Use of the method of metastable defocusing for the analysis of the processes involved in the fragmentation of lycoctonine bases

The metastable transitions in the mass spectra of 21 lycoctonine bases have been studied by the method of metastable defocusing (MD). It has been established that as a criterion of the monotypicity of single-stage fragmentation reactions it is possible to use a linear dependence of the relative intensities of the metastable peaks (MPs) on the stability of the daughter ion. In the MD spectra of the ions formed in several stages, to characterize the generality of the breakdown reactions, in addition to the intensities of the MPs, the accurate positions of their maxima and the general shape of the curve are important.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 481–495, July–August, 1984.     

B/E linked scanning spectra of the molecular and fragmentary ions of lycoctonine bases

The B/E linked scanning spectra of the M⁺, (M-15)⁺, and (M-OR₁)⁺ ions and those of some other series have been investigated. The characteristic nature of the individual intensities of the metastable peaks (the magnitudes A) with the same R₁ radicals for different groups of alkaloids has been shown for the spectra of the M⁺ and (M-15)⁺ ions. The reason for the quantitative differences of the B/E spectra of the (M-OH)⁺ ions from the spectra of the (M-OCH₃)⁺ and (M-OAc)⁺ ions, consisting in the influence of alternative methods of eliminating an OH radical, has been found. It has been confirmed that the values of A of analogous transitions calculated from the B/E and MD spectra are close to one another. On the other hand, the values of the energy of the metastable transitions obtained by these two methods differ from one another by two orders of magnitude.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Special Design Bureau of Analytical Instrument Construction, Scientific and Technical Branch, Academy of Sciences of the USSR, Leningrad. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 72–84, January–February, 1991.     

Mass-spectrometric investigation of some new derivatives of the alkaloid lupinine

The mass spectra of some new derivatives of lupinine have been studied with the use of the spectra of metastable ions. On the basis of the results of an investigation of DADI spectra it has been shown that in the formation of low-mass quinolizidine ions the ions with m/z 152–150 are of considerable importance.A. S. Sadykov Institute of Biororganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 508–512, July–August, 1990.     

Analysis of metastable defocusing spectra of lycoctonine bases having 7,8-methylenedioxy groups

The parameters of the MD spectra of the fragmentary ions of 21 lycoctonine alkaloids with 7,8-MDOGs have been investigated. On this basis, the monotypicity of the main fragmentation processes characteristic for the individual groups of compounds have been confirmed. A decrease in the number of common group characteristics of the MD spectra of the ions arising as the result of multistage breakdown processes is caused by alternative methods for their formation. This is not shown only by the doublet nature of the fragmentary ions. The results of a comparison of the MD spectra with the structures of the molecules have confirmed the hypothesis expressed previously concerning the 7,8-MDOG as the center of localization of the charge, competing with the nitrogen atom and facilitating the elimination of various substituents from the diterpene skeleton. A comparison has been made of two methods of evaluating the common nature of the fragmentation reaction: from the energies of the metastable transitions and from the relative intensities of the metastable peaks. The two methods give mutually supplementary information concerning the nature of the fragmentation processes.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 397–407, May–June, 1987.     

Features of the mass spectra of hetisine bases with an OH group at C-14

The EI mass spectra of five hetisine bases with an OH group at C-14 have been investigated. The main directions of fragmentation are initiated by the cleavage of the C-14-C-20 bond. With the aid of measurements of the elementary compositions of the molecular and fragmentary ions and of a comparison of the B/E linked-scanning and metastable defocusing spectra, the mechanism of the formation of the key fragments has been established and alternative methods for the production of certain ions have been revealed.Institute of Chemistry of Plant Substances, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 82–89, January–February, 1992.     

Fragmentation of sesquiterpene lactones related to leucomisin

The mass spectra of seven sesquiterpene lactones — leucomisin, austricin, parishin B, parishin C, matricarin, artelin, and artelin diacetate — have been studied. It has been shown that the presence of the conjugated bonds C(1)=C(10), C(2)=0, and C(3)=C(4), and also C(5)=C(6), stabilizes M⁺, and the main fragmentation process is that of the splitting out of the lactone ring. The presence of hydroxy substituents at C(3) and C(8) of the guaiane system does not change the stability of M⁺ under electron impact. The directions of fragmentation have been confirmed by an analysis of spectra obtained by the metastable defocussing of daughter ions and by measuring the accurate masses of the main peaks of the fragmentary ions.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 96–101, January–February, 1987.     

Secondary-ion mass spectra of pennogenin glycosides

LSIMS mass spectra of pennogenin glycosides have been studied; the most characteristic ions are (M+H–H₂O)⁺ (with glycerol as the liquid matrix) and (M+Na)⁺ (with glycerol +NaCl as matrix). In both cases the peaks of ions formed as the result of the successive elimination of the carbohydrate units, the breakdown of the bonds of the terminal pyranoses, the cleavage of the bonds of the rings D and E, and the peaks of the ions Agl⁺ and (Agl–H₂O)⁺ were observed.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. All-Union Scientific-Research Institute for Agricultural Biotechnology, All-Union Academy of Agricultural Sciences, Moscow. Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 523–525, July–August, 1991.     

Features of the mass spectra of C18-diterpene alkaloids

Fragmentation under electron impact of eleven C₁₈-diterpene alkaloids with an oxygen function at C-4 has been investigated. The contributions of various modes of forming the (M - CH₃)⁺ ions have been determined. The mechanism of the appearance of the fragments (M - CH₃)⁺ and (M - OCH₃)⁺ at the expense of the methoxy groups at C-14 and C-16 has been considered. The characteristic nature of the parameters of the metastable peaks in the transitions to these daughter ions has been shown. Minor directions of the fragmentation of 3,4-epoxy- and 4-hydroxy bases have been characterized.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 95–106, January–February, 1989.     

Secondary-ion mass spectrometry of some catalpol and mussaenoside derivatives

The iridoid glycosides catalpol, veronicoside, catalposide, mussaenoside, and 8-epiloganin have been investigated by secondary-ion mass spectrometry (SIMS). A tendency of these compounds to give cationized1 form of the molecular ions in the SIMS regime has been shown. In the SIMS spectra of veronicoside and catalposide the maximum peaks were those of acyl cations, and in the cases of mussaenoside and 8-epilonganin they were the peaks of ions formed by the elimination of a glucose molecule.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 62–65, January–February, 1996. Original article submitted Spetemebr 17, 1995.     

Circular dichroism of some sesquiterpene lactones of the germacrane type

The CD spectra of a series of germacranolides have been considered, and the parameters of the Cotton effects observed have been correlated with the stereochemistries of the compounds studied. The applicability for germanocranolides of the Waddell-Stocklin-Geissman rule is discussed.Deceased.Institute of the Chemistry of Plant Substances of the Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 176–179, March–April, 1986.     

GC-MS analysis of hydroxy and epoxy acids from seed oil of Hippopha? rhamnoides

By the GC-MS method using a packed column, in the mixture of TMS derivatives of hydroxy acid methyl esters obtained from the seed oil of the sea buckthorn, in ten chromatographic peaks (CPs) 13 monohydroxy compounds have been characterized by their mass spectra, the main ones being derivatives of dimorphecolic and coriolic acids. Structures are proposed for four dihydroxy acids of the C₁₇–C₂₀ series. The mixture of methyl esters of di- and tetra-TMS derivatives obtained from the mixture of epoxy acids from the same source has been analyzed by a similar method. In seven CPs, 11 compounds, reflecting the presence of nine epoxy acids in the initial mixture, have been characterized by their mass spectra. The main component of the mixture was 15,16-epoxyoctadeca-9,12-dienoic acid.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 626–634, September–October, 1989.     

Mass spectrometry of pennogenin glycosides

The electron-impact mass spectra of five unesterified pennogenin glycosides, which contain the M⁺ or (M - H₂O)⁺ peaks, have been obtained. The characteristic features of the fragmentation of these compounds have been studied. In addition to ions characterizing the successive elimination of carbohydrate units, fragments have been detected which show the breakdown of the terminal pyranose ring. Five new directions of the fragmentation of the spirostanol skeleton due to the presence of an OH group at C-17 have been found.Institute of the Chemistry of Plant Substance, Academy of Sciences of the Uzbek SSR, Tashkent. Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Science Center of the Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 337–341, May–June, 1986.     

C-10 dipertide derivatives of colchicine

The methyl esters of colchicidylglycyl-L-leucine, -L-phenylalanine, and-L-tryptophan and the ethyl esters of colchicidylglycylglycine, -L-isoleucine,-L-valine, -L-tyrosine, and -L-glutamic acid have been obtained by the condensation of colchicidylglycine and esters of amino acids. The structures of the compounds have been confirmed on the basis of their UV spectra and nuclear magnetic resonance spectra.Institute of Molecular Biology and Biochemistry, Kazakh SSR Academy of Sciences, Alma-Ata. Institute of Molecular Biology, Academy of Sciences of the USSR, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 91–95, January–February, 1989.     

PMR spectra of catechins and their derivatives

Summary The PMR spectra of catechins, gallocatechins, epigallocatechin gallate, and their acetyl derivatives have been analyzed and the structures of the compounds investigated have been confirmed.The parameters of the signals of the H-2 and H-3 protons that have been found and also the nature of their change on acetylation enable a compound investigated to be assigned unambiguously to the normal or to the epi series.Division of Bioorganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 46–50, January–February, 1976.     

13C and1H NMR spectra of spiropiperidine alkaloids of Nitraria

A detailed interpretation is given of the¹³C and¹H NMR spectroscopy of the spiropiperidine alkaloids of the nitramine group, and the results are generalized. The assignment has been made of the carbon-13 resonance lines in the spectra of five natural compounds. A dependence of the parameters on the spatial structures of the compounds of this series has been found. The overall PMR spectra of seven natural alkaloids and some of their derivatives are discussed. The conformations of acyl derivatives have been established.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 82–91, January–February, 1988.     

Mass spectra of polyhydrosysteroids of the starfishPatiria pectinifera

The electron-impact fragmentation of six polyhydroxysteroids from the starfishPatiria pectinifera, including three glycosides, has been studied. In addition to the directions of fragmentation that are characteristic for sterols from other sources and for steroid compounds of other classes, fragments have been found that result from the unusual arrangement of hydroxy groups in the molecules of the samples investigated. Two breakdown pathways of the furanose ring have been found in the spectra of the glycosides.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek, SSR, Tashkent. Pacific Ocean Institute of Bioogranic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 361–367, May–June, 1985.     

Chemical-ionization mass spectra of diterpene alkaloids

The chemical-ionization spectra of diterpene alkaloids have been investigated for the first time with the recording of positive and negative ions [Cl(+) and (–)). A comparison has been made of the CI(+) spectra with the EI and SIMS spectra. It has been shown that the nature of the CI(+) and (–) spectra depends greatly on the type and position of substituents in the lycoctonine skeleton.Deceased.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 114–122, January-February, 1995. Original article submitted October 31, 1994.     

Mass spectrum of glycosides of ecdysteroids and their peracetates

Features of the fragmentation of the carbohydrate chains of galactopyranosides of ecdysteroids (sileneosides A–D) and their peracetates under electron impact are discussed. The migration of Gal and AcGal residues from C-22 to C-20 has been detected. The secondary-ion mass spectra of the sileneosides using liquid matrices are considered.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. All-Union Scientific-Research Institute of Agricultural Biotechnology, V. I. Lenin All-Union Academy of Agricultural Sciences, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 226–231, March–April, 1991.     

Sesquiterpene lactones as stimulators of photodynamically active porphyrins

The photosensitizing properties of sesquiterpene lactones have been considered by means of a study of their influence on the pigmentary system of plants. An investigation of the action of germacranolides, eudesmanolides, guaianolides, and pseudoguaianolides on the fluorescence spectra of leaves in the presence of exogenous 5-aminolevulinic acid (5-ALA) has permitted the conclusion that these compounds are capable of inhibiting the transformation of 5-ALA in the chain of the biosynthesis of chlorophyll.Institute of Organic Synthesis and Coal Chemistry, Kazakhstan Academy of Sciences. Institute of Physiologically Active Compounds, Russian Academy of Sciences, Chernogolovka. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 637–640, November–December, 1992.     

Alkaloids of the epigeal part of Aconitum orientale structure of orgetine

From the total alkaloids of the epigeal part of the plantAconitum orientale have been isolated the known alkaloid kobusine and a new alkaloid, which has been called orgetine. A structure has been put forward for orgetine on the basis of spectral characteristics (IR, PMR,¹³C NMR, and mass spectra) and the production of a triacetate.I. G. Kutateladze Institute of Pharmacochemistry, Georgian Academy of Sciences, Tbilisi. Institute of Chemistry of Plant Substances, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 240–243, March–April, 1992.