Tris(boratabenzene) Lanthanum Complexes: Synthesis, Structure, and Reactivity

A series of tris­(boratabenzene) lanthanum complexes were synthesized and structurally characterized. Salt elimination of anhydrous LaCl₃ with Li­[C₅H₅BR] (R = H, NEt₂) provided tris­(boratabenzene) lanthanum complexes [C₅H₅BH]₃­LaLiCl (<b>1</b>) and [C₅H₅BNEt₂]₃­LaLiCl­(THF) (<b>2</b>) in high yields. Hydroboration of 1-hexene or 3-hexyne with <b>1</b> gave the alkyl- or alkenyl-functionalized boratabenzene lanthanum complexes, [C₅H₅B­(CH₂)₅CH₃]₃­LaLiCl­(THF) (<b>3</b>) and [C₅H₅BC­(C₂H₅)CH­(C₂H₅)]₃­LaLiCl­(THF) (<b>4</b>), in good yields. Hydroboration of <i>N</i>,<i>N</i>′-diisopropylcarbodiimide with <b>1</b> gave the monohydroboration product [C₅H₅BN­(^<i>i</i>Pr)­CHN­(^<i>i</i>Pr)]­[C₅H₅BH]₂La (<b>5</b>) due to the steric bulk of the [C₅H₅BN­(^<i>i</i>Pr)­CHN­(^<i>i</i>Pr)]⁻ ligand. Complex <b>5</b> can undergo further hydroboration with 3-hexyne or dehydrogenative coupling with phenyl acetylene to afford [C₅H₅BN­(^<i>i</i>Pr)­CHN­(^<i>i</i>Pr)]­[C₅H₅BC­(C₂H₅)CH­(C₂H₅)]₂La (<b>6</b>) or [C₅H₅BN­(^<i>i</i>Pr)­CHN­(^<i>i</i>Pr)]­[C₅H₅BCCPh)]₂La (<b>7</b>)

Synthesis and Structure of Silicon-Bridged Boratabenzene Fluorenyl Rare-Earth Metal Complexes

A silicon-bridged boratabenzene fluorenyl ligand [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]^2– (<b>L</b>^2–) was designed and synthesized. By employment of this ligand, two divalent rare-earth metal complexes [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­Ln­(THF)₂ (Ln = Sm (<b>1</b>), Yb (<b>2</b>)) were obtained from salt metathesis of K₂[Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)] (<b>K</b>_<b>2</b><b>L</b>) with LnI₂­(THF)₂ in THF. Complex <b>2</b> undergoes redox reaction with cyclooctatetraene to give a trivalent Yb complex [(C₈H₈)­Yb]₂­[μ-{Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)}₂] (<b>3</b>), accompanied with oxidative coupling of two fluorenyl groups. A series of chloro-bridged trimeric trivalent rare-earth metal complexes [Li­(THF)₄]₂­[{[Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­Ln­(μ-Cl)­Li­(THF)₃}₃­(μ-Cl)₃­(μ₃-Cl)₂] (Ln = Nd (<b>4</b>), Sm (<b>5</b>), and Gd (<b>6</b>)) were synthesized by reactions of Li₂[Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)] (<b>Li</b>_<b>2</b><b>L</b>) with LnCl₃ in THF. Treatment of K₂[Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)] (<b>K</b>_<b>2</b><b>L</b>) with LnI₃(THF)_<i>n</i> gave the monomeric complexes [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­LnI­(THF) (Ln = La (<b>7</b>), Nd (<b>8</b>), Sm (<b>9</b>), and Gd (<b>10</b>)). These iodides were subsequently reacted with K­[CH₂C₆H₄-<i>o</i>-NMe₂] to afford THF coordinated benzyl complexes [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­Ln­(CH₂C₆H₄-<i>o</i>-NMe₂)­(THF) (Ln = La (<b>11</b>), Nd (<b>12</b>), and Gd (<b>13a</b>)) and non-THF coordinated complex [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­Gd­(CH₂C₆H₄-<i>o</i>-NMe₂) (<b>13b</b>)

Synthesis and Structure of Silicon-Bridged Boratabenzene Fluorenyl Rare-Earth Metal Complexes

A silicon-bridged boratabenzene fluorenyl ligand [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]^2– (<b>L</b>^2–) was designed and synthesized. By employment of this ligand, two divalent rare-earth metal complexes [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­Ln­(THF)₂ (Ln = Sm (<b>1</b>), Yb (<b>2</b>)) were obtained from salt metathesis of K₂[Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)] (<b>K</b>_<b>2</b><b>L</b>) with LnI₂­(THF)₂ in THF. Complex <b>2</b> undergoes redox reaction with cyclooctatetraene to give a trivalent Yb complex [(C₈H₈)­Yb]₂­[μ-{Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)}₂] (<b>3</b>), accompanied with oxidative coupling of two fluorenyl groups. A series of chloro-bridged trimeric trivalent rare-earth metal complexes [Li­(THF)₄]₂­[{[Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­Ln­(μ-Cl)­Li­(THF)₃}₃­(μ-Cl)₃­(μ₃-Cl)₂] (Ln = Nd (<b>4</b>), Sm (<b>5</b>), and Gd (<b>6</b>)) were synthesized by reactions of Li₂[Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)] (<b>Li</b>_<b>2</b><b>L</b>) with LnCl₃ in THF. Treatment of K₂[Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)] (<b>K</b>_<b>2</b><b>L</b>) with LnI₃(THF)_<i>n</i> gave the monomeric complexes [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­LnI­(THF) (Ln = La (<b>7</b>), Nd (<b>8</b>), Sm (<b>9</b>), and Gd (<b>10</b>)). These iodides were subsequently reacted with K­[CH₂C₆H₄-<i>o</i>-NMe₂] to afford THF coordinated benzyl complexes [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­Ln­(CH₂C₆H₄-<i>o</i>-NMe₂)­(THF) (Ln = La (<b>11</b>), Nd (<b>12</b>), and Gd (<b>13a</b>)) and non-THF coordinated complex [Me₂Si­(C₁₃H₈)­(C₅H₄BNEt₂)]­Gd­(CH₂C₆H₄-<i>o</i>-NMe₂) (<b>13b</b>)

MOESM1 of IL-33 reflects dynamics of disease activity in patients with autoimmune hemolytic anemia by regulating autoantibody production

Additional file 1: Figures. Gating strategy for anti-RBC antibody analysis, serum levels of sST2 in AIHA patients, Th2 cytokines in AIHA mice co-injected with IL-33 protein or IL-33 neutralizing antibody, B cell response to IL-33 stimulation or IL-33 blockade, and effect of IL-6 on IL-33-mediated autoantibody production were presented

MOESM1 of MicroRNA-125b promotes tumor metastasis through targeting tumor protein 53-induced nuclear protein 1 in patients with non-small-cell lung cancer

Additional file 1: Figure S1. Expressions of miR-125b and TP53INP1 in isolated NSCLC cells were determined by qPCR and analyzed for their negative correlation

¹⁸F‑Alanine Derivative Serves as an ASCT2 Marker for Cancer Imaging

Amino acids derivative are well established molecular probes for diagnosis of a variety of cancer using positron emission tomography (PET). Recently, boramino acid (BAAs) was found as a prospective molecular platform for developing PET tracer. The objective of this study was to develop a ¹⁸F-labeled alanine derivative through displacing its carboxylate by trifluoroborate as a selective ASCT2 marker for cancer imaging. ¹⁸F-Ala-BF₃ was first evaluated in healthy FVB/N mice <i>in vivo</i>, exhibiting rapid renal clearance with almost negligible uptake in stomach (1.53 ± 0.31%ID/g). Notable uptake was observed in thyroid (3.71 ± 0.49%ID/g, 40 min post injection), of which the uptake was significantly inhibited by co-injection with natural L-alanine. In addition, we further established ¹⁸F-Ala-BF₃ on a human gastric cancer cell (BGC-823) xenografts bearing mouse model. Dynamic PET-CT scan revealed the optimal time window for tumor imaging, it was between 40 and 60 min post injection, when the BGC-823 xenografts uptake was 5.49 ± 1.47%ID/g (<i>n</i> = 4), and the tumor-to-stomach, tumor-to-blood, tumor-to-muscle, and tumor-to-brain ratios were 3.27 ± 1.53, 3.80 ± 1.48, 3.47 ± 1.48, and 6.20 ± 1.47, respectively

Expression of hematopoietic surface markers in E8-10 (embryonic day 8–10) murine yolk sacs.

<p>Representative flow cytometric data from more than three independent analyses were shown.</p

Exposure to BQ upregulated Nrf2 protein expression and caused Nrf2 nuclear accumulation.

<p>Western Blot analysis of nuclear and cytoplasmic extracts from YS-HSCs treated with increasing concentrations of BQ for 6 hours. Histone H1 and GAPDH antibodies were used as loading controls for nuclear and cytoplasmic extracts, respectively. Left panels: representative blotting results. Densitometry of the immunoblotting results was shown in the right panels. Values are presented as means ± SDs (n = 3−5). * <i>P</i><0.05, **<i>P</i><0.01, # <i>P</i><0.001.</p

The ROS-generating NADPH oxidase NOX1 was induced by BQ.

<p>Immunoblotting data were shown in the upper panel. GAPDH was measured as loading control. Densitometry of immunoblotting results was shown in the lower panel. Values are presented as means ± SDs (n = 3−5). *, <i>P</i><0.05; **, <i>P</i><0.01; #, <i>P</i><0.001 compared with controls.</p

Increased expression of Nrf2-ARE pathway proteins were observed in the BQ-treated YS-HSCs.

<p>Induction of catalase, SOD1, SOD2, HMOX1 and NQO1 protein levels by BQ. Immunoblotting data were shown in the upper panel. GAPDH was measured as loading control. Densitometry of immunoblot results was shown in the lower panel. Values are presented as means ± SDs (n = 3−5). *, <i>P</i><0.05; **, <i>P</i><0.01; #, <i>P</i><0.001 compared with controls.</p