Contribution of theanine to the temperature-induced changes in aroma profile of Wuyi rock tea.

Theanine is a distinctive amino acid in tea that plays a vital role in tea flavor during the roasting process. Model thermal reactions of total amino acids and sugars with different roasting conditions (low-fire, middle-fire, and high-fire) showed theanine competitively inhibited the formation of indole, skatole, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, and Strecker aldehydes, while greatly stimulated the production of roasty pyrazines. In addition, highest amounts of pyrazines were obtained under high-fire degree.

Formation of dimethyl sulfide from the decomposition of S-methylmethionine in tea (Camellia sinensis) during manufacturing process and infusion brewing.

Dimethyl sulfide (DMS) is a typical odorant contributing a cooked corn-like odor to tea (Camellia sinensis). In the study, noticeable increases of DMS (>350%) occurred in green, black, yellow, and white tea during brewing. Thermal model and quantitative analysis of S-methylmethionine (SMM) confirmed the thermal decomposition of SMM into DMS (44-80%) in tea infusion.

Platinum thiolate complexes supported by PBP and POCOP pincer ligands as efficient catalysts for the hydrosilylation of carbonyl compounds.

Diphosphino-boryl-based PBP pincer platinum thiolate complexes, [Pt(SR){B(NCHPBu)-1,2-CH}] (R = H, 1a; Ph, 1b), and benzene-based bisphosphinite POCOP pincer platinum thiolate complexes, [Pt(SR)(BuPO)-1,3-CH] (R = H, 2a; Ph, 2b), were prepared and fully characterized by multinuclear NMR, X-ray crystallography, HRMS and elemental analyses. The application of these complexes in the catalytic hydrosilylation of aldehydes and ketones was investigated. It was found that these platinum thiolate complexes are efficient catalysts for the hydrosilylation of aldehydes and ketones at 65-75 °C.

The Stability of Diphosphino-Boryl PBP Pincer Backbone: PBP to POP Ligand Hydrolysis.

Since moisture may frequently be present in many solvents, it is important to know the reactivity of a catalyst against water for catalytic reactions. In order to explore the stability and understand the transformation process of diphosphino-boryl-based PBP pincer platform, [PdCl{B(NCH P Bu ) -o-C H }] (1) was treated with PdCl , HB(NCH PPh ) -o-C H was reacted with [PdCl (cod)] (cod=cyclo-octa-1,5-diene) and [Pd (dba) ] (dba=dibenzylideneacetone), respectively, in the presence of water. Some novel palladium POP complexes, [Pd Cl (μ-Cl){μ-κ -P,O,P-OB(NCH P Bu ) -o-C H }] (2 a), [Pd (μ-Cl) (μ-O) {μ-κ -P,O,P-OB(NCH PPh ) -o-C H } ] (2 b), [Pd {μ-κ -P,P,P,P-O(B(NCH PPh ) -o-C H ) }{μ-κ -P,P-(NHCH PPh ) -o-C H }] (3), were obtained.

FBXO38 mediates PD-1 ubiquitination and regulates anti-tumour immunity of T cells.

Dysfunctional T cells in the tumour microenvironment have abnormally high expression of PD-1 and antibody inhibitors against PD-1 or its ligand (PD-L1) have become commonly used drugs to treat various types of cancer. The clinical success of these inhibitors highlights the need to study the mechanisms by which PD-1 is regulated. Here we report a mechanism of PD-1 degradation and the importance of this mechanism in anti-tumour immunity in preclinical models.

Cholesterol Metabolism in T Cells.

Compartmentalization and spatial control of biochemical reactions is the foundation of cell-based life on earth. The lipid bilayer system employed by eukaryote cells not only keeps them separate from the environment but also provides a platform for key receptors to sense and interact with outside factors. Arguably one of the cell types most reliant on interactions of this kind, immune cells depend on their membrane to keep functioning properly.

Dynamic regulation of CD28 conformation and signaling by charged lipids and ions.

CD28 provides an essential costimulatory signal for T cell activation, and its function is critical in antitumor immunity. However, the molecular mechanism of CD28 transmembrane signaling remains elusive. Here we show that the conformation and signaling of CD28 are regulated by two counteractive charged factors, acidic phospholipids and Ca ions.