Stepwise Asymmetric Allylic Substitution-Isomerization Enabled Mimetic Synthesis of Axially Chiral B,N-Heterocycles.

Axially chiral molecules bearing multiple stereogenic axes are of great importance in the field of organic chemistry. However, the efficient construction of atropisomers featuring two different types of stereogenic axes has rarely been explored. Herein, we report the novel atroposelective synthesis of configurationally stable axially chiral B,N-heterocycles. By using stepwise asymmetric allylic substitution-isomerization (AASI) strategy, diaxially chiral B,N-heterocycles bearing B-C and C-N axes that are related to the moieties of axially chiral enamines and arylborons were also obtained. In this case, all four stereoisomers of diaxially chiral B,N-heterocycles were stereodivergently afforded in high enantioselectivities. Density functional theory (DFT) studies demonstrated that the NH⋅⋅⋅π interactions played a unique role in the promotion of stereospecific isomerization, thereby leading to the highly efficient central-to-axial chirality transfer.

Brønsted acid-enhanced copper-catalyzed atroposelective cycloisomerization to axially chiral arylquinolizones via dearomatization of pyridine.

The construction of axially chiral N-heterobiaryls is of great interest as a result of their occurrence in organocatalysts, chiral ligands, natural products, and biologically active molecules. Despite remarkable achievements in this area, strategies for the preparation of new classes of axially chiral N-heterobiaryls remain to be further explored. Herein, we report the enantioselective synthesis of axially chiral arylquinolizones through an intramolecular atroposelective cycloisomerization. The reaction proceeds via the Brønsted acid-enhanced dearomatization of pyridine by a copper catalyst that allows for the formation of the desired products in excellent yields and enantioselectivities. The utility of this methodology is illustrated by a synthesis on gram scale production and transformation of the products into chiral thiourea catalysts. Mechanistic studies demonstrate that Brønsted acid plays a significant role in promoting the reactivity of the reaction, while both the steric and electronic effects of aryl substituents in substrate play a role in controlling the stereoselectivity.

Photoaccelerated energy transfer catalysis of the Suzuki-Miyaura coupling through ligand regulation on Ir(iii)-Pd(ii) bimetallic complexes.

Three bimetallic Ir(iii)-Pd(ii) complexes [Ir(ppy)2(bpm)PdCl2](PF6) (ppy = 2-phenylpyridine, 1), [Ir(dfppy)2(bpm)PdCl2](PF6) (dfppy = (4,6-difluorophenyl)pyridine, 2), and [Ir(pq)2(bpm)PdCl2](PF6) (pq = 2-phenylquinoline, 3) were synthesized by using 2,2'-bipyrimidine (bpm) as a bridging ligand. The influences of the cyclometalated ligand at the Ir(iii) center on the photophysical and electrochemical properties as well as photocatalytic activity for the Suzuki-Miyaura coupling reaction under mild conditions were evaluated. The results revealed that complex 3 enables dramatically accelerating the Suzuki-Miyaura coupling reaction under visible light irradiation at room temperature, due to the effective absorption of visible light and appropriate locus of the excited chromophore. Mechanism studies showed that the chromophore [Ir(pq)2(bpm)] fragment absorbs visible light to produce the triplet excited state centering on the bridging ligand which boosts the formation of electron rich Pd(ii) units and facilitates the oxidative addition step of the catalytic cycle. Simultaneously, the excited chromophore undergoes energy transfer efficiently to the Pd(ii) reaction site to form the excited Pd(ii) species, resulting in enhancement of Pd(ii) reduction steps of the Suzuki-Miyaura coupling reaction and increasing the reactivity of the catalyst. This provides a new strategy for designing photocatalysts for coupling reaction through altering the cyclometalated ligand to modulate the photophysical properties and the cooperation between two metal units.

[Effect of Regulating PPARγ by mTOR Signaling on Adipogenesis of Bone Marrow Mesenchymal Stem Cells from Aplastic Anemia].

OBJECTIVE: To study the effect and mechanism of mTOR signaling on adipogenesis of bone marrow mesenchymal stem cells(BM-MSCs) from aplastic anemia (AA) patients through regulation of PPARγ. METHODS: BM-MSCs were isolated from 24 newly diagnosed AA patients and 24 healthy controls. The surface antigen expression of BM-MSCs was identified by flow cytometry. The capacity of adipogenic differentiation of BM-MSCs was determined by lipid droplets based on Oil Red O staining and by the expression of FABP4 based on Western blot. Protein levels of mTOR signaling and PPARγ were tested by immunofluorescence and Western blot. RESULTS: AA BM-MSCs displayed an enhanced capacity of differentiating into adipocytes, compared with control BM-MSCs. It was found that mTOR was activated in AA BM-MSCs. Moreover, the expression levels of p-mTOR and PPAR-γ in AA BM-MSCs showed a parallel differentiation-dependent increase during adipogenic differentiation, which were significantly higher than that of control BM-MSCs at the same time point of adipogenic differentiation. mTOR inhibitor rapamycin did not only inhibit the adipogenic differentiation of BM-MSCs from AA pateints at the early-middle stage, but also partly reversed the adipogenic differention of BM-MSCs from AA pateints at the late stage by PPARγ regulation. CONCLUSION: mTOR signaling may play a critical role in the adipogenic differentiation of BM-MSCs from AA patients by positively regulating PPARγ expression.

[Serum level of IL-17 in patients with multiple myeloma and its clinical significance].

This study was purposed to detect the serum concentrations of interleukin-17 (IL-17) in patients with multiple myeloma (MM), and to investigate its clinical significance. the serum IL-17 levels in 33 patients with MM and 20 normal control subjects were quantified by using double antibody sandwich ELISA, and serum ß2-microglobulin (ß2-MG) levels were detected by radioimmunoassay. The results showed that the serum concentrations of IL-17 and ß2-MG in patients with MM were significantly higher than those in the control group (P < 0.001), the serum concentrations of IL-17 and ß2-MG in active stage were significantly higher than those in stable stage (P < 0.05), the serum concentrations of IL-17 and ß2-MG were significantly higher in stage III than that in stage II according to International Staging System (ISS) (P < 0.05), the serum IL-17 and ß2-MG levels were significantly correlated (r = 0.690, P < 0.05). It is concluded that the serum IL-17 level correlates with active/stable stages of MM and staging of MM, IL-17 may play an important role in development stage and prognosis of this disease.

[The role of DNA methylation in the pathogenesis of adult idiopathic thrombocytopenic purpura].

OBJECTIVE: To explore the role of DNA methylation in pathogenesis of adult idiopathic thrombocytopenic purpura (ITP). METHODS: We measured DNA methyltransferases (DNMTs) 1, 3A and 3B mRNA expression in peripheral blood mononuclear cells of 48 adult ITP patients and 36 normal controls using real-time polymerase chain reaction, as well as the plasma levels of S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) with reversed phase high performance liquid chromatography (HPLC). Furthermore, we determined the expression of CD(11a)/LFA-1 on CD(4)(+) or CD(8)(+) T cells by three-color flow cytometry. RESULTS: The mRNA expression of two DNA methyltransferases (DNMT3A and DNMT3B) was significantly lower when comparing ITP patients with healthy controls (P < 0.01). Although there were decreased tendency when comparing expression of DNMT1 of ITP patients with healthy controls, no significant differences were found (P > 0.05). The SAH concentration in the plasma of ITP patients was significantly elevated than that in the healthy controls (P < 0.05). However we found significant differences of SAM and SAM/SAH ratio in the plasma of ITP patients when compared with the healthy subjects (both P > 0.05). In addition, CD(11a)/LFA-1 expression on CD(8)(+) T lymphocytes increased in ITP patients compared with the control group (P < 0.01), whereas CD(11a)/LFA-1 expression on CD(4)(+) T lymphocytes and CD(4)(+)CD(11a)(+)/CD(8)(+)CD(11a)(+) ratio was significantly decreased in ITP patients than that in control group (both P < 0.01). CONCLUSION: Aberrant DNA methylation in peripheral blood and CD(11a)/LFA-1 expression on T cell surface may play an important role in the pathogenesis of ITP, although the underlying mechanisms still await further investigation.

[The role of intercellular adhesion molecule-1 in binding of acute myeloid leukemic blasts cells to human umbilical vein endothelial cells].

OBJECTIVE: To evaluate the adhesion of acute myeloid leukemia (AML) blasts to human umbilical vein endothelial cells (HUVECs) and the roles of intercellular adhesion molecule-1 (ICAM-1) and its ligand lymphocyte function associated antigen-1 (LFA-1) in binding of leukemic blasts to HUVECs. METHODS: AML blasts attachment to unactivated or tumor necrosis factor alpha (TNF alpha) activated-endothelial cell monolayers was investigate in vitro; The adhesion of leukemic blasts co cultured with unactivated endothelial cells under static conditions at 37 degrees C for 24 hours was observed;The binding of neutrophils and unactivated endothelial cell monolayers exposed to supernatant of blasts were tested. ICAM-1 on endothelial cell surface and sICAM-1 of endothelial cell supernatant were determined by flow cytometry and ELISA detection. We also observed the adhesion of leukemic blasts in the presence of the adhesion blocking mAbs anti-ICAM-1 and anti-LFA-1. RESULTS: This study has shown that the blast cells attached to unactivated endothelium was little (24.33 +/- 2.87)% and increased after exposure of endothelium to TNF alpha (81.87 +/- 4.08)% (n = 21, P < 0.001); The binding of blasts to endothelium also increased significantly after 24 hours co cultured with unactivated HUVEC (82.06 +/- 7.05)%, (n = 21, P < 0.001); The adhesion of neutrophils and unactivated endothelial cell monolayers exposed to supernatant of blasts was increased significantly (83.99 +/- 3.86)%, (n = 21, P < 0.001). Lower levels of ICAM-1 and sICAM-1 expression was detected on unactivated HUVECs (55.81 +/- 4.11)%, (0.839 +/- 0.236) microg/L respectively. Treatment of HUVECs with AML blasts supernatant for 24 hours increased the expression of ICAM-1 (65.36 +/- 5.97)%, (1.424 +/- 0.469) microg/L respectively (n = 21, P < 0.05) and anti-ICAM-1 and anti-LFA-1 significantly inhibited the adhesion of AML blasts attachment to TNF alpha activated-endothelial cell monolayers (20.12 +/- 1.73)%, (n = 10, P < 0.001). CONCLUSION: Our results indicate that leukemic blasts have the ability to generate some factors that stimulate endothelial cell to secrete ICAM-1 ane to promote their own adhesion to vascular endothelium, interaction of ICAM-1 and its ligand LFA-1 has a key role in adhesion of leukemic blasts and HUVECs.

[Anatomic observation of the prostate for clinical application of local drug injection through the rectum for chronic prostatitis].

OBJECTIVE: To provide anatomic evidences for local drug injection through the rectum for treating chronic prostatitis and observe the therapeutic effect of this treatment. METHODS: Anatomic observation of the median sagittal plane of 16 male pelvic specimens was conducted, with special attention to the structures between the prostate and the rectum. The distance from the posterior wall of the prostate to the anterior wall of the rectum, the scope that allowed the entry of the puncture needle, the appropriate puncture depth, and the distance from the anus to the safe were carefully measured. Analysis of the clinical record was performed in 51 chronic prostatitis cases treated with local injection of prednisolone, antibiotic and lidocaine through the rectum. RESULTS: Only some fat tissues and venous plexus were found between the prostate and the anterior wall of the rectum, and the distance from posterior wall of the prostate to the anterior wall of the rectum averaged 5.773+/-0.710 mm. The scope for possible puncture was 15.408 8+/-1.438 2 mm with a depth of 15.703 1+/-0.944 1 mm. The maximum and minimum distances from the anus to the puncture were 47.594+/-2.432 mm and 35.781+/-1.850 mm, respectively. Among the 51 cases investigated, the total cure rate was 84.31%, and improvement was achieved in 13.73% of the case, with only one case (2%) failed to respond to the treatment. CONCLUSION: Local drug injection through the rectum can be ideal for the treatment of prostatitis for its safety and effectiveness.