lambda carrageenan

Lambda carrageenan is a natural sulfated polysaccharide derived from red seaweed (Rhodophyceae). Unlike kappa and iota carrageenans, lambda carrageenan contains three sulfate groups per disaccharide unit and lacks 3,6-anhydrogalactose, which prevents it from forming a rigid gel and allows it to remain as a highly viscous, soluble random coil in aqueous solutions. It acts as a broad-spectrum, virus-agnostic entry inhibitor. Its negatively charged ester sulfate groups bind via electrostatic interactions to positively charged viral surface proteins (such as the L1 capsid protein of HPV, gp120 of HIV-1, hemagglutinin of influenza, and the spike protein of SARS-CoV-2), physically blocking viral attachment and entry into host cells. It has been clinically evaluated in vaginal gel formulations (such as PC-503 and Divine 9) for the prevention of sexually transmitted infections, demonstrating significant protective efficacy against human papillomavirus (HPV) in Phase II trials, and is also being investigated for the prevention of respiratory viral infections.

Brand names

CarragenixDivine 9Divine9Divine-9

Other names

L-CRGlambda-CGNlambda-carrageenanλ-carrageenan