In this task, you are given a sentence in the Spanish language. Your task is to translate the Spanish sentence into the English language.

Los sistemas 2,4-diaminopteridinas, tales como aminopterina o metotrexato, son buenos agentes antitumorales ya que reducen la biosintesis de purinas y pirimidinas al inhibir a la enzima
The 2,4-diaminopteridine systems, such as aminopterin or methotrexate, are good antitumor agents since they reduce the biosynthesis of purines and pyrimidines by inhibiting the enzyme