25272
At pH 3 . 0 and 5 . 0 , the fluorescence intensity ( FI ) was greater than values obtained at pH 7 . 0 and 9 . 0 , which suggests that the microenvironment of tryptophan was less hydrophilic at acidic pH .
 Chemical: tryptophan
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: tryptophan