Indoloquinazoline Alkaloids from Araliopsis tabouensis

• Published in: Helvetica chimica acta Vol. 86; no. 8; pp. 2914 - 2918
• Main Authors: Christopher, Ezugwu, Bedir, Erdal, Dunbar, Chuck, Khan, Ikhlas A., Okunji, Christopher O., Schuster, Brian M., Iwu, Maurice M.
• Format: Journal Article
• Language: English
• Published: Basel WILEY-VCH Verlag 01.08.2003; WILEY‐VCH Verlag; Wiley
• Subjects: Chemistry; Chemistry, Multidisciplinary; Physical Sciences; Science & Technology
• ISSN: 0018-019X; 1522-2675
• DOI: 10.1002/hlca.200390239

Three new indoloquinazolidine‐type alkaloids, 8,13‐dihydro‐2‐methoxyindolo[2′,3′: 3,4]pyrido[2,1‐b]quinazolin‐5(7H)‐one (1), 8,13‐dihydro‐2‐methoxy‐13‐methylindolo[2′,3′: 3,4]pyrido[2,1‐b]quinazolin‐5(7H)‐one (2), and 5,8,13,14‐tetrahydro‐2‐methoxy‐14‐methyl‐5‐oxo‐7H‐indolo[2′,3′: 3,4]pyrido[2,1‐b]quinazolim‐6‐iun chloride (3) were isolated from Araliopsis tabouensis, together with three known compounds. The structures of the new compounds were determined primarily from 1D‐ and 2D‐NMR analysis. The antimalarial activities of compounds 1–5 were evaluated against Plasmodium falciparum D6 and W2 clones. The IC50 values in antimalarial bioassay for compounds 2–5 varied from 1.8 to 4.7 μg/ml.