Evidence map›Paper›PMID 42649459›Full record

ArticleMetabolomics : Official journal of the Metabolomic Society2026

From known chemical space to unannotated metabolites: a cluster-guided retention-time driven framework for biologically informed annotation.

Dipendra Bhandari, Henry A Paz, Keith Henderson, Kiran Kumar Adepu, Ahmad Mani-Varnosfaderani, Hailemariam Abrha Assress, Brian D Piccolo, Renny S Lan, Elisabet Børsheim, Colin D Kay and 1 more

Abstract read
In one paragraph

Article in Metabolomics : Official journal of the Metabolomic Society, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

11 authors.

Dipendra Bhandari *Arkansas Children's Nutrition Center and Arkansas Children's Research Institute, 15 Children's Way, Little Rock, AR, 72202, USA.ORCID http://orcid.org/0000-0003-4291-0128
Henry A Paz *Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA.ORCID http://orcid.org/0000-0002-2231-9368
Keith HendersonArkansas Children's Nutrition Center and Arkansas Children's Research Institute, 15 Children's Way, Little Rock, AR, 72202, USA.ORCID http://orcid.org/0009-0005-2166-9912
Kiran Kumar AdepuDepartment of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA.ORCID http://orcid.org/0000-0001-6612-1823
Ahmad Mani-VarnosfaderaniDepartment of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA.ORCID http://orcid.org/0000-0003-1142-1057
Hailemariam Abrha AssressDepartment of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA.ORCID http://orcid.org/0000-0002-4967-3981
Brian D PiccoloArkansas Children's Nutrition Center and Arkansas Children's Research Institute, 15 Children's Way, Little Rock, AR, 72202, USA.ORCID http://orcid.org/0000-0002-1789-4587
Renny S LanDepartment of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA.ORCID http://orcid.org/0000-0001-8346-043X
Elisabet BørsheimArkansas Children's Nutrition Center and Arkansas Children's Research Institute, 15 Children's Way, Little Rock, AR, 72202, USA.ORCID http://orcid.org/0000-0002-7842-0625
Colin D KayArkansas Children's Nutrition Center and Arkansas Children's Research Institute, 15 Children's Way, Little Rock, AR, 72202, USA.ORCID http://orcid.org/0000-0001-7290-4496
Sree V ChintapalliArkansas Children's Nutrition Center and Arkansas Children's Research Institute, 15 Children's Way, Little Rock, AR, 72202, USA. svchintapalli@uams.edu.ORCID http://orcid.org/0000-0001-8457-9643

Funding

USDA-ARS 6026-10700-001-000D
6 · The paper itself

Abstract

introductionUntargeted metabolomics often results in a significant portion of unannotated metabolites, or "metabolic dark matter," which hinders biological interpretation.

objectivesA two-step analytical approach was developed to systematically prioritize and interpret unannotated metabolites using plasma LC-MS/MS data from pregnant women with obesity as a biologically relevant test dataset.

methodsThe first step involved clustering 1,021 known metabolites into ten structurally coherent groups based on the Tanimoto similarity, thus defining the biologically relevant chemical space of the dataset. These metabolites were further characterized by Absorption, Distribution, Metabolism, and Excretion (ADME) profiling, protein target prediction, molecular docking and Kyoto Encyclopedia of Genes and Genomes pathway mapping analysis, to establish biological plausibility and functional perspective. Candidate structures for 1,836 unannotated features were retrieved from PubChem using molecular formula and molecular weight matching within a ±0.5 Da tolerance.

resultsThis search yielded 569,115 candidate structures, of which 368,197 unique structures were retained after curation. Tanimoto coefficient filtering reduced the candidate pool to 19,868 structurally plausible candidates, and retention time-based prioritization further refined this set to 418 high confidence candidate annotations, including 83 database-supported candidates identified through HMDB and LIPID MAPS structure database cross-referencing. RT-based prioritization effectively distinguished positional isomers sharing the same molecular formula by incorporating agreement between predicted and experimentally observed retention times.

conclusionThis improved discrimination among structurally similar candidates, expanded metabolite annotation confidence, and provided a scalable framework for prioritizing dark matter metabolites in untargeted metabolomics.

Indexed as

MetabolomeMetabolomicsCluster AnalysisClustering AlgorithmsFemaleHumansLiquid Chromatography-Mass SpectrometryObesityPregnancyTandem Mass SpectrometryDark matterGeneIn silicoMetabolomicsProteinRetention timeTarget prediction

Identifiers

PMID42649459
PMCPMC13518442

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.