Retinoid X receptor (RXR) is a nuclear receptor that heterodimerizes with several nuclear receptors, integrating ligand-mediated signals across the heterodimers. Synthetic RXR agonists have been developed to cure certain inflammatory diseases, including inflammatory bowel diseases (IBDs). However, pre-existing RXR agonists, which are lipophilic and readily absorbed in the upper intestine, cause considerable adverse effects such as hepatomegaly, hyperlipidemia, and hypothyroidism. To minimize these adverse effects, we have developed an RXR agonist, NEt-3IB, which has lipophilic and thus poorly absorptive properties. In this study, we evaluated the effects of NEt-3IB in an experimental murine colitis model induced through the adoptive transfer of CD45RBhighCD4+ T cells. Pharmacokinetic studies demonstrated that the major portion of NEt-3IB was successfully delivered to the large intestine after oral administration. Notably, NEt-3IB treatment suppressed the development of T cell-mediated chronic colitis, as indicated by improvement of wasting symptoms, inflammatory infiltration, and mucosal hyperplasia. The protective effect of NEt-3IB was mediated by the suppression of IFN-γ-producing Th1 cell expansion in the colon. In conclusion, NEt-3IB, a large intestine-directed RXR agonist, is a promising drug candidate for IBDs.

No abstract

Small-molecular drugs, which are generally inexpensive compared with biopharmaceuticals and can often be taken orally, may contribute to the Sustainable Development Goals (SDGs) adopted by the United Nations. We previously reported the retinoid X receptor (RXR) agonist 4-(ethyl(3-isobutoxy-4-isopropylphenyl)amino)benzoic acid (NEt-3IB, 1) as a small-molecular drug candidate to replace biopharmaceuticals for the treatment of inflammatory bowel disease. The previous synthetic method to 1 required a large amount of organic solvent and extensive purification. In line with the SDGs, we aimed to develop an environmentally friendly, inexpensive method for the large-scale synthesis of 1. The developed method requires only a hydrophobic ether and EtOH as reaction and extraction solvents. The product was purified by recrystallization twice to afford 99% pure 1 at 100 mmol scale in about 30% yield. The optimized process showed a 35-fold improvement of the E-factor (an index of environmental impact) compared to the original method. This work, which changes the solvent used to environmentally preferable ones based on the existing synthetic method for 1, illustrates how synthetic methods for small-molecular drugs can be adapted and improved to contribute to the SDGs.

No abstract

a 2,4(1H,3H)-Quinazolinedione Skeleton. -The title compound (III) and its derivatives (V) inhibit puromycin-sensitive amino-peptidase in a non-competitive manner. -(KAKUTA, H.; TANATANI, A.; NAGASAWA, K.; HASHIMOTO*, Y.; Chem.