Photocatalytic Tandem Radical Cyclization Enables Expeditious Total Synthesis of Epoxyhinokiol Analogues for Anticancer Activity Evaluation.

A photocatalytic radical cascade with an unusual endo-trig cyclization was developed, which enables the efficient assembly of divergent tricyclic diterpenoid frameworks. The first total synthesis of abietane 10-epi-epoxyhinoliol was thus achieved in six steps by a subsequent reductive coupling of i-PrBr under photoredox/nickel dual catalysis. Inhibitory tests of chiral 10-epi-epoxyhinoliol and its analogues in 4T1 cancer cells demonstrated the critical role of the C12 hydroxyl group, leading to a discovery of the simplified analogue with better activity.

Immobilization and enzymatic properties of glutamate decarboxylase from Enterococcus faecium by affinity adsorption on regenerated chitin.

Glutamate decarboxylase (GAD, EC 4.1.1.15) is an important enzyme in gamma-aminobutyric acid biosynthesis and DL-glutamic acid resolution. In this study, the Enterococcus faecium-derived GAD was successfully immobilized by regenerated chitin (RC) via specific adsorption of cellulose-binding domain (CBD). The optimal binding buffer was 20 mmol/L phosphate buffer saline (pH 8.0), and the RC binding capacity was 1.77 ± 0.11 mgcbd-gad/grc under this condition. The ratio of wet RC and crude enzyme solution used for immobilization was recommended to 3:50 (g/mL). To evaluate the effect of RC immobilization on GAD, properties of the immobilize GAD (RC-CBD-GAD) were investigated. Results indicated RC-CBD-GAD was relatively stable at pH 4.4-5.6 and temperature - 20-40 °C, and the optimal reaction pH value and temperature were pH 4.8 and 50 °C, respectively. When it was reacted with 5 mmol/L of follow chemical reagents respectively, the activity of RC-CBD-GAD was hardly affected by EDTA, KCl, and NaCl, and significantly inactivated by AgNO3, MnSO4, MgSO4, CuSO4, ZnSO4, FeCl2, FeCl3, AlCl3, CaCl2, and Pb(CH3COO)2. The apparent Km and Vmax were 28.35 mmol/L and 147.06 µmol/(gRC-CBD-GAD·min), respectively. The optimum time for a batch of catalytic reaction without exogenous pH control was 2 h. Under this reaction time, RC-CBD-GAD had a good reusability with a half-life of 23 cycles, indicating that it was very attractive for GABA industry. As a novel, efficient, and green CBD binding carrier, RC provides an alternative way to protein immobilization.

Effect of Selective Thrombus Aspiration on Serum Lipoprotein-Associated Phospholipase A2 in Patients with ST-Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention with High Thrombus Burden.

BACKGROUND: Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a potential therapeutic target in acute coronary syndromes. Although recent evidence does not support the routine use of manual thrombus aspiration (TA) in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI), the use of TA is associated with a significant improvement in myocardial reperfusion, especially in patients with high thrombus burden (HTB). We hypothesized that TA would reduce the serum Lp-PLA2 levels in STEMI patients undergoing PPCI with HTB. METHODS AND RESULTS: Our study cohort included 320 consecutive STEMI patients undergoing PPCI with HTB who were randomly assigned to receive either TA before PPCI (TA group, n = 160) or PPCI alone (standard PPCI group, n = 160). The baseline characteristics of study participants were well-matched. After 30 ± 2 days, serum Lp-PLA2 levels decreased by 53.9% in the TA group (152.9 ± 58.1 ng/mL) and decreased by 31.2% in the standard PPCI group (84.2 ± 86.6 ng/mL, p < 0.001). The TA group had a significantly lower prevalence of balloon predilatation, number of stents used, total stent length and corrected thrombolysis in myocardial infarction frame count, and a higher percentage of myocardial blush grade ≥ 2 compared with the standard PPCI group (all p < 0.001). No significant difference between the groups was observed in 30 ± 2 days for major adverse cardiovascular and cerebrovascular events (p = 0.702). CONCLUSIONS: After 30 ± 2 days of treatment, TA may significantly reduce serum levels of Lp-PLA2 in STEMI patients undergoing PPCI with HTB.