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.

Example Input: Tethered dimers as NAD synthetase inhibitors with antibacterial activity.
Example Output: NAD

Example Input: Doxorubicin decreases paraquat accumulation and toxicity in Caco-2 cells.
Example Output: paraquat

Example Input: Studies on the antioxidant potential of flavones of Allium vineale isolated from its water-soluble fraction.
Example Output:
flavones