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.

Input: Consider Input: Synthesis of novel estrogen receptor antagonists using metal-catalyzed coupling reactions and characterization of their biological activity.

Output: estrogen


Input: Consider Input: The inhibitory effect of the leukotriene receptor antagonist on leukotriene D4-induced MUC2/5AC gene expression and mucin secretion in human airway epithelial cells.

Output: leukotriene


Input: Consider Input: Evaluation of in vivo anti-hyperglycemic and antioxidant potentials of α-santalol and sandalwood oil.


Output: α-santalol