14.3.10 Phytochemistry and Pharmacological Activities
of A. Pneumatophora
14.3.10.1 Anti-melanogenic Properties
Koyama et al. isolated various alkaloids (3, 24, 286, 309, 320–327) from the
methanolic extract of A. pneumatophora leaves (Fig. 14.57) and evaluated its
anti-melanogenic properties (Koyama et al. 2010a). A melanin inducer
(3-isobutyl-1-methylxanthine) stimulated B16 melanoma cells were cultured with
various concentration of (6.3–100 µM) isolated alkaloids for four days.
A dose-dependent cell viability (IC 50 = 58.3, and 68.9 µM, respectively) and a less
Alstrostine G (304)
Alstrostine H (305)
Alstrostine I (306)
Alstrostine J (307)
Alstrostine K (308)
Echitamidine (309)
N
N
H
O
O
OH
N
4 -Demethyl alstogustine (310)
N
4 -Demethyl-12-methoxy
alstogustine N
4 oxide (312)
N
O
N
H
O
O
6,7-Seco angustilobine B (311)
17-O-Acetyl-Nbdemethylechitamine (314)
Nb-Methyl-aspidodasycarpine (315)
Anthirine (316)
Eburenine (313)
N
N
H
O
O
O
O
N
H
N
O
COOCH 3
N
O
N
OH
COOCH 3
N
H
N
COOCH 3
O
H
N
H
COO
O
N
N
N
H
O
O
OH
N
N
H
O
O
O
OH
N
O
O
O
O
OH
N
H
N
N
H
O
OH
O
O
OH
N
H
N
N
N
Fig. 14.55 Chemical structures of alkaloids from A. rostrata (304–316)
Winphylline A (317)
Winphylline B (318)
17-O-Acetyl norechitamine (319)
N
OHC
N
OH
COOMe
HOH 2 C
N
H
OH
COOMe
N
OH
O
H
H
N
H
N
OH
COOMe
AcOH 2 C
Fig. 14.56 Chemical structures of various alkaloids from A. rostrata (317–319)
516
A. T. Paul et al.