20(S)-tubotaiwine (103)
N
N
H
O
O
N
4 -methyl angustilobine B (101)
O
O
O
N
N
H
Angustilobine B N
4 -oxide (102)
O
O
O
N
N
O
H
6,7-secoangustilobine (104)
N
O
NH
O
O
H
N
OH
N
H
H
(+)-manilamine (100)
Fig. 14.24 Chemical structures of various alkaloids from A. scholaris (100–104)
Table 14.11 Anti-tubercular
activities of various alkaloids
from A. scholaris
Compound
MIC (µg/mL)
94
>128
100
>128
102
>128
101
>128
103
>100
104
>128
Rifampicin
98% inhibition at 0.125 µg/mL
Echitamidine N-oxide (107)
N
+
N
H
O
O
O
-
OH
Akuammiginone (105)
N
+
HN
O
O
O
OH
Echitaminic acid (106)
N
+
OH
O
HO
OH
N
H
N
+
- O
O
N
O
OH
N
b -Demethylalstogustine (110)
N
- O
O
N
OH
N
b -Demethylalstogustine N-oxide (108) Akuammicine N-oxide (109)
N
+
N
H
O
O
O
-
Fig. 14.25 Chemical structures of various alkaloids from A. scholaris (105–110)
14 Pharmaceutical Application of Bio-actives …
487