19898
This indicates that the beta - lactam amides did not require metabolic activation to have antiproliferative effects , in contrast to the phosphate series .
 Chemical: beta - lactam amides; Chemical: phosphate
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: beta - lactam amides; Chemical: phosphate