3924
The effect of ( - ) - carvone was compared with that of the classical calcium channel blocker ( CCB ) verapamil .
 ( - ) - carvone, calcium, verapamil
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 ( - ) - carvone, calcium, verapamil