Fisetin 98%

Cut from the wood of the smoke tree Cotinus coggygria, where it sits beside the dihydroflavonol fustin, fisetin is a yellow flavonol isolated by ethanol extraction and purification. It is the 3,7,3′,4′-tetrahydroxy flavone, a plant polyphenol whose catechol ring makes it reactive toward metals and oxygen.

The primary grade is 98% fisetin by HPLC, in Food / Dietary Supplement Grade. The yellow powder is insoluble in water. It is supplied for formulations that need the single flavonol and not a mixed Cotinus extract, so identity, source and handling data matter more than a dose figure.

SKU: BOT-PHY-0014 Category: Phytochemicals Tags: Bark & Stem, Ethanol Extracted, Flavonoids, Plant Compounds, Smoke Tree, Softgels & Oil Fills

Fisetin Chemical Identity

Fisetin has the molecular formula C15H10O6 and a molecular weight of 286.2. It is a flavonol, meaning a flavone with a hydroxyl group at position 3, and it carries further hydroxyls at positions 7, 3′ and 4′. The catechol pair on the B-ring is the feature that matters in practice. It binds iron and copper, it oxidizes in air, and it gives the compound its yellow color, which deepens when metal ions are present.

The natural source here is the wood of Cotinus coggygria Scop., a shrub of the family Anacardiaceae whose heartwood was long used as a yellow dye. Fisetin also occurs in small amounts in other plants, so the source statement belongs next to the name. Leaves and flower clusters of the shrub are a different material and are not used. The compound sits at the end of a chain of related products from the same plant, the 1–50% Cotinus coggygria Extract 1–50% Fisetin-type and the 10:1 Cotinus Coggygria Extract Powder. Both are mixtures, whereas the purified flavonol here is a single molecule with its own identifiers. Related flavonols such as quercetin and kaempferol differ by the number and position of their hydroxyl groups. Fisetin lacks the 5-hydroxyl of those relatives, and that missing group changes its spectrum, polarity and retention time.

Typical Specifications

Specification Item	Product Information
Natural Source	Cotinus coggygria wood
Plant Part	Bark & Stem
Processing	Ethanol Extraction & Purification
Compound Class	Flavonoids, Polyphenols
Chemical Name (IUPAC)	2-(3,4-dihydroxyphenyl)-3,7-dihydroxychromen-4-one
CAS Number	528-48-3
Molecular Formula	C15H10O6
Molecular Weight	286.24
PubChem CID	5281614
InChIKey	XHEFDIBZLJXQHF-UHFFFAOYSA-N
SMILES	C1=CC(=C(C=C1C2=C(C(=O)C3=C(O2)C=C(C=C3)O)O)O)O
Purity	98% (HPLC)
Grade	Food / Dietary Supplement Grade
Appearance	Yellow powder
Solubility / Dispersibility	Insoluble in Water
Quality Parameters
Moisture (LOD)	≤5.0%
Total Ash	≤5.0%
Heavy Metals	Lead ≤2 ppm · Arsenic ≤1 ppm · Cadmium ≤1 ppm · Mercury ≤0.1 ppm
Microbiology	TPC ≤1,000 cfu/g · Yeast & Mold ≤100 cfu/g · E. coli Negative · Salmonella Negative/25 g
Shelf Life	24 months in unopened original packaging, cool and dry storage

Fisetin Purity Grades & Impurities

An HPLC purity figure for fisetin is only as meaningful as its calculation. A normalized area figure divides the fisetin peak by all detected peaks, while an external-standard figure compares the peak with a weighed reference. For the same lot the two can differ widely, because the second also reflects water, residual solvent and non-absorbing matter. The specification therefore names HPLC as the method and treats moisture and ash as separate limits.

The related substances of fisetin from Cotinus wood are its companions in the same biosynthetic family: fustin, the dihydro form that lacks the double bond in the C-ring, and other hydroxylated flavonoids and gallic acid derivatives from the tannin-rich wood. Fustin elutes close to fisetin and shares part of its spectrum, so resolution between the two is the first quality check on a trace. Oxidation products form when the catechol is exposed to air and alkaline conditions, and they appear as late peaks and a browner color.

Plant-derived and synthetic fisetin can share one main peak. The synthetic route leaves different impurities, such as reaction by-products, while wood-derived material carries the plant companions. Since the table names the natural source, buyers can match the impurity profile to the origin and review it against their own method.

Heavy-metal carry-over from wood and from processing equipment is limited in the table. A color check on the dry powder gives a quick comparison between lots, since a clean yellow powder reads differently from a duller, greener or browner one that has met metals or oxygen.

Fisetin Solubility & Delivery

Fisetin is practically insoluble in water and dissolves in ethanol, acetone and dimethyl sulfoxide. The flat, hydrogen-bonding ring system packs tightly in the crystal, which is why dissolution is slow even in good solvents and why crystals can re-form when an alcoholic stock is diluted into water. Its logP is moderate, so it partitions into lipid phases better than into water, but not so strongly that an oil solution is easy to make at high strength.

Delivery therefore rests on dispersion, not on solubility. Fine milling, wetting agents, cyclodextrin complexes, phospholipid complexes and oil-based fills are the approaches described in the literature, and each changes color or taste to some degree. Because the catechol ring is the weak point, formulators keep the pH below neutral, add a chelating agent where metal contact is likely, and use opaque, oxygen-limited packaging. A blend that turns darker yellow or brown on storage is the usual first sign of oxidation.

In solid dosage forms the issue is the rate of dissolution and the contact with metal-bearing excipients, not the amount that dissolves. Magnesium stearate, iron oxides and trace-metal-rich fillers can darken a blend, so excipient certificates are worth reading, and a short stability trial of the finished blend shows early color change.

Application Areas

Capsule Fills of the Pure Flavonol

Capsules take fisetin at very low inclusion, usually as a premix with a flow agent. Static makes the fine yellow powder cling to scoops, so anti-static tools and a two-stage dilution in a dry carrier give an even fill weight.

Softgel Oil Suspensions

Softgel fills suspend milled fisetin in a lipid carrier with an emulsifier. Settling should be checked before encapsulation, and an antioxidant in the oil phase protects the catechol ring during storage and the fill cycle.

Dispersion and Complex Systems

Cyclodextrin and phospholipid complexes are used to raise dispersion of the insoluble flavonol. The complex is built in a solvent step, dried and milled, and a retained sample of each lot lets the formulator compare color and dissolution when the process is repeated.

Dry Premixes for Sticks

Sticks hold fisetin only at high dilution in a masking base, since it does not dissolve and leaves a yellow haze in water. Add it to opaque, flavored mixes, sieve the premix to remove specks, and keep iron-containing minerals out of the same blend.

Packaging & Commercial Supply

Essencefield supports product evaluation, formulation trials, commercial orders, and ongoing ingredient supply. Packaging, storage, and shipping arrangements are determined by product characteristics, order quantity, stability requirements, and destination-market needs.

Supply Item	General Information
Sample	Available upon request for formulation, testing, and supplier evaluation
Order Quantities	100 g · 1 kg · 5 kg · 25 kg · 100 kg · 500 kg · Bulk
Sample Lead Time	Typically 5–7 days after sample confirmation
Production Lead Time	Typically 15–30 days after order and specification confirmation
Packaging	Suitable protective inner packaging with bags, cartons, drums, or other appropriate outer packaging
Storage	Store in tightly sealed, suitable protective packaging in a cool, dry environment. Protect from moisture, heat, and direct sunlight. Specific storage conditions follow the approved product specification.
Documentation	COA · Product Specification · TDS · SDS · Applicable declarations (as applicable)

Final order quantities, lead times, packaging, documentation, and shipping arrangements are confirmed according to the selected product and commercial requirements.