Phosphatidylserine capsules

A finished hard capsule carrying phosphatidyl-L-serine, the acidic glycerophospholipid abbreviated PS or Ptd-L-Ser. It is a class of molecules rather than one compound: L-serine is esterified to the phosphate of a 1,2-diacyl-sn-glycero-3-phosphate backbone, and the two fatty acids vary with the source lecithin, so commercial PS is always a mixture of molecular species. CAS 51446-62-9 is the number normally quoted on trade paperwork for phosphatidyl-L-serine and is carried as a synonym on PubChem CID 9547096, where the reference species is the distearoyl form, C42H82NO10P, 792.1 g/mol. That single formula does not describe a commercial lot, which is why the contract should be written on the PS assay percentage and the analytical method rather than on the CAS. Origin is the commercial fault line on this ingredient. Phosphatidylserine was originally isolated from bovine cerebral cortex, and that source was abandoned over the risk of transmitting bovine spongiform encephalopathy. Thovek does not offer bovine-cortex material and this capsule is BSE/TSE-free by construction. Current material is made enzymatically: phospholipase D, typically from a Streptomyces species, catalyses transphosphatidylation of soybean phosphatidylcholine with L-serine as co-substrate, converting abundant lecithin PC into a PS-enriched concentrate that is then standardised. The conversion route exists because native PS is scarce in the feedstock, running at roughly 3% of total phospholipids in soy lecithin. Soy lecithin is the default substrate, which makes a soy allergen declaration mandatory unless you specify the sunflower-lecithin route; sunflower PS is the soy-free option and prices above soy. Both are plant-derived and vegan on the standard HPMC shell. Traded as 20%, 50% and 70% PS concentrates, with the balance made up of the other lecithin phospholipids and carrier, so a 20% capsule and a 50% capsule are not interchangeable at the same fill weight and the label must declare PS content rather than concentrate weight. PS carries polyunsaturated fatty acids and oxidises, so hold peroxide value and acid value on every lot, use a nitrogen blanket where the buyer's specification calls for it, and store cool, dry and dark. Lots are released against HPLC-ELSD or 31P NMR assay, USP <467> residual solvents, USP <2232> elemental impurities and USP <2021>/<2022> microbial limits. On copy, describe composition and phospholipid nutrition only. The US qualified health claim language associated with phosphatidylserine is disease-related and Thovek does not supply it as label text; and do not name or imply equivalence to any branded PS article, which would require a licence from the trademark owner.