Synthesis of the Novel Firefly Luciferase Inhibitor Benzothiophene Dehydroluciferin Sulfamoyl Adenosine

By: Derrick Roy '15

Advising Faculty: Bruce Branchini

Firefly luciferase (Luc) catalyzes the production of light from O2, Mg-ATP, and beetle luciferin (LH2). Modern applications of Luc focus on its uses in reporter and bio-imaging assays. However, the rapid flash and decay kinetics typically produced by Luc with LH2 are not desirable in most reporter applications. To overcome this limitation the Branchini lab analyzed the kinetics and bioluminescence of various heterocyclic analogs of firefly luciferin with Luc. The most promising substrate, benzothiophene luciferin (BtLH2), was found to display sustained glow kinetics and a blue shifted bioluminescence emission. To better understand the unique properties of BtLH2, a structurally related Luc inhibitor (benzothiophene dehydroluciferin sulfamoyl adenosine (BtDLSA)) was synthesized for use in crystallographic studies with Luc. The eight-step synthesis of BtDLSA was adapted from a previously reported method used to make the thiazole analog dehydroluciferin sulfamoyl adenosine (DLSA). Six novel compounds were synthesized and were fully characterized by HRMS, IR, and NMR. The convergent synthetic route to BtDLSA involved the preparation of the benzothiophene analog of dehydroluciferin (BtL) and sulfamoyl adenosine, both containing hydroxyl protecting groups. Following condensation of the two precursors, the protecting groups were removed under acidic conditions, and the crude product purified by HPLC. The purified BtDLSA will be evaluated with Luc for planned crystallographic studies.

Related Fields: Biochemistry, Cellular and Molecular Biology, Chemistry/ Biochemistry, Environmental Chemistry