LPS (RAP99-LPS) Is a TLR4 Agonist That Inhibits Lung Metastasis and Enhances TLR3-Mediated Chemokine Expression.

The lipopolysaccharides (LPSs) of are reported to be TLR4 antagonists. Accordingly, the extract of (RAP99) is used as a health supplement for humans and animals in Japan to regulate immune responses . We previously analyzed the LPS structure of RAP99 (RAP99-LPS) and found it is different from that of -LPS but similar to lipid A from (RSLA), a known antagonist of TLR4, with both having three C14 fatty acyl groups, two C10 fatty acyl groups, and two phosphates.

Structural analysis of a novel lipooligosaccharide (LOS) from Rhodobacter azotoformans.

Lipopolysaccharides (LPS) are components of the Gram-negative bacterial cell surface that stimulate the host innate immune system through the Toll-like receptor (TLR) 4-MD-2 complex. Rhodobacter sp. have been reported to produce LPS that lack endotoxic activity, and instead act as antagonists of other endotoxins.