Hazunta

Among plumeran alkaloids isolated from the leaves of T. coffeoides (Hazunta modesta), two minor compounds were not previously discussed (70). One was recognized as 3-oxotabersonine (68, C21H22N203, MP 151.5-153°C, [a]D -11.4°) identical to the product isolated by Sakai from the seeds of Amsonia elliptica (198). Compound 68 was also obtained in 32% yield by KMn04 oxidation of tabersonine (67). 

Ervatamia, Gabunia, Hazunta, Muntafara, Pagiantha, Pandaca, Peschiera, Phrissocarpus, and Stenosolen, All of these contain alkaloids related to Ibogaine. 

In a chemotaxonomic survey of seven of the eight species of the genus Hazunta, which is endemic to the Malagasy Republic, twenty-four alkaloids have been encountered, of which ten are new.64" Reserpiline and 3-isoreserpiline were the only alkaloids of this group to be isolated, and these were found in only one of the seven species, H. membranacea (DC.) Pichon forma pilifera Mgf. 

Catharanthine—Ibogamine-Cleavamine Group. Catharanthine is one of the alkaloids produced in suspension cultures of the 200 GW cell line of Catharanthus roseus, 2a and ibogamine has been found in the stem and root bark of Hazunta modesta var. modesta subvar. montana.62 Four Ervatamia species have been shown to contain several alkaloids of this group.64 Thus, E. orientalis (R. Brown) Domin contains voacangine, conopharyngine, pandine, and pandoline, E. daemeliana... 

Alkaloid T, isolated earlier1340 from the stems and roots of Hazunta costata, proves134 to be tabernaelegantine A (305), and Alkaloid X, a new alkaloid from the... 

Oxosilicine (163), a new alkaloid of a Malagasy plant, Hazunta silicicola Pichon, has an a-acylindole structure related to 20-epiervatamine. Although details of the isolation are still not available, the synthesis of (163) has already been announced (Scheme 19) this constitutes the first total synthesis of an alkaloid of the dihydrovobasine-ervatamine group. The major feature of the route adopted is that the acylindole linkage is formed at the outset, and the bond to C-7 (indole jS -position) formed much later. This route may well be applicable to the synthesis of other 2-acylindole alkaloids. 

Hydroxy-ll-methoxy-tabersonine Hazunta modesta var. brevituba L 114 141... 

Apodine (93) has been obtained from Peschiera van heurckii (Muell.-Arg.) L. Allorge (131) and P. buchtieni (Tabernaemontana buchtieni Mgf.) (34). Deoxapodine (modestanine, 94) occurs in Hazunta modesta var. mod-esta subvar. montana (103) and Ervatamia corymbosa Roxb. ex Wall. (132). Vandrikine (95) occurs in E. corymbosa (132), and hedrantherine (96) in P. van heurckii (131). 

A dihydroxy derivative of vincadifformine, formulated as 14,15-dihydroxyvincadifformine (101), has been isolated from Hazunta modesta var. modesta subvar. montana (103). Unfortunately, the paucity of alkaloid obtained precluded determination of its stereochemistry. 

Aspidosperma polyneuron Hazunta modesta var. brevituba Rauvolfia suaveolens Rauvolfia volkensii Strychnos potatorum Voacanga chalotiana... 

A second new /3-anilinoacrylate alkaloid was also obtained from Hazunta velutina by Potier and co-workers (33). Hazuntinine [a]D-482° showed a molecular ion at 412 mu for a probable molecular formula of C23H28N2O5. The mass spectrum showed a base peak at m/e 138 and a... 

Further extractions of the roots of Hazunta modesta have resulted in the isolation of six additional alkaloids, of which 16-demethoxycarbonyl-20-ep/-ervatamine and 6-oxosilicine belong to this group. ... 

Iboga alkaloids are found in other genera [e.g., Conopha-ryngia, Ervatamia, Hazunta, Melodinus, Pagiantha, Pan-daca, Tabernaemontanae, and Voacanga (Apocynaceae). 

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