5788
The results showed that combining an ester group combined with the presence of an amino acid moiety led to a 10 - fold improved anti - tumor activity .
 Chemical: ester; Chemical: amino acid
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: ester; Chemical: amino acid