Dha

Docosahexaenoic acid (DHA) is a long‑chain omega‑3 polyunsaturated fatty acid (C22:6n‑3) that constitutes ~40 % of the polyunsaturated fatty acids in the human brain and retina.

• It is an essential structural component of neuronal membranes, where it modulates fluidity, signaling, and neuro‑development.
• Humans synthesize DHA only in limited amounts from α‑linolenic acid, making dietary or supplemental DHA the primary means of maintaining optimal tissue levels.

• IUPAC name: (4Z,7Z,10Z,13Z,16Z,19Z)-Docosahexaenoic acid.
• Molecular formula: C₂₂H₃₂O₂; molecular weight 328.49 g/mol.
• Structure: A 22‑carbon chain with six cis‑double bonds at positions 4, 7, 10, 13, 16, and 19, giving a highly unsaturated, amphiphilic molecule.
  • The terminal carboxyl group confers acidic character (pKa ≈ 4.8), while the long hydrocarbon chain provides lipophilicity.
  • DHA is a constituent of phospholipid membranes, mainly as sn‑2 acyl chain of phosphatidyl‑cholines.
  • Its high degree of unsaturation makes it prone to oxidation; thus, antioxidant‑stabilized formulations (e.g., vitamin E‑coated capsules) are common to prevent peroxidation.

• Natural DHA is predominantly derived from marine sources: wild‑caught fatty fish (salmon, mackerel, sardines) and micro‑algae (Schizochytrium, Crypthecodinium).
  • Algal DHA is the preferred source for vegetarian/vegan supplements and offers a controlled, contaminant‑free product.
• Extraction typically uses supercritical CO₂ or solvent-based methods, followed by molecular distillation to concentrate DHA and remove EPA, heavy metals, and oxidized lipids.
• High‑purity DHA (>95 % total omega‑3) is verified by gas‑chromatography or LC‑MS.
• Quality‑focused manufacturers employ nitrogen‑flushed, opaque packaging with added antioxidants (e.g., tocopherols) to maintain stability.
• Third‑party certifications (e.g., IFOS, USP) assure potency, purity, and absence of environmental contaminants.