Provided is a compound represented by the following formula (I) or a pharmaceutically acceptable salt thereof:
[in the formula, R
1
to R
5
, A, and *1 to *3 are as defined in Description].
nanoparticle (AuNP) adjuvants are prepared through computer-aided molecule design and machine learning to discover agonist ligands, and sulfur-Au coordination chemistry guided well-ordered presentation of ligands on AuNP surface. These AuNP adjuvants show advantages in multi-toll like receptor (TLR) targeting and application as broad-spectrum adjuvants to boost robust multifaceted anti-tumor vaccine responses