Asubio Pharma Co. Ltd.

To avoid production of a phospholipidosis-inducing metabolite, we replaced the amide structure of SUN13837 (1) with a 1,2,3-triazole. The resulting 1,2,3-triazole analog of 1 (compound 2) displayed greater neuroprotective activity than 1. Structural modification of 2 yielded compound 10, which showed improved neuroprotective activity and negligible mechanism-based inactivation against CYP3A4. In addition, installation of a methyl group at the 5-position of 1,2,3-triazole of 10 significantly boosted the neuroprotective activity. These 1,2,3-triazole derivatives displayed reduced phospholipidosis risk, sufficient systemic exposure, and high central nervous system penetration, and therefore may be potentially useful agents for the treatment of neurodegenerative diseases.

XCT, a well-known cystine transporter, is reported to be involved in the proliferation of various cells, such as cancer cells, immune cells, and fibroblasts. xCT inhibitor is expected to be a promising drug for cancer or immune diseases. However, there are little studies reporting that xCT inhibitors improve disease progression in vivo. To invent potent xCT inhibitors in vivo, we established a new in vivo model for assessing efficacy of xCT inhibition.DL-propargylglycine (PPG) was administered i.p. to wild-type C57BL/6J mice. Concentration of cystathionine, another substrate of xCT, in the thymus and spleen was measured by LC-MS/MS.PPG increased cystathionin amounts in the thymus and spleen in a dose- and time-dependent manner. At 7 h after PPG administration, the efficacy of erastin, a representative xCT inhibitor, was clearly shown. This paper synthesized a new compound, compound A, which had much higher inhibitory effect on xCT than erastin both in vitro and in vivo.This paper established a mouse model of PPG-induced cystathionine accumulation for assessing xCT inhibition in vivo. By using this model, we discovered that compound A was approx. 15 times more effective in vivo than erastin.

A novel series of benzothiophene derivatives was discovered as phosphodiesterase 10A (PDE10A) inhibitors. Structure-activity relationship studies on high-throughput screening hit compound 1 led to the identification of 7-acetyl-3-methyl-N-(quinolin-2-yl)-1-benzothiophene-2-carboxamide (16), with potent inhibitory activity (PDE10A IC₅₀ = 7.6 nM) and selectivity (>1300-fold selectivity over the other tested phosphodiesterases). In addition, a novel methyl-induced conformational alteration of the benzothiophene-2-carboxamide derivatives is reported.