppress malignant biological characteristics of leukemia cells. The mechanisms may be related to regulating the expression of Bcl-2 family proteins, hydrolytically activating Caspase-3 and inhibiting the activation of TLR4/NF-κB signaling pathway.
Humans
;
Leukemia, Myeloid, Acute/immunology*
;
Hydroxychloroquine/pharmacology*
;
Receptors, CXCR4/metabolism*
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Apoptosis/drug effects*
;
Tumor Necrosis Factor-alpha/metabolism*
;
Chemokine CXCL12/metabolism*
;
Interleukin-8/metabolism*
;
Interleukin-6/metabolism*
;
Receptors, CXCR/metabolism*
;
Mesenchymal Stem Cells
;
THP-1 Cells
4.Histaminergic Innervation of the Ventral Anterior Thalamic Nucleus Alleviates Motor Deficits in a 6-OHDA-Induced Rat Model of Parkinson's Disease.
Han-Ting XU ; Xiao-Ya XI ; Shuang ZHOU ; Yun-Yong XIE ; Zhi-San CUI ; Bei-Bei ZHANG ; Shu-Tao XIE ; Hong-Zhao LI ; Qi-Peng ZHANG ; Yang PAN ; Xiao-Yang ZHANG ; Jing-Ning ZHU
Neuroscience Bulletin 2025;41(4):551-568
The ventral anterior (VA) nucleus of the thalamus is a major target of the basal ganglia and is closely associated with the pathogenesis of Parkinson's disease (PD). Notably, the VA receives direct innervation from the hypothalamic histaminergic system. However, its role in PD remains unknown. Here, we assessed the contribution of histamine to VA neuronal activity and PD motor deficits. Functional magnetic resonance imaging showed reduced VA activity in PD patients. Optogenetic activation of VA neurons or histaminergic afferents significantly alleviated motor deficits in 6-OHDA-induced PD rats. Furthermore, histamine excited VA neurons via H1 and H2 receptors and their coupled hyperpolarization-activated cyclic nucleotide-gated channels, inward-rectifier K+ channels, or Ca2+-activated K+ channels. These results demonstrate that histaminergic afferents actively compensate for Parkinsonian motor deficits by biasing VA activity. These findings suggest that targeting VA histamine receptors and downstream ion channels may be a potential therapeutic strategy for PD motor dysfunction.
Animals
;
Histamine/metabolism*
;
Male
;
Oxidopamine/toxicity*
;
Rats
;
Ventral Thalamic Nuclei/physiopathology*
;
Rats, Sprague-Dawley
;
Disease Models, Animal
;
Parkinson Disease/metabolism*
;
Neurons/physiology*
;
Humans
;
Optogenetics
5.Association of Body Mass Index with All-Cause Mortality and Cause-Specific Mortality in Rural China: 10-Year Follow-up of a Population-Based Multicenter Prospective Study.
Juan Juan HUANG ; Yuan Zhi DI ; Ling Yu SHEN ; Jian Guo LIANG ; Jiang DU ; Xue Fang CAO ; Wei Tao DUAN ; Ai Wei HE ; Jun LIANG ; Li Mei ZHU ; Zi Sen LIU ; Fang LIU ; Shu Min YANG ; Zu Hui XU ; Cheng CHEN ; Bin ZHANG ; Jiao Xia YAN ; Yan Chun LIANG ; Rong LIU ; Tao ZHU ; Hong Zhi LI ; Fei SHEN ; Bo Xuan FENG ; Yi Jun HE ; Zi Han LI ; Ya Qi ZHAO ; Tong Lei GUO ; Li Qiong BAI ; Wei LU ; Qi JIN ; Lei GAO ; He Nan XIN
Biomedical and Environmental Sciences 2025;38(10):1179-1193
OBJECTIVE:
This study aimed to explore the association between body mass index (BMI) and mortality based on the 10-year population-based multicenter prospective study.
METHODS:
A general population-based multicenter prospective study was conducted at four sites in rural China between 2013 and 2023. Multivariate Cox proportional hazards models and restricted cubic spline analyses were used to assess the association between BMI and mortality. Stratified analyses were performed based on the individual characteristics of the participants.
RESULTS:
Overall, 19,107 participants with a sum of 163,095 person-years were included and 1,910 participants died. The underweight (< 18.5 kg/m 2) presented an increase in all-cause mortality (adjusted hazards ratio [ aHR] = 2.00, 95% confidence interval [ CI]: 1.66-2.41), while overweight (≥ 24.0 to < 28.0 kg/m 2) and obesity (≥ 28.0 kg/m 2) presented a decrease with an aHR of 0.61 (95% CI: 0.52-0.73) and 0.51 (95% CI: 0.37-0.70), respectively. Overweight ( aHR = 0.76, 95% CI: 0.67-0.86) and mild obesity ( aHR = 0.72, 95% CI: 0.59-0.87) had a positive impact on mortality in people older than 60 years. All-cause mortality decreased rapidly until reaching a BMI of 25.7 kg/m 2 ( aHR = 0.95, 95% CI: 0.92-0.98) and increased slightly above that value, indicating a U-shaped association. The beneficial impact of being overweight on mortality was robust in most subgroups and sensitivity analyses.
CONCLUSION
This study provides additional evidence that overweight and mild obesity may be inversely related to the risk of death in individuals older than 60 years. Therefore, it is essential to consider age differences when formulating health and weight management strategies.
Humans
;
Body Mass Index
;
China/epidemiology*
;
Male
;
Female
;
Middle Aged
;
Prospective Studies
;
Rural Population/statistics & numerical data*
;
Aged
;
Follow-Up Studies
;
Adult
;
Mortality
;
Cause of Death
;
Obesity/mortality*
;
Overweight/mortality*
6.Impact of PCSK9 Inhibitor Recaticimab on Hyperlipidemia and Plasma Glucose: A Randomized, Double-Blind, Placebo-Controlled Phase 1b/2 Study.
Ye HU ; Chen CHEN ; Xiao Hui HE ; Shu Yu ZHANG ; Xu Hong WANG
Biomedical and Environmental Sciences 2025;38(10):1246-1254
OBJECTIVE:
Recaticimab (SHR-1209) significantly reduces low-density lipoprotein cholesterol levels. However, its effect on glucose metabolism remains unclear. This study aimed to evaluate its effect on glycemic parameters in a Chinese population.
METHODS:
Recaticimab versus placebo was administered in a 5:1 ratio to 110 hyperlipidemia patients who were followed up for 24 weeks. Glycated hemoglobin (HbA1c) levels were measured at baseline every 12 weeks. Fasting plasma glucose (FPG) levels were measured at baseline at week 1, 3, 5, 8, 12, 16, 20, and 24. Repeated-measures mixed-effects models were used to determine the longitudinal association between reacticimab and FPG and HbA1c levels.
RESULTS:
Among the 81 participants with normal glucose metabolism, HbA1c levels significantly decreased ( F = 4.568, P = 0.036). In the 29 participants with abnormal glucose metabolism, a significant time effect was observed for FPG levels ( F = 2.492, P = 0.016). For participants with normal and abnormal glucose metabolism, no significant group × time interaction effects on FPG or HbA1c levels were identified.
CONCLUSION
Recaticimab showed no adverse glycemic effects in participants with normal or abnormal glucose metabolism, indicating its safety in patients with or without diabetes.
Humans
;
Male
;
Female
;
Blood Glucose/drug effects*
;
Middle Aged
;
Double-Blind Method
;
Hyperlipidemias/blood*
;
Antibodies, Monoclonal, Humanized/therapeutic use*
;
PCSK9 Inhibitors
;
Glycated Hemoglobin
;
Aged
;
Adult
;
Proprotein Convertase 9
7.Diagnostic value of vena contracta area measurement for grading tricuspid regurgitation severity under different etiologies:a three-dimensional echocardiography study
Bei-Qi CHEN ; Yu LIU ; Wu-Xu ZUO ; Quan LI ; Yuan-Feng WU ; De-Hong KONG ; Cui-Zhen PAN ; Li-Li DONG ; Xian-Hong SHU
Fudan University Journal of Medical Sciences 2024;51(4):484-493,504
Objective To explore the cut-off value of three dimensional(3D)vena contracta area(VCA)in diagnosing severe tricuspid regrugitation(TR)under different etiologies and its accuracy and practicality in clinical application.Methods From Mar 2019 to May 2021,ninety-two patients with confirmed TR underwent two dimensional(2D)and 3D transthoracic echocardiography.The correlation and consistency between 3D VCA 3D calculated based on the proximal isokinetic surface area(PISA)effective regurgitant orifice area(EROA)was calculated.Comprehensive 2D multi-parameter method was used as a reference method to calculate the cut-off value of the diagnosis of severe TR.Results A total of 85 patients were ultimately included.3D VCA and 3D PISA EROA had similar and acceptable correlations in both primary TR and secondary TR(primary TR:r=0.831,P<0.01;secondary TR:r=0.806,P<0.01).Bland-Altman analysis showed that 3D VCA overestimated TR compared with 3D PISA EROA(62%overestimated in the total patient population,51%overestimated in primary TR,and 74%overestimated in secondary TR).In secondary TR,the cut-off value of 3D VCA for diagnosing severe TR was 0.45 cm2(sensitivity 89%,specificity 82%);combining clinical symptoms,positive 2D PISA EROA results and 3D VCA results for severe TR,the chi-square value was higher than those only included clinical symptoms or incorporated clinical symptoms and positive 2D PISA EROA results(42.168 vs.26.059 and 16.759,P<0.01).Conclusion 3D VCA would overestimate TR,and had high and incremental diagnostic value for evaluating severe TR in secondary TR.
8.A multi-center epidemiological study on pneumococcal meningitis in children from 2019 to 2020
Cai-Yun WANG ; Hong-Mei XU ; Gang LIU ; Jing LIU ; Hui YU ; Bi-Quan CHEN ; Guo ZHENG ; Min SHU ; Li-Jun DU ; Zhi-Wei XU ; Li-Su HUANG ; Hai-Bo LI ; Dong WANG ; Song-Ting BAI ; Qing-Wen SHAN ; Chun-Hui ZHU ; Jian-Mei TIAN ; Jian-Hua HAO ; Ai-Wei LIN ; Dao-Jiong LIN ; Jin-Zhun WU ; Xin-Hua ZHANG ; Qing CAO ; Zhong-Bin TAO ; Yuan CHEN ; Guo-Long ZHU ; Ping XUE ; Zheng-Zhen TANG ; Xue-Wen SU ; Zheng-Hai QU ; Shi-Yong ZHAO ; Lin PANG ; Hui-Ling DENG ; Sai-Nan SHU ; Ying-Hu CHEN
Chinese Journal of Contemporary Pediatrics 2024;26(2):131-138
Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]
9.A multicenter study of neonatal stroke in Shenzhen,China
Li-Xiu SHI ; Jin-Xing FENG ; Yan-Fang WEI ; Xin-Ru LU ; Yu-Xi ZHANG ; Lin-Ying YANG ; Sheng-Nan HE ; Pei-Juan CHEN ; Jing HAN ; Cheng CHEN ; Hui-Ying TU ; Zhang-Bin YU ; Jin-Jie HUANG ; Shu-Juan ZENG ; Wan-Ling CHEN ; Ying LIU ; Yan-Ping GUO ; Jiao-Yu MAO ; Xiao-Dong LI ; Qian-Shen ZHANG ; Zhi-Li XIE ; Mei-Ying HUANG ; Kun-Shan YAN ; Er-Ya YING ; Jun CHEN ; Yan-Rong WANG ; Ya-Ping LIU ; Bo SONG ; Hua-Yan LIU ; Xiao-Dong XIAO ; Hong TANG ; Yu-Na WANG ; Yin-Sha CAI ; Qi LONG ; Han-Qiang XU ; Hui-Zhan WANG ; Qian SUN ; Fang HAN ; Rui-Biao ZHANG ; Chuan-Zhong YANG ; Lei DOU ; Hui-Ju SHI ; Rui WANG ; Ping JIANG ; Shenzhen Neonatal Data Network
Chinese Journal of Contemporary Pediatrics 2024;26(5):450-455
Objective To investigate the incidence rate,clinical characteristics,and prognosis of neonatal stroke in Shenzhen,China.Methods Led by Shenzhen Children's Hospital,the Shenzhen Neonatal Data Collaboration Network organized 21 institutions to collect 36 cases of neonatal stroke from January 2020 to December 2022.The incidence,clinical characteristics,treatment,and prognosis of neonatal stroke in Shenzhen were analyzed.Results The incidence rate of neonatal stroke in 21 hospitals from 2020 to 2022 was 1/15 137,1/6 060,and 1/7 704,respectively.Ischemic stroke accounted for 75%(27/36);boys accounted for 64%(23/36).Among the 36 neonates,31(86%)had disease onset within 3 days after birth,and 19(53%)had convulsion as the initial presentation.Cerebral MRI showed that 22 neonates(61%)had left cerebral infarction and 13(36%)had basal ganglia infarction.Magnetic resonance angiography was performed for 12 neonates,among whom 9(75%)had involvement of the middle cerebral artery.Electroencephalography was performed for 29 neonates,with sharp waves in 21 neonates(72%)and seizures in 10 neonates(34%).Symptomatic/supportive treatment varied across different hospitals.Neonatal Behavioral Neurological Assessment was performed for 12 neonates(33%,12/36),with a mean score of(32±4)points.The prognosis of 27 neonates was followed up to around 12 months of age,with 44%(12/27)of the neonates having a good prognosis.Conclusions Ischemic stroke is the main type of neonatal stroke,often with convulsions as the initial presentation,involvement of the middle cerebral artery,sharp waves on electroencephalography,and a relatively low neurodevelopment score.Symptomatic/supportive treatment is the main treatment method,and some neonates tend to have a poor prognosis.
10.Insight of N-Lauroyl-L-alanine Molecular Assembly Using Solid-State Nuclear Magnetic Resonance Technique
Zi-Hui QIU ; Ling-Yun XU ; Yi-Jian CHEN ; Hong-Chun DONG ; Jie SHU ; Zhi-Gang YAO
Chinese Journal of Analytical Chemistry 2024;52(6):866-875
Amino acid surfactants (AAS) have excellent properties such as low toxicity,antibacterial,mildness,and corrosion resistance. In recent years,they have been widely applied in the field of daily chemicals,food and pharmaceutical industry. It is pointed out that the structure at molecular level largely affects the physical and chemical properties of AAS materials. In this work,the structures of solid-state N-lauroyl-L-alanine (NLLA) including intermolecular interactions,molecular local dynamics and molecular assembly were investigated by a variety of solid-state nuclear magnetic resonance (SSNMR) techniques. Based on 2D 1H-1H double quantum-single quantum (2D 1H-1H DQ-SQ),1H-1H DQ sideband pattern and molecular simulation,it was found that there was a stable intermolecular hydrogen bond formed between the carboxyl units of two NLLA molecules. Combined with the study of 2D frequency switched Lee—Goldberg heteronuclear correlation (2D 13C-1H FSLG-HETCOR) and 13C T1,another type of hydrogen bond was probed,which existed between amide units of neighboring molecules. In addition,the conformation of alkyl chain ends was investigated. According to 1D 13C{1H}cross polarization/magic angle spinning (CP/MAS) and 2D 13C-1H FSLG-HETCOR spectra,it was revealed that the alkyl-chain ends had both gauche and trans conformations. Moreover,the trans conformation showed two distinct 13C chemical shifts,originated from two NLLA molecular assembly forms. Accordingly,two NLLA molecular assembly structures were suggested which were transoid form and cisoid form. This work provided a SSNMR investigation strategy for characterizing the molecular local structure and dynamics of AAS materials,which helped task of researching and developing materials with improved chemical and physical properties.

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