Mercaptan Definition

Cysteine (L-cysteine, Cys, C) proteinogenic amino acid molecule

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by Anne Marie Helmenstine, Ph.D.
Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels.
Updated October 03, 2019

Definition: Mercaptan is an organic sulfur compound composed of an alkyl or aryl group and a thiol group.
General formula: R-SH where R is an alkyl or aryl group.

Also Known As: thiol

Examples: The amino acid cysteine is a mercaptan.