Synthesis of luciferin glycosides as substrates for novel ultrasensitive enzyme assays

• Published in: Carbohydrate research 1990-09, Vol.205, p.225-233
• Main Authors: Amess, Robert, Baggett, Neil, Darby, Paul R., Goode, Anthony R., Vickers, Ernest E.
• Format: Article
• Language: English
• Subjects: Chemistry; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with n hetero atom and also o and/or s, se, te hetero atoms; Organic chemistry; Preparations and properties
• ISSN: 0008-6215; 1873-426X
• DOI: 10.1016/0008-6215(90)80142-P

Condensation of 2-cyano-6-hydroxybenzothiazole with acetohalogeno derivatives of d-glucose, d-galactose, and 2-acetamido-2-deoxy- d-glucose gave the corresponding β-glycosides. Attempted basic deacetylation caused methanolysis of the nitrile group. Condensation of the first two acetylated glycosides with d-cysteine, followed by deacetylation, gave the firefly luciferin β-glycosides that were substrates for the corresponding glycohydrolases. The liberated luciferin was determined by fluorescence spectroscopy and, in one instance, by coupled-bioluminescence assay with firefly luciferase. The amount of luciferin released and determined by bioluminescence assay, was only ∼65% of that determined by fluorescence spectroscopy, which suggested that the luciferin was partly racemised. Because of the great sensitivity of bioluminescence detection, these novel substrates provide potentially ultrasensitive assays for glycohydrolases, but their syntheses are more difficult than those of the corresponding fluorogenic substrates.