polymethoxylated flavones
compound class / compound-pmfs
ポリメトキシフラボン類
Methoxylated citrus flavones, abbreviated PMFs.
On this page (8 sections)
Reading the bitterness
In a mixture test at concentrations equivalent to orange juice, polymethoxyflavones below the perception threshold enhanced the perceived bitterness of limonoids. This is a result obtained in a specific reconstituted-taste mixture system, and the magnitude of the synergistic effect common to all citrus fruits and concentrations has not been shown.
There is a description stating that tangeretin and nobiletin are important contributors to the bitterness of citrus peel, while it is also noted that they are not abundant enough in juice to contribute significantly to bitterness. This is a discussion citing another study, and the absolute amounts in peel and juice and their degree of contribution to bitterness are not results measured by this material itself.
In molecular docking using the cryo-EM structure of T2R46, PDB 7XP6, tangeretin and nobiletin were predicted to interact with the same binding-pocket residue, with predicted binding energies of -7.4983 kcal/mol and -7.8191 kcal/mol, respectively. This is a computational binding prediction, not a value confirming cell response or human bitterness perception in this study.
Sources for this overview
Decoding the Nonvolatile Sensometabolome of Orange Juice (Citrus sinensis)
Checked for this overview: Matched the enhancement of perceived limonoid bitterness by subthreshold PMFs with the limitation that this is confined to a specific mixture system.
Checked for this overview: Matched the cited description of tangeretin's and nobiletin's contribution to bitterness in peel and juice with the limitation that this is a secondary citation.
Checked for this overview: Matched the docking conditions against the T2R46 structure, the shared binding-pocket residue, and the binding energies with the limitation that receptor activation was not confirmed.
Follow the connections
polymethoxylated flavones →is documented as having→ bitterness →can be measured separately …→ astringency
polymethoxylated flavones →is reported to activate→ TAS2R46
Structured claims — open a section to read each claim's confidence, evidence and limits
Composition and content (1)
Scope: Layer: literature. Discussion in a bitterness study of juice from Citrus and Citrus × Poncirus trifoliata hybrids.
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compound-pmfs —is_documented_as_having→ sensation-bitterSensory (1)
Scope: A concentration range equivalent to orange juice in the cited study
Note: The mixture effect must not be converted into a fixed, additive bitterness score.
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compound-pmfs —can_enhance→ "Perceived bitterness of limonoids at subthreshold PMF concentrations"Mechanism and receptors (1)
Scope: Layer: literature. A computational (molecular docking) prediction, not a cell or sensory experiment. A molecular docking simulation of tangeretin, nobiletin, and amarogentin (with strychnine separately as a positive control) against the cryo-EM structure of the human bitter taste receptor T2R46 (PDB 7XP6).
Note: Preliminary because this is a computational docking prediction, not confirmation of functional receptor activation by a cell assay or similar. The statement that tangeretin and nobiletin activate T2R46 in vitro is a citation of Kuroda et al. 2016 (a secondary citation), but the binding-energy values themselves are primary data from this paper's own docking calculations.
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compound-pmfs —is_reported_to_activate→ receptor-tas2r46