A base-mediated aerobic oxidative synthesis of cyclopent-2-enol derivatives from doubly activated cyclopropanes and substituted acetonitriles.

We report here that polysubstituted cyclopent-2-enols can be constructed by the one-pot reaction of doubly activated cyclopropanes and α-EWG substituted acetonitriles under mild basic conditions via a domino-ring-opening-cyclization/deacylation/oxidation sequence. Moreover, the synthetic applications of these cyclopent-2-enols have been demonstrated in the late-stage derivatization into functionalized cyclopentapyrimidin-4-ones and 2-hydroxy cyclopentanones with good yields.

Novel synthesis of fused spiro piperidone-cyclopropanes from cyclopropyl amides and electron-deficient alkenes.

We report here that a series of bridged O,O-ketal fused spiro piperidone-cyclopropane derivatives 3 can be constructed with excellent yields and good diastereoselectivity by the one-pot reaction of 1-acylcyclopropanecarboxamides 1 with electron-deficient alkene 2a (EWG = CHO) via the domino process involving [4 + 2] annulation/intermolecular electrophilic addition/intramolecular cyclization. Furthermore, reactions of 1 with 2b/2c (EWG = CN, COOMe), leading to spiro piperidone-cyclopropane derivatives 4 or 5 by base catalyst selection, were also presented.

Astaxanthin attenuates total body irradiation-induced hematopoietic system injury in mice via inhibition of oxidative stress and apoptosis.

BACKGROUND: The hematopoietic system is especially sensitive to total body irradiation (TBI), and myelosuppression is one of the major effects of TBI. Astaxanthin (ATX) is a powerful natural anti-oxidant with low toxicity. In this study, the effect of ATX on hematopoietic system injury after TBI was investigated. METHODS: Flow cytometry was used to detect the proportion of hematopoietic progenitor cells (HPCs) and hematopoietic stem cells (HSCs), the level of intracellular reactive oxygen species (ROS), expression of cytochrome C, cell apoptosis, and NRF2-related proteins. Immunofluorescence staining was used to detect Nrf2 translocation. Western blot analysis was used to evaluate the expression of apoptotic-related proteins. Enzymatic activities assay kits were used to analyze SOD2, CAT, and GPX1 activities. RESULTS: Compared with the TBI group, ATX can improve radiation-induced skewed differentiation of peripheral blood cells and accelerate hematopoietic self-renewal and regeneration. The radio-protective effect of ATX is probably attributable to the scavenging of ROS and the reduction of cell apoptosis. These changes were associated with increased activation of Nrf2 and downstream anti-oxidative proteins, and regulation of apoptotic-related proteins. CONCLUSIONS: This study suggests that ATX could be used as a potent therapeutic agent to protect the hematopoietic system against TBI-induced bone marrow suppression.

[Rituximab and Dexamethasone Combined with Cyclophosphamide for Treatment of Relapsed and Refractory Immune Thrombocytopenia].

OBJECTIVE: To evaluate the efficiency and safety of rituximab and dexamethasone combined with cyclophosphamide for treating patients with relapsed and refractory immune thrombocytopenia (ITP). METHODS: Twelve patients with relapsed and refractory immune thrombocytopenia were prospectively enrolled in this study, and received rituximab 375 mg/m(2) once a week for 4 weeks, dexamethasone 40 mg once a day for consecutive 4 days, and cyclophosphamide 500 mg/m(2) biweekly for 2 weeks. The levels of IFN-r and IL-4 in peripheral blood of patients were measured by enzyme-linked immunosorbent assay (ELISA), and the percentages of Breg, Treg and Th17 cells were detected by flow cytometry before and after treatment. Efficiency was evaluated according to platelet counts, and side effects were observed. RESULTS: Six out of 12 patients reached to complete remission and 4 patients reached to partial remission, with the total response rate 83.33%. The platelet counts [(115.42 ± 76.60) × 10(9)/L] after treatment were significantly higher than that before treatment [(115.42 ± 76.60) × 10(9)/L] (P < 0.001). The ratio of IFN-r/ IL4 after treatment (5.89 ± 2.30) was very significantly lower than that before treatment (7.00 ± 2.73) (P = 0.002). The percentage of Breg cells after treatment [(21.27 ± 4.28)%] were much significantly higher than that before treatment [(15.48 ± 1.67)%] (P < 0.001). The ratio of Treg/Th17 after treatment (3.07 ± 1.50) was significantly higher than that before treatment (0.98 ± 0.45) (P < 0.001). Infusion reaction was observed in 1 patient, secondary hypertension and hyperglycemia were in 1 patient, and pneumonia in 2 patients. CONCLUSION: Rituximab and dexamethasone combined with cyclophosphamide can improve the outcomes of patients with relapsed and refractory immune thrombocytopenia patients and they were well tolerated, its mechanism may be related with the balance between T cell sunsets and Treg cells.

Single sevoflurane exposure increases methyl-CpG island binding protein 2 phosphorylation in the hippocampus of developing mice.

Sevoflurane is an inhaled anesthetic that is widely used in clinical practice, particularly for pediatric anesthesia. Previous studies have suggested that sevoflurane may induce neurotoxicity in the brains of neonatal mice. In the present study, the possible mechanism of neurodegeneration induced by sevoflurane in the developing brain, and the possibility that memantine treatment is able to reverse this phenomenon, were investigated. On postnatal day 7 (P7) C57BL/6 mice were continuously exposed to 1.5% sevoflurane for 2 h following pre-injection of saline or memantine. Methyl-CpG island binding protein 2 (MeCP2), cAMP response element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF) expression in the hippocampus was measured by western blotting. Exposure to 1.5% sevoflurane resulted in increased MeCP2 phosphorylation in the hippocampus, which was reversed by memantine injection. However, neither CREB phosphorylation nor BDNF expression were significantly altered by sevoflurane treatment. The current study indicated that sevoflurane causes neurotoxicity in the developing brain, and that this may be attributed to increased MeCP2 phosphorylation in the hippocampus. It was also demonstrated that this neurotoxicity can be prevented by the N-methyl-D-aspartate glutamate receptor inhibitor memantine.

Synthesis of acridines and persubstituted phenols from cyclobutenones and active methylene ketones.

A new benzannulation strategy that proceeds via a regiospecific [4 + 2] cycloaddition of readily available cyclobutenones and active methylene ketones has been developed. On the basis of this strategy, persubstituted phenols/anilines with up to six different functional groups on the benzene ring were synthesized in a single step. In addition, a series of acridine derivatives were prepared in excellent yield from persubstituted phenols/anilines.

Highly efficient synthesis of 3-amino-/alkylthio-cyclobut-2-en-1-ones based on the cyclization of acyl ketene dithioacetals.

A new strategy for the highly efficient one-pot synthesis of 3-amino-/alkylthio-cyclobut-2-en-1-ones based on the cyclization of acyl ketene dithioacetals is disclosed. In addition, the rearrangement of 3-amino-cyclobut-2-en-1-ones to 4-quinolone derivatives is described.

AlCl3-mediated direct carbon-carbon bond-forming reaction of alpha-hydroxyketene-S,S-acetals with arenes and synthesis of 3,4-disubstituted dihydrocoumarin derivatives.

A simple and efficient AlCl(3)-mediated C-C coupling reaction between readily available alpha-hydroxyketene-S,S-acetals and various arenes via direct substitution of the hydroxy group in alcohols has been developed. On the basis of this C-C coupling reaction, a series of bio- and pharmacologically important 3,4-disubstituted dihydrocoumarins, difficult to obtain by other methods, were prepared in high yields by a sequential Friedel-Crafts alkylation and intramolecular annulation reaction of alpha-hydroxyketene acyclic-S,S-acetals with phenols under mild conditions.