Natural products (NPs) have long held a significant position in various fields such as medicine, food, agriculture, and materials. The chemical space covered by NPs is extensive but often underexplored. Therefore, high-throughput and efficient methodologies for the annotation and discovery of NPs are desired to address the complexity and diversity of NP-based systems. Mass spectrometry (MS) has emerged as a powerful platform for the annotation and discovery of NPs. MS databases provide vital support for the structural characterization of NPs by integrating extensive mass spectral data and sample information. Additionally, the released annotation methodologies, based on a variety of informatics tools, continuously improve the ability to annotate the structure and properties of compounds. This review examines the current mainstream databases and annotation methodologies, focusing on their advantages and limitations. Prospects for future technological advancements are then discussed in terms of novel applications and research objectives. Through a systematic overview, this review aims to provide valuable insights and a reference for MS-based NPs annotation, thereby promoting the discovery of novel natural entities.
Biological Products/chemistry* ; Mass Spectrometry/methods* ; Databases, Factual ; Drug Discovery/methods* ; Humans

Aconiti Lateralis Radix Praeparata (Fuzi) represents a significant traditional Chinese medicine (TCM) that exhibits both notable pharmacological effects and toxicity. Various processing methods are implemented to reduce the toxicity of raw Fuzi by modifying its toxic and effective components, primarily diterpenoid alkaloids. To comprehensively analyze the chemical variations between different Fuzi products, ultra-high performance liquid chromatography-linear ion trap quadrupole Orbitrap mass spectrometry (UHPLC-LTQ-Orbitrap MS) was employed to systematically characterize Shengfuzi, Heishunpian and Baifupian. A total of 249 diterpenoid alkaloids present in Shengfuzi were identified, while only 111 and 61 in Heishunpian and Baifupian were detected respectively, indicating substantial differences among these products. An untargeted metabolomics approach combined with multivariate statistical analysis revealed 42 potential chemical markers. Through subsequent validation using 52 batches of commercial Heishunpian and Baifupian samples, 8 robust markers distinguishing these products were identified, including AC1-propanoic acid-3OH, HE-glucoside, HE-hydroxyvaleric acid-2OH, dihydrosphingosine, N-dodecoxycarbonylvaline and three unknown compounds. Additionally, the MS imaging (MSI) technique was utilized to visualize the spatial distribution of chemical constituents in raw Fuzi, revealing how different processing procedures affect the chemical variations between Heishunpian and Baifupian. The distribution patterns of different diterpenoid alkaloid subtypes partially explained the chemical differences among products. This research provides valuable insights into the material basis for future investigations of different Fuzi products.
Diterpenes/chemistry* ; Alkaloids/chemistry* ; Chromatography, High Pressure Liquid/methods* ; Aconitum/chemistry* ; Drugs, Chinese Herbal/chemistry* ; Metabolomics ; Mass Spectrometry/methods* ; Plant Roots/chemistry* ; Molecular Structure

Flavonoids are key bioactive components for evaluating the pharmacological activities of Chimonanthus praecox. Exploring the potential flavonoids and pharmacological mechanisms of C. praecox lays a foundation for the rational development and efficient utilization of this plant. This study employed ultra-performance liquid chromatography-tandem mass spectrometry-based widely targeted metabolomics to comprehensively identify the flavonoids in C. praecox. Network pharmacology was employed to explore the bioactive flavonoids and their mechanisms of action. Molecular docking was adopted to validate the predicted results. Finally, the content of bioactive flavonoids in different varieties of C. praecox was measured. The widely targeted metabolomics analysis identified 387 flavonoids in C. praecox, and the flavonoids varied among different varieties. Network pharmacology predicted 96 chemical components including 19 bioactive compounds, 181 corresponding targets and 2 504 disease targets, among which 99 targets were shared by the active components and the disease. Thirty-three core targets were predicted, involving 229 gene ontology terms and 99 pathways (P≤0.05), which indicated that the flavonoids components of C. praecox exhibited pharmacological activities including antioxidant, anti-inflammatory, antimicrobial, and antiviral activities. Topological analysis screened out five core components (salvigenin, laricitrin, isorhamnetin, quercetin, and 6-hydroxyluteolin) and five core targets (SRC, PIK3R1, AKT1, ESR1, and AKR1C3). The predicted bioactive flavonoids from C. praecox stably bound to key targets, which indicated that these flavonoids possessed potential bioactivities in their interactions with the targets. The flavonoids in C. praecox exerted pharmacological activities in a multi-component, multi-target, and multi-pathway manner. The combined application of metabolomics and network pharmacology provides a theoretical basis for in-depth studies on the pharmacological effects and mechanisms of C. praecox.
Flavonoids/metabolism* ; Network Pharmacology ; Metabolomics/methods* ; Molecular Docking Simulation ; Calycanthaceae/chemistry* ; Tandem Mass Spectrometry ; Drugs, Chinese Herbal/chemistry*

OBJECTIVE: To explore the results of four types of Urea cycle disorders (UCDs) in newborns from the Xuzhou region, assess the efficacy of newborn screening by tandem mass spectrometry (MS/MS), and analyze their genetic characteristics. METHODS: A retrospective analysis was performed using tandem mass spectrometry to screen for inherited metabolic disorders in 691 712 newborns at the Maternal and Child Health Care Hospital of Xuzhou from November 2015 to December 2023. Ten children (cases 1-10) were diagnosed with Ornithine transcarbamylase deficiency (OTCD), Carbamoylphosphate synthase 1 deficiency (CPS1D), Arginase deficiency (ARGD), and Argininosuccinate synthase deficiency (ASSD) based on MS/MS and genetic testing. This study was approved by the Medical Ethics Committee of Xuzhou Maternity and Child Health Care Hospital (Ethics No.XZFY2024-051K-01J). RESULTS: A total of 691 712 neonates were screened for UCDs using MS/MS, which identified 1 237, 1 237, 510, and 1 009 initial positive cases for OTCD, CPS1D, ASSD, and ARGD, respectively. After genetic testing, 1 case of OTCD, 1 case of CPS1D, 1 case of ASSD, and 7 cases of ARGD were confirmed. The overall positive predictive value for these four UCDs was 0.362%. Among the 10 diagnosed UCD cases, four novel variants were identified, which included OTC: c.1024C>A (p.L342M) and ASS1: c.826A>G (p.M276V), c.695C>T (p.P232L) and c.694C>T (p.P232S). Bioinformatic analysis has rated these as variants of uncertain clinical significance or likely pathogenic based on guidelines from the American College of Medical Genetics and Genomics (ACMG). CONCLUSION The incidence of four UCDs in neonates from the Xuzhou area is relatively low, and there is a correlation between genetic variants and clinical phenotypes. For novel variants with uncertain clinical significance or suspected pathogenicity, their pathogenicity should be clarified in conjunction with clinical and biochemical indicators. The four novel pathogenic variants of UCDs identified in this study have enriched the mutational spectrum of UCDs-associated genes in the Xuzhou region.
Humans ; Infant, Newborn ; Tandem Mass Spectrometry/methods* ; Urea Cycle Disorders, Inborn/diagnosis* ; Neonatal Screening/methods* ; Genetic Testing/methods* ; Female ; Retrospective Studies ; Male ; Ornithine Carbamoyltransferase Deficiency Disease/diagnosis* ; Mutation ; Carbamoyl-Phosphate Synthase (Ammonia)/genetics* ; Ornithine Carbamoyltransferase/genetics*

A method for determining volatile organic compounds (VOCs) emitted from medical molecular sieve oxygen concentrators was developed using thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). The oxygen concentrator gas was sampled at a flow rate of 0.5 L/min through a branched sampling system onto Tenax GR/carbopack B adsorption tubes. The adsorbed compounds were desorbed and introduced using a programmed temperature vaporization inlet system, followed by chromatographic separation on an SH-I-624Sil MS column. Four VOCs (BHT-Q, PTBP, BHT-quinol, and EHB) were detected in the medical oxygen concentrator using this method. Calibration curves for these compounds exhibited excellent linearity ( R ²>0.99) within the range of 3~100 ng. With a sampling volume of 20 L, the detection limit of the four VOCs ranged from 0.003 9 to 0.022 2 μg/m ³. Spike recovery rates for the four VOCs were between 95% and 115%, with relative standard deviations (RSDs) below 5% ( n=6). The method is simple, rapid, highly sensitive, and accurate, making it suitable for VOCs detection in medical molecular sieve oxygen concentrators.
Volatile Organic Compounds/analysis* ; Gas Chromatography-Mass Spectrometry/methods* ; Oxygen

OBJECTIVES: Tiletamine, a veterinary anesthetic, has emerged as a novel psychoactive substance and has been abused in many parts of the world, causing great harm to public health. However, the sensitivity of existing detection methods cannot meet the needs of forensic practice. This study aims to establish an ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the determination of tiletamine and its metabolite desethyltiletamine in human biological samples, and to verify its applicability in forensic practice. METHODS: SKF_525A was used as the internal standard. Biological samples were extracted with acetonitrile containing 1 ng/mL SKF_525A, vortexed for 10 min, ultrasonicated for 20 min, centrifuged at 10 000 r/min for 10 min, and 500 μL of the supernatant was filtered through a 0.22 μm membrane. Analyses were performed using an ACQUITY UPLC H-Class PLUS system and an XEVO TQ-S Micro triple quadrupole mass spectrometer. An ACQUITY UPLC^® BEH C18 (1.7 µm, 2.1 mm×100 mm) column at a flow rate of 0.3 mL/min was used, and four mobile phase systems were tested to optimize separation. Detection used positive electrospray ionization (ESI+) in multiple reaction monitoring (MRM) mode, with quantifier ion transitions of mass to charge 224.043→179.016 for tiletamine and mass to charge 196.08→151.06 for desethyltiletamine. Calibration curves were established over 0.1-200 ng/mL in spiked blood samples. The linear range, limit of detection (LOD), and limit of quantification (LOQ) were determined. Low (5 ng/mL), medium (20 ng/mL), and high (100 ng/mL) concentrations of tiletamine were spiked into blood, liver, and kidney to evaluate precision, accuracy, matrix effect, recovery, and stability. Finally, actual forensic case samples were tested to validate applicability. RESULTS: The established UPLC-MS/MS method achieved simultaneous detection of tiletamine and desethyltiletamine in human biological samples, with retention times of 3.42 min and 2.82 min, respectively. Using mobile phase A (20 mmol/L ammonium acetate and 0.1% formic acid in water) and mobile phase B (acetonitrile) produced the best separation. In blood, tiletamine showed good linearity from 0.1-200 ng/mL (r=0.992, R²=0.983), LOD 0.03 ng/mL, LOQ 0.1 ng/mL, recovery 92%-107%, and matrix effect 71%-99%. In liver and kidney, recoveries were 91%-98% and 93%-104%, and matrix effects were 69%-96% and 72%-100%, respectively. Intra- and inter-day precision [expressed as relative standard deviation (RSD)] and accuracy [expressed as relative error (RE)] were within 15%, and samples were stable at -20 ℃. Tiletamine was detected in actual case samples at 0.37 μg/mL (blood), 0.15 μg/g (liver), 0.11 μg/g (kidney) in case 1, and 8.75 ng/mL (blood) in case 2; desethyltiletamine was also detected in blood. CONCLUSIONS The UPLC-MS/MS method is efficient, accurate, and sensitive, and is suitable for detecting tiletamine and desethyltiletamine in human biological samples.
Tandem Mass Spectrometry/methods* ; Humans ; Chromatography, High Pressure Liquid/methods* ; Substance Abuse Detection/methods* ; Liquid Chromatography-Mass Spectrometry

OBJECTIVES: To evaluate the clinical value of next-generation sequencing (NGS) in neonatal disease screening, particularly its advantages when combined with tandem mass spectrometry (MS/MS). METHODS: A prospective study was conducted involving blood samples from 1 999 neonates born at the Shenzhen Guangming District People's Hospital, between May and August 2021. All samples were initially screened using MS/MS and fluorescence immunoassay, followed by NGS to detect high-frequency variation sites in 135 related pathogenic genes. Suspected positive variants were validated using Sanger sequencing or multiplex ligation-dependent probe amplification in family studies. RESULTS: No confirmed positive cases were found in the MS/MS analysis of the 1 999 neonates. Genetic screening identified 58 positive cases (2.90%), 732 carriers of pathogenic genes (36.62%), and 1 209 negative cases (60.48%). One case of neonatal intrahepatic cholestasis was diagnosed (0.05%, 1/1 999). Fluorescence immunoassay identified 39 cases of glucose-6-phosphate dehydrogenase (G6PD) deficiency (1.95%, 39/1 999), while genetic screening identified 43 cases of G6PD deficiency (2.15%, 43/1 999). The fluorescence immunoassay also detected 6 cases of hyperthyrotropinemia (0.30%, 6/1 999), all of whom carried DUOX2 gene variants. The top ten pathogenic gene carrier rates were G6PD (12.8%), DUOX2 (8.7%), HBB (8.2%), ATP7B (6.6%), GJB2 (5.7%), SLC26A4 (5.6%), PAH (5.6%), ACADSB (4.6%), SLC25A13 (4.2%), and SLC22A5 (4.1%). CONCLUSIONS NGS can serve as an effective complement to MS/MS, significantly improving the detection rate of inherited metabolic disorders in neonates. When combined with family validation, it enables precise diagnosis, particularly demonstrating complementary advantages in screening for monogenic diseases such as G6PD deficiency.
Humans ; Infant, Newborn ; High-Throughput Nucleotide Sequencing/methods* ; Neonatal Screening/methods* ; Tandem Mass Spectrometry ; Prospective Studies ; Female ; Male ; Infant, Newborn, Diseases/diagnosis* ; Genetic Testing

OBJECTIVES: To explore the lipidomic characteristics of children with bronchial asthma (hereafter referred to as asthma) and identify potential biomarkers for asthma. METHODS: A total of 26 asthmatic children were prospectively enrolled as the asthma group, and 20 healthy children served as the healthy control group. The asthma group was further divided into atopic (n=13) and non-atopic (n=13) subgroups based on IgE levels. Serum lipid metabolites were analyzed using liquid chromatography-mass spectrometry, followed by statistical analysis and data visualization. RESULTS: A total of 1 435 lipids were detected in the 46 children, primarily glycerophospholipids (625/1 435, 43.55%). Significant differences were observed in serum lipid profiles between the asthma and control groups. Twelve significantly differential lipids were identified, with receiver operating characteristic curve analysis showing that phosphatidylserine (PS)(18:0/20:4) and ceramide (Cer)(c16:0) exhibited the highest diagnostic value for asthma. The relative abundances of PS(18:0/20:4) and PS(18:0/22:6) were higher in the atopic subgroup than in the non-atopic subgroup (P<0.05) and positively correlated with total IgE levels in asthmatic children (r=0.675 and 0.740, respectively; P<0.05). CONCLUSIONS Asthmatic children exhibit significant lipid metabolic disturbances, primarily characterized by abnormal glycerophospholipid metabolism. Among these, PS(18:0/20:4) and Cer(c16:0) demonstrate specific alterations and may serve as potential diagnostic biomarkers for asthma. Furthermore, the positive correlation between PS(18:0/20:4) and PS(18:0/22:6) levels and serum total IgE suggests their possible involvement in immune regulation in asthma.
Humans ; Asthma/metabolism* ; Male ; Child ; Female ; Prospective Studies ; Mass Spectrometry/methods* ; Lipids/blood* ; Chromatography, Liquid/methods* ; Child, Preschool ; Immunoglobulin E/blood* ; Biomarkers/blood* ; Adolescent ; Liquid Chromatography-Mass Spectrometry

BACKGROUND: Icaridin and DEET are common insect repellents widely used on human skin and clothing (skin-insect repellents [skin-IR]) to repel common pests, such as mosquitoes and biting flies. Novel analytical methods for urinary skin-IR exposure biomarkers that can be effectively applied in epidemiological studies and provide strong evidence related to risk assessment associated with daily exposure are required. In this study, we aimed to develop a method for analyzing the concentrations of icaridin, DEET, and two DEET metabolites N,N-diethyl-3-(hydroxymethyl) benzamide and 3-(diethylcarbamoyl) benzoic acid in human urine. METHODS: In this analysis, after formic acid-induced acidification of the urine sample, exposure biomarkers were extracted using solid-phase extraction composed of a modified polystyrenedivinylbenzene polymer for reversed phase (hydrophobic) retention. Subsequently, high-performance liquid chromatography-tandem mass spectrometry was performed within 10 min for a separation analysis. The present method was applied to five Japanese adults (aged 20-43 years) who used icaridin or DEET-containing products within a week. RESULTS: Limits of detection were 0.06-0.11 µg/L. Extraction recoveries were 74%-88%. The intraday and interday variations were 1.5-17.5 and 0.9-15.8% relative standard deviation, respectively. All exposure biomarkers were successfully detected in all five adults. Urinary concentrations of exposure biomarkers reached their maximum values within 15 h after starting to use skin-IR. CONCLUSIONS This method was successful in measuring urinary exposure biomarkers of skin-IR, including icaridin and DEET. Moreover, this study presents the first application of biomonitoring of urinary icaridin concentrations after using a commercial product.
Humans ; Solid Phase Extraction/methods* ; Tandem Mass Spectrometry/methods* ; Adult ; Insect Repellents/urine* ; DEET/urine* ; Young Adult ; Male ; Japan ; Female ; Chromatography, Liquid ; Biomarkers/urine* ; Chromatography, High Pressure Liquid ; East Asian People

Processing for deodorization is widely used in the production of animal-derived Chinese medicinal materials. In this study, Heracles Neo ultra-fast gas-phase electronic nose combined with chemometrics was employed to analyze the overall odor difference of Cervi Cornu Pantotrichum(focusing on that derived from Cervus nippon Temminck in this study) before and after processing. The results showed that the electronic nose effectively distinguished between the medicinal materials and decoction pieces of Cervi Cornu Pantotrichum. HS-GC-MS was used to identify and quantify the volatile components in the medicinal materials and decoction pieces of Cervi Cornu Pantotrichum, and 35 and 37 volatile components were detected in the medicinal materials and decoction pieces, respectively. The medicinal materials and decoction pieces contained 28 common volatile components contributing to the odor of Cervi Cornu Pantotrichum. The odor activity value(OAV) of each volatile component was calculated based on the olfactory threshold and relative content. The results showed that there were 17 key odor substances such as isovaleraldehyde, 2-methylbutanal, isobutyraldehyde, hexanal, and methanethiol in the medicinal materials and decoction pieces of Cervi Cornu Pantotrichum. All of them had bad odor and were the main source of the odor of Cervi Cornu Pantotrichum. The results of principal component analysis(PCA) and orthogonal partial least squares-discriminant analysis(OPLS-DA) showed that there were significant differences in volatile components between the medicinal materials and decoction pieces of Cervi Cornu Pantotrichum. Based on the thresholds of P<0.05 and Variable Importance in Projection(VIP)>1, 21 differential volatile odor components were screened out. Among them, isopentanol, isovaleraldehyde, 2-methylbutanal, n-nonanal, and dimethylamine were the key differential odor compounds between the medicinal materials and decoction pieces of Cervi Cornu Pantotrichum. The odor compounds and their relative content reduced, and some flavor substances such as esters were produced after processing with wine, which was the main reason for the reduction of the odor after processing of Cervi Cornu Pantotrichum.
Odorants/analysis* ; Electronic Nose ; Gas Chromatography-Mass Spectrometry/methods* ; Animals ; Volatile Organic Compounds/analysis* ; Deer ; Drugs, Chinese Herbal/chemistry*