10550
Their absolute configurations were assigned by the application of the CD technique for the first time among the ent - 3 , 4 - seco - labdane - type diterpenes .
 ent - 3 , 4 - seco - labdane, diterpenes
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 ent - 3 , 4 - seco - labdane, diterpenes