Fucoidan & Other Seaweed Polysaccharides

Two suppliers can both quote a powder at "fucoidan 85%" and still be selling two different materials. That is not a quality dispute — it is the nature of the product. Fucoidan is the family name for the sulfated polysaccharides that brown seaweeds build, and each species builds them its own way: the fucose-to-sulfate balance shifts, xylose and galactose creep into the backbone, and the chains come out longer or shorter depending on where and when the weed was cut. Buying on a single percentage therefore tells you very little. Eata Marisource quotes fucoidan the way it should be bought — by source species, by marker content and, just as importantly, by molecular-weight window.

Everything we ship starts as cleaned, traceable biomass and is released against a batch COA that names the method behind every figure. Alongside fucoidan we keep the rest of the seaweed polysaccharide shelf in stock — laminarin, ulvan and porphyran — so a glycoscience programme can source its whole marine carbohydrate panel from one supplier, in gram quantities for the bench or tonne quantities for a production line.

One Name, Many Molecules

Chemically, fucoidans are built on an α-(1→3)-L-fucose backbone decorated with sulfate esters, mostly at the 2- and 4-positions. What separates one commercial fucoidan from the next is everything hanging off that backbone. Fucus vesiculosus fucoidan is almost pure fucose; Ascophyllum brings xylose and galactose side residues; Undaria pinnatifida — the source of so-called U-fucoidan — carries so much xylose and galactose that its fucose share drops below half of the sugars released on hydrolysis. The table below shows published profiles that illustrate the spread:

What We Keep on the Shelf

Agar, carrageenan and alginate sit in their own catalogue sections; the list above is the sulfated-and-bioactive corner of the range.

Molecular Weight Is the Working Variable

Native fucoidan usually lands somewhere between 100 and 800 kDa, and at that size it dissolves slowly, penetrates membranes poorly and behaves quite differently from the fractions researchers read about in papers. Published work keeps making the same point: anticoagulant-type activity shows up in fractions spanning roughly 0.05–100 kDa and fades in chains beyond ~850 kDa, while low-molecular-weight fucoidans of around 5–10 kDa combine high solubility with the strongest antioxidant performance. The catch is that depolymerisation must trim the backbone without stripping the sulfate esters that carry the biology.

Our low-MW grades are cut under controlled conditions and released with a GPC/SEC trace so you can see the actual distribution, not just a single average. If your protocol specifies a 10 kDa cut-off or a 5–30 kDa window, that is a production parameter for us, not a special favour.

From Wet Biomass to Defined Fraction

Fucoidan is locked inside a cell wall that is also full of alginate, so the first job of any extraction is getting one out without the other. Our default route is hot-water extraction of cleaned, milled biomass, followed by calcium treatment to precipitate alginate out of the liquor. Where the target demands it we run dilute-acid extraction, or enzyme-assisted work with cellulase, protease and alginate lyase cocktails that release the fucoidan under mild conditions; ultrasonication shortens contact time and, at controlled energy inputs, doubles as the first step of depolymerisation.

Clarification and purification then proceed in stages — sealed-tube centrifugation lifts fine suspended solids, vacuum filtration polishes the liquor, and ethanol or solvent-step fractionation narrows the molecular-weight spread before spray- or freeze-drying finishes the job. Sulfate groups are fragile at high temperature and extreme pH, so every hold time in the process is written down and respected.

Numbers We Certify on Every Lot

• Fucose content after TFA hydrolysis, by HPLC or GC — total carbohydrate by phenol–sulfuric acid is reported separately because it counts every sugar, not just fucose
• Sulfate content by ion chromatography or BaCl₂–gelatin turbidimetry
• Molecular-weight distribution by GPC/SEC, with the full trace attached
• FTIR identity fingerprint against a retained reference
• Alginate and protein carry-over, the two contaminants that distort fucoidan assays
• Iodine, total arsenic and inorganic arsenic — marine-specific tests most buyers now expect
• Heavy metals by ICP-MS, moisture by Karl Fischer, microbial limits, particle size and bulk density

Formats, Packaging and Storage

• Trial packs from 100 g, then 1 kg and 5 kg foil bags; 25 kg fibre drums with double poly liners for production scale
• Hygroscopic by nature: reseal promptly, store cool and dry, protect from light; sealed stock keeps 24 months
• Powder, granulated or tableted forms available; liquid concentrates at agreed solids for in-line dosing
• COA, TDS and MSDS travel with every shipment, plus origin documentation on request

Built Around Your Specification

Most enquiries are answered from stock, but the interesting ones rarely are. A target assay on a defined reporting basis, a molecular-weight window with a hard ceiling, a species switch to change the sugar profile, a finer mesh or a clearer solution at your working concentration — send us the number and the reason behind it. We develop against your in-house method, confirm on pilot batches, and scale the lot that passes from kilograms to full production without changing the recipe.

For Research or Industrial Raw Materials, Not For Personal Medical Use!