Mass-spectrometric study of alkaloids of the lycorine type

Summary 1. The mass spectra of six alkaloids of the lycorine type (caranine, pluviine, lycorine, methylpseudolycorine, ungminorine, and galanthine) and four derivatives of these alkaloids have been studied.2. Three main directions of fragmentation of the molecular ions of the compounds studied have been established: the formation of the ion (M-1), the cleavage of ring B in the form of a retrodiene reaction, and the successive elimination of the substituents from rings B and C in the ion (M-1)⁺.Khimiya Frirodnykh Soedinenii, Vol. 4, No. 1, pp. 19–22, 1968     

Chemistry, bioactivity and geographical diversity of steroidal alkaloids from the Liliaceae family

Plants belonging to the Liliaceae family have been the topic of research in many phytochemical and pharmacological laboratories because they contain structurally complex and biologically fascinating steroidal alkaloids. This review, citing 153 references, summarises the chemistry, bioactivity and geographical diversity of steroidal alkaloids isolated from Veratrum and Fritillaria species, so as to illustrate the chemo-diversity and biological significance of these alkaloids, along with their geographical distribution where this is discernible.     

Mass-spectrometric study of the structure of the alkaloids of lolium

Conclusions 1. The results of a study of the fragmentation of substances (I)-(IX) under the conditions of mass spectroscopy have confirmed the positions of the side-chain nitrogen atom and the ethereal oxygen.2. When the functional groups in position C₁ in the molecules of substances (I)-(IX) change, the main fragments remain the same for all the compounds studied and specific fragments appear for each compound.3. A possible scheme of fragmentation is given for substances (I)-(IX).Khimiya Prirodynkh Soedinenii, Vol. 4, No. 5, pp. 298–304, 1968     

Mass-spectrometric study of nitrogen compounds from petroleum distillates

A mass-spectrometric method is given for the determination of the pyridine-quinoline type distribution, including subdistribution according to naphthenicity, in corresponding concentrates from petrolium fractions. Its results are in good agreement with those of ultraviolet spectrometry. In non-base nitrogen concentrates indole-carbazole distributions can be determined similarly. The method uses peak intensity summations comprising the parent and parent-minus-one series, starting from the first naptheno-aromatic skeleton conceivable that is built up of condensed five-membered naptheno rings. It is based on current concepts on total ionization. The presence of mono- and dinaptheno-pyridines, mono-naptheno-quinolines and naptheno-carbazoles in oil fractions was demonstrated. Besides, basic nitrogen concentrates were obtained containing one sulphur atom per heteroaromatic ring system. Here,combined application of mass- and ultraviolet spectrometry before and after selective hydrogenation led to detailed conclusions regarding their heteroaromatic nucleus.     

Mass-spectrometric method of analyzing mixtures of diterpene bases from plants of the genus Aconitum

The qualitative composition of the mixture of diterpene alkaloids from the roots ofAconitum septentrionale from various growth sites has been studied. Twenty-one bases have been detected. The mass-spectrometric method of multipeak monitoring has been used for the rapid checking of the amounts of the main component and seven subsidiary components.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 532–536, July–August, 1989.     

Mass-spectrometric study of carbohydrates

Summary The mass spectra have been recorded of three anhydrosugars: 2,3,4-tri-O-methyl-1, 6-anhydro-D-glucose, methyl 2,4-di-O-methyl--D-glucopyranoside, and methyl 2,5-di-O-methyl-3,6-anhydro--D-glucofuranoside. An interpretation of the spectra obtained has been given.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 3, pp. 152–158, 1966     

Mass-spectrometric study of benzopyridofulvenes

The dissociative ionization of benzopyridofulvenes that differ with respect to the position of the nitrogen atom in the azafluorene ring and the position and character of the substituents in the molecule was investigated. It is shown that the characteristic peculiarities of the fragmentation of these compounds can be explained by cyclization processes in the step involving the formation of [M-R]⁺ ions, where R=CH₃ and C₆H₅ and are the substituents attached to the exocyclic carbon atom. Calculations of the -bond energies of the molecular ion and the fragments by the Pariser-Parr-Pople method confirm the energie favorability of the formation of rings in the [M-R]⁺ions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 377–383, March, 1982.     

Mass-spectrometric method of analyzing mixtures of diterpene bases from plants of the genus Aconitum

The qualitative composition of the mixture of diterpene alkaloids from the roots ofAconitum septentrionale from various growth sites has been studied. Twenty-one bases have been detected. The mass-spectrometric method of multipeak monitoring has been used for the rapid checking of the amounts of the main component and seven subsidiary components. Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 532–536, July–August, 1989.     

New oxidized isocularine alkaloids from sarcocapnos plants

Structures 1a, 3 and 6 were deduced for the new oxoisocularine alkaloids, oxosarcophylline, yagonine and aristoyagonine, respectively, on the basis of spectroscopic studies and synthesis.