19521
Spectroscopic data of the natural ( anti ) and semisynthetic ( syn ) derivatives obtained by acid - catalyzed rearrangement of cryptocapsin - 5 , 8 - epoxide stereoisomers were compared for structural elucidation .
 cryptocapsin - 5 , 8 - epoxide
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 cryptocapsin - 5 , 8 - epoxide