The only things I recall showing up the the prequels that originated in the literary EU (i.e. not comic art like Aayla, Vos, etc.) was the odd planet/species name mention, mostly for already established things from the OT that WEG named. Purely cosmetic stuff, nothing really in terms of narrative or to give any indication that Lucas pulled it himself from a novel. More likely it was a suggestion from someone in "the room", or he just had some of the reference books to hand while filling out the details.
Even then, most of the prominent references were taken from 'Droids' of all things (Boonta & Bogden leap to mind) but that was developed mostly in-house at LF, so he was actually involved in that to some extent. Same deal with Splinter of the Mind's Eye.
So yeah, Lucas probably just flicked through some of the "essential guides" books once or twice when he needed a name for something. Nothing more.