Selective Reduction of Peptidic Ergot Alkaloids

2000 ◽  
Vol 65 (11) ◽  
pp. 1762-1776 ◽  
Author(s):  
Ladislav Cvak ◽  
Josef Stuchlík ◽  
Magdalena Schreiberová ◽  
Petr Sedmera ◽  
Vladimír Havlíček ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Ergot Alkaloids ◽  
Selective Reduction ◽  
Lithium Aluminium Hydride ◽  
Lithium Aluminium ◽  
New Compounds ◽  
Representative Member

Five 6'-deoxoergopeptines were prepared in 51-68% yield by selective reduction of parent alkaloids with lithium aluminium hydride in tetrahydrofuran at low temperature. New compounds were characterized by mass spectrometry and NMR spectroscopy. The conformation of the peptide part in starting compounds and reduced derivatives is discussed on the basis of crystal structure determination of 6'-deoxo-9,10-dihydroergotamine dihydrate butan-2-one solvate as a representative member of the series.

scholarly journals Exploring the Structural Chemistry of Pyrophosphoramides: N,N′,N″,N‴-Tetraisopropylpyrophosphoramide

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 149-163
Author(s):  
Duncan Micallef ◽  
Liana Vella-Zarb ◽  
Ulrich Baisch
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Hydrogen Bonding ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray Diffraction ◽  
X Ray

N,N′,N″,N‴-Tetraisopropylpyrophosphoramide 1 is a pyrophosphoramide with documented butyrylcholinesterase inhibition, a property shared with the more widely studied octamethylphosphoramide (Schradan). Unlike Schradan, 1 is a solid at room temperature making it one of a few known pyrophosphoramide solids. The crystal structure of 1 was determined by single-crystal X-ray diffraction and compared with that of other previously described solid pyrophosphoramides. The pyrophosphoramide discussed in this study was synthesised by reacting iso-propyl amine with pyrophosphoryl tetrachloride under anhydrous conditions. A unique supramolecular motif was observed when compared with previously published pyrophosphoramide structures having two different intermolecular hydrogen bonding synthons. Furthermore, the potential of a wider variety of supramolecular structures in which similar pyrophosphoramides can crystallise was recognised. Proton (1H) and Phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy, infrared (IR) spectroscopy, mass spectrometry (MS) were carried out to complete the analysis of the compound.

Two lithium tricyanomethanide compounds: syntheses and single-crystal structure determination of LiK[C(CN)3]2 and Li[C(CN)3]·½ (H3C)2CO

2015 ◽  
Vol 70 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Olaf Reckeweg ◽  
Francis J. DiSalvo
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
Structure Determination ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Cell Parameters ◽  
New Compounds

AbstractThe new compounds LiK[C(CN)3]2 and Li[C(CN)3]·½ (H3C)2CO were synthesized and their crystal structures were determined. Li[C(CN)3]·½ (H3C)2CO crystallizes in the orthorhombic space group Ima2 (no. 46) with the cell parameters a=794.97(14), b=1165.1(2) and c=1485.4(3) pm, while LiK[C(CN)3]2 adopts the monoclinic space group P21/c (no. 14) with the cell parameters a=1265.7(2), b=1068.0(2) and c=778.36(12) pm and the angle β=95.775(7)°. Single crystals of K[C(CN)3] were also acquired, and the crystal structure was refined more precisely than before corroborating earlier results.

Developments in mycotoxin analysis: an update for 2015-2016

2017 ◽  
Vol 10 (1) ◽  
pp. 5-29 ◽  
Author(s):  
F. Berthiller ◽  
C. Brera ◽  
M.H. Iha ◽  
R. Krska ◽  
V.M.T. Lattanzio ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Critical Review ◽  
Analytical Methods ◽  
Ergot Alkaloids ◽  
Sampling Strategies ◽  
Liquid Chromatography Mass Spectrometry ◽  
Recent Developments ◽  
Mycotoxin Analysis

This review summarises developments in the determination of mycotoxins over a period between mid-2015 and mid-2016. Analytical methods to determine aflatoxins, Alternaria toxins, ergot alkaloids, fumonisins, ochratoxins, patulin, trichothecenes and zearalenone are covered in individual sections. Advances in proper sampling strategies are discussed in a dedicated section, as are methods used to analyse botanicals and spices and newly developed liquid chromatography mass spectrometry based multi-mycotoxin methods. This critical review aims to briefly discuss the most important recent developments and trends in mycotoxin determination as well as to address limitations of presented methodologies.

Crystal-Structure Determination of Powdered Paramagnetic Lanthanide Complexes by Proton NMR Spectroscopy

2009 ◽  
Vol 121 (17) ◽  
pp. 3128-3132 ◽  
Author(s):  
Gwendal Kervern ◽  
Anthony D'Aléo ◽  
Loïc Toupet ◽  
Olivier Maury ◽  
Lyndon Emsley ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Structure Determination ◽  
Lanthanide Complexes ◽  
Proton Nmr ◽  
Crystal Structure Determination ◽  
Proton Nmr Spectroscopy

Methansulfinylchlorid-Lewissäure-Addukte CH3S(Cl)OMF5 (M = As, Sb) und Kristallstruktur von CH3S(Cl)OSbCl5 [1] / Methanesulfinylchloride Lewis Acid Adducts CH3S(Cl)OMF5 (M = As, Sb) and Crystal Structure of CH3S(Cl)OSbCl5 [1]

1996 ◽  
Vol 51 (1) ◽  
pp. 133-138 ◽  
Author(s):  
Rolf Minkwitz ◽  
Ulrike Lohmann ◽  
Hans Preut
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Lewis Acid ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Space Group ◽  
New Compounds ◽  
Lewis Acid Adducts

Abstract CH3S(0)C1 reacts in HF as solvent with MF5 (M = As, Sb) to give products CH3S(Cl)OMF5 (M = As, Sb). The new compounds are stable below 253 K and were charac­ terized by Raman and NMR spectroscopy.In addition, the crystal structure of CH3S(Cl)OSbCl5 has been determinated. The complex crystallizes in the monoclinic space group P21/n with a = 644.3(5), b = 1905.9(14), c = 900.0(7) pm, β = 99.27(6)° with four formula units per unit cell.

Chemie polyfunktioneller Liganden, 69 [1] Über drei Organo-Arsen-Käfigverbindungen mit Noradamantanstruktur / Chemistry of Polyfunctional Ligands, 69 [1] Three Organo-Arsenic Cage Compounds with Noradamantane Structure

1981 ◽  
Vol 36 (12) ◽  
pp. 1532-1537 ◽  
Author(s):  
Jochen Ellermann ◽  
Martin Lietz
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Cage Compounds ◽  
H Nmr ◽  
New Compounds

Abstract The reaction of l.l.l-tris(diiodarsinomethyl)ethane, CH3C(CH2Asl2)3 (1), with H2C(COOC2H5)2, H2C(COOCH3)2 and H2C(COC6H5)2 in presence of the auxiliary base (C2H5)3N gives the noradamantane structured compounds CH3C(CH2As)3E2 [E=C(COOC2H 5)2 (2), C(COOCH3)2 (3) and C(COC6H5)2 (4)].The new compounds have been characterized by mass spectrometry and infrared, Raman and 1H NMR spectroscopy.

scholarly journals Where Are the tpy Embraces in [Zn{4′-(EtO)2OPC6H4tpy}2][CF3SO3]2?

Crystals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 461 ◽  
Author(s):  
Davood Zare ◽  
Alessandro Prescimone ◽  
Edwin C. Constable ◽  
Catherine E. Housecroft
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Electrospray Mass Spectrometry ◽  
Stacking Interactions ◽  
Adjacent Pair ◽  
Single Crystal Structures ◽  
Π Stacking ◽  
Multinuclear Nmr Spectroscopy ◽  
Packing Interactions

In this paper, the bromo- and phosphonate-ester-functionalized complexes [Zn(1)2][CF3SO3]2 and [Zn(2)2][CF3SO3]2 (1 = 4′-(4-bromophenyl)-2,2′:6′,2″-terpyridine, 2 = diethyl (4-([2,2′:6′,2″-terpyridin]-4′-yl)phenyl)phosphonate) are reported. The complexes have been characterized by electrospray mass spectrometry, IR and absorption spectroscopies, and multinuclear NMR spectroscopy. The single-crystal structures of [Zn(1)2][CF3SO3]2.MeCN.1/2Et2O and [Zn(2)2][CF3SO3]2 have been determined and they confirm {Zn(tpy)2}2+ cores (tpy = 2,2′:6′,2″-terpyridine). Ongoing from X = Br to P(O)(OEt)2, the {Zn(4′-XC6H4tpy)2}2+ unit exhibits significant “bowing” of the backbone, which is associated with changes in packing interactions. The [Zn(1)2]2+ cations engage in head-to-tail 4′-Phtpy...4′-Phtpy embraces with efficient pyridine...phenylene π-stacking interactions. The [Zn(2)2]2+ cations pack with one of the two ligands involved in pyridine...pyridine π-stacking; steric hindrance between one C6H4PO(OEt)2 group and an adjacent pair of π-stacked pyridine rings results in distortion of backbone of the ligand. This report is the first crystallographic determination of a salt of a homoleptic [M{4′-(RO)2OPC6H4tpy}2]n+ cation.

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