Hyaluronic acid (HA) is an anionic nonsulfated glycosaminoglycan distributed widely throughout connective epithelial and neural tissues. It is unique among glycosaminoglycans in that it is nonsulfated forms in the plasma membrane instead of the Golgi and can be very large with its molecular weight often reaching the millions.

Aristolochic acid B is one of the major components of the carcinogenic plant extract aristolochic acid, is known to be mutagenic and to form DNA adducts in vitro and in vivo.

(Arg)9 TFA (Nona-L-arginine TFA), a cell-penetrating peptide, exhibits neuroprotective activity with an IC50 of 0.78 μM in the glutamic acid model.Poly-arginine (e.g. (Arg)9) and arginine-rich peptides (e.g. TAT, penetratin), which belong to a class of peptides with cell-penetrating properties are neuroprotective.