New alkaloids from Strychnos icaja

New Antimalarial and Cytotoxic Sungucine Derivatives from Strychnos icaja Roots

“…The UV spectrum of (10) was superimposable on that of isosungucine (8) and the molecular weight, established by HRE-SIMS, 651.3326, corresponds to the molecular formula C 42 H 42 N 4 O 3 , suggesting a hydroxy substituent on the isosungucine skeleton. 1 H-1 H COSY, 1 H and 13 C, HMQC and HMBC spectra were mainly similar to those of isosungucine.…”

“…After extraction and purification, 11 pure compounds, namely icajine (1), vomicine (2), 19,20-a-epoxynovacine (3), 19,20-aepoxy,15-hydroxynovacine (4), strychnine, isostrychnine (5) bisnordihydrotoxiferine (6), sungucine (7), isosungucine (8), 18-hydroxysungucine (9), 18-hydroxyisosungucine (10), were isolated. Vomicine (2), identified by comparison of its UV, IR, MS, TLC properties with an authentic sample was previously described in the leaves (7), (8). Isostrychnine (5) whose hemisynthesis from strychnine had been realised (6) was later found in Strychnos nux-vomica roots and leaves (6).…”

“…The pH 8 extract was fractionated first by MPLC on 180 g Merck LichroPrep Si 60 40 ± 63 mm (Merck 9336) with CH 2 Cl 2 /MeOH (0 to 1 l: 100 % CH 2 Cl 2 ; 1 to 2.2 l: 0.5 % MeOH; 2.2 to 3.1 l: 1 % MeOH; 3.1 to 5 l: 2 % MeOH; 5 to 7 l: 3 % MeOH; 7 to 8.9 l: MeOH 4 %; 8.9 to 9.6 l: MeOH 5 %; 9.6 to 11 l: MeOH 7.5 %; 11 to 12 l: 10 % MeOH; 12 to 13 l: 50 % MeOH; end: 100 % MeOH) to give (I ± XXVI) fractions, detected by TLC (EtOAC/2-PrOH/NH 4 OH, 80 : 15 : 5). Sungucine (40 mg) (7) and isosungucine (30 mg) (8) were present in the same fractions (X to XIV, 5415 to 9840 ml, 3 g). Preparative TLC were carried out to separate the two compounds: one migration with the system: hexane ± CHCl 3 ± MeOH ± H 2 O (3:7:5:5) (organic phase) and three migrations with the system CHCl 3 -MeOH (14 : 1) on silica gel F254 plates.…”

“…Thus, bioassay-guided fractionation using antimalarial activity testing was carried out with the root extract. This has resulted in the isolation and identification of the three new sungucine derivatives 8, 9 and 10 as well as of two known compounds, isostrychnine (5), previously found in Strychnos nux-vomica (6) and vomicine (2), previously found in the leaves along with 15 other monomers (7), (8).…”

“…Structures of compounds 1 ± 10.385(5), 345(10), 317(20), 274 (33), 236(22), 220 (34), 182(5), 144(8), 133(10), 122 (25), 107 (10); 1 H-and13 C-NMR data are given inTables 1 and 2; CD (MeOH) nm (De) 200 (± 68.30), 236(+ 8.20), 280 (± 6.83), 300 (± 2.04).18-Hydroxy-sungucine (9): White amorphous powder. On TLC, it gave a blue fluorescence at 366 nm after spraying with cerium sulfate reagent; UV (MeOH): l max (log e) = 220 (4.38), 265 (3.88), 292 (4.03), 302 nm (4.06); IR (KBr): u max = 3436, 2927, 1668, 1630, 1594, 1481, 1462, 1418, 1359, 1281, 1145, 754 cm ±1 ; ESIMS: m/z (rel.…”