I have some question for k-mer ligands of BioLiP database .

Hello,

I read a BioLiP paper, and have a question for ligand types.
In this paper, I can see the k-mer ligands such as UUU,III, and NUC.
However, there are no information at PDB.
UUU, III, and NUC ligands are not in PDB database.
Can I get this ligand information? structure or how to find these ligand and so on.

Thank you.