Integral intensities of the IR bands of the stretching vibrations of the NH,C=O,and C=C groups in theVinca alkaloids

Summary 1. The frequencies and integral intensities of the bands of the stretching vibrations of the NH, C=O, and C=C groups in some indoline, indole, and hydroxyindole alkaloids and certain other compounds have been investigated.2. From the changes in the intensities of the NH bands in vincanine, akuammicine, vinervine O-methyl ether, and their dihydro derivatives, it has been concluded that the first-mentioned compounds contain chelate bonds.3. On the basis of the results of the measurements of the intensities for vincanine and dihydrovincanine, the bands in the 1500–1700 cm^–1 region have been identified.4. The bands in the 1600–1700 cm^–1 region of a number of natural alkaloids are due to the complex vibrations of the whole grouping.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 3, pp. 185–192, 1966     

Applications of1H and13C NMR spectroscopy in structural investigations of Vinca indole alkaloids

This review considers the laws connecting the parameters of the¹H and¹³C NMR spectra with the structure of the substances and the use of these laws for solving structural and stereochemical problems of theVinca indole alkaloids and other compounds of closely related structure. For each type of alkaloids, characteristic features of the PMR and¹³C NMR spectra are given that permit the structures of similar bases to be established and their stereochemical identification to be performed.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 3–15, January–February, 1986.     

13C NMR spectrum of lagochilin and its derivatives

Summary The¹³C NMR spectra of lagochilin and its derivatives have been studied. A complete assignment has been made of the lines of the spectrum and the values of the chemical shifts of the carbon atoms have been discussed in connection with the spatial structure of the molecules of these compounds.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 41–43, January–February, 1979.     

Studies of Erythrina alkaloids: VII—13C NMR spectral studies of some Erythina alkaloids

A variety of alkaloids have been isolated from the seeds of a range of Erythrina species, including dienoid, alkenoid and lactonic derivatives. The ¹³C NMR spectra of these compounds have been assigned by internal comparisons within this series of related compounds and also by the use of model compounds.     

13C NMR spectra of arylnaphthalene lignans

The¹³C NMR spectra have been investigated of a number of arylnaphthalene lignans of plant origin: daurinol and its acetyl derivative and reduction product, justicidin A, justicidin B and its reduction product and the diacetyl derivative of the reduction product, and diphyllin and its acetate. The values of the chemical shifts of the carbon atoms in the spectra of the compounds investigated and the nature of their change according to structural factors are discussed and an assignment is made of the resonance lines in the spectra. The characteristics of the spectrum of one compound are used as models for others. The parameters of the¹³C NMR spectra of a number of naphthalene derivatives are also used. On the basis of the results of the assignment of the signals, difference values of the chemical shifts of the carbon atoms in the series of compounds investigated have been determined. Using the experimental results as a background, some examples taken from the literature of investigations of the¹³C NMR spectra of related compounds have been analyzed.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 76–90, January–February, 1987.     

NMR study of alkaloids. V.13C NMR spectra and reconsideration of the structures of 11- and 10-hydroxypleiocarpamines and the structures of new alkaloids fromVinca erecta

The structures of phenolic alkaloids isolated previously fromVinca erecta Rgl. et Schmalh. have been reconsidered on the basis of the results of a study of their¹³C NMR spectra, and it has been shown that a base with mp 228–229° has the structure of 11-hydroxystrictamine and an amorphous base of the same composition isomeric with it is 10-hydroxystrictamine. The structures of two new indolenine alkaloids — ercinamine and ercinaminine — have been determined from an analysis of¹³C NMR spectra, and also on the basis of PMR and IR spectra and chemical transformations.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 483–488, July–August, 1983.     

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     

Some physicochemical properties of the structure of 4a-indolyl derivatives of fervenulin and its 3-substituted analogues

The¹H and¹³C NMR and the IR spectra of the antibiotic fervenulin and its 3-substituted analogues and their 4a-indolyl derivatives are considered. Diagnostic spectral characteristics of the compounds mentioned have been revealed. Information on the structure of the 4a-indolyl derivatives of the fervenulins obtained with the aid of NMR and IR spectroscopies has been confirmed and supplemented by an x-ray structural analysis performed for crystals 4a-(indol-3-yl)-6,8-dimethyl-2,4a-5,6,7,8-hexahydropyrimido[5,4-e] [1,2,4]triazine-5,6-dione.S. M. Kirov Urals Polytechnic Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 110–117, January–February, 1991.     

The structure of luteidine

Summary On the basis of UV,¹³C NMR, and mass spectra, it has been established that luteidine belongs to the group of homoproaporphine alkaloids.The IR, PMR, and¹³C NMR spectra of luteidine and the products of its transformations have permitted the structure of 1-hydroxy-2,13-dimethoxy-11-oxo-9,10-dihydrohomoproaporphine to be proposed for this base.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 354–359, May–June, 1976.     

Effect of hydroxy groups on conformational equilibrium in bis-quinolizidine systems

A review of the 99 ¹³C NMR spectra of 72 hydroxy, methoxy or ester derivatives of alkaloids with the sparteine skeleton has been made. An improved method of determination of the conformer fractions in conformational equilibria in bis-quinolizidine compounds of sparteine type has been used to estimate the energy of the hydroxy group effect at various positions. The effect can be explained by intermolecular hydrogen bonds.     

Synthesis and IR spectra of some derivatives of phenanthridine and 4,9-diazapyrene

A number of acylamino- and diacylaminobiphenyls and the corresponding derivatives of phenanthridine and 4, 9-diazapyrene, including the previously unknown 2,2-dipropionamidobiphenyl, 5, 10-diethyl-4, 9-diazapyrene, 2, 4-dibenzamidobiphenyl, and 3-benzamido-6-phenylphenanthridine, have been synthesized. The IR spectra of all the compounds have been studied and a group of bands characteristic for the phenanthridine ring in the 1570–1620 cm^–1 region and a group of five bands characteristic for the 4, 9-diazapyrene ring in the 1330–1640 cm^–1 region have been identified. The nature of the IR spectra of phenanthridine derivatives containing unsubstituted amide groups has also been established.     

The13C NMR, UV and IR spectra of 2-fluoropyridine methyl derivatives

¹³C NMR, UV, and IR spectra of methyl derivatives of 2-fluoropyridine have been recorded. The influence of the substituents on the spectral characteristics of the compounds has been discussed. The electronic spectra have been calculated by a modified INDO method. Transition energies, intensities, and assignments are compared with UV spectra.Department of Organic Chemistry, Academy of Economics, Pl-53 342 Wroclaw, Poland Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 763–773, June, 1999.     

Photochemical isomers of tropolone alkaloids

This review, which covers the literature up to 1989, generalizes advances in the field of the study of the photochemical isomers of colchicine and tropolone alkaloids related to it. Information is given on their natural sources, methods of isolation, structure, and configuration, and photochemical and thermal interconversions. Characteristics distinguishing them from the topolone alkaloids in their UV, IR, mass, and²H and¹³C NMR spectra of the photochemical isomers are pointed out.Deceased.Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 147–165, March–April, 1990.     

The NMR investigation of alkaloids. IX.13C NMR spectra and stereochemistry of convolvine,convolamine, convoline,convolidine, subhirsine,and 6-hydroxyhyoscyamine

On the basis of the results of a study of the¹³C NMR spectra, a correlation has been made of the CSs of the¹³C carbon nuclei with the structure and stereochemistry of the tropane alkaloids convolvine, convolamine, convoline, convolidine, subhirsine, and 6-hydroxyhyoscyamine. It has been established that the N-CH₃ group in convolamine and the N-OH group in convoline are oriented equatorially, and the N-CH₃ in hydroxyhyoscyamine axially.Institute of the Chemistry of Plant Substances of the Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 80–84, January–February, 1986.     

Methylphosphonothionates of N-(β-hydroxypropyl)anabasine — Synthesis,structure, and sensitivity of cholinesterases to them

The synthesis has been effected of alkyl anabasinoprop-2-yl and alkyl piperidinoprop-2-yl methylphosphonothionates. It has been shown by¹H,¹³C and³¹P NMR spectroscopies that the anabasine derivatives exist in solution as four diastereomeric forms. The kinetics of the interaction of the compounds synthesized with two types of cholinesterases has been studied.A. S. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent, Fax 627071. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 70–74, January–February, 1994.     

Nuclear magnetic resonance spectra of polyalkylindoles obtained by transformations of 3-nitropyridenium salts

Data are correlated on the ¹E and ¹³C NMR spectra of a representative series of polyalkylindoles obtained by the reaction of alkyl-substituted 3-nitropyridinium salts with ketimines. It has been shown that the use of a combined approach to the interpretation of the ¹H and ¹³C NMR spectra enables reliable information to be obtained on the structure of these previously unknown indole derivatives. The long range ¹³C-H coupling constants give particularly valuable information. A reliable demonstration of the structure of the reaction products is the basis for establishing the route of the indolization.Dedicated to Professor A. R. Katritzky on his 65th birthday.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 899–906, July, 1993.     

Triterpene glycosides ofThalictrum squarrosum I. Structure of squarrofuric acid

Squarrofuric acid has been isolated fromThalictrum squarrosum by the acid hydryolysis of a methanolic extract. It is suggested that is is an artefact formed on hydrolysis and has the structure of 3, 30-dihydroxy-22,25-epoxylanost-9(11)-en-21-oic acid.¹H and¹³C NMR spectra are given for squarrofuric acid and nine of its derivatives. The mass-spectral characteristics and physicochemical constants of the compounds studied are presented.Irkutsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Irkutsk State University. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 376–384, May–June, 1987.     

Mass spectra of diterpene alkaloids with the hetisine skeleton

An analysis of literature material has shown that the stability of the M⁺ ions of bases with the hetisine skeleton decreases considerably when an OR group is present at C-1, C-6, or C-9. The directions of fragmentation are not monotypical and depend greatly on the positions of the oxygen substituents. A similar conclusion can be made from a study of the group and individual features of the breakdown of hetisine, nominine, talatisine, and their derivatives revealed with the aid of high-resolution mass spectrometry and MD spectra. An unusual property of these spectra is the formation of nitrogen-free fragments. The mass spectra of hetisine alkaloids of a new type — zeraconine and its N-oxide — have been characterized.Institute of the Chemistry of Plant Substances of the Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 542–553, July–August, 1987.     

NMR investigation of alkaloids I.13C NMR spectra and stereochemistry of pentacyclic oxindole alkaloids of the heteroyohimbine group of the epiallo and allo series

The¹³C NMR spectra of pentacyclic oxindole alkaloids of the heteroyohimbine group of the allo and epiallo series have been studied and an assignment has been made of the CSs of the carbon atoms. Characteristic differences have been noted in the¹³C CSs of the C₂, C₃, C₇, C₁₄, C₁₅, and C₁₉ carbon atoms that may be useful for solving stereochemical problems in new bases of this series from their¹³C NMR spectra.Communicated at the All-Union Conference on Recent Advances in High-resolution NMR spectroscopy, Tashkent, September, 1979 [1].Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 217–224, March–April, 1980.     

Synthesis and spectral properties of 3-furyl-4-hydroxycoumarins

3-(5-Ethoxycarbonyl-2-furyl)-4-hydroxy-6-R-7-methoxycoumarins and their 4-acyl derivatives have been synthesized. Their¹H and¹³C NMR and IR spectra, and also their absorption and fluorescence spectra, have been studied. It has been shown that some of the substances synthesized can be used as fluorescent probes in the study of membranes and of protein preparations.Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 45–51, January–February, 1998.