ML089

Cell lines

HeLa cells (human epithelial immortal cell line)

Preparation Method

HeLa cells were seeded and grown to approximately 70% confluency in 24-well plates. Cells were incubated with ML089 for 2h at 37°C, followed by simultaneous addition of 50μCi/mL [2-³H]-mannose and 5μCi/mL ³⁵S-Met/Cys Trans label and further incubation at 37°C for 1h.

Reaction Conditions

20–40µM; 2 hours pre-incubation

Applications

ML089 produced a dose-dependent increase in ³H-mannose incorporation normalized to ³⁵S-Met/Cys incorporation in HeLa cells, indicating diverted mannose flux from catabolism toward glycoprotein N-linked glycosylation via inhibition of cellular phosphomannose isomerase (PMI). Over the tested concentration range, ML089 showed enhanced glycosylation signal with a favorable cellular efficacy–toxicity profile; decreased ³⁵S-Met/Cys incorporation at higher concentrations was observed but was attributed by the authors to off‑target activity rather than to on‑target PMM2 inhibition, as PMM2-deficient CDG-Ia patient fibroblasts grew normally in the presence of the PMI inhibitors without reduced ³⁵S-incorporation.

Animal models

C57BL/6 mice

Preparation Method

Mice were administered ML089 via a single intravenous bolus injection at 5mg/kg or a single oral gavage at 20mg/kg. At predetermined time points following dosing (p.o.: 0.5h, 1h, 2h, 4h, and 6h; i.v.: 10min, 0.5h, 1h, 2h, 4h, and 6h).

Dosage form

5mg/kg; i.v., single dose; 20mg/kg, p.o., single dose

Applications

ML089 produced quantifiable plasma exposure after both routes of administration in C57BL/6 mice, with an oral Cmax of 162 ± 32nM reached at Tmax of 45 ± 21min, an AUC₀₋ₜ of 305 ± 34nM·h, a plasma elimination half-life of 1.3 ± 0.64h, and an estimated oral bioavailability (F) of 35%.

References:
[1] Dahl R, Bravo Y, Sharma V, et al. Potent, selective, and orally available benzoisothiazolone phosphomannose isomerase inhibitors as probes for congenital disorder of glycosylation Ia. J Med Chem. 2011 May 26;54(10):3661-8.