Voaphylline hydroxyindolenine

From the seeds of T. dichotoma, Verpoorte et al. (88) isolated voaphylline hydroxyindolenine (90, by preparative TLC. Because the solution... 

On the basis of their 13C n.m.r. spectra, and in particular on the similarity of the C-5 and C-6 resonances, the 7-chloroindolenine derivatives of the cleavamines and quebrachamines have been concluded to have the same stereochemistry at C-7 as voaphylline hydroxyindolenine, whose configuration is known 14,15-dehydroquebrachamine 7-chloroindolenine thus has the stereochemistry shown in (125).88... 

Vinca minor, cultivated in Georgia, USSR, has been shown to contain ( )-vincadifformine and vincine, both already known to occur in this species, together with apovincamine and 11-methoxyvincadifformine.92 Voaphylline, voaphylline hydroxyindolenine, and 11-hydroxytabersonine have been isolated from the leaves of Tabernanthe pubescens,43/ and 5,22-dioxokopsane (177) from the root bark of Alstonia venenata R. Br. 93 this is the first report of an alkaloid of the heptacyclic kopsine group in this species. 

Several new sources of quebrachamine (5) (10-16) and, particularly, voaphylline (conoflorine, 6) (15,17-34) have been found in recent years. Other known alkaloids encountered in recent extractions include vincadine (7) (35,36), 14,15-didehydro-epivincadine (8) (37), rhazidine (9) (38), and 12-methoxyvoaphylline (10) (39-41). New alkaloids include quebrachamine hydroxyindolenine (strictanol, 11), which has been found in the fruits (42) and leaves (43) of R. stricta, and voaphylline hydroxyindolenine (12), for which five sources have been reported (20,22,27,34,44). In common with many other hydroxyindolenine derivatives of easily oxidized alkaloids, these may well prove to be artifacts of the extraction process. Ervayunine (13), the enantiomer of voaphylline, occurs in the roots of Ervatamia yunnanensis... 

Three alkaloids of this group, voaphylline (135), 12-methoxyvoaphyl-line (136), and voaphylline hydroxyindolenine (137), were isolated from Tabernaemontana dichotoma. Seeds of this plant afforded voaphylline (135) and voaphylline hydroxyindolenine (137) (89), whereas the fruits and leaves yielded 12-methoxyvoaphylIine (136) and voaphylline hydroxyindolenine (137) (91,92). 

Voaphylline (42d) from Voacanga afrieana is 14,15-dehydro-(—)-quebracha-mine-l4,15-/ -epoxide also isolated in this study5 le were the corresponding diol (42e) and voaphylline 7-hydroxyindolenine. 

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