369
Proline was first isolated in 1900 by Richard Willstätter who obtained the amino acid while studying N-methylproline .
 person: Richard Willstätter
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 person: Richard Willstätter