21212
By combining phase - modulation two - dimensional fluorescence spectroscopy ( 2D FS ) with linear absorbance and fluorimetry , we determined that the zinc porphyrin tweezer adopts a mixture of folded and extended conformations in the membrane .
 Chemical: zinc porphyrin
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: zinc porphyrin