Sterubin (Flavanone · Neuroprotective · Ageing Neuron Research)

Compound	Sterubin
Chemical class	Polyphenol — Flavanone (Eriodictyol 7-methyl ether)
CAS	3145-22-4
Primary source	Eriodictyon californicum (yerba santa leaves)
Key applications	Neuroprotective, ageing neuron support, anti-inflammatory
Claim strength	Emerging
Typical form	Yerba santa extract; research-grade isolate

Name origin: Named after the Sterculiaceae family context of its initial characterisation; primary commercial botanical source is Eriodictyon californicum (yerba santa). Sterubin is the 7-methyl ether of eriodictyol — a flavanone in the same structural series as naringenin (naringenin → sakuranetin) and hesperetin (eriodictyol → sterubin). Traditional use: Yerba santa has traditional use in Californian indigenous and settler medicine for respiratory complaints, congestion, and as a general tonic. Sterubin is identified specifically in the context of neuroprotection research, not traditional botanical practice. Research trajectory: Sterubin has emerged from phenotypic screening programmes for compounds that protect aged neurons from multiple cell-death pathways simultaneously — an approach pioneered by the Schubert laboratory at the Salk Institute. It is a lead compound in the context of Alzheimer’s and age-related neurodegeneration research. Commercial source: Not commercially available at supplement scale; yerba santa extract provides sterubin as a minor constituent.

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Evidence for Sterubin Applications

Neuroprotection in ageing neuron models: Sterubin has demonstrated potent neuroprotective activity across multiple oxidative, ferroptotic, and oxytotic cell-death pathways in HT22 hippocampal neuron models. In head-to-head screening against hundreds of flavonoids, sterubin showed superior activity at low nanomolar concentrations. It activates the Nrf2/HO-1 antioxidant pathway and suppresses ferroptosis via GPX4 stabilisation. Claim strength: Emerging (compelling preclinical; no human data).

Anti-inflammatory signalling: Sterubin inhibits NF-κB and reduces neuroinflammatory cytokine production in microglial models. Co-occurrence with eriodictyol in yerba santa means that anti-inflammatory evidence for yerba santa extract is partially attributable to sterubin alongside its parent compound. Claim strength: Emerging.

Alzheimer’s disease research relevance: In aged mouse models, oral sterubin administration has been reported to reduce amyloid pathology markers and improve memory performance. These are early-stage animal results; human translation is unproven. Sterubin is regarded as a scientifically interesting lead compound for neurodegeneration drug discovery. Claim strength: Emerging.

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Dosage & Formulator Specification

No established supplement dose. Animal studies have used 5–20 mg/kg oral doses in mouse models. Human equivalent doses based on body surface area scaling are speculative; bioavailability data in humans are absent.

Sterubin is not available as a standalone supplement ingredient at any commercial scale. Yerba santa (Eriodictyon californicum) leaf extract provides sterubin as a minor flavanone alongside eriodictyol. No commercial extract is standardised to sterubin content.

For formulators tracking the neuroprotection space, sterubin is one to watch as a potential future ingredient if extraction scale-up or synthesis becomes viable. Current positioning should reference yerba santa extract rather than sterubin specifically in supplement contexts.

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Frequently Asked Questions — Sterubin

Why has sterubin attracted attention despite limited clinical evidence?
The Salk Institute screening programme that identified sterubin used a rigorous multi-pathway phenotypic approach: compounds had to protect neurons from ferroptosis, oxytosis, and mitochondrial dysfunction simultaneously. Most flavonoids failed this multi-pathway screen; sterubin passed at nanomolar concentrations — a profile that distinguishes it from most botanical neuroprotectants.

Is sterubin related to eriodictyol in bioactivity?
Structurally yes — sterubin is eriodictyol’s 7-methyl ether. The methylation substantially changes its potency and mechanism profile. Sterubin is considerably more neuroprotective than eriodictyol in head-to-head assays, suggesting the methyl group is critical for CNS-relevant activity, likely through improved BBB permeability.

Can yerba santa extract be used as a sterubin source?
Technically yes, but no commercial yerba santa extract is standardised to sterubin. Formulators would need to commission custom HPLC analysis to quantify sterubin content in any yerba santa material. The eriodictyol content is more reliably characterised in commercial extracts.

When might sterubin become a commercially viable supplement ingredient?
This depends on synthetic or semi-synthetic scale-up feasibility, safety characterisation in humans, and regulatory pathway. Given the current state of development (early animal studies, academic discovery stage), commercial supplement availability is likely 5–10+ years away absent a significant drug development programme driving supply chain development.

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Claim-strength scale – High = multiple human RCTs; Moderate = limited trials or strong preclinical convergence; Emerging = early-stage lab or animal data.

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