Tryptophan

Tryptophan is an essential amino acid. Abbreviations: Trp, W.

Let us draw it in LaTeX; it is hard to make because of the two rings. Here is the picture, and below is the code. Notice how I separated the alpha carbon with the amino and hydroxyl groups into a submolecule and called it \achain.

\documentclass[varwidth,border=2pt]{standalone}
\usepackage{chemfig}
\usepackage{amsmath}
\setchemfig{atom sep=2em}
\definesubmol{\achain}{C(-[:180]H_2N)(-[:90]H)(-[:0]C(=[:45]O)(-[:-45]OH))}
\begin{document}
 
\chemfig{*6(=-*5(-N(-[:-90]H)-=(-[:90]CH_2-[:90]!{\achain})-=)--=-)}

\end{document}

This SVG and code is for the charged state at pH=7.4.

Tryptophan molecule chemical formula charged

\documentclass[varwidth,border={2pt 2pt 4pt 2pt}]{standalone}
\usepackage{chemfig}
\usepackage{amsmath}
\setchemfig{atom sep=2em}
\newcommand{\minusch}{\textcolor{blue}{\charge{80:8pt=$\scriptstyle-$}{}}}
\newcommand{\plusch}{\textcolor{red}{\charge{80:8pt=$\scriptstyle+$}{}}}
\definesubmol{\achain}{C(-[:180]H_3N\plusch)(-[:90]H)(-[:0]C(=[:45]O)(-[:-45]O\minusch))}
\begin{document}
 
\chemfig{*6(=-*5(-N(-[:-90]H)-=(-[:90]CH_2-[:90]!{\achain})-=)--=-)}

\end{document}

Do you wish to know how to compile this LaTeX code? See this general amino acid structure page.

Page published: March 05, 2026