A Ventura County man accused of jumping a pedestrian on a La Jolla roadside, throwing her to the ground and sexually assaulting her, pleaded not guilty Friday to assault with intent to commit rape and other charges. Villasenor, of Oxnard, allegedly ran up to the woman from behind and attacked her as she was walking to her car in the 7700 block of Exchange Place shortly after 9 p.m. Wednesday.