Properties of the Alkaloids

Cassaine, C24H39O4N, crystallizes from ether in glossy flakes, belonging to the rhombic system. It melts at 142.5° and has [a] —113° (ethanol) and [a] —117° (iV/10 hydrochloric acid) (10). 

Isolation. The bark of E. guineense (5 kg.) in a finely ground condition was soaked with half its weight of 10% ammonia and extracted with ether. The combined ex- 

Cassaine is a tertiary base that can be satisfactorily titrated with methyl red, bromophenol green, or iodoeosin as indicators it gives a yellow-colored solution in sulfuric acid which in the presence of vanadium pentoxide becomes green. The bisulfate, B H2SO4 2H2O, melts with decomposition at 290° and the hydrochloride, B-HC1-H20, melts at 212-213° (17). 

The presence of a hydroxyl and a carbonyl in cassaine are proved by the formation of a basic monoacetyl derivative (m.p. 123-124°) and of an oxime (m.p. 123-125°). The two remaining oxygen atoms are accounted for by an ester linkage which is hydrolyzed by acids as follows  

The resultant cassaic acid melts at 203° and has —126.3° (ethanol). It forms a methyl ester (m.p. 189-190°) and a monoacetyl derivative (m.p. 

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Evidence in favor of structures 1-15 for the alkaloids in this group has been furnished in Volume XI, Chapter 10, Section II. The uncertainty relating to the structure of the alkaloids nerispine, parkamine, niflexine, and amaryllidine, however, still remains. The structures of narcissidine (Volume XI, p. 331) and of the related alkaloids parkacine (p. 332) and ungiminorine (p. 333) have, on the other hand, been revised by means of X-ray analysis. Work has been devoted to the study of the physical properties of the alkaloids in this group in an attempt to establish a general relationship between structure and behavior as well as to the study of the correlation of same with other classes of alkaloids and to the investigation of the chemical reactivity of representative members. 

Cocculine (C17H21N02) and cocculidine (ClgH23N04) were isolated from C. laurifolius in 1950 (77) but escaped mention in previous reviews of this treatise because only a partial structure, unrelated to the Erythrina alkaloids, had been advanced (78). On the basis of the spectroscopic properties of the alkaloids and their Hofmann degradation products, structures 56 and 54 (without stereochemistry) were proposed for cocculine and cocculidine, respectively (79) however, a different group (80) proposed structures 69 and 70, respectively, on the basis of similar evidence. The... 

A paper has appeared on some aspects of the physiological properties of the alkaloids of Stemmddenid donnell-smithii (76). 

The encapsulation efficiency of a thalidasine liposome injection was studied using Sephadex G-50 column fluorimetry. The free alkaloid was separated from the liposome particles by the column, with satisfactory recovery of the liposome particles, as well as column reproducibility. The encapsulation efficiency of this particular liposome preparation (139-2) was approximately 93% due to the highly lipophilic property of the alkaloid. The authors concluded that the method was suitable for the quality control of encapsulation efficiency of this polyphase liposome injection [147]. 

The poisonous properties of the alkaloidal material obtained from the yew tree were first investigated by Borchers in 1876 [18], but its structural characterization was exceedingly slow, despite intensive work by numerous research groups. The first clue came only in 1923, when Winterstein, the chemist who coined the classical definition of an alkaloid, showed that taxine is the ester of a polyalkol esterified with acetic acid and (L)-P-dimethylamino-P-phenylpropionic acid [19], This P-aminoacid was then named after Winterstein. The early studies on taxine were... 

The discovery of the anticancer properties of the alkaloids of Vinca rosea constitutes a particularly beautiful example of pharmacological feed-back. Preparations from this plant had the reputation in some popular medicines to possess antidiabetic virtues. During a controlled pharmacological test, these extracts were proven to be devoid of hypoglycemic activity. On the other hand, it was frequently... 

The further treatment of the extract follows the known procedure with recognition of the chemical and physical properties of the alkaloids. 

Ipalbidine and ipalbine have been re-isolated from Ipomoea alba (Convolvulaceae) together with ipomine (844), not previously known from this source, and four new alkaloids (557). In this study, NMR spectra were reported for the first time for naturally occurring 842 and 843, and fiirfcer interesting facts about the chiroptical properties of the alkaloids emerged. For ipalbidine, the major alkaloid (26% of the total), the optical rotation was measur as -18 (c 0.64, EtOH), a smaller value than that reported for (- )-ipalbidine obtained by resolution of a synthetic racemate ([a]o -237°, c 1, CHCI3) (555). Since (+ )-ipalbidine is a known natural product (555), the authors suspected that the compound they isolated was in fact scalemic, in line with earlier speculations about the partially racemic... 

In the previous summary of the monoterpene alkaloids (2), many of the properties of the alkaloids then known were presented. In this chapter, some references to and examples of the various physical data for the monoterpene alkaloids were discussed as the information for the various newly isolated alkaloids was examined. Table III summarizes the more recently available information for the known alkaloids, as well as those alkaloids discussed for the first time in this review. 

Several useful reviews and compilations of data on pyrrolizidine alkaloids have been published. These include a review of all aspects of pyrrolizidine alkaloid chemistry and biochemistry this is comprehensive, but rather idiosyncratic in its balance (sixteen pages are devoted to the synthesis of necines and necic acids whereas physical and spectroscopic properties of the alkaloids are discussed in barely two.) Nevertheless, this up-to-date work will certainly be of great interest and usefulness to workers in the field. Klasek has surveyed the investigations on pyrrolizidine alkaloids carried out at Olomouc, and Atal and Sawhney have produced a useful compilation of data on alkaloids from Indian Crotalaria species. Pyrrolizidine alkaloids from the Orchidaceae have been surveyed by Luning" and by Brandange. Pyrrolizidine alkaloids are included in a comprehensive compilation of data on alkaloids isolated from plants occurring in the U.S.S.R. ... 

Ochrobirine has been identified among the alkaloids of Corydalis vaginans The isolation of fumariline from Fumaria indica has been reported.The new alkaloids yenhusomine (181) and yenhusomidine (182) have been isolated, along with ochotensimine, from Corydalis ochotensis. The isolation and properties of the alkaloid corydalispirone [hypecorinine (117)] are discussed in Section 10. 

Caffeine was first studied scientifically by two French chemists, Joseph Bienaime Caventou (1795-1877) and Pierre Joseph Pelletier (1788-1842), who were very interested in the chemical properties of the alkaloids. Between 1817... 

The discovery of the anticancer properties of the alkaloids of Vinca rosea constitutes a particularly beautiful... 

In the first paper, Perkin gives a short history of the discovery of and earlier work on berberine, taking great pains to confirm the empirical formula of Perrins (167) which was based on the analysis of salts and therefore were actually written as C2oHi704N. The physical properties of the alkaloid and many of its salts were described, as well as a number of color reactions. 

The formulation proposed (2) for atisine therefore serves to explain the properties of the alkaloid, if it is assumed (a) that the 6-ethyl-l-methyl-phenanthrene isolated from its dehydrogenation products represents the major portion of the carbon skeleton of atisine, and is not an artifact, and... 

Speisky, H., Cassels, B.K., Lissi, E.A., Videla, L.A. (1991). Antioxidant properties of the alkaloid boldine in systems imdergoing lipid peroxidation and enzyme inactivation. Biochem. Pharmacol, 41(11), 1575-1581. 

Akhmedhodzhaeva KhS, Polievtsev NP (1963) Sedative properties of the alkaloid perforine and its synergy with soporifics and narcotics. In Voprosy biologii i krayevoi meditsinui (Issues of Biology and Regional Medicine), no 4. Izdatelstvo Akademii Nauk UzSSR, Tashkent (in Russian)... 

Berzelius said the basic properties of the alkaloids may be explained in three ways (i) they combine with acids in the same way as metallic oxides, (ii) they contain ammonia as a constituent, (iii) they resemble ammonia in requiring the addition of an atom of water to act as bases (2NH3 + HjO + SO3). He leaves the question open. Robiquet, he says, had suggested the second alternative. 

The present volume breaks new ground from the point of view of presentation, since the special type of reactivity of the indole system is placed in the forefront and related to the properties of the alkaloids and their biogenesis. This treatment is original and it will certainly be found instructive. 

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