Biologically active alkaloids from Alstonia angustiloba / Ku Wai Foong

The alkaloidal content of Malaysian plant, Alstonia angustiloba Miq., was investigated and the results are summarized as below (Table). A total of 20 alkaloids were isolated and characterized, of which, three were new alkaloids, viz., angustilobine C (1), andransinine (2), and angustiphylline (3). A...

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Main Author: Ku, Wai Foong
Format: Thesis
Published: 2011
Subjects:
Online Access:http://studentsrepo.um.edu.my/3897/1/1._Title_page%2C_abstract%2C_content.pdf
http://studentsrepo.um.edu.my/3897/2/c_1_Introduction.pdf
http://studentsrepo.um.edu.my/3897/3/c_2_Results_and_Discussions.pdf
http://studentsrepo.um.edu.my/3897/4/c_3_Experimental.pdf
http://studentsrepo.um.edu.my/3897/5/References.pdf
http://pendeta.um.edu.my/client/default/search/results?qu=Biologically+active+alkaloids+from+Alstonia+angustiloba&te=
http://studentsrepo.um.edu.my/3897/
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Summary:The alkaloidal content of Malaysian plant, Alstonia angustiloba Miq., was investigated and the results are summarized as below (Table). A total of 20 alkaloids were isolated and characterized, of which, three were new alkaloids, viz., angustilobine C (1), andransinine (2), and angustiphylline (3). Angustilobine C (1) and andransinine (2) are alkaloids of the angustilobine- and andranginine type, respectively, while angustiphylline (3) is a new bisindole alkaloid constituted from the union of uleine and secovallesamine moieties. Alkaloids 1 and 2 were obtained from the leaf extract while the bisindole 3 was isolated from the bark extract. In addition to the new alkaloids, seventeen known alkaloids were also obtained which were: 19,20-E-vallesamine (4), 17-O-acetylvallesamine (5), yunnannensine (6), angustilobine A (7), angustilobine B (8), nor-6,7-secoangustilobine B (9), nor-6,7-seco-19,20-epoxyangustilobine B (10), undulifoline (11), condylocarpine (12), 20S-tubotaiwine (13), N(4)-demethylechitamine (14), 17-O-acetyl-N(4)-demethylechitamine (15), alstolucine B (16), vincamine (17), 16R,19E-isositsirikine (18), venoterpine (19), and cantleyine (20). Angustilobine C (1) showed moderate cytotoxicity towards both drug-sensitive and vincristine-resistant KB cells (IC50 7.76 and 7.33 g/mL, respectively), while andransinine (2) reversed multidrug resistance in vincristine-resistant KB cells (KB/VJ300 cells, IC50 1.61 g/mL in the presence of 0.1 g/mL of vincristine).