Indole is an organic compound with the chemical formula C8H7N. It consists of a benzene ring fused to a pyrrole ring, giving it a unique structure. Indole is found in various natural sources, including plants, bacteria, and animal products. It is known for its distinct odor, often described as floral or fecal, depending on its concentration. In addition to its presence in nature, indole plays a significant role in the synthesis of various biologically active compounds. It is a precursor to many important substances, including tryptophan, an essential amino acid, and serotonin, a neurotransmitter that regulates mood and behavior.