Mass spectrometric investigation of transformed steroids and related compounds

Conclusions The basic pathways of the decomposition of certain polyhydroxyketones of the pregene series and their partially acetylated derivatives under electron impact were elucidated, and the principles relating the nature of the mass spectrum to the configuration of the substituents in the D ring were found.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2510–2515, November, 1973.     

Mass spectrometric investigation of benzyliderieaniline

The mass spectral fragmentation of benzylideneaniline has been studied by deuterium labelling. Under electron impact, molecular ions undergo simple fission at the phenyl–N, phenyl–C and C?N bonds, hydrogen migration reactions, and skeletal rearrangement fragmentations. Except in the skeletal rearrangement reactions, hydrogen scrambling does not feature in benzylideneaniline upon electron impact.     

Mass spectrometric investigation of carbohydrates

Conclusions The pathways of the fragmentation of completely methylated- methyl-L-arabopyranoside were studied in detail. The data obtained will serve as a basis for establishing the structure of the partially methylated pentopyranosides.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 277–283, February, 1967.The authors would like to express their deep gratitude to R. A. Khmel'nitskii and A. A. Polyakova for kindly permitting the use of a mass spectrometer, equipped with a multiloop oscillograph.     

Mass spectrometric investigation of carbohydrates

Conclusions The pathways of fragmentation of 2,3,4-tri-O-methyl--methyl-D-fucoside were studied. The data obtained serve as the basis for establishing the structure of partially methylated 6-deoxyhexoses.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 543–548, March, 1967.     

全乙酰化低聚木糖的质谱研究

本文报道了全乙酰化木糖(1)～木六糖(6)的电子轰击质谱(70eV,20eV)及化学电离(反应气体CH_4,i-C_4H_(10),NH_3)质谱的研究结果.根据亚稳峰及高分辨测定资料,阐述了木糖全乙酰化物的碎裂途径,讨论了木二糖～木六糖全乙酰化物的碎裂机理,指出了低聚木糖质谱的特征碎片离子.在所研究的电子轰击质谱中均未观察到分子离子,只有以NH_3为反应气体的化学电离质谱才获得准分子离子,其中全乙酰化木糖(1)～木三糖(3)的[M+NH_4]~+为基峰,而全乙酰化木四糖(4)～木六糖(6)的[M+NH_4]~+离子强度较弱。     

Mass spectrometric investigation of phenylthiovinyl chlorides

Three isomeric phenylthiovinyl chlorides (β-, E and Z, and α-) have been examined under EI and FI conditions with particular attention paid to the fragmentation leading to [C₈H₇S]⁺ ions via loss of Cl˙. Kinetic energy release data, MIKE and CAD MIKE spectra obtained with these precursors, as well as with model compounds, suggest the thioacylium ion PhCH₂CS⁺ as the predominant structure observed for the [C₈H₇S]⁺ species in all cases examined. A comparison is made with the solution behaviour of incipient β-thiovinyl carbenium ions, which are known to rearrange to the S-bridged thiirenium structure.     

Mass spectrometric study of camptothecin and related compounds

The electron impact mass spectrometric behavior of ten camptothecin analogs (1-10) is described and discussed in detail with the aid of accurate mass measurement and metastable experiment.     

Mass spectrometric investigation of acetylated amidosulfates of D-galactose

Conclusions Acetates of the 2-dimethylamidosulfate of galactose are characterized by the presence of peaks of ions with m/e 259, 245, 222, 199, 180, 139; for the 3-dimethylamidosulfate ions with m/e 288, 242, 200, 140 are observed; for the 4-dimethylamidosulfate m/e 288, 271, 245, 211; for the 6-dimethylamidosulfate m/e 455, 307, 234, 183.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1084–1088, May, 1975.     

Mass spectrometric investigation of substituted 1,3-emthiolane S-oxides

The electron impact mass spectrometry of four model 2-phenyl-2-alkyl-l,3-dithiolane S-oxides is described and discussed with the aid of B/E mass-analysed ion kinetic energy collisional spectroscopy and labelling experiments, as well as of fast atom bombardment spectra. The mechanisms of the common fragmentation patterns are given.     

喜树碱及其类似物的质谱研究

本文对喜树碱及其类似物进行了质谱研究,阐明了它们在电子轰击下的裂解规律,对同类型新生物碱和药物代谢产物的结构鉴定提供依据。     

Mass spectrometric study of transformed steroids and related compounds

Conclusions The basic pathways of decomposition of acetates of dihydroxyketones and thiolketones of the pregnene series were elucidated.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2505–2510, November, 1973.     

Mass spectrometric investigation of adduct formation by methylated cyclodextrins

FABMS has been employed to detect the formation of supramolecular adducts between methylated cyclodextrins and (i) organic ammonium salts, (ii) organometallic cations, and (iii) neutral metalloorganic complexes. This is a facile technique for studying the second sphere coordination of transition metal complexes by chemically-modified cyclodextrins.     

Mass spectrometric investigation of isomeric 1,2,3,4-tetrahydro-4-oxoquinazolines

Six isomeric methylphenyl-1,2,3,4-tetrahydro-4-oxoquinazolines have been prepared and their fragmentation patterns upon electron impact studied. Deuterium labelling and high-resolution measurements were performed in order to facilitate the interpretation of the spectra. The dissociation of the molecular ion follows two main routes, the fragmentation being governed by the position of the phenyl group.