From Tabernaemontana

Abe F, Tatsuo Y, Guevara- BQ. Indole alkaloids from Tabernaemontana pandaeaqui in the Philippines. Biochem Syst Ecol 1993 21 847-848. 

Toh-Seok K, Kooi-Mow S. Conodurine, conoduramine, and ervahanine derivatives from Tabernaemontana corymbosa. Phytochemistry 1992 63 625-629. 

Indole alkaloids from Tabernaemontana plants are all biogenetically derived from tryptophan (tryptamine) and secologanine, which constitute the indole and terpenic portions, respectively, and can be classified into nine main types depending on the structural characteristics of their skeleton (Fig. 1). 

Fig. 1. Classification of indole alkaloids isolated from Tabernaemontana plants.

B. Indole Alkaloids Isolated from Tabernaemontana Species... 

Srivastava, S., Singh, M. M., Kulshreshtha, D. K. 2001. A new alkaloid and other anti-implantation principles from Tabernaemontana heyneana. Planta Medica, 67 577-579. 

Van Beek, T. A., Verpoorte, R., Baerheim Svendsen, A. and Fokkens, R. 1985. Antimicrobially active alkaloids from Tabernaemontana chippi. Journal of Natural Products, 48 400 23. 

Finally, condensation of the indolo-azepine (278) with 4-chlorobutanal gave107 an epimeric mixture of intermediate quaternary salts, formulated as (291), either of which, on reaction with triethylamine, suffered fragmentation and re-cyclization, with formation of desethylibophyllidine (292), which is the alkaloid recently isolated14e from Tabernaemontana albiflora (Scheme 41). 

Tabernaemontana divaricata (double flower variety) provided an unusual minor alkaloid, voaharine (178), whose structure was established by X-ray analysis [137]. Voaharine is exceptional in being in all probability a tryptamine and jccologanine derived alkaloid but possessing a 3-quinolone instead of an indole chromophore. Voaharine is probably derived from voaphylline (180) (which is also present in the plant) via oxidation and rearrangement and represents the first instance of a 3-quinolone-type alkaloid obtained from Tabernaemontana. Besides these, and the known alkaloids N-methylvoaphylline (181), pachysiphine (tabersonine-P-epoxide) and apparicine, as well as two new bisindoles (vide infra), the plant also provided several new alkaloids of the aspidosperma-type including (-)-mehranine (179), voafinine (182), N-methylvoafinine (183), voafinidine (184) and voalenine (185) which were obtained in minute amounts [138-140]. 

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). 

Tubotaiwine (168), a condylocarpine-type indole alkaloid, obtained from Tabernaemontana dichotoma of Sri Lankan origin, was subjected to a stereochemical investigation with extensive NMR studies involving NOE dif-... 

In an extensive study of indole alkaloids from Tabernaemontana dichotoma, Perera and co-workers reported the isolation and characterization of eight bisindole alkaloids of the vobasine-coronaridine type (90,93). Of these, the previously known alkaloids tabernamine (173), voacamine (175), and 3 R/S-hydroxyvoacamine (178) were identified from their spectral characteristics and co-TLC with authentic samples (91). UV, IR, and XH NMR data of three of the bisindole alkaloids indicated a close structural relationship to tabernamine (173), and the XH NMR of one of these alkaloids was identical to that of tabernamine, except that the signal at 6 2.62 ppm due to the N-Me group was missing. The MS and IR spectroscopic data... 

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