BayCysLT2, an isophthalic acid derivative, is a selective and potent CysLT2 receptor antagonist [1].

Cysteinyl leukotrienes (CysLTs) belong to a family of G protein-coupled receptors (GPCRs). The cysteinyl leukotrienes (CysLTs) are inflammatory mediators associated with neuronal injury after brain ischemia through the activation of their receptors, CysLT1R and CysLT2R [2].

In vitro: BayCysLT2 inhibited radioligand binding of LTD4 to CysLT2 and CysLT1 receptor cell lines with IC50 values of 35 and >10,000 nM, respectively [1]. BayCysLT2 reversed LTC4-stimulated perfusion pressure increase and contractility decrease in isolated Langendorff-perfused guinea pig hearts in a concentration-dependent manner [1]. BayCysLT2 protected astrocytes from ischemic injury [3].

In vivo: BayCysLT2 attenuated myocardial infarction damage but also inhibited LTD4-induced Evans blue dye leakage in the mouse ear vasculature [4].

References:
[1] M.  Harter, J. Erguden, F. Wunder, et al. Isophtalic acid derivatives. 10/537,623, 1-104 (2006).
[2] Takasaki J, Kamohara M, Matsumoto M, et al.  The molecular characterization and tissue distribution of the human cysteinyl leukotriene CysLT 2 receptor[J]. Biochemical and biophysical research communications, 2000, 274(2): 316-322.
[3] X. J. Huang, W.P. Zhang, C.T. Li, W.Z. Shi, S.H. Fang, Y.B. Lu, Z. Chen, E.Q. Wei. Activation of CysLT receptors induces astrocyte proliferation and death after oxygen–glucose deprivation. Glia, 56 (2008), pp. 27–37
[4] N. C. Ni, D. Yan, L.L. Ballantyne, A. Barajas-Espinosa St, T. Amand, D.A. Pratt, C.D. Funk. A selective cysteinyl leukotriene receptor 2 antagonist blocks myocardial ischemia/reperfusion injury and vascular permeability in mice. J. Pharmacol. Exp. Ther., 339 (2011), pp. 768–778