Mass spectra of N-oxides of pyrrolizidine alkaloids

Summary The mass spectra of the N-oxides of pyrrolizidine alkaloids show three main types of ions formed as the result of the detachment of the oxygen of the NO group, dehydration with subsequent dehydrogenation, and isomerization of the nucleus. In a number of spectra the proportion of ions formed by the localization of the charge in the side chain increases.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 620–626, September–October, 1974.     

New Homoaporphine Base from Merendera robusta

The alkaloid composition of the bulb casing of Merendera robusta Bge. (Liliaceae) was investigated. The tropolone alkaloid colchicine was identified. A new homoaporphine base for which the structure methylmerenderine hydroxide was established by spectral and chemical methods was isolated.     

2,10-Didemethylcolchicine — A new alkaloid from Merendera robusta

The alkaloid complex ofMerendera robusta Bge. (familyLiliaceae) growing in the Tashkent province of the Uzbek SSR has been investigated. The main alkaloids of this plant are colchicine and colchamine. Eleven tropolone alkaloids and their photochemical isomers have been isolated and identified. A new alkaloid of phenolic nature has been isolated for which the structure of 2,10-didemethylcolchicine has been established.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 67–71, January–February, 1991.     

Structure of the steroid alkaloid radpetine from Petilium raddeana

A new base with the composition C₂₉H₄₅NO₃ has been isolated from the plantPetilium raddeana and has been called radpetine. Its structure has been established as 3-hydroxy-23,28-epoxy-23-ethyl-^22(N)-22,26-iminocholestan-y-one-by the x-ray structural method (diffractometer, CuK, 1046 reflections, direct method, MLS in the anisotropic approximation, R = 0.118). Radpetine belongs to a new type of steroid alkaloids with a spiro-methyloxirane grouping at C-23 in the azomethine ring F.Deceased.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 384–388, May–June, 1991.     

Oleanane Saponins from Rhizome of Anemone raddeana

Two new oleanolic acid‐type triterpenoid saponins, raddeanosides R₂₂ and R₂₃ ( 1 and 2 , resp.), together with four known saponins were isolated from the rhizome of Anemone raddeana Regel. The structures of the new compounds were elucidated as oleanolic acid 3‐O‐β‐D ‐glucopyranosyl(1→2)[β‐D ‐glucopyranosyl(1→4)]‐α‐L ‐arabinopyranoside ( 1 ) and oleanolic acid 3‐O‐α‐L ‐arabinopyranosyl(1→3)‐α‐L ‐rhamnopyranosyl(1→2)[β‐D ‐glucopyranosyl(1→4)]‐α‐L ‐arabinopyranoside ( 2 ). The four known compounds were identified as oleanolic acid 3‐O‐α‐L ‐arabinopyranoside ( 3 ), oleanolic acid 3‐O‐β‐D ‐glucopyranosyl(1→4)‐α‐L ‐arabinopyranoside ( 4 ), hederasaponin B ( 5 ), and hederacholchiside E ( 6 ) on the basis of chemical and spectral evidences. Compound 4 is reported for the first time from the Anemone genus, while the other three known compounds have been already found in this plant.     

Alkaloids of Merendera iolantae

Summary The alkaloids ofMerendera iolantae E. Czerniak have been studied for the first time. The total alkaloids consist of tropolone compounds and bases without a tropolone ring. From this plant we isolated the known alkaloids colchicine, colchamine, -lumicolchicine, colchameine, and 2-demethylcolchiceine, and four new, nontropolone, bases — MI-1 (iolantamine), MI-2, MI-3, and MI-4. The presence of colchiceine, 3-demethylcolchamine, and two unknown bases with R _f 0.49 and 0.53 was shown by chromatographic methods.A developed formula has been put forward for iolantamine on the basis of its spectral characteristics.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 487–493, July–August, 1972.     

A new triterpenoid saponin from Anemone raddeana

A new triterpenoid bisglycoside, named raddeanoside R19, was isolated from the roots of Anemone raddeana. Its structure was elucidated on the basis of ESI-MS, ^13C NMR, and chemical methods.     

Syntheses of aporphine and homoaporphine alkaloids by intramolecular ortho-arylation of phenols with aryl halides via SRN1 reactions in liquid ammonia

The photostimulated intramolecular ortho-arylation reactions of bromoarenes linked with pendant phenoxy containing N-substituted tetrahydroisoquinolines in liquid ammonia afforded aporphine (54-82% yield) alkaloid derivatives via SRN1 reactions. This strategy was extended for the first time to the synthesis of a homoaporphine derivative (40% yield). Tetrahydroisoquinoline precursors that contained electron-withdrawing groups on nitrogen (i.e., amides, sulfonamides, and carbamates) gave cyclized products, whereas precursors with basic nitrogens (i.e., NH or NMe) either failed to yield cyclized products or gave aporphines in only low yield.     

Mass-Spectrometric analysis of homoaporphine bases structure of szovitsinine

Summary The mass spectra of homoaporphine bases have been studied. The main decomposition of these bases is connected with the elimination of the substituent in position C₃.The mass spectrum of the new base szovitsinine has been studied and the structure of 2,4-dihydroxy-3,5,6-trimethoxyhomoaporphine has been proposed as the most probable form of it.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 230–234, March–April, 1977.