Draft:Metabolic velocity

• Comment: Of the 7 cited sources, only one of them (Ref. 4, an ArXiv preprint and therefore not a reliable source) mentions metabolic velocity at all. Ref. 1 is completely off-topic, 2 is a paper on an adjacent but different topic and doesn't use the term, 3 is for a definition, and 5-7 are for general mathematical procedures that are not specifically related to the topic at hand. So we have effectively an unsourced article. This is not acceptable. I suspect AI was involved in drafting this article, due to the off-topic references (though I can't prove anything). Please find real sources that are on-topic, significant, reliable, and ideally secondary. If I see this article submitted again without such sourcing I will reject. WeirdNAnnoyed (talk) 23:29, 8 December 2025 (UTC)

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Metabolic velocity is a quantitative, non-targeted measure in metabolomicsto assess the direction and intensity of overall metabolic shifts between two biological states (e.g., control vs. disease, or treated vs. untreated). Unlike classical metabolic flux analysis, this concept does not require the identification of specific metabolic pathways or individual reaction rates.  This concept aims to overcome the dependency of traditional metabolic flow analysis on intact metabolic pathway annotations, and provides better replicability.

Definition and calculation

Metabolic velocity is derived by calculating the standardized difference in the robust statistical moment (especially position and scale estimates) of the molecular weight distribution of all detected metabolites in the two comparison groups, or metabolites of a particular classification. The molecular weight distribution is constructed by weighting the molecular weight of each detected metabolite with its relative strength or concentration. The concept has two main components:

1. Position velocity ($\upsilon _{\text{L}}$): Position of molecular weight distribution measured by using Hodges-Lehmann estimation (${\hat {L}}$), quantifying the change in the concentration trend of molecular weight distribution. $\upsilon _{\text{L}}=2\times {\frac {{\hat {L}}_{A}-{\hat {L}}_{B}}{{\hat {L}}_{A}+{\hat {L}}_{B}}}$

symbol$\upsilon _{\text{L}}$	Molecular weight distribution changes	Inferred direction (Group B vs. Group A)
Negative ( $\upsilon _{\text{L}}$< 0)	Center Shift Right (${\hat {L}}_{B}>{\hat {L}}_{A}$)	Anabolic: Tends to produce larger molecules.
positive ( $\upsilon _{\text{L}}$> 0)	Center Shift Left (${\hat {L}}_{B}<{\hat {L}}_{A}$)	Catabolic: Tends to break down into smaller molecules.

2. Scale velocity ($\upsilon _{\text{S}}$): Scale of molecular weight distribution measured by using Bicker-Lehmann spread (${\hat {S}}$), quantifying the variation in the dispersion or range of molecular weight distribution. $\upsilon _{\text{S}}=2\times {\frac {{\hat {S}}_{A}-{\hat {S}}_{B}}{{\hat {S}}_{A}+{\hat {S}}_{B}}}$

symbol$\upsilon _{\text{S}}$	Molecular weight distribution changes	Inferred direction (Group B vs. Group A)
positive ( $\upsilon _{\text{S}}$> 0)	Narrowing of distribution (${\hat {S}}_{B}<{\hat {S}}_{A}$)	Centrabolic: Metabolites tend to be medium-sized (convergent).
Negative ( $\upsilon _{\text{S}}$< 0)	Distribution widens (${\hat {S}}_{B}<{\hat {S}}_{A}$)	Duobolic: Metabolites tend to be extremely small and extremely large (divergent).

Explanation

combine $\upsilon _{\text{L}}$ and  $\upsilon _{\text{S}}$ can define a metabolic momentum map that places the overall metabolic state of one group relative to another in one of four quadrants (e.g., anabolic and centripetal metabolism, or catabolism and bidirectional metabolism). Magnitude of velocity $|\upsilon |={\sqrt {\upsilon _{\text{L}}^{2}+\upsilon _{\text{S}}^{2}}}$ indicates the intensity of metabolic shifts.