Alstonia alkaloids

A partial synthesis101 of alstonerine (178) from macroline (179) (shown in Scheme 17) is of considerable interest, in view of the strategic position occupied by macroline as a possible precursor of both the monomeric Alstonia alkaloids (e.g. alstonerine) and the dimeric alkaloids (e.g. villalstonine and macralstonine). 

Nordman, C. E., and Nakatsu, K. Interpretation of the Patterson function of crystals containing an unknown molecular fragment. The structure of an Alstonia alkaloid. J. Amer. Chem. Soc. 85, 353-354 (1963). 

Table II 15a, 29-43) lists the Alstonia alkaloids that have been reported during the period under review included in the table are...

In the period that has elapsed since the preparation of Volume VIII in this series, some notable investigations on the Alstonia alkaloids have been reported and several new alkaloids have been isolated the occurrence of Alstonia alkaloids in other genera has also been observed. The... 

In another remarkable contribution on the Alstonia alkaloids Hesse, Schmid, Taylor, and their collaborators have very recently discussed in detail the chemistry of macralstonine, for which the structure XLI is proposed (10). The molecular formula C43H52N4O5, mol. wt. 704,... 

Akuammiclne, Akuammidine s. Alstonia alkaloids. Alamethldn see ionophores. 

Alstonia alkaloids. A group of over 250 differing monomeric and dimeric monoterpenoid indole alkaloids from the genus Alstonia (Apocynaceae) having aspidospermidine, corynanthean, heteroyohimbane, and related indole skeletons. The A. a. are isolated from leaves, roots, and bark of wild Alstonia species (bushes, often fairly large evergreen trees) with the exception of A. scholaris which can be cultivated. 

C21H22N2O3, Mr 350.42, amorphous, [a]D -52° (CHCI3). 0 unstable, reactive alkaloid, existing as /d -immonium salts, isolated from Guettarda exi-mia (Rubiaceae) and synthesized enzymatically with enzymes from Catharanthus roseus cell suspension cultures C. plays a key role in the biosynthesis of monoterpenoid indole alkaloids, e.g., the hetero-yohimbine alkaloids such as ajmalicine, 19-epi-aj-malicine, and tetrahydroalstonine (see Alstonia alkaloids). 

Indole alkaloids of the sarpagme/ajmaline/macroline type comprise one of the most important groups of structurally related natural products. Many compounds of this class of alkaloids have been isolated mainly from the genera Alstonia and Rauwolfia of the family Apocynaceae. ° Much of the early isolation and stmctural work was performed on the Alstonia alkaloids in the laboratories of Elderfield and Schmid and was followed by the biomimetic interconversions of LeQuesne et al. " ... 

The sarpagjne-related alkaloids occur mainly in the plant family Apoc-ynaceae, the most important genera being Rauwoljia and Alstonia. Alkaloid-rich species of these families have been used in folk medicine against a variety of diseases because of their interesting anticancer, antibacterial, antiar-... 

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