The purpose of this study is to evaluate the safety and tolerance of single intravenous (through a vein) doses of trodusquemine. Different amounts of trodusquemine will be given to each volunteer group throughout the study. Another purpose is to evaluate the pharmacokinetics (PK - the study of the way the drug enters and leaves the blood and tissues over time) of trodusquemine. Finally, this study will also determine whether trodusquemine has any effect on appetite, mood or behavior, and selective biomarkers (substances in your blood that may change in response to the study drug).