Isoquinoline, 5-iodo- (9CI)

Uses

DSRM-3716 (5-Iodoisoquinoline) is a potent and selective SARM1 NADase inhibitor with an IC50 of 75 nM. DSRM-3716 is selective against other NAD+-processing enzymes, receptors, and transporters. DSRM-3716 provides robust axon protection[1].

Biological Activity

DSRM-3716 is a potent and selective SARM1 NADase inhibitor (NAD+ hydrolysis IC50 = 75 nM using recombinant SARM1 SAM-TIR construct) th at recapitulates the SARM1-/- phenotype and protects axons from degeneration induced by axotomy (EC50 = 2.1/1.9 μM by fragmentation/NfL release using mouse DRG neurons; 81/88% protection by 1/3 μM DSRM-3716 using human iPSC-derived motor neurons) or mitochondrial dysfunction (3-30 μM DSRM-3716 against 25 μM rotenone-induced injury; mouse DRG neurons). Mechanistically, DSRM-3716 undergoes base exchange with the nicotinamide (NAM) moiety of nicotinamide adenine dinucleotide (NAD+) to yield the bona fide inhibitor 1AD.

Synthesis

Step A - Preparation of Intermediate 58-1: To a hydrochloric acid/water (40 mL/40 mL) solution of 5-aminoisoquinoline (14 g, 97.2 mmol) was added sodium nitrite (8 g, 116 mmol) in batches at 0 °C. The reaction mixture was stirred at 0 °C for 1 h. Potassium iodide (32 g, 194 mmol) was then added slowly and the mixture was refluxed overnight. Upon completion of the reaction, the mixture was cooled to room temperature, poured into ammonia (40 mL) and extracted with dichloromethane (50 mL x 3). The organic layers were combined, washed with brine (40 mL), dried over anhydrous sodium sulfate and concentrated. The residue was purified by column chromatography (eluent: ethyl acetate/petroleum ether=1:10) to give Intermediate 58-1 (6.5 g). Mass spectrum (ESI): m/z (M+H)+ 256.

storage

Store at -20°C

References

[1] Robert O Hughes, et al. Small Molecule SARM1 Inhibitors Recapitulate the SARM1 -/- Phenotype and Allow Recovery of a Metastable Pool of Axons Fated to Degenerate. Cell Rep. 2021 Jan 5;34(1):108588. DOI:10.1016/j.celrep.2020.108588