Full specification page: Quercetin Extract 95% (HPLC) — grades, cluster articles and documentation →
| Common name | Quercetin (Quercetin Dihydrate) |
| IUPAC name | 2-(3,4-Dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one |
| Synonyms | Sophoretin; Meletin; Quercetine; 3,3',4',5,7-Pentahydroxyflavone |
| CAS number (dihydrate) | 6151-25-3 |
| CAS number (anhydrous) | 117-39-5 |
| Molecular formula | C₁₅H₁₀O₇ (anhydrous); C₁₅H₁₀O₇·2H₂O (dihydrate) |
| Molecular weight | 302.24 g/mol (anhydrous); 338.27 g/mol (dihydrate) |
| Appearance | Yellow to yellow-green fine crystalline powder |
| Assay (HPLC) | ≥98.0% quercetin (anhydrous basis) |
| Botanical source | Sophora japonica (flower buds) — Fabaceae family |
| Solubility | Practically insoluble in water (0.06 mg/mL); soluble in ethanol, DMSO, propylene glycol; markedly improved with cyclodextrin or phytosome complexation |
| Melting point | 316–317°C (anhydrous form) |
| pH (1% suspension) | 3.5–5.5 |
| Moisture content | NMT 2.5% (dihydrate form) — moisture is part of crystal structure |
| Loss on drying | NMT 0.5% (on anhydrous basis, after dehydration) |
| Heavy metals | NMT 10 ppm total; Lead NMT 0.5 ppm; Arsenic NMT 0.5 ppm |
| Pesticide residues | Complies with EU Regulation 396/2005 MRLs |
| Microbial limits | Total aerobic count NMT 10³ CFU/g; Absence of Salmonella, E. coli |
| Shelf life | 24 months in original sealed packaging |
| Storage | Below 25°C, away from light and moisture; avoid humidity above 60% RH |
Every Quercetin batch is tested by HPLC for flavonol content, absence of rutin and isoquercetin impurities, heavy metals panel, and microbial safety — with COA explicitly reporting quercetin content, not total flavonoids.
COA reports specific quercetin content by HPLC, not total flavonoid content. Rutin and isoquercetin (quercetin glycosides) have different bioavailability profiles and must be distinguished from the aglycone/dihydrate.
Japanese pagoda tree flower buds contain 15–25% quercetin by dry weight — the richest commercial plant source. Consistent botanical identity verified by TLC and HPLC fingerprinting on each raw material batch.
Sophora japonica raw material is tested for pesticide residues (EU MRLs), lead (NMT 0.5 ppm), mercury, arsenic, cadmium, and microbial contamination to USP and BP pharmacopoeia standards.
COA, MSDS, Certificate of Origin, Phytosanitary Certificate provided with every shipment. Halal and Kosher certificates available on request for specific markets.
The quercetin market has expanded dramatically post-2020, driven by demand across the immune and longevity categories. But there is significant confusion in the market between quercetin forms (aglycone vs dihydrate vs glycosides vs phytosome), and between quercetin purity specs and total flavonoid content. This guide helps formulators specify the right grade and build effective quercetin-containing products.
The workhorse ingredient for most supplement manufacturers. Yellow crystalline powder, excellent shelf stability, good flow for capsule filling. The "dihydrate" refers to 2 water molecules of crystallisation — biologically identical to aglycone once metabolised. Specify HPLC-confirmed ≥98% quercetin dihydrate on your COA — not "total flavonoids."
Quercetin complexed with phosphatidylcholine (soy or sunflower lecithin). The phospholipid matrix dramatically improves mucosal absorption, with studies showing up to 20× higher Cmax vs standard quercetin. The choice for premium anti-aging and longevity formulations where bioavailability is the primary differentiator. Higher cost per gram but lower effective dose required.
A pre-blended combination grade supplied where a formulator wants both actives in a single specified ratio rather than blending in-house. Bromelain is a proteolytic enzyme derived from pineapple. Standard ratio: quercetin 500mg + bromelain 500 GDU per serving. SV Botanica can supply both separately or as a pre-blended combination.
Where a format cannot carry a practically water-insoluble flavonol, the phosphatidylcholine complex is the usual specification; the unmodified dihydrate suits dry formats where dispersion is not the constraint. Confirm the assay basis of each before comparing supplier certificates.
Supplied as a bulk ingredient for further manufacture. Buyers are responsible for compliance with the regulations of their destination market. This product is not intended to diagnose, treat, cure or prevent any disease.
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