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A Switchable Palladium(II) Trefoil Entangled Tetrahedron with Temperature Dependence and Concentration Independence. Angew Chem Int Ed Engl 2022; 61:e202210476. [PMID: 35922393 PMCID: PMC9805230 DOI: 10.1002/anie.202210476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Indexed: 01/09/2023]
Abstract
Self-assembly makes metallo-interlocked architectures attractive targets, but being in equilibrium with smaller species means that they can suffer from dilution effects. We show that a junctioned system gives rise to a [Pd4 (L)2 ]8+ trefoil entangled tetrahedron irrespective of concentration. Heating the sample reversibly shifts the equilibrium from the knot to an isomeric non-interlocked dual metallo-cycle, demonstrating that thermodynamic equilibria can still be exploited for switching even in the absence of concentration effects.
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2
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Roles of Metal Ions in Foldamers and Other Conformationally Flexible Supramolecular Systems. ACS ORGANIC & INORGANIC AU 2022; 2:464-476. [PMID: 36855532 PMCID: PMC9955367 DOI: 10.1021/acsorginorgau.2c00021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 08/04/2022] [Accepted: 08/08/2022] [Indexed: 11/28/2022]
Abstract
Conformational control is a key prerequisite for much molecular function. As chemists seek to create complex molecules that have applications beyond the academic laboratory, correct spatial positioning is critical. This is particularly true of flexible systems. Conformationally flexible molecules show potential because they resemble in many cases naturally occurring analogues such as the secondary structures found in proteins and peptides such as α-helices and β-sheets. One of the ways in which conformation can be controlled in these molecules is through interaction with or coordination to metal ions. This review explores how secondary structure (i.e., controlled local conformation) in foldamers and other conformationally flexible systems can be enforced or modified through coordination to metal ions. We hope to provide examples that illustrate the power of metal ions to influence this structure toward multiple different outcomes.
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A Switchable Palladium(II) Trefoil Entangled Tetrahedron with Temperature Dependence and Concentration Independence. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202210476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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4
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Ferrocene Rotary Switches Featuring 2‐Pyridyl‐1,2,3‐triazole “Click” Chelates. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202100948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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5
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Can 2-Pyridyl-1,2,3-triazole "Click" Ligands be Used to Develop Cu(I)/Cu(II) Molecular Switches? ACS OMEGA 2021; 6:30115-30129. [PMID: 34778683 PMCID: PMC8582268 DOI: 10.1021/acsomega.1c04977] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 10/15/2021] [Indexed: 06/13/2023]
Abstract
Molecular switching processes are important in a range of areas including the development of molecular machines. While there are numerous organic switching systems available, there are far less examples that exploit inorganic materials. The most common inorganic switching system remains the copper(I)/copper(II) switch developed by Sauvage and co-workers over 20 years ago. Herein, we examine if bidentate 2-(1-benzyl-1H-1,2,3-triazol-4-yl)pyridine (pytri) and tridentate 2,6-bis[(4-phenyl-1H-1,2,3-triazol-1-yl)methyl]pyridine (tripy) moieties can be used to replace the more commonly exploited polypyridyl ligands 2,2'-bypyridine (bpy)/1,10-phenanthroline (phen) and 2,2';6',2″-terpyridine (terpy) in a copper(I)/(II) switching system. Two new ditopic ligands that feature bidentate (pytri, L1 or bpytri, L2) and tridentate tripy metal binding pockets were synthesized and used to generate a family of heteroleptic copper(I) and copper(II) 6,6'-dimesityl-2,2'-bipyridine (diMesbpy) complexes. Additionally, we synthesized a series of model copper(I) and copper(II) diMesbpy complexes. A combination of techniques including nuclear magnetic resonance (NMR) and UV-vis spectroscopies, high-resolution electrospray ionization mass spectrometry, and X-ray crystallography was used to examine the behavior of the compounds. It was found that L1 and L2 formed [(diMesbpy)Cu(L1 or L2)]2+ complexes where the copper(II) diMesbpy unit was coordinated exclusively in the tridenate tripy binding site. However, when the ligands (L1 and L2) were complexed with copper(I) diMesbpy units, a complex mixture was obtained. NMR and MS data indicated that a 1:1 stoichiometry of [Cu(diMesbpy)]+ and either L1 or L2 generated three complexes in solution, the dimetallic [(diMesbpy)2Cu2(L1 or L2)]2+ and the monometallic [(diMesbpy)Cu(L1 or L2)]+ isomers where the [Cu(diMesbpy)]+ unit is coordinated to either the bidentate or tridentate tripy binding sites of the ditopic ligands. The dimetallic [(diMesbpy)2Cu2(L1 or L2)](PF6)2 complexes were structurally characterized using X-ray crystallography. Both complexes feature a [Cu(diMesbpy)]+ coordinated to the bidentate (pytri or bpytri) pocket of the ditopic ligands (L1 or L2), as expected. They also feature a second [Cu(diMesbpy)]+ coordinated to the nominally tridentate tripy binding site in a four-coordinate hypodentate κ2-fashion. Competition experiments with model complexes showed that the binding strength of the bidentate pytri is similar to that of the κ2-tripy ligand, leading to the lack of selectivity. The results suggest that the pytri/tripy and bpytri/tripy ligand pairs cannot be used as replacements for the more common bpy/phen-terpy partners due to the lack of selectivity in the copper(I) state.
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Self-Assembly of a Redox Active, Metallosupramolecular [Pd 3 L 6 ] 6+ Complex Using a Rotationally Flexible Ferrocene Ligand. Chem Asian J 2020; 16:39-43. [PMID: 33251757 DOI: 10.1002/asia.202001277] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 11/24/2020] [Indexed: 11/08/2022]
Abstract
A new ferrocene-containing [Pd3 (L4EFc )6 ]6+ (X- )6 (C ⋅ BF4 and C ⋅ SbF6 where X=BF4 - or SbF6 - ) self-assembled double-walled triangle has been synthesized from the known, rotationally flexible, 1,1'-bis(4-pyridylethynyl)ferrocene ligand (L4EFc ), and characterized by 1 H, 13 C and diffusion ordered (DOSY) NMR spectroscopies, high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), X-ray crystallography and cyclic voltammetry (CV). The molecular structures confirmed that double-walled triangle cage systems (C ⋅ BF4 and C ⋅ SbF6 ) were generated. C ⋅ BF4 was shown to interact with the anionic guest, p-toluenesulfonate. CV experiments revealed that the triangles were redox active, however addition of the guest did not influence the redox potentials.
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7
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A Reduced‐Symmetry Heterobimetallic [PdPtL
4
]
4+
Cage: Assembly, Guest Binding, and Stimulus‐Induced Switching. Angew Chem Int Ed Engl 2020; 59:11101-11107. [DOI: 10.1002/anie.202003220] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Indexed: 12/16/2022]
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8
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A Reduced‐Symmetry Heterobimetallic [PdPtL
4
]
4+
Cage: Assembly, Guest Binding, and Stimulus‐Induced Switching. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202003220] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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9
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Planar 2‐Pyridyl‐1,2,3‐triazole Derived Metallo‐ligands: Self‐assembly with PdCl2and Photocatalysis. Chem Asian J 2020; 15:1567-1573. [DOI: 10.1002/asia.202000284] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 03/24/2020] [Indexed: 12/12/2022]
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10
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Long-lived MLCT states for Ru(ii) complexes of ferrocene-appended 2,2'-bipyridines. Dalton Trans 2019; 48:15713-15722. [PMID: 31549707 DOI: 10.1039/c9dt02025j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study, we present two ruthenium(ii) diimine complexes appended with ferrocene which show metal to ligand charge transfer 3MLCT emission lifetimes around 630 ns. We also present a similar complex with two ferrocene units which has decreased emission. These complexes have been studied by electrochemical, electronic absorption, and Raman, resonance Raman and transient resonance Raman means, coupled with density functional theoretical approaches. For these systems, the optical spectra are dominated by a low energy ruthenium(ii) MLCT transition; which can be modulated by the presence of pendant ferrocene units and the extent of conjugation of the ferrocenyl bipyridine backbone. Tuning of the lowest energy transition in terms of intensity (4 to 18 × 10-3 M-1 cm-1) and energy (535 to 563 nm) was achieved by these means.
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11
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Redox active [Pd 2L 4] 4+ cages constructed from rotationally flexible 1,1'-disubstituted ferrocene ligands. Chem Commun (Camb) 2019; 55:7506-7509. [PMID: 31187814 DOI: 10.1039/c9cc03321a] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Two new ferrocene-containing [Pd2(LFc)4]4+(X-)4 (where X- = BF4- or SbF6-) self-assembled cages (C·BF4 and C·SbF6) were synthesised from the known, rotationally flexible, 1,1'-bis(3-pyridylethynyl)ferrocene ligand (LFc), and characterised by 1H, 13C and diffusion ordered (DOSY) NMR and UV-visible absorption spectroscopies, high resolution electrospray ionisation mass spectrometry (HR-ESI-MS), elemental analysis, X-ray crystallography and cyclic voltammetry (CV). The molecular structures confirmed that cage-like systems (C·BF4 and C·SbF6) were generated. Similar to related [Pd2L4]4+(X-)4, C·SbF6 was able to interact with a range of neutral and anionic guests, with p-toluenesulfonate showing the strongest association constant. Cyclic voltammetry studies revealed that the cage systems were redox active. However, the redox potential of the cage was unperturbed upon the addition of guests.
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12
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Synthesis, Characterisation and Antimicrobial Studies of some 2,6‐
bis
(1,2,3‐Triazol‐4‐yl)Pyridine Ruthenium(II) “Click” Complexes. ASIAN J ORG CHEM 2019. [DOI: 10.1002/ajoc.201900088] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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13
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Recognition Properties and Self‐assembly of Planar [M(2‐pyridyl‐1,2,3‐triazole)2]2+Metallo‐ligands. Chem Asian J 2018; 14:1136-1142. [DOI: 10.1002/asia.201801132] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Indexed: 11/11/2022]
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14
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Synthesis and Light-Induced Actuation of Photo-Labile 2-Pyridyl-1,2,3-Triazole Ru(bis-bipyridyl) Appended Ferrocene Rotors. Molecules 2018; 23:E2037. [PMID: 30110981 PMCID: PMC6222349 DOI: 10.3390/molecules23082037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 08/09/2018] [Accepted: 08/09/2018] [Indexed: 11/16/2022] Open
Abstract
To realise useful control over molecular motion in the future an extensive toolbox of both actionable molecules and stimuli-responsive units must be developed. Previously, our laboratory has reported 1,1'-disubstituted ferrocene (Fc) rotor units which assume a contracted/π-stacked conformation until complexation of cationic metal ions causes rotation about the Ferrocene (Fc) molecular 'ball-bearing'. Herein, we explore the potential of using the photochemical ejection of [Ru(2,2'-bipyridyl)₂]2+ units as a stimulus for the rotational contraction of new ferrocene rotor units. Fc rotors with both 'regular' and 'inverse' 2-pyridyl-1,2,3-triazole binding pockets and their corresponding [Ru(2,2'-bipyridyl)₂]2+ complexes were synthesised. The rotors and complexes were characterised using nuclear magnetic resonance (NMR) and ultraviolet (UV)-visible spectroscopies, Electro-Spray Ionisation Mass Spectrometry (ESI⁻MS), and electrochemistry. The 1,1'-disubstituted Fc ligands were shown to π-stack both in solution and solid state. Density Functional Theory (DFT) calculations (CAM-B3LYP/6-31G(d)) support the notion that complexation to [Ru(2,2'-bipyridyl)₂]2+ caused a rotation from the syn- to the anti-conformation. Upon photo-irradiation with UV light (254 nm), photo-ejection of the [Ru(2,2'-bipyridyl)₂(CH₃CN)₂]2+ units in acetonitrile was observed. The re-complexation of the [Ru(2,2'-bipyridyl)₂]2+ units could be achieved using acetone as the reaction solvent. However, the process was exceedingly slowly. Additionally, the Fc ligands slowly decomposed when exposed to UV irradiation meaning that only one extension and contraction cycle could be completed.
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Metallosupramolecular Architectures Formed with Ferrocene-Linked Bis-Bidentate Ligands: Synthesis, Structures, and Electrochemical Studies. Inorg Chem 2018; 57:3602-3614. [PMID: 29381330 DOI: 10.1021/acs.inorgchem.7b02503] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The self-assembly of ligands of different geometries with metal ions gives rise to metallosupramolecular architectures of differing structural types. The rotational flexibility of ferrocene allows for conformational diversity, and, as such, self-assembly processes with 1,1'-disubstituted ferrocene ligands could lead to a variety of interesting architectures. Herein, we report a small family of three bis-bidentate 1,1'-disubstituted ferrocene ligands, functionalized with either 2,2'-bipyridine or 2-pyridyl-1,2,3-triazole chelating units. The self-assembly of these ligands with the (usually) four-coordinate, diamagnetic metal ions Cu(I), Ag(I), and Pd(II) was examined using a range of techniques including 1H and DOSY NMR spectroscopies, high-resolution electrospray ionization mass spectrometry, X-ray crystallography, and density functional theory calculations. Additionally, the electrochemical properties of these redox-active metallosupramolecular assemblies were examined using cyclic voltammetry and differential pulse voltammetry. The copper(I) complexes of the 1,1'-disubstituted ferrocene ligands were found to be coordination polymers, while the silver(I) and palladium(II) complexes formed discrete [1 + 1] or [2 + 2] metallomacrocyclic architectures.
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17
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An appraisal of the management of spina bifida cystica. DEVELOPMENTAL MEDICINE AND CHILD NEUROLOGY. SUPPLEMENT 2008; 20:86-90. [PMID: 4905069 DOI: 10.1111/j.1469-8749.1969.tb09252.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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18
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Abstract
The structure of a new triterpenoid saponin, frondoside D, isolated from Cucumaria frondosa has been determined principally by high field 1D and 2D NMR and FAB-MS spectrometry. Frondoside D was shown to be 3 beta-[3-O-methyl-O-beta-D-glucopyranosyl-(1-3)-O-beta-D- xylopyranosyl-(1-4)-[O-beta-D-xylopyranosyl-(1-2)]-O-beta-D- quinovopyranosyl-(1-2)-O-beta-D-4-sulfonatoxylo-pyranosyl]-1 6 beta-acetoxy-23S-hydroxy-holost-7-ene, sodium salt.
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19
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Bioactive isocoumarins and related metabolites from conifer endophytes. JOURNAL OF NATURAL PRODUCTS 1995; 58:1759-1766. [PMID: 8594154 DOI: 10.1021/np50125a021] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Six new [1-4, 7, 9] and two known [6 and 8] metabolites have been isolated from culture filtrates of conifer endophyte strains of Canoplea elegantula. Their structures have been determined by spectroscopic means. Compound 1 was toxic to spruce budworm cells, and both 1 and 3 were toxic to spruce budworm larvae.
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20
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Quantitative differences in the histology of the attachment zones of the meniscal horns in the knee joint of man. J Anat 1991; 177:127-34. [PMID: 1769887 PMCID: PMC1260420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The attachment zones of the meniscal horns of 7 dissecting room cadavers were examined by routine histology. All the knees were devoid of gross pathological change and no discoid menisci were included. Significant differences are reported in the thickness of the zones of uncalcified fibrocartilage and cortical calcified tissue (calcified fibrocartilage and underlying lamellar bone) and in the percentage of bone:bone marrow. There was a thicker zone of uncalcified fibrocartilage and a greater quantity of calcified tissue at the horns of the lateral than the medial meniscus. The differences in uncalcified fibrocartilage were largely attributable to the posterior horns, but the variations in calcified tissue mainly reflected differences between the anterior horns. It is suggested that the greater mobility of the lateral meniscus and the blending of its anterior horn with the anterior cruciate ligament are important factors accounting for the quantitative differences in the meniscal attachment zones.
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Abstract
Nine 5 alpha, 8 alpha-epidioxy delta 6 and delta 6,9(11) sterols were identified including the hitherto unknown (22E)-5,8-epidioxy-5 alpha, 8 alpha-stigmasta-6,9(11),22-trien-3 beta-ol 9 from the sea anenome Metridium senile based on 200 MHz 1Hnmr and mass spectral data.
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22
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Antibacterial constituents of the diatom Navicula delognei. JOURNAL OF NATURAL PRODUCTS 1984; 47:815-818. [PMID: 6512534 DOI: 10.1021/np50035a010] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The novel ester (E)-phytol (5Z,8Z,11Z,14Z,17Z)-eicosapentaenoate++ + (1); (6Z,9Z,12Z,15Z)-hexadecatetraenoic acid; (6Z,9Z,12Z,15Z)-octadecatetraenoic acid; and (6Z,9Z,12Z)-hexadecatrienoic acid isolated from the diatom Navicula delognei f. elliptica, show significant antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis, Salmonella typhimurium, and Proteus vulgaris. beta-Carotene, alpha-cryptoxanthin, fucoxanthin, lutein, trans-phytol, and plastoquinone-9 were also isolated from this diatom.
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23
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Islet organ, blood glucose and glucose tolerance of lean and obese Mongolian gerbils. A quantitative study. Cell Tissue Res 1981; 220:623-36. [PMID: 7028271 DOI: 10.1007/bf00216765] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Gerbils were divided, on the basis of body weight, into obese (greater than 80 gms) and lean (less than 80 gms) groups. Fasting blood glucose estimations on all 31 gerbils, and glucose tolerance tests on 9 lean and 6 obese animals, were carried out. All lean and some obese gerbils were normoglycaemic and other obese were hyperglycaemic. All obese gerbils exhibited glucose intolerance. General morphological studies were undertaken as follows: (i) assessment of mesenteric fat deposits, (ii) measurement of anterior abdominal wall thickness, (iii) ratio of animal length to width at specified loci (index of shape). The degree of obesity was less than previously reported in this species though blood glucose abnormality was comparable. The index of animal shape showed a strong correlation with body weight. The following kinds of histological observation were made on pancreases from 4 lean and 4 obese gerbils: (i) % islet representation, (ii) islet size distribution, (iii) beta-cell granularity, (iv) islet vascularity, (v) islet/duct association, (vi) proportions of alpha- and D-cells, (vii) glycogen deposition in islet and duct cells. The pancreases of obese gerbils contained a higher proportion of islet tissue than those of lean due to generally larger islets: this hyperplasia was mainly attributable to beta-cell proliferation. Many obese gerbil islets exhibited hyperaemia and beta-cell degranulation. There was no evidence of glycogen deposition.
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Histology and cytology of the islets of Langerhans in the Mongolian gerbil (Meriones unguiculatus). ACTA ANATOMICA 1980; 108:446-62. [PMID: 6168162 DOI: 10.1159/000145344] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The histology and cell types of the islets of Langerhans were studies in the Mongolian gerbil during post-natal development using granule stains, fluorescence methods and electron microscopy. Relative islet volume, islet size distribution, islet-duct association, islet-fat association, alpha- and D cell populations and the size distribution of secretion granules in islet cells were quantified. In adult gerbils islets have an elliptical profile enclosed by a thin collagenous capsule, a central core of beta-cells, a peripheral shell of alpha-cells and an incomplete layer of D cells between. In animals of 1 week or less, islets lack a capsule, are poorly vascularized and not innervated, though alpha, beta- and D cells are present. alpha-Cells exhibit green fluorescence during these early stages that disappears when adrenergic nerve fibres grow into the islets. Electron microscopy shows a fourth (unidentified) granular islet cell type, and small granular cells, that probably correspond to intensely fluorescent cells, were found within islets and neuroinsular complexes.
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Revised consultant contract. BRITISH MEDICAL JOURNAL 1979; 2:1371. [PMID: 519469 PMCID: PMC1597372 DOI: 10.1136/bmj.2.6201.1371-c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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26
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Points from letters: Action by consultants. West J Med 1976. [DOI: 10.1136/bmj.2.6033.481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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27
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Growth changes in the mandible of the ox. ACTA ANATOMICA 1974; 88:125-36. [PMID: 4838370 DOI: 10.1159/000144230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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28
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A combined biochemical and histological study on the islets of Langerhans in the genetically obese hyperglycaemic mouse and the lean mouse, including observations on the effects of streptozotocin treatment. J Endocrinol 1973; 56:571-83. [PMID: 4266834 DOI: 10.1677/joe.0.0560571] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
SUMMARY
The biochemical parameters of blood glucose, serum insulin and pancreatic insulin and glucagon were determined after single injections of the diabetogenic agent streptozotocin and in untreated animals from a strain of genetically obese mice and their lean litter-mates. Histological observations on α and β islet cells were also made in these animals by employing the phosphotungstic acid—haematoxylin and aldehyde—fuchsin staining techniques.
In untreated obese mice, endocrine hyperactivity was indicated by the presence of exceptionally large, highly vascular islets and by duct cell-islet metaplasia.
After streptozotocin injection, approximately half of the lean mice showed extensive β-cell necrosis and these animals became hyperglycaemic and hypoinsulinaemic with a much reduced pancreatic insulin over a long term. The remaining treated lean mice, whose biochemical parameters did not differ significantly from normal, showed little or no evidence of islet damage. The response of obese mice to streptozotocin treatment was less clear-cut than that of lean animals. Essentially similar histological changes were observed, though these were not consistently correlated with biochemical data. There was histological and biochemical evidence of islet cell recovery from the effects of the drug both in lean and in obese mice, and in all hyperglycaemic animals with initial severe islet damage a marked α-cell response was observed, namely an increased proportion of α cells and their random deployment throughout the islets.
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30
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Synthesis of a flavipucine reduction product. JOURNAL OF THE CHEMICAL SOCIETY. PERKIN TRANSACTIONS 1 1972; 23:2962-3. [PMID: 4675918 DOI: 10.1039/p19720002962] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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31
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Flavipucine (3'-isovaleryl-6-methylpyridine-3-spiro-2'-oxiran-2(1H),-4(3H)-dione), an antibiotic from Aspergillus flavipes. JOURNAL OF THE CHEMICAL SOCIETY. PERKIN TRANSACTIONS 1 1972; 16:2071-4. [PMID: 4627703 DOI: 10.1039/p19720002071] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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32
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Increased insulin output following stimulation of the vagal supply to the perfused rabbit pancreas. J Anat 1969; 104:580. [PMID: 5804568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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33
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The use of tetracyclines for measuring mandibular growth in the rat. ACTA ANATOMICA 1969; 72:263-75. [PMID: 5802815 DOI: 10.1159/000143251] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Cytology of beta-cells in rabbit pancreas pieces incubated in vitro; Effects of glucose and tolbutamide. Diabetologia 1968; 4:150-60. [PMID: 4902711 DOI: 10.1007/bf01219436] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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A synthetic attractant for the male spruce budworm moth Choristoneura fumiferana (Clem.). EXPERIENTIA 1967; 23:377-8. [PMID: 6065778 DOI: 10.1007/bf02144526] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Similar structural bases for the storage and release of secretory material in adreno-medullary and beta-pancreatic cells. ZEITSCHRIFT FUR ZELLFORSCHUNG UND MIKROSKOPISCHE ANATOMIE (VIENNA, AUSTRIA : 1948) 1966; 74:317-24. [PMID: 5986584 DOI: 10.1007/bf00401260] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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