Single Crystals of Insoluble Porous Salicylimine Cages.

Porous organic cages (POCs) are meanwhile an established class of porous materials. Most of them are soluble to a certain extend and thus processable in or from solution. However, a few of larger salicylimine cages were reported to be insoluble in any organic solvents and thus characterized as amorphous materials. These cages were now synthesized as single-crystalline materials to get insight into packing motifs and preferred intermolecular interactions. Furthermore, the pairs of crystalline and amorphous materials for each cage allowed to compare their gas-sorption properties in both morphological states.

Chiral Self-sorting of Giant Cubic [8+12] Salicylimine Cage Compounds.

Chiral self-sorting is intricately connected to the complicated chiral processes observed in nature and no artificial systems of comparably complexity have been generated by chemists. However, only a few examples of purely organic molecules have been reported so far, where the self-sorting process could be controlled. Herein, we describe the chiral self-sorting of large cubic [8+12] salicylimine cage compounds based on a chiral TBTQ precursor. Out of 23 possible cage isomers only the enantiopure and a meso cage were observed to be formed, which have been unambiguously characterized by single crystal X-ray diffraction. Furthermore, by careful choice of solvent the formation of meso cage could be controlled. With internal diameters of din =3.3-3.5 nm these cages are among the largest organic cage compounds characterized and show very high specific surface areas up to approx. 1500 m2 g-1 after desolvation.

Luminogens for Aggregation-Induced Emission via Titanium-Mediated Double Nucleophilic Addition to 2,5-Dialkynylpyridines: Formation and Transformation of the Emitting Aggregates.

Invited for the cover of this issue are Lutz H. Gade, Claudia Backes, and co-workers at Heidelberg University. The image depicts 2-(1,2,2-triarylvinyl)-pyridines, which are luminogens for aggregation-induced emission which "light up" upon irradiation. Read the full text of the article at 10.1002/chem.201905611.

Luminogens for Aggregation-Induced Emission via Titanium-Mediated Double Nucleophilic Addition to 2,5-Dialkynylpyridines: Formation and Transformation of the Emitting Aggregates.

New luminogens for aggregation-induced emission (AIE), which are characterized by a branched cross-conjugated 2,6-bis(1,2,2-triarylvinyl)pyridine motif, have been synthesized exploiting the one-pot Ti-mediated tetraarylation of 2,6-bis(arylethynyl)pyridines. Thin layer solid-state emitters were prepared by spin-coating of the luminogens, while AIE-colloidal dispersions were investigated in terms of optical density and scattering behaviour. This has given insight into particle size distributions, time evolution of the aggregation and the influence of different functionalization patterns on the luminescence of molecular aggregates. In particular, a combination of extinction spectroscopy and dynamic light scattering is being proposed as a powerful method for investigating the dynamic aggregation process in AIE-type colloids.

A Robust Porous Quinoline Cage: Transformation of a [4+6] Salicylimine Cage by Povarov Cyclization.

Porous shape-persistent organic cages have become the object of interest in recent years because they are soluble and thus processable from solution. A variety of cages can be achieved by applying dynamic covalent chemistry (DCC), but they are less chemically stable. Here the transformation of a salicylimine cage into a quinoline cage by a twelve-fold Povarov reaction as the key step is described. Besides the chemical stability of the cage over a broad pH regime, it shows a unique absorption and emission depending on acid concentration. Furthermore, thin films for the vapor detection of acids were investigated, showing color switches from pale-yellow to red, and characteristic emission profiles.

The Impact of Aggregation on the Photophysics of Spiro-Bridged Heterotriangulenes.

We report on the impact of the central heteroatom on structural, electronic, and spectroscopic properties of a series of spirofluorene-bridged heterotriangulenes and provide a detailed study on their aggregates. The in-depth analysis of their molecular structure by NMR spectroscopy and X-ray crystallography was further complemented by density functional theory calculations. With the aid of extensive photophysical analysis the complex fluorescence spectra were deconvoluted showing contributions from the peripheral fluorenes and the heteroaromatic cores. Beyond the molecular scale, we examined the aggregation behavior of these heterotriangulenes in THF/H2 O mixtures and analyzed the aggregates by static and dynamic light scattering. The excited-state interactions within the aggregates were found to be similar to those found in the solid state. A plethora of morphologies and superstructures were observed by scanning electron microscopy of drop-casted dispersions.

Transformation of a [4+6] Salicylbisimine Cage to Chemically Robust Amide Cages.

In recent years, interest in shape-persistent organic cage compounds has steadily increased, not least because dynamic covalent bond formation enables such structures to be made in high to excellent yields. One often used type of dynamic bond formation is the generation of an imine bond from an aldehyde and an amine. Although the reversibility of the imine bond formation is advantageous for high yields, it is disadvantageous for the chemical stability of the compounds. Amide bonds are, in contrast to imine bonds much more robust. Shape-persistent amide cages have so far been made by irreversible amide bond formations in multiple steps, very often accompanied by low yields. Here, we present an approach to shape-persistent amide cages by exploiting a high-yielding reversible cage formation in the first step, and a Pinnick oxidation as a key step to access the amide cages in just three steps. These chemically robust amide cages can be further transformed by bromination or nitration to allow post-functionalization in high yields. The impact of the substituents on the gas sorption behavior was also investigated.

Shape-Persistent [4+4] Imine Cages with a Truncated Tetrahedral Geometry.

The synthesis of shape-persistent organic cage compounds is often based on the usage of multiple dynamic covalent bond formation (such as imines) of readily available precursors. By careful choice of the precursors geometry, the geometry and size of the resulting cage can be accurately designed and indeed a number of different geometries and sizes have been realized to date. Despite of this fact, little is known about the precursors conformational rigidity and steric preorganization of reacting functional groups on the outcome of the reaction. Herein, the influence of conformational rigidity in the precursors on the formation of a [4+4] imine cage with truncated tetrahedral geometry is discussed.

Discrete Triptycene-Based Hexakis(metalsalphens): Extrinsic Soluble Porous Molecules of Isostructural Constitution.

In 2013 the concept of OMIMs (organic molecules of intrinsic microporosity) was introduced by McKeown et al. These OMIMs are constructed on the basis of rigid molecular cores such as triptycene, spirobifluorenes, and others. Like shape-persistent organic cages, these are soluble discrete molecules and therefore an interesting alternative to 3D, insoluble porous materials, such as metal-organic frameworks, covalent-organic frameworks, or zeolites. OMIMs are chemically and thermally robust because the formation of strong covalent bonds has been used for their synthesis. To date, a few OMIMs have been reported, though most of them did not contain any functional unit to enhance gas sorption properties. This work introduces an isostructural series of metal-salphene based OMIMs with different metal ions (Zn2+ , Ni2+ , Cu2+ , Pd2+ , and Pt2+ ) integrated into the backbone. The influence of the metal centers on interaction with gas molecules has been investigated by gas sorption experiments.

Shape-Persistent Tetrahedral [4+6] Boronic Ester Cages with Different Degrees of Fluoride Substitution.

In recent years the interest of shape-persistent organic cage compounds synthesized by dynamic covalent chemistry (DCC) has risen, because these cages are potentially interesting for gas sorption or -separation. One such reaction in DCC is the condensation of boronic acids with diols to form boronic esters. Most interestingly, the variety of geometries and sizes for boronic ester cages is much lower than that of, for example, imine-based cages. Here, a small series of shape-persistent [4+6] tetrahedral boronic ester cages is introduced. One cage has a high specific surface area of 511 m2 g-1 and selectively adsorbs ethane over ethylene and acetylene.

Identification of a Prognostic Gene Signature Based on Lipid Metabolism-Related Genes in Esophageal Squamous Cell Carcinoma.

Background: Dysregulation of lipid metabolism is common in cancer. However, the molecular mechanism underlying lipid metabolism in esophageal squamous cell carcinoma (ESCC) and its effect on patient prognosis are not well understood. The objective of our study was to construct a lipid metabolism-related prognostic model to improve prognosis prediction in ESCC. Methods: We downloaded the mRNA expression profiles and corresponding survival data of patients with ESCC from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. We performed differential expression analysis to identify differentially expressed lipid metabolism-related genes (DELMGs). We used Univariate Cox regression and least absolute shrinkage and selection operator (LASSO) analyses to establish a risk model in the GEO cohort and used data of patients with ESCC from the TCGA cohort for validation. We also explored the relationship between the risk model and the immune microenvironment via infiltrated immune cells and immune checkpoints. Results: The result showed that 132 unique DELMGs distinguished patients with ESCC from the controls. We identified four genes (ACAA1, ACOT11, B4GALNT1, and DDHD1) as prognostic gene expression signatures to construct a risk model. Patients were classified into high- and low-risk groups as per the signature-based risk score. We used the receiver operating characteristic (ROC) curve and the Kaplan-Meier (KM) survival analysis to validate the predictive performance of the 4-gene signature in both the training and validation sets. Infiltrated immune cells and immune checkpoints indicated a difference in the immune status between the two risk groups. Conclusion: The results of our study indicated that a prognostic model based on the 4-gene signature related to lipid metabolism was useful for the prediction of prognosis in patients with ESCC.

Highly Selective Adsorption of Perfluorinated Greenhouse Gases by Porous Organic Cages.

Anthropogenic greenhouse gases contribute to global warming. Among those gases, perfluorocarbons (PFCs) are thousands to tens of thousands of times more harmful to the environment than comparable amounts of carbon dioxide. To date, materials that selectively adsorb perfluorocarbons in favor of other less harmful gases have not been reported. Here, a series of porous organic cage compounds with alkyl-, fluoroalkyl-, and partially fluorinated alkyl groups is presented. Their isomorphic crystalline states allow the study of the structure-property relationship between the degree of fluorination of the alkyl chains and the gas sorption properties for PFCs and their selective uptakes in comparison to other, nonfluorinated gases. By this approach, one compound having superior selectivities of PFCs versus N2 or CO2 under ambient conditions is identified.

[The Effect and Mechanism of Novel Telomerase Inhibitor Nilo 22 on Leukemia Cells].

OBJECTIVE: To investigate the cytotoxic effect and its mechanism of the micromolecule compound on the leukemia cells. METHODS: The cytotoxic effects of 28 Nilotinib derivatives on K562, KA, KG, HA and 32D cell lines were detected by MTT assays, and the compound Nilo 22 was screen out. Cell apoptosis and cell cycle on leukemia cells were detected by flow cytometry. The effect of compound screened out on leukemogenesis potential of MLL-AF9 leukemia mice GFP+ cells was tested by colony-forming units assays (CFU). The cytotoxic effect was further detected by transplant assays ex vivo. Telomerase activity assay, C-circle assay were used to measure the effects of compound on the length mechanism of telomere, RT-PCR was used to detected the changes of telomere. RESULTS: Nilo 22 serves as the most outstanding candidate out of 28 Nilotinib derivatives, which impairs leukemia cell lines, but spares normal hematopoietic cell line. Comparing with Nilotinib, Nilo 22 could induce the apoptosis of GFP+ cells significantly, slightly arrests the cell cycle at G0/G1 phase, and significantly inhibits colony formation and prolong the progression in MLL-AF9 leukemia mice model. The expression showed that the compound could slow the disease progression in MLL-AF9 leukemia mice significantly. Mechanistically, Nilo 22 could reduce the length of telomere by inhibiting telomerase activity and alternative lengthening of telomere (ALT). CONCLUSION: Nilo 22 shows a significant cytotoxic effect on mice and human leukemia cells, especially for drug resistance cells. Nilo 22 is a promising anti-leukemia agent to solve the common clinical problems of drug resistance and relapse of leukemia.

[Screening and Verification of Antioxidant Small Molecular Compounds for Expansion of Human Hematopoietic Stem Cells Ex Vitro].

OBJECTIVE: To screen the antioxidant small molecular compounds with optimal efficiency of expansing the human hematopoietic stem cells (hHSC) In vitro based on antioxidant small molecular compound database of LKT laboratory, and to verify the effects of these compounds on the biological functions of hHSC. METHODS: The umbilial cord blood CD34+ cells were enriched by using the MACS beads; the absolute number and percentage of CD34+ cells and CD34+ CD49f+ cells were detected by high throughput flow cytometry after culture of hHSC with compounds in vitro for 1 week, the SR1 (1 µmol/L) was used as positive control, the candidate compounds were screened out; then 4 compounds were selected for follow-up experiments by comprehensive evaluation of concentration, safety and expansion efficacy, the optimal used concentrations of selected compounds were determined through the concentration gradient analysis, and CFC short-term colony-forming cell test was performed by using the determined concentration so as to verify the effect of compounds on the self-renewal, multilineage differentiation. RESULTS: Out of 85 antioxidant small molecular compounds, 4 compounds (C2968, D3331, B1753 and B3358) with obvious expansion efficacy for CD34+ cells and CD34+ CD49f+ cells were screened out by high throughput flow cytometry; their optimal concentrations of 4 compounds were 0.5 µmol/L for C2968, 1.5 µmol/L for D3331 and 1.5 µmol/L for B1753 and 15 µmol/L for B3358. The CFC assay showed the colony formation number in compound-treated group significantly increased as compared with control group, moreover the self-renewal and multilineage differentiation were maintained. CONCLUSION: The antioxidant small molecular compounds C2968 (0.5 µmol/L), D3331 (1.5 µmol/L), B1753 (1.5 µmol/L) and B3358 (1.5 µmol/L) possess good expansion efficacy for hHSC, they can maintain hHSC self-renewal, at the same time ensure the multilineage differentiation potentiality of hHSC.

Transforming a chemically labile [2+3] imine cage into a robust carbamate cage.

The synthesis of a highly acid and base-stable shape-persistent porous carbamate cage is presented. This cage is stable even in hot (100 °C) 1 M hydrochloric acid (pH = 0) or in concentrated hydrochloric acid (pH = -1) at room temperature without decomposition.

[Clinical manifestation of Kaposi sarcoma in otorhinolaryngology head and neck surgery].

OBJECTIVE: To improve the knowledge of Kaposi sarcoma and the relationship between Kaposi sarcoma and human immunodeficiency virus (HIV) infection, and to improve the ability to diagnose and treat Kaposi sarcoma and acquired immune deficiency syndrome (AIDS). METHODS: Symptoms, signs and results of 121 patients encountered in the department of otorhinolaryngology head and neck surgery in Tanzania, who was diagnosed as Kaposi sarcoma actually with HIV infection and AIDS, were retrospectively analyzed in this study. RESULTS: There were 46 males and 75 females with age ranged from 5 to 65 years, medium 30 year. The mucous membranes and skin lesions was the most commonly seen clinical manifestation in 121 cases, these lesions appeared as raised blotches or lumps that might be purple, brown, or red, early stages typical lesions began as flat or slightly raised colored spots. Among the cases reported here, 25 patients (20.66%) showed progressive nose blockage and nose bleeding and the purple-red new-grows were found in the nose of these patients. Fifteen patients (12.40%) had flat or slightly raised colored spots in their mucous membrane of mouth (palate or tongue), and in other 7 patients, purple small lumps were found in the gums of the patients. There were same lesions in their pharynx in 9 cases. In 10 patients (8.26%), Kaposi sarcoma was found in tonsil looked like tonsillitis with enlarged tonsils by two to three degree. Twelve patients (9.92%) had masses in the neck with no pain. Thirty-five patients (28.92%)had lesions of purple black nodules, including 10 patients who had the same lesions with ulcer formation in the nodules. All patients had been followed-up for at least two-years. Eighty-five patients passed away in one year, survival rate of one year was 21.48% (26/121), only 12 patients survived from the disease over two years, two years' survival rate was 9.92% (12/121). CONCLUSIONS: Kaposi sarcoma is the characteristic disease for AIDS, mainly found on the membranes and skin. These lesions appears as raised blotches or lumps that may be purple, brown, or red, early stages typical lesions begin as flat or slightly raised colored spots. Patients who had kaposi sarcoma often died in a short-time without treatment.

[Clinical manifestation of HIV infection and AIDS in otorhinolaryngology head and neck surgery].

OBJECTIVE: To improve the recognition of clinical manifestation of human immunodeficiency virus(HIV) infection and acquired immunodeficiency syndrome (AIDS) in otorhinolaryngology head and neck surgery, and to emphasize the early diagnosis, correct treatment and effective protection. METHODS: Fifty-five patients with HIV infection and AIDS encountered in the department of otorhinolaryngology head and neck surgery in Tanzania were included in this study. There were 23 males and 32 female with age ranged from 3 - 67 years, medium 31 year. The clinical manifestation and prognosis of the patients were analyzed and summed up. RESULTS: Parotid glands swelling was the most commonly seen clinical manifestation in the 55 cases. Among the cases reported here, 17 (30.9%) showed parotid glands swelling, 19 (34.5%) had Kaposi's sarcoma in nasal cavity or oral cavity or pharynx, 12(21.8%) were accompanied with chronic suppurative otitis media, 11 (20.0%) had masses in the neck, 7 (12.7%) had masses in the pharynx, 6 (10.9%) were seen to have ulcer in oral and pharyngeal mucosa, 2 (3.6%) showed infection due to candidaalbicans. The infection in most cases could be controlled and symptoms relieved, but recurrence could occur over time and got worse gradually. CONCLUSIONS: Many patients with HIV infection and AIDS first see a doctor in otorhinolaryngology head and neck surgery. Patients who had the above clinical manifestations in repeated poor results should be observed carefully, early diagnosis and treatment are important to prevent transmission, prolong life and maximize the quality of life of the patients.