Thiamet G is a potent, selective O-GlcNAcase inhibitor with Kiof 21 nM, while exhibiting 37, 000-fold selectivity over human lysosomal –hexosaminidase.

O-GlcNAcase (OGA):21 nM(Ki)

在NGF诱导分化的PC-12细胞中，Thiamet G通过抑制O-GlcNAcase，使细胞内O-GlcNAc水平上升，EC50约为30 nM。Thiamet G (100 mM) 分别使Ser396、Thr231、Ser422和Ser262的tau蛋白磷酸化水平降低约2.1倍、2.7倍、1.2倍和1.3倍。[1] Thiamet G (12.5 nM和25 nM)通过增加O-GlcNAcylation，在肾小球系细胞中显著增强p38磷酸化。[2] 在O-GlcNAc转移酶或O-GlcNAcase功能增强的细胞中，Thiamet-G能够恢复纺锤体的组装，并部分挽救组蛋白的磷酸化。[3]

在大鼠中，经静脉注射给予Thiamet G（50 mg/kg）后，该化合物能跨越血脑屏障，随着剂量和时间的增加，大脑中的O-GlcNAc水平上升，并且减少大鼠大脑中tau蛋白的磷酸化作用。Thiamet G也具有口服生物利用度。[1]由Thiamet G引起的O-GlcNAc积累，通过增加分化标志基因的表达以及MMP-2和-9活性的增加，促进C57/bl小鼠的软骨分化。[4]

All enzymatic assays are performed in triplicate at 37°C using 4-methylumbelliferyl N-acetyl-β-d-glucosaminide dehydrate as substrate. 1 nM of purified OGA is incubated with the compounds for 5 min, and then 0.2 mM of the substrate is added. The liberation of 4-methylumbellifery is monitored by kinetic reading at excitation/emission 355/460 nm using a Tecan M200 plate in a mode of 60 s/cycle and 15 cycles in total.

Jurkat cells are seeded at 6000 cells/well in a 96-well plate, and 12 h later, cells are treated with compounds for the indicated time. Cell viability is determined by XTT assay.