15804
Ten compounds were synthesized via multistep organic synthesis , and the corresponding Gd complexes were investigated for their affinity to HSA , lipophilicity , and relaxivity in the absence and presence of HSA .
 Gd
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 Gd