D-Serine

Stereoselective recognition using "tailor-made" chiral ionic liquids (CILs) is an effective approach to obtaining enantiopure compounds through crystallization resolutionIn this study, CILs were used as additives to stereoselectively inhibit the nucleation and growth of unwanted enantiomers via a conformational matching mechanism.Interestingly, a cosolvency phenomenon was found in the threonine-CILs-ethanol solvent system.Based on this, an enhanced stereoselective crystallization resolution strategy that combines ultrasound and cosolvency was proposed.The goal of this strategy was to improve the crystallization yield and enantiomeric purity.The results showed that the crystallization resolution yield of the cosolvency system was 33.43%, higher than that of the pure water system (13.56%).More importantly, the introduction of ultrasonic enhancement further increased the crystallization resolution yield to 39.45%.This work will facilitate the exploration of the unlimited potential of utilizing the cosolvency phenomenon and ultrasonic enhancement for crystallization resolution

The dysfunction of the N-methyl-d-aspartate receptor (NMDAR) has been implicated in depression, and D‑serine, an endogenous co-agonist of NMDAR, plays a critical role in its function. However, the pattern and relationship of alterations in central and peripheral D‑serine concentrations in depression remain unclear. In this study, we conducted two parallel cross-sectional studies to investigate D‑serine alterations in depression. In the clinical study, we recruited drug-naïve patients with major depressive disorder (MDD) and age and sex-matched healthy controls to assess peripheral D‑serine levels in serum. In the preclinical study, a chronic social defeat stress (CSDS) mouse model of depression was used to measure both peripheral and hippocampal D‑serine levels, given the hippocampus's key role in depression. Our results revealed significantly higher levels of D‑serine and the D‑serine/L‑serine ratio in the serum of MDD patients compared to controls, while L‑serine levels showed no significant differences. Similarly, in the CSDS mouse model, serum D‑serine levels were also increased. However, hippocampal D‑serine and L‑serine levels were decreased in depressed mice compared to controls, with no significant correlation observed between blood and hippocampal D‑serine levels. These findings suggest a potential pattern of D‑serine concentrations between peripheral blood and the hippocampus in depression. However, the clinical implications of contrasting changes in D‑serine in the peripheral and central systems, as well as the underlying mechanisms, require further investigation.