the conclusion that these compounds are not cytotoxic in nature (IC 50 > 25 µg/mL).
148–150 comprised of picraline-type skeletons (arise through a corynanthe-type
skeleton) while 147 consists of an ajmaline-type skeleton.
Cheenpracha et al. isolated 11 alkaloids (118, 151–160) from the methanolic
extract of A. macrophylla bark (Fig. 14.33) and evaluated the antiplasmodial
activity (P. falciparum K1, MDR) and cytotoxicity activities in KB cell lines
(Cheenpracha et al. 2013). Alstonisine (158) exhibited moderate antiplasmodial
activity (IC 50 of 7.6 µM), while dihydroartemisinin was used as a positive control
(IC 50 = 1.41 nM). Remaining screened compounds did not exhibit any antiplasmodial activity. In cytotoxicity assays, all the screened compounds were not
cytotoxic to the KB cell line (IC 50 = >100 µM). Doxorubicin (IC 50 = 0.55 µM)
and ellipticine (IC 50 = 4.87 µM) were used as reference cytotoxic substance and
positive control.
2(S) cathafoline (138); R = H
2(S)-10-methoxycathafoline (139); R = OMe
N
N
O
O
H
N
N
O
O
H
2(R)-3-Hydroxycathafoline (137)
HO
N
N
HO
O
O
N
N
O
O
O
O
MeO
MeO
O
O
Macrocarpine (132)
HO
H
N
N
O
N
N
O
O
H
H
H
H
N
N
H
H
H
H
O
O
N
N
H
H
H
H
O
O
O
H
HO
Macrodasine H (133)
O
HO
HN
N
O
OMe
Alstonoxine C (134)
OH
HO
HN
N
O
OMe
Alstonoxine D (135)
N
N
H
CH 2 OH
H
H
N
N
H
H
COOMe
10-Demethoxyvincorine (140); R
1 = R
2 = H
11-methoxyvincorine (141); R
1 = R
2 = OMe
N
N
H
H
COOMe
10-demethoxyvincorine-N
4 -oxide (142); R = H
Vincorine-N
4 -oxide (143); R = OMe
O
N
N
H
H
MeO
H COOMe
O
19,20-Z-affinisine (136)
Alstofolinine A (130)
20,21-Dihydroalstonerine (131)
R
R
1
R
2
R
Fig. 14.31 Chemical structures of various alkaloids from A. macrophylla (130–146)
14 Pharmaceutical Application of Bio-actives …
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