DL-TBOA

Inhibitory activities

DL-threo-b-Benzyloxyaspartate (DL-TBOA) was synthesized and examined as an inhibitor of sodium-dependent glutamate/aspartate (excitatory amino acid) transporters. DL-TBOA inhibited the uptake of glutamate in COS-1 cells expressing the human excitatory amino acid transporter-1 (EAAT1) (Ki=42 mM). With regard to the human excitatory amino acid transporter-2(EAAT2), the Ki of DL-TBOA 5.7 mM.

Cell lines

COS-1 cells

Preparation method

The solubility of this compound in DMSO is >10 mM. General tips for obtaining a higher concentration: Please warm the tube at 37℃ for 10 minutes and/or shake it in the ultrasonic bath for a while. Stock solution can be stored below -20℃ for several months.

Reacting condition

Measurements of glutamate uptake in transfected COS-1 cells assey: 37℃ for 12 min.

Applications

DL-TBOA markedly inhibited glutamate (1 mM) uptake in transfected cells in a dosedependent manner. The subconfluent cells were washed two times with 300 μl of modified phosphate-buffered saline that contained 137 mM NaCl, 2.7 mM KCl, 8.1 mM Na2HPO4, 1.5 mM KH2PO4,1mM MgCl2, 1mM CaCl2, and 10 mM D-glucose, pH 7.4, and preincubated in 300 μl of the same buffer at 37℃ for 12 min. After aspiration of the buffer, cells were incubated with 1 μM L-glutamate in 100 μl of modified phosphate-buffered saline in the absence or presence of DL-TBOA at various concentrations at 37℃ for 12 min.

Animal models

Males Wistar rats

Dosage form

500 μM DL-TBOA

Preparation method

Dissolved in Ringer Krebs medium which containing (in mM): NaCl 118, KCl 4.5, MgSO4 1.18, KH2PO4 1.2, CaCl2 2.5, NaHCO3 25.

Application

Microdialysis administration of 500μM DL-TBOA into the hippocampus increased 3.4- and nine-fold the extracellular levels of aspartate and glutamate, respectively.

Other notes

Please test the solubility of all compounds indoor, and the actual solubility may slightly differ with the theoretical value. This is caused by an experimental system error and it is normal.

References:

[1]. KEIKO SHIMAMOTO, BRUNO LEBRUN, YOSHIMI YASUDA-KAMATANI, at al. DL-threo-b-Benzyloxyaspartate, A Potent Blocker of Excitatory Amino Acid Transporters. MOLECULAR PHARMACOLOGY, 53:195–201 (1998).

[2]. T. MONTIEL,A. CAMACHO,A. M. ESTRADA-S?NCHEZ AND L. MASSIEU. DIFFERENTIAL EFFECTS OF THE SUBSTRATE INHIBITOR L-TRANSPYRROLIDINE-2,4-DICARBOXYLATE (PDC) AND THE NON-SUBSTRATE INHIBITOR DL-THREO-β-BENZYLOXYASPARTATE (DL-TBOA) OF GLUTAMATE TRANSPORTERS ON NEURONAL DAMAGE AND EXTRACELLULAR AMINO ACID LEVELS IN RAT BRAIN IN VIVO. Neuroscience 133 (2005) 667–678.