\documentclass[12pt,border=3pt,tikz,class=scrartcl,multi=false]{standalone}
\usepackage{times}
\usepackage[T1]{fontenc}
\usepackage[latin1]{inputenc}
\usepackage{mathtools,amssymb,gensymb}
\usepackage{pgfplots}
\pgfplotsset{compat=1.12}
\usetikzlibrary{positioning,calc,arrows,fit,backgrounds,decorations.text,shapes}
 
\usepackage{chemfig,chemmacros}
\renewcommand*{\familydefault}{\sfdefault}
\renewcommand*\printatom[1]{\ensuremath{\mathsf{#1}}}
\setatomsep{2.5em}
\setdoublesep{.6ex}
\setarrowdefault{,1,ultra thick}
\setbondstyle{very thick,cap=but}
\definesubmol\nobond{-[0,.6,,,draw=none]}
 
\pagestyle{empty}
\thispagestyle{empty}
\begin{document}
\renewcommand{\baselinestretch}{1}
\scriptsize 
\begin{tikzpicture}[thick, >=latex']
	\node [inner sep=3pt] (n1) {\chemfig{
		[18]*5((<:OH)-
		(<N*5(-*6(=N-=N-(-NH_2)=-)--N=-))
		-O-
		(<-[::-60]S-[::-60]-[::60]-[::-60](<[::-60]NH_2)-[::60](-[::-60]OH)=[::60]O)
		-(<:OH)-)
	} };
\end{tikzpicture}
\end{document}