Structures and absolute stereochemistry of (-)-echitoveniline, (-)-11-methoxyechitoveniline and (-)-11-methoxyechitovenedine—new indole alkaloids of

Monoterpenoid Indole Alkaloids from Alstonia yunnanensis

“…Many of them, such as reserpine, 2 vincristine, 3 and yohimbine, 4 are well known for their pharmacological significance. In our previous study of the monoterpenoid indole alkaloids from the family Apocynaceae, a series of alkaloids, including scholarisines A-G, (19,20)-E-alstoscholarine, and (19,20)-Z-alstoscholarine, have been isolated from Alstonia scholaris. [5][6][7] As a continuation of our search for biologically active alkaloids, Alstonia yunnanensis Diels, a medicinal plant used for the treatment of fever, headache, and inflammation in the southwest of China, 8 has been investigated.…”

Melodinines M–U, Cytotoxic Alkaloids from Melodinus suaveolens

“…Compounds 2 and 3 are Aspidosperma -type alkaloids each bearing a methyl group at C-10, a type seldom reported previously. Structures of the new alkaloids were elucidated by spectroscopic methods, while the known alkaloids were identified as 11-hydroxytabersonine ( 10 ), 11-methoxytabersonine ( 11 ), tabersonine ( 12 ), 19-( R )-acetoxytabersonine ( 13 ), 11-methoxy-19-( R )-hydroxytabersonine ( 14 ), lochnericine ( 15 ), 3α-acetonyltabersonine ( 16 ), 3-oxo-tabersonine, venalstonine, scandine, and 10-hydroxyscandine by comparison with data (1D NMR and MS) in the literature. All of the compounds were evaluated for cytotoxicity against five human cancer cell lines.…”

Monoterpenoid Indole Alkaloids from Alstonia mairei

“…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).…”

“…The center. Detailed analysis of 13 C-NMR and DEPT data revealed that 1 belongs to the aspidosperma-type alkaloids [25]. Comparison with venalstonidine [26] indicated that 1 was similar to this alkaloid with the exception for absence of a COOMe group, which is replaced by an additional CH 2 (3)) and 58.6 (d, C (15)) pointed to the presence of a 14,15-epoxy moiety (Fig.…”

“…Absence of a NOE correlation between HÀC (14) and HÀC(15) with any key H-atoms in the ROESY spectrum suggested a-orientation of the epoxy moiety, which was supported by an upfield shift of C (21) C-NMR and DEPT data showed the presence of 3,4,5-trimethoxycinnamic acid moiety (d(C) 166.3 (s, C(9')), 153.3 (s, C(3',5')), 143.9 (d, C(7')), 139.7 (s, C(4')), 129.8 (s, C(1')), 117.0 (d, C(8')), 105.1 (s, C(2',6')), 60.9 (q, MeOÀC(4')), 56.1 (q, MeOÀC(3',5'))) [28]. 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')).…”