Ionization constants of a number of alkaloids used in medicine

The pK_a values of a number of alkaloids in water or in aqueous ethanol have been measured by the potentiometric titration method: nuphleine — 4.59, 6.98; brevicolline — 5.17, 8.02; chelidonine — 6.40; sanguinarine — 7.32; chelerythrine — 7.53; stepharine — 8.48; d-pseudoephedrine — 9.49. For nuphleine and brevicolline, each of which has two nitrogen atoms capable of protonation, assignments have been made of pK_a values to the corresponding atoms on the basis of the results of UV spectroscopy.All-Union Scientific-Research Institute of Medicinal Plants, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 337–341, May–June, 1984.     

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.     

Corumdephine — A new alkaloid fromDelphinium corumbosum

The epigeal part ofDelphinium corumbosum Rgl., collected in the flowering phase in the environs of Pokatilovka (Dzhungarian Ala-Tau) has yielded — in addition to the known alkaloids methyllycaconitine, lycoctonine, delcorine, deoxydelcorine, delcoridine, dehydrodelcorine, dephatine, browniine, dictysine, and dictysine acetonide — a new diterpene alkaloid with the composition C₂₅H₃₉NO₆ (I), which has been called corumdephine. The structure of corumdephine has been established on the basis of a passage from (I) to deoxydelcorine and spectral characteristics.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 95–98, January–February, 1985.     

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.     

Quantitative determination of the alkaloids ofAnabasis aphylla by thin-layer chromatography

Summary A chromatographic method has been developed for the quantitative determination of the alkaloids ofAnabasis aphylla — anabasine, aphylline, lupinine, aphyllidine, and anabasamine — and also pachycarpine in the mixture of reduction products of the high-boiling fraction of alkaloids, in a thin layer of alumina.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 772–776, November–December, 1976.     

Alkaloids ofNuphar luteum

Summary 1. The dry rhizomes ofNuphar luteum L. have yielded three sulfur-containing alkaloids: two — thiobinupharidine and neothiobinupharidine — were known substances, the third with composition C₃₀H₄₂O₄N₂S being new and having been given the name of nuphleine.2. A possible structure has been proposed for nuphleine.Khimiya Prirodnykh Soedinenii, Vol. 3, No. 2, pp. 178–182, 1967     

Alkaloids ofColchicum luteum

The paper gives a review of the alkaloids ofColchium luteum Baker from various growth sites. The structure of luteidine — one of the main alkaloids of the plant — has been established. In addition, two new alkaloids have been isolated from the plant and the structure of one of them has been established as collutine N-oxide.M. I Kalinin Turkmen Agricultural Institute, Ashkhabad, and V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 810–815, November–December, 1985.     

Alkaloids of a new type fromSophora alopecuroides L.

Summary The structures of aloperine and allylaloperine (fromSophora alopecuroides L.) — alkaloids of a new structural type for the genusSophora — have been established by chemical and spectral methods. A number of parameters, NMR spectra, and mass spectra characterizing this class of compounds has been obtained. The partial synthesis of allylaloperine has been performed.All-Union Scientific-Research Institute of Medicinal Plants. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 30–37, January–February, 1975.     

An investigation by the NMR method of the structure of the alkaloid sophorine fromSophora alopecuroides

A new base — sophorine, with mp 59–60°C, [] _D ²³ -18.9° (c 0.98; ethanol) — has been isolated from the epigeal part of the plantSophora alopecuroides L. Its IR spectrum and the nature of its mass spectrometric composition have permitted sophorine to be assigned to the quinolizidine alkaloids. The¹³C NMR spectrum has shown the presence of 19 carbon atoms. The analysis of several of the carbon signals has confirmed the results of IR and mass spectroscopy. Additional details of the structure of sophorine have been obtained from its PMR spectrum.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 604–608, September–October, 1981.