LYCOPODIUM ALKALOIDS XIII. MASS SPECTRA OF REPRESENTATIVE ALKALOIDS

1963 ◽  
Vol 41 (10) ◽  
pp. 2654-2670 ◽  
Author(s):  
D. B. MacLean
Keyword(s):  
Mass Spectra ◽  
Fragmentation Process ◽  
Structural Types ◽  
Lycopodium Alkaloids

The mass spectra of a number of Lycopodium alkaloids are recorded and schemes proposed for their fragmentation. The loss of the bridge dominates the fragmentation process in the structural types examined.

LYCOPODIUM ALKALOIDS: XV. STRUCTURE AND MASS SPECTRA OF SOME MINOR ALKALOIDS OF L. FLABELLIFORME

1964 ◽  
Vol 42 (11) ◽  
pp. 2456-2466 ◽  
Author(s):  
S. N. Alam ◽  
K. A. H. Adams ◽  
D. B. MacLean
Keyword(s):  
Mass Spectra ◽  
Physical Evidence ◽  
Lycopodium Alkaloid ◽  
Lycopodium Alkaloids

Hydroxy-des-N-methyl-α-obscurine, C16H24O2N2, has been isolated from L. flabelliforme and a structure assigned to it on the basis of physical evidence. A structure is assigned to Lycopodium alkaloid L.5, which we have named flabellidine, on the basis of physical evidence and its chemical derivation from lycodine. The mass spectra of hydroxy-des-N-methyl-α-obscurine, flabellidine, and flabelline are discussed.

scholarly journals Identification of Pavinane Alkaloids in the Genera Argemone and Eschscholzia by GC-MS

2012 ◽  
Vol 7 (10) ◽  
pp. 1934578X1200701 ◽  
Author(s):  
Lucie Cahlíková ◽  
Radim Kučera ◽  
Anna Hošt’álková ◽  
Jiří Klimeš ◽  
Lubomír Opletal
Keyword(s):  
Mass Spectra ◽  
Fragmentation Pathway ◽  
Rich Source ◽  
Natural Sources ◽  
Structural Types ◽  
Alkaloid Extracts ◽  
Reported Data ◽  
First Time

The genera Eschscholtzia and Argemone(Papaveraceae) represent a rich source of pavinane alkaloids, the identification of which in alkaloid extracts is generally problematic without standards. The alkaloid extracts of three Argemone and four Eschscholtzia species were analyzed using GC-MS. The alkaloids were identified based on comparison of their mass spectra with commercial libraries, with reported data in the literature and with spectra of reference compounds. A total of 23 alkaloids of six structural types (pavinane, protopine, benzylisoquinoline, benzophenanthridine, aporphine and protoberberine) were identified. The fragmentation pathway of pavinane alkaloids was used for their identification. O-Methylneocaryachine has been reported for the first time from a natural sources and the alkaloid pattern of Eschscholzia pulchella has been analyzed and described for the first time.

LYCOPODIUM ALKALOIDS: XVII. MASS SPECTRA OF ANNOTINE AND SOME ANNOTINE DERIVATIVES

1966 ◽  
Vol 44 (5) ◽  
pp. 611-620 ◽  
Author(s):  
D. B. MacLean ◽  
M. Curcumelli-Rodostamo
Keyword(s):  
High Resolution ◽  
Mass Spectra ◽  
Fragmentation Mechanisms ◽  
Lycopodium Alkaloids

The mass spectra of annotine and some of its derivatives are recorded and discussed. Fragmentation mechanisms are proposed to account for the formation of the major peaks in the spectra. The composition of the ions has been verified by measurement of the high-resolution spectra of four of the five compounds. The results lend support to the structure previously proposed for this alkaloid.

Mass spectra of alkylquinolines

1968 ◽  
Vol 46 (9) ◽  
pp. 1487-1497 ◽  
Author(s):  
P. M. Draper ◽  
D. B. MacLean
Keyword(s):  
Nitrogen Atom ◽  
Electron Impact ◽  
Mass Spectra ◽  
Fragmentation Process ◽  
Side Chains ◽  
Molecular Ion ◽  
Alkyl Side Chains ◽  
Insight Into

A study has been made of the fragmentation upon electron impact of monomethylquinolines, di-methylquinolines, monoethylquinolines, and monopropylquinolines. Deuterium labelled analogues of some of the alkylquinolines have been prepared and their fragmentation studied to gain insight into the mechanism of fragmentation. The fragmentation of the alkylquinolines is closely analogous to that of alkylbenzenes. Rearrangement of the molecular ion appears to precede the fragmentation process in many of the compounds studied. The fragmentation of 2- and 8-ethyl- and n-propylquinolines are influenced by the proximity of their alkyl side chains to the nitrogen atom.

Hydrogenolytic opening of 4,4-dimethyl-4a,5-epoxy-a-homocholestane derivatives and mass spectra of some reaction products

1983 ◽  
Vol 48 (3) ◽  
pp. 937-955 ◽  
Author(s):  
Helena Velgová ◽  
Antonín Trka
Keyword(s):  
Double Bond ◽  
Carbon Atom ◽  
Mass Spectra ◽  
Molecular Ions ◽  
Fragmentation Process ◽  
Epoxide Ring ◽  
Allylic Alcohols ◽  
Reaction Products ◽  
Metastable Peak ◽  
Reaction Proceeds

The hydrogenolytic opening of the epoxide ring of all four stereoisomeric 3-acetoxy-4,4-dimethyl-4a,5-epoxy-A-homocholestanes was investigated. The reaction proceeds at the more substituted carbon atom C(5), giving rise to 4a-hydroxy-5,6-unsaturated derivatives. The hydrogenation of the 5,6-double bond of these allylic alcohols affords 4,4-dimethyl-A-homo-5β-cholestane derivatives. The mass spectra of 3,4a-diketones XI and XVII and 4a-ketones XVI and XXVIII to XXX were also studied. In the case of the saturated diketone XVII it was observed that the most abundant metastable peak corresponds to a two-step fragmentation process. The decomposition of the molecular ion of the unsaturated diketone XI is associated with ring A expansion. The mass spectra of 3-acetoxy ketones XVI and XXVIII are characterized by an elimination of a C4H8 molecule from the contracted ring A of the ion [M-CH3COOH]+. The unexpected elimination of the species C6H11, C6H12, and C6H13 from the ring A of the molecular ions of 3-hydroxy ketones XXIX and XXX is shown to be preceded by hydroxyl migration and ring A rearrangement.

Molecular Orbital Study of the Losses of CO2 and H2O in the Fast Atom Bombardment Mass Spectra of Polyether Antibiotics

1987 ◽  
Vol 41 (7) ◽  
pp. 1227-1231 ◽  
Author(s):  
Marshall M. Siegel ◽  
Norman B. Colthup
Keyword(s):  
Molecular Orbital ◽  
Mass Spectra ◽  
Fast Atom Bombardment ◽  
Acid Group ◽  
Fragmentation Process ◽  
Molecular Orbital Calculations ◽  
Spectroscopy Study ◽  
Carboxylic Acid Group ◽  
Molecular Orbital Study ◽  
Unusual Fragmentation

In an earlier fast atom bombardment mass spectroscopy study of polyether antibiotics containing a β-hemiketal carboxylic acid group, the base peak was found to originate from the unusual fragmentation process where both CO2 and H2O were lost from the metal-adduct molecular ion. In this paper, the details of this fragmentation process are studied by ab initio molecular orbital calculations, which indicate that the concerted loss of both CO2 and H2O is much favored over sequential losses of CO2 and H2O.

scholarly journals Spark-Source Mass Spectra of Several Aromatic Hydrocarbons Using a Spinning Electrode

1967 ◽  
Vol 21 (2) ◽  
pp. 81-85 ◽  
Author(s):  
T. Kessler ◽  
A. G. Sharkey ◽  
W. M. Hickam ◽  
G. G. Sweeney
Keyword(s):  
Aromatic Hydrocarbons ◽  
Mass Spectra ◽  
Coal Tar ◽  
Electrode System ◽  
Source Mass ◽  
Molecular Weights ◽  
Structural Types ◽  
Mass Spectrograph ◽  
Electron Impact Mass ◽  
Impact Mass

The purpose of this investigation was to evaluate the application of a spark-source mass spectrograph equipped with a spinning-electrode system for the study of various high molecular-weight materials derived from coal. Eight structural types having molecular weights from 178 to 252 corresponding to those substances previously seen in an electron-impact mass spectrum of the coal-tar pitch were affirmed by this technique. Easily interpreted mass spectra of phenanthrene, anthracene, and chrysene were obtained by the spinning-electrode system. Mass spectra obtained from synthetic mixtures of anthracene and chrysene demonstrated that the technique is applicable for semiquanitative analysis.

LYCOPODIUM ALKALOIDS: VII. LYCODOLINE (ALKALOID L.8)

1964 ◽  
Vol 42 (11) ◽  
pp. 2514-2522 ◽  
Author(s):  
W. A. Ayer ◽  
G. G. Iverach
Keyword(s):  
Infrared Spectroscopy ◽  
Mass Spectra ◽  
Optical Rotatory Dispersion ◽  
Rotatory Dispersion ◽  
Optical Rotatory ◽  
Lycopodium Alkaloids

Lycodoline (alkaloid L.8) is shown to have the structure and stereochemistry depicted in II. The transformation of lycodoline into lycopodine is described. The use of infrared spectroscopy in assigning the configuration at C-12 and the nitrogen in these and related alkaloids is described. The effect of the configuration at C-12 on the optical rotatory dispersion spectra and on the mass spectra of lycopodine (I) and 12-epilycopodine (X) is discussesd.

The reaction of 4-Amino-5-aminomethyl-2-methylpyrimidine with amidine salts

1973 ◽  
Vol 26 (7) ◽  
pp. 1599 ◽  
Author(s):  
RF Evans ◽  
AV Robertson
Keyword(s):  
Structure Determination ◽  
Mass Spectra ◽  
Mass Spectrometric ◽  
Mass Spectrometric Analysis ◽  
Fragmentation Process ◽  
Spectrometric Analysis ◽  
Present Structure

Treatment of 4-amino-5-aminomethyl-2-methylpyrimidine with formamidine salts yields not the expected dihydropyrimidopyrimidine, but rather its ring-opened hydrate, 4-amino-5-formamidomethyl-2-methylpyrimidine. Other workers had previously prepared the latter compound by other methods, but had assigned a wrong structure. The present structure determination is based mainly on i.r., N.M.R., and mass spectrometric analysis, as well as examination of the corresponding acetamido series. Mass spectra include a noteworthy fragmentation process, expulsion of neutral, even-electron NH.

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