New Bioactive Aromatic Indole Molecules with Monosaccharide Core

Abstract

1,1,2-trimethyl-1H-benzo[e]indole is an important heterocyclic compound, it is available in rea­sonable price and can easily be modified to make a good intermediate for synthesis of other derivatives. It can be used as a starting material for the synthesis of a new series of compounds by coupling with other biomolecules such as monosaccharide amines after a simple modification. The current work aims to synthe­size new potentially bioactive compounds by coupling 1,1,2-trimethyl-1H-benzo[e]indole with one or two molecules of both 2-deoxy-2-amino-d-glucose and 6-deoxy-6-amino-d-glucose. The mono-substituted de­rivative were prepared in two steps, the first step is the functionalization reaction to create two reactions centers via the treatment of 1,1,2-trimethyl-1H-benzo[e]indole (1) with POCl3 to produce 2-(1,1-dimethyl-1H-benzo[e]indol-2(3H)-ylidene) malonaldehyde (2) with two reaction centers represented by aldehyde groups, while in the second step the latter was coupled with two amino sugars. Four new molecules resulted from this reaction, two mono-substituted derivatives (3,5) when we apply the last reaction for a short time, while the di-substituted molecules (4,6) take long time for the same reaction conditions in order to over­come the steric hindrance at one reaction center. The purity and characterization of the target molecules were confirmed using spectroscopic methods including 1H NMR and 13C NMR. The synthesized compounds, especially the di-substituted derivatives, show a good biological activity as antibacterial and antifungal agents and they can find their way in medical application as they are soluble in water due to the presences of sugar moiety in their structures.