8720
A chiral ampicillin analogue was discovered to have a 2 . 4 +/- 0 . 2 nM K ( i ) for SHV K234R ; the chiral ampicillin analogue formed a more complex hydrogen - bonding network in SHV K234R vs SHV - 1 .
 Chemical: ampicillin; Chemical: ampicillin; Chemical: hydrogen
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: ampicillin; Chemical: ampicillin; Chemical: hydrogen