Bacterial lipopolysaccharides have long been recognized as the active component of gram negative bacterial endotoxins

LPS from Escherichia coli O111:B4 is a smooth strain of LPS that is isolated by a modification of the phenol extraction method of Westphal and Jann. Smooth strain LPS are dispersable in aqueous solvents at concentrations of up to 5.0 mg/ml.

These unique macromolecules have been extensively studied by investigators in many disciplines in efforts to elucidate and define relevant pathophysiologival parameters of endotoxin shock, a profound life-threatening consequence of bacterial sepsis. Lipopolysaccharides have generated intense interest as being among the most potent natural products capable of pluripotential immunostimulation manifested by the activation of host cells (e.g. B. lymphocytes, macrophages) to functional differentiation. Host cell activation by lipopolysaccharides produces a spectrum of hormone-active lymphokines and monokines, including interferons (alpha, beta and gamma), interleukins 1 and 6, tumor necrosis factor, platelet activating factor and procoagulant tissue factor. The documented capacity of lipopolysaccharids or their active lipid A component to initiate a variety of biochemical pathways (protein kinase C, cAMP dependent protein kinase, phosphatidyl inositol turnover, arachidonate metabolism, protein myristolation and activation of G-proteins) provides investigators with powerful molecular tools by which to study cellular activation mechanisms.