A
Toll-like
receptor (TLR) is an indispensable component of an
innate immune system and plays a key role in identifying and coping with microbial pathogens. TLR7, TLR8, and TLR9 are located in the
endosome-
lysosome compartment within the
cell and then exclusively used to detect nucleic acids of a
microorganism after the
microorganism is swallowed and reaches the
endosome compartment. The biological importance of the
TLR agonists lies in that they can be used as powerful tools for studying innate immune responses, developing vaccines and potential therapeutic applications. In addition,
TLR agonists have been explored for use as
immunotherapy, while these TLR antagonists can be used as new pathogenic nodes in the context of different autoimmune diseases. Therefore, the agonists and antagonists of the endosomal TLR have therapeutic significance in different clinical backgrounds. The previous study on 8-oxo adenines shows that the C-6-site-NH2 group is extremely important for the recognition of agonistic active sites and the subsequent induction of
interferon (IFN). The present invention explores the ability of a
hydrogen-substituted 8-oxopurine derivative that does not contain an essential C-6 amine group. The C-6 amino group in the 8-oxopurine derivative is substituted by
hydrogen (H), providing an exciting opinion for regulating the
endosome TLRs (
Toll-Like Receptors). The ability of 8-oxopurine derivatives to modulate the endosomal TLR has been reported, which derivatives are related / interrelated to various substitutions at N-7, N-9 and C-2, all derivatives containing
hydrogen at C-6. Structure 1