19894
The synthesis and biochemical activities of novel water - soluble beta - lactam analogues of combretastatin A - 4 are described .
 Chemical: beta - lactam; Chemical: combretastatin A - 4
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; Chemical: combretastatin A - 4