Crinum

Demethylvasconine (85) (9-methoxy-5-methyl-phenanthridin-8-olate) presented in Scheme 31 was found in Crinum kirkii (95P1291) (Amaryllidaceae). Although published as cation, no information about the anion of this alkaloid is given. Its relationship to other alkaloids of this class, however, makes a betainic structure more than likely and this is confirmed by a comparison of the NMR data of 85 with the cationic and betainic alkaloids presented in Table III. This betaine is isoconjugate with the 2-methylphenanthrene anion and thus defined the alkaloid as a member of class 1 (odd alternant hydrocarbon anions). Whereas substitution of the isoconjugate phenanthridinium moiety at the 1-position with an anionic fragment results in zwitterions (cf. Section III.D), the phenanthridinium-2-olate is a mesomeric betaine. 

Criasbetaine (100) was isolated from Crinum asiaticum (98MI2, 90P805, 86P1975, 86JCR(S)112, 56JA4145). Syntheses of Ungerimine and... 

Houghton PJ, Agbedahunsi JM, Adegbulugbe A, Choline esterase inhibitory properties of alkaloids from two Nigerian Crinum species. Phytochemistry 65 2893-2896, 2004. 

Some typical genera Behria Crinum Cyrtanthus Haemanthus Hippeastrum Hymenocallis Leucojum Narcissus Zephyranthes... 

Bolt, H. G., Dopke, W. and Slender, W. 1957. Alkaloide aus Crinum, Zephyranthes, Leucojum und Clivia Arte. Chemische Berichte, 90 2203-2206. 

Machocho, A., Chabra, S. C., Viladomat, F., Codina, C. and Bastida, J. 1998. Alkaloids from Crinum stuhlmannii. Planta Medico, 64 679-680. 

Abd El Hafiz, M. A., Ramadan, M. A., Jung, M. L., Beck, J. P. and Anton, R. 1991. Cytotoxic activity of Amaryllidaceae alkaloids from Crinum augustum and Crinum bulbispermum. Planta Medica, 57 437-439. 

Ramadan, M.A. et al.. Minor phenolics from Crinum bulbispermum bulbs, Phytochemistry, 54, 891, 2000. 

Long recognized as a family of their own, the amaryllids are now included in the Liliaceae by Cronquist but perhaps not generally. They are distributed throughout the world, mostly in the tropics and subtropics, and valued for their garden flowers (Amaryllis, Crinum, Lycoris, Narcissus, etc.). 

Forty-five samples representing 35 species were tested nine had been known to contain alkaloids Amaryllis belladonna, Ammo-charis coranica, Crinum asiaticum, C. giganleum, Haemanthus mul-liflorus, Hippeaslrum villatum, Lycoris radiata, Narcissus pseudonarcissus, Sprekelia formosissima. 

Two alkaloids tentatively identified as hamayne (377) and 3-acetylhamayne (378) have also been reported to be components of Crinum zeylanicum L. (44). Although certain physical properties for the alkaloid assigned to be 377 and its diacetate were not identical with those previously reported for hamayne and hamayne diacetate, the H-NMR spectrum at 100 MHz of the base alleged to be hamayne was superimposable with that of an authentic sample of 377, and partial hydrolysis of its diacetate furnished a substance that was identical with 3-acetylhamayne (378) (44). While the discrepancies in the physical data for the alkaloid isolated from Crinum zeylanicum L. and hamayne might be due to polymorphic crystals, this was not established, and further structural work on these compounds should resolve the differences. 

As a result of mass spectral studies of alkaloid extracts of Crinum ornatum, the new alkaloids omazamine, and omazidine were identified, and the tentative structure assignments of 403-405, respectively, were made (42). The stereochemistry depicted is based on the obvious relationship between these alkaloids and pretazettine (395), but no stereochemical details were given in the original report (42). The structures of ungvedine (399) (83) and varadine (402) (54), the latter of which represented a new structural type in the Amaryllidaceae alkaloids, were determined by spectroscopic studies. Further chemical support for the proposed structure of ungvedine (399) was obtained by hydrogenation of O-methyltazettine to give 399 (83). 

Latisoline (577) is a novel glucosyl alkaloid that was isolated from Crinum latifolium (36), and the structural assignment was based on its hydrolysis with emulsin to provide the aglycone latisodine (578) and D-glucose. Further support... 

Although the alkaloids of the mesembrane type are structurally similar to certain alkaloids of the family Amaryllidaceae, they are generally found in the plants of the family Aizoaceae, but there have been several exceptions to this generalization. For example, amisine (580) has been isolated from Hymenocallis arenicola Northrop (57), and mesembrenol (581) has been isolated from Crinum oliganthum (41). The isolation of 580 and 581 represented the first instances in... 

Augustamine (582), which was isolated from Crinum augustum Rox., represents a new structural type of alkaloid in the family Amaryllidaceae (26), and its structure was deduced by extensive H- and 13C-NMR studies, which resulted in the complete assignments of the H- and 13C-NMR spectra, together with an analysis of its mass spectrum. The assignment of the cis ring fusions were based on analysis of vicinal coupling constants of the relevant protons. 

Latifine (594) is a new phenolic base isomeric with cheiylline (595) that has been isolated from Crinum latifolium L. (227). The (S) configuration at C-4 of 594 was deduced from an observed negative Cotton effect in the ORD curve of 594 and 595, and this assignment was confirmed by an X-ray analysis of the N-bromobenzamide derivative of 594. 

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