- Open-shell and antiaromatic character induced by the highly symmetric geometry of the planar heptalene structure: Synthesis and characterization of a nonalternant isomer of bisanthene
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A nonbenzenoid hydrocarbon, difluoreno-[1,9,8-alkj:1′,9′,8′-gfed]heptalene 1, is synthesized. Experimental and theoretical investigations demonstrate that the planar and symmetric heptalene core within 1 effectively induces the antiaromatic and open-shell character. These properties are not shared by bisanthene 2, a benzenoid isomer of 1.
- Konishi, Akihito,Horii, Koki,Shiomi, Daisuke,Sato, Kazunobu,Takui, Takeji,Yasuda, Makoto
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- Practical synthesis of an open geodesic polyarene with a fullerene-type 6:6-double bond at the center: Diindeno[1,2,3,4-defg;l′,2′,3′,4′-mnop]chrysene
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Diindeno[1,2,3,4-defg;l′,2′,3′,4′-mnop]chrysene (1), the smallest possible alkene-centered C60 substructure with a curved π-system, is obtained in 25-35% yield by flash vacuum pyrolysis of the twisted 1,1′-dibromobifluorenylidene (2) on a 100 mg scale at 1050 °C. At 1200 °C, the bowl-shaped hydrocarbon I rearranges to the planar isomer diindeno[5,6,7,1-defg;5′,6′,7′,1′-Imnop]chrysene (14) by a double 5/6 ring-expansion/ring-contraction. X-ray crystallography establishes that the central carbon atoms of 1 are nearly 80% as pyramidalized as the carbon atoms of C60 (POAV angles = 9.0° and 11.6° for 1 and C60, respectively). A four-step synthesis has been developed to prepare the pyrolysis precursor (2) as a mixture of (E)- and (Z)-isomers in 39% overall yield from commercially available 9-fluorenone-l-carboxylic acid (10).
- Bronstein, Hindy E.,Choi, Neil,Scott, Lawrence T.
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- Anticancer activity studies of novel metal complexes of ligands derived from polycyclic aromatic compound via greener route
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Methoxy and tert-butyl substituted carboxamide, carboxylic acid and hydrazone Schiff base groups have been assembled into our newly designed fluorenone based ligands and prepared coordination compounds of some first row transition metals and characterized thoroughly with spectroscopic (1H and 13C NMR, IR, GC–MS, UV–Vis), analytical, TGA and molar conductance measurements. The stoichiometry of all the metal complexes is found to be 1: 2 (M: L2) with the general formula, [M(L)2], where L is a singly deprotonated ligand and the geometry of all the metal complexes is found to be octahedral. Ligands and their metal complexes successfully cleaved the pBR322 plasmid DNA and in case of anticancer activity against MCF–7 (human breast adenocarcinoma) cell line, the synthesized compounds found to exhibit excellent activity with prominent apoptotic effect which is characterized by cell shrinkage, cell breakage and turgidity and results were compared with the standard drug cisplatin. Very significant anticancer activity was observed for compounds L1H, Cu(L1)2, Cu(L2)2, Ni(L1)2 and Ni(L2)2 with IC50 value of ?1. Molecular docking studies were performed to assess the bonding mode of synthesized compounds. In case of antioxidant activity study, the compounds L1H, Ni(L1)2, Ni(L2)2, Cu(L1)2 and Cu(L2)2 exhibited significant scavenging activity with good percentage when compared with remaining tested compounds.
- Hosakeri, Joy H.,Kinnal, Shivashankar M.,Kumbar, Mahantesh,Patil, Sangamesh A.,Shettar, Arun,Toragalmath, Shivakumar S.
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- Synthesis and biological evaluation of 9-fluorenone derivatives for SPECT imaging of α7-nicotinic acetylcholine receptor
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The α7-nicotinic acetylcholine receptor (α7-nAChR) subtype, is found to have a connection with the pathogenesis of a variety of psychiatric and neurological disorders. Herein, we report the development of radioiodinated 9-fluorenone derivatives as single-photon emission computed tomography (SPECT) imaging tracers for α7-nAChRs. Among the derivatives, the best member of the series 10 (Ki = 2.23 nM) were radiolabeled with 125I for in vitro and in vivo studies. The radiotracer [125I]10 exhibited robust brain uptake and specifically labeled α7-nAChRs with a peak uptake value of 9.49 ± 0.87%ID/g in brain. Blocking studies demonstrated that the tracer was highly specific toward α7-nAChR. Furthermore, ex vivo autoradiography and micro-SPECT/CT dynamic imaging in mice confirmed the excellent imaging properties. In addition, molecular docking was also performed to rationalize the potency of the chosen compounds towards α7-nAChRs. To conclude, compound 10 could serve as a promising radiotracer for the α7-nAChRs.
- Gao, Hang,Wang, Shuxia,Qi, Yueheng,He, Guoxue,Qiang, Bingchao,Wang, Sixuan,Zhang, Huabei
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- Design, synthesis and biological evaluation of 1,4-Diazobicylco[3.2.2]nonane derivatives as α7-Nicotinic acetylcholine receptor PET/CT imaging agents and agonists for Alzheimer's disease
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α7-Nicotinic acetylcholine receptor (α7-nAChR) agonists are promising therapeutic drug candidates for treating the cognitive impairment associated with Alzheimer's disease (AD). Thus, a novel class of derivatives of 1,4-diazobicylco[3.2.2]nonane has been synthesized and evaluated as α7-nAChR ligands. Five of them displayed high binding affinity (Ki = 0.001–25 nM). In particular, the Ki of 14 was 0.0069 nM, which is superior to that of the most potent ligand that was previously reported by an order of magnitude. Four of them had high selectivity for α7-nAChRs over α4β2-nAChRs and no significant hERG (human ether-a-go-go-related gene) inhibition. Their agonist activity was also discussed preliminarily. One of the compounds, 15 (Ki = 2.98 ± 1.41 nM), was further radiolabeled with 18F to afford [18F]15 for PET imaging, which exhibited high initial brain uptake (11.60 ± 0.14%ID/g at 15 min post injection), brain/blood value (9.57 at 30 min post injection), specific labeling of α7-nAChRs and fast clearance from the brain. Blocking studies demonstrated that [18F]15 was α7-nAChR selective. In addition, micro-PET/CT imaging in normal rats further indicated that [18F]15 had obvious accumulation in the brain. Therefore, [18F]15 was proved to be a potential PET radiotracer for α7-nAChR imaging.
- Wang, Shuxia,Fang, Yu,Wang, Huan,Gao, Hang,Jiang, Guohua,Liu, Jianping,Xue, Qianqian,Qi, Yueheng,Cao, Mengying,Qiang, Bingchao,Zhang, Huabei
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- Synthesis of novel metal (II) complexes tailored from 9-oxo-9H-fluorene-1-carboxylic acid via green protocol: DNA cleavage and anticancer studies
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Despite being a polycyclic aromatic compound, fluorenone is not classified as carcinogenic. Some of the derivatives of fluorenone and metal complexes embedded with fluorenone based ligands exhibited challenging biological activities, including anticancer activity. The current investigation hence focuses on synthesis, characterization and anticancer activities of fluorenone based ligands and their coordinate compounds of some first row transition metals. The stoichiometry of all the synthesized metal complexes is found to be 1: 2 (metal: ligand) with the general formula [M(L)2], L = singly deprotonated ligand, whereas the geometry of all the metal complexes is found to be octahedral. The synthesized ligands and their respective metal (II) complexes were found to cleave the pBR322 DNA, during gel electrophoresis studies. The inhibition of cancer cell growth has been confirmed by fluorescence imaging techniques using DAPI as staining dye. The IC50 values of ligands and their metal (II) complexes suggest that synthesized compounds are more active towards A549 (human lung adenocarcinoma) cell line when compared with the standard drug Paclitaxel. In case of MCF-7 (human breast carcinoma) cell line, compound Cu(L2)2 is found to be more active than the standard drug Paclitaxel.
- Kumbar, Mahantesh,Patil, Sangamesh A.,Toragalmath, Shivakumar S.,Jawoor, Shailaja S.,Shettar, Arun
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- Open-Shell and Antiaromatic Character Induced by the Highly Symmetric Geometry of the Planar Heptalene Structure: Synthesis and Characterization of a Nonalternant Isomer of Bisanthene
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A nonbenzenoid hydrocarbon, difluoreno[1,9,8-alkj:1′,9′,8′-gfed]heptalene 1, is synthesized. Experimental and theoretical investigations demonstrate that the planar and symmetric heptalene core within 1 effectively induces the antiaromatic and open-shell character. These properties are not shared by bisanthene 2, a benzenoid isomer of 1.
- Konishi, Akihito,Horii, Koki,Shiomi, Daisuke,Sato, Kazunobu,Takui, Takeji,Yasuda, Makoto
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p. 10165 - 10170
(2019/08/28)
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- Fluorenone ligand compounds of alpha7 nicotine acetylcholine receptor and application of compounds
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Embodiments of the invention provide fluorenone ligand compounds of an alpha7 nicotinic acetylcholine receptor. The compounds are represented by a formula (I) shown in the description, wherein X is a6-10 membered nitrogen-containing heterocyclic group, and the nitrogen-containing heterocyclic group is unsubstituted or substituted by C1-C4 alkyl; R1 is one selected from the group consisting of amino, nitro, halogen and halogen radioisotopes, and R2 is hydrogen, or the R1 is hydrogen and the R2 is one selected from the group consisting of the amino, the nitro, the halogen or the halogen radioisotopes; and when the X is a group represented in the description, the R1 and the R2 are not selected from the amino, fluorine and fluorine radioisotopes. The ligand compounds provided by the inventionhave higher affinity with the alpha7 nicotinic acetylcholine receptor, and are excellent ligand compounds of the alpha7 nicotinic acetylcholine receptor; and further, the ligand compounds of the alpha7 nicotinic acetylcholine receptor can be used as a PET imaging agent or a single-photon emission computed tomography (SPECT) imaging agent after being radiochemically labeled.
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Paragraph 0056-0060
(2019/08/12)
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- Ligand compound of alpha7 nicotinic acetylcholine receptor and application of ligand compound
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The embodiment of the invention provides a ligand compound of an alpha7 nicotinic acetylcholine receptor, the ligand compound has one of the following general formulas: wherein (1) X and R1 are shown in the description, and R7 is halogen; (2) R2 is hydrogen, and R3 is halogen or amino; or R3 is hydrogen, and R2 is halogen or amino; (3) R6 is hydrogen, and R4 and R5 are synthesized into a compound shown in the description; or R4 is hydrogen, and R5 and R6 are synthesized into a compound shown in the description; R8 is halogen; and (4) Y is nitrogen or carbon, Z is shown in the description, and R9 and R10 are respectively halogens. The provided ligand compound is an excellent ligand compound of the alpha7 nicotinic acetylcholine receptor. After being chemically marked radioactively, the provided ligand compound of the alpha7 nicotinic acetylcholine receptor can serve as a PET photographic developer.
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Paragraph 0072; 0073; 0074
(2017/10/09)
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- BENZOFLUORANTHENE COMPOUND AND ORGANIC LIGHT-EMITTING DEVICE USING THE COMPOUND
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There are provided a novel benzofluoranthene compound and an organic light-emitting device which uses the benzofluoranthene compound, gives a blue emission hue with extremely good purity, and has an optical output with a high efficiency, a high luminance, and a long life. Specifically, there are provided a benzofluoranthene compound represented by the general formula shown below and an organic light-emitting device including a pair of electrodes including an anode and a cathode one of which is a transparent or translucent electrode material, and an organic compound layer disposed between the pair of electrodes and including a material for an organic light-emitting device containing the benzofluoranthene compound. In the general formula (1), one of X1, X2, X3, X4, X5, and X6 represents a substituted or unsubstituted fused heterocyclic group having four or less rings, and the others of X1, X2, X3, X4, X5, and X6 each represent a hydrogen atom.
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Page/Page column 68
(2008/12/07)
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- Formation of cyclopent[a]indene and acenaphthylene from allyl esters of biphenyl mono- and di-carboxylic acids and from biphenyl dicarboxylic anhydrides on flash vacuum pyrolysis at 1000-1100°C
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Flash vacuum pyrolysis at 1000-1100°C of the allyl esters of the three isomeric biphenylcarboxylic acids, of the allyl esters of the 12 biphenyldicarboxylic acids and of the three biphenyldicarboxylic anhydrides gave pyrolysates which were examined by 1H n.m.r. spectroscopy at temperatures below -50°C. In all cases the spectra showed the presence of cyclopent[a]indene and acenaphthylene together with other products. Possible mechanisms for these ring contraction and cyclization processes are discussed and the results of pyrolyses of [2,3-13C2]biphenyl-2,3-dicarboxylic anhydride, and [3,4-13C2]-and (2-2H1)-biphenyl-3,4-dicarboxylic anhydrides are reported.
- Bapat, Jayant B.,Brown, Roger F.C.,Bulmer, Glenn H.,Childs, Trevor,Coulston, Karen J.,Eastwood, Frank W.,Taylor, Dennis K.
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p. 1159 - 1182
(2007/10/03)
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- Aspects of Tautomerism: Part X - Neighbouring Group Effects on the Structure and Reactivity Patterns of Acid Chlorides
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The influence of neighbouring groups on the structure and reactivity patterns of over one hundred acid chlorides derived from γ- and δ-keto acids, 1,2- and 1,3-dicarboxylic acid half-esters and diacid chlorides have been examined.Contrary to reports in the literature, text books and monographs, evidence has been obtained for the non-existence of tautomerism between the isomeric pairs of either acid chlorides or half-ester acid chlorides.ce.
- Bhatt, M. Vivekananda,El Ashry, Shaker H.,Somayaji, Vishwanatha
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p. 473 - 486
(2007/10/02)
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