Crinum powellii

Similarly, from Crinum powellii, avoiding basic treatment, criwelline (241) was not obtained but the amorphous precriwelline (243) whose hydrochloride melted at 199-201° was isolated. The sequence leading from 243 to 245 and 247, the known alkaloid macronine (Vol. XI, p. 381), and its synthetic iV-demethyl derivative, respectively, established structure 243. The compound 247 was isolated from Crinum erubescens along with the carbamate 253 which probably arose from 247 during the extraction by the action of chloroform and ethanol. Epimacronine (246), another lactonic alkaloid of this series, was obtained in small amounts from 8. formosissima (50, 51). 

Dihydrohaemanthidine (hippawine) has been isolated from the Hippeastrum hybrid Queen of the Whites (32), and dihydrohaeman-thamine was detected in Crinum powellii var. harlemense (20). 

Several substances have been detected in the course of Amarylli-daceae alkaloid isolations which cannot be classified within any of the previous sections. Of these, belladine and 0-methylnorbelladine are basic substances of singular importance in the biosynthesis of the alkaloids of the family. Further discussion of these bases is reserved for Section X. Hordenine has been isolated from Pancratium maritimum (3) and Ungernia victoris (61). It appears to be a metabolite of tyrosine, an important amino acid percursor of the alkaloids of the family. Ismine, C15H15NO3 (mp 99.5°-100.5° [a]p +0° in CHCI3 picrate, mp 158°-159°), has been isolated from an unidentified Ismene spp., Crinum powellii, and Sprekelia formosissima in minute amounts (6). 

Cherylline, an unusual tetrahydroisoqulnoline alkaloid, was isolated from Crinum powellii.23 Structure 16 was assigned to it from spectral and degradative evidence and was confirmed by an unambiguous synthesis.2 The structures of two unnamed pseudoprotoberberine alkaloids from Papaver orientals have been assigned as J7 and 18.2 Cancentrine, from Dicentra canadensis. is a new type of dimeric benzylisoquinoline... 

Crinine is isolated from the bulbs of Crinum powellii and other species [10,11], and is considered to be formed by the para,para -phtno oxidative coupling of O-methylnorbeUadine. 

Velten R, Erdelen C, Gehling M, Gohrt A, Gondol D, Lenz J, Lockhoff O, Wachendorff U, Wendisch D (1998) Cripowellin A and B, a novel type of amaryllidaceae alkaloid from Crinum powellii. Tetrahedron Lett 39 1737... 

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