In this task, you are given a sentence. You are expected to recognize the name of any form of chemical substances. Although there might be several correct answers, you need to write one of them.

Q: Reinforcement enhancing effects of nicotine via smoking.

A: nicotine
****
Q: A novel membrane sensor for histamine H1-receptor antagonist "fexofenadine".

A: histamine
****
Q: Novel inhibitors complexed with glutamate dehydrogenase: allosteric regulation by control of protein dynamics.

A:
glutamate
****