Provided herein are organic solvent-based processes for the isolation of purified natural rubber from non-Hevea plants. The processes are particularly useful with plant matter that comprises at least 90% by weight roots sourced from Taraxacum kok-saghyz (Russian dandelion), Scorzonera tau-saghyz (Tau-Saghyz), Scorzonera uzbekistanica, and combinations thereof. Also provided herein is a purified non-Hevea rubber product containing 100 phr of rubber sourced from Taraxacum kok-saghyz, Scorzon-era tau-saghyz, Scorzonera uzbekistanica, and combinations thereof, having a specified purity level. Additionally provided are sulfur-vulcanizable rubber compounds and sulfur-vulcanized rubber compounds that incorporate 10-100 phr of purified non-Hevea rubber product sourced from Taraxacum kok-saghyz, Scorzonera tau-saghyz, Scorzonera uzbekistanica, and combinations thereof, having a specified purity level.