Design and synthesis of selective sphingosine-1-phosphate receptor 1 agonists with increased phosphorylation rates

FTY720 and IMMH002, prodrugs for sphingosine-1-phosphate receptor 1 (S1P) agonists, show inadequate and inconsistent levels of phosphorylation in humans compared to that in rats. In this study, FTY720 or IMMH002 analogues (-) were designed and synthesized with modified head pieces to improve the biotransformation of the prodrugs to the active phosphorylated forms. Target compounds were synthesized a convergent route using the key and optically pure building block , which was first synthesized asymmetrically catalyzed amination. The phosphorylation rates of these analogues in rat or human blood were compared. The new methyl-substituted analogue compound showed higher phosphorylation rates in both rats and humans than the parent compound, whereas compound showed improvements in rats, but not in humans. In pharmacokinetics studies of rats, compounds and both had higher levels of phosphorylation than FTY720 and IMMH002. Thus, our study not only yielded new compounds with therapeutic potential, but also showed species differences between rats and humans in response to the structural modifications, which might be useful for predicting the biotransformation behavior and efficacy of this class of prodrugs in the clinic.

A novel S1P1 modulator IMMH002 ameliorates psoriasis in multiple animal models

Psoriasis is characterized by abnormal proliferation of keratinocytes, as well as infiltration of immune cells into the dermis and epidermis, causing itchy, scaly and erythematous plaques of skin. The understanding of this chronic inflammatory skin disease remains unclear and all available treatments have their limitations currently. Here, we showed that IMMH002, a novel orally active S1P modulator, desensitized peripheral pathogenic lymphocytes to egress signal from secondary lymphoid organs and thymus. Using different psoriasis animal models, we demonstrated that IMMH002 could significantly relieve skin damage as revealed by PASI score and pathological injure evaluation. Mechanistically, IMMH002 regulated CD3 T lymphocytes re-distribution by inducing lymphocytes' homing, thus decreased T lymphocytes allocation in the peripheral blood and skin but increased in the thymus. Our results suggest that the novel S1P agonist, IMMH002, exert extraordinary capacity to rapidly modulate T lymphocytes distribution, representing a promising drug candidate for psoriasis treatment.

Anti-rejection study in mice skin transplantation of a novel immunosuppressant SYL934 / 中国药理学通报

Aim To determine the effect of SYL934 , a novel immunosuppressant, on skin allograft rejec-tion. Methods HTRF-IP1 assay was used to evaluate the agonistic activity of SYL934-P, the active form of SYL934 in vivo, on S1P1 and S1P3 in vitro. SD rat peripheral blood lymphocytes ( PBL ) test and heart rate test was used to assess the in vivo immunosuppres-sive effect and heart rate effect of SYL934 . Mice skin graft transplantation experiment was used to observe the effect of SYL934 on skin allograft refection. ResultsSYL934-P selectively activated S1 P1 but not S1 P3 in vitro. Single orally administration of SD rats with SYL934 decreased the PBL significantly and played an obviously immunosuppressant role, but did not affect the heart rate. Daily orally administration of mice with SYL934 significantly increased the survival rate of al-lografts of skin slice in mice. Conclusion SYL934 has great selectivity in vitro and good activity in vivo, which indicated it potential use as an anti-rejection drug in skin transplantation.