Isolation and structure of perakine

Regiospecific, Enantiospecific Total Synthesis of C-19 Methyl Substituted Sarpagine Alkaloids Dihydroperaksine-17-al and Dihydroperaksine

“…A number of alkaloids are known which belong to the sarpagineajmaline series, and share this unique feature. 5b These include the sarpagine alkaloids 10-hydroxy dihydroperaksine ( 3 ), 4 O-acetyl preperakine ( 4 ), 5,6 and the ajmaline-related alkaloids perakine ( 5 ) 5b,7,8 and raucaffrinoline ( 6 ) 5b,7,9 illustrated in Figure 1, as well as macrosalhine chloride, 5 peraksine, 5 verticillatine, 5 10-methoxyperakine, 5b,7 and vincawajine. 5b,7 No enantiospecific total synthesis of this class of sarpagine-ajmaline alkaloids has appeared to date.…”

Monoterpenoid Indole Alkaloids from Alstonia mairei

“…The remaining 13 C-NMR data (see Table 1 [12]. Two moieties were connected at C(19) and C(9') which was supported by the HMBC correlation between d(H) 4.89 (q, J ¼ 6.5, HÀC (19) and d(C) 166.3 (s, C(9')). The configuration of 2 was identical to that of 11-methoxyminovincinine, as supported by its negative specific rotation and ROESY spectra.…”

“…In this article, we describe the isolation and structure elucidation of three new alkaloids, (14a,15a)-14,15-epoxyaspidofractinine (1), and maireines A and B (2 and 3, resp. ), together with 19 known isolates, venalstonine (4) [10], (À)-minovincinine (5) [11], (À)-11-methoxyminovincinine (6) [12], (À)-echitovenine (7) [13], echitovenaldine (8) [14], echitovenidine (9) [15], 11-methoxyechitovenidine (10) [15], echitoveniline (11) [13], 11-methoxyechitoveniline (12) [13], echitoserpidine (13) [16], 11-methoxyechitoserpidine (14) [17], (19S)-vindolinine (15) [10], lochnericine (16) [18], tabersonine (17) [18], perakine (18) [19], picrinine (19) [20], deacetylpicraline 3,4,5-trimethoxybenzoate (20) [21], picralinal (21) [22], and rhazimol (22) [23] (Fig. 1).…”

Alkaloid Distribution in Some African Rauvolfia Species

“…Although KoMpis et al [40] hypothesised that indolenines such as perakine [42] could be derived by simple reactions with no rearrangements from aj maline -type compounds, it can also be argued that the indolenines are intermediate between the sarpagans such as normacusine B and the dihydroindoles and are therefore present often in trace amounts. Vomilenine for example can be so related to ajmaline and 21-deoxy-vomilenine to tetraphyllicine, the presence of the indolenine NaC2 double bond facilitating the methylation of the Na atom.…”