SGLT inhibitory potential was assessed by monitoring inhibition of uptake of
methyl-a-D-glucopyranoside in cultured cells expressing SGLT1 or SGLT2. As
represented in Table 14.13, 10-methoxy-N
1 -methylburnamine-17-O-veratrate
(177) resulted in a significant SGLT inhibition, followed by 150 and 175 (95.8,
89.9, and 65.2 for SGLT1 inhibition; 102.6, 101.4, and 103.8 for SGLT2,
respectively). The remaining compounds exhibited a moderate to poor SGLT
inhibition activity (0–30% inhibition).
Alstiphyllanine E (174)
N
N
O
O
O
O
O
O
O
H
N
N
O
O
O
O
O
O
O
O
O
H
Alstiphyllanine F (175)
Alstiphyllanine G (176)
N
N
O
O
HO
O
O
N
N O
O
O
O
O
OMe
OMe
10-Methoxy-N(1)-methylburnamine17-O-veratrate (177); R
1 = OMe, R
2 = H, R' = Me
Burnamine-17-O-30,40,50-trimethoxybenzoate (178);
R
1 = H = R' = H, R
2 = OMe
R'
R
1
N
N
O
O
O
O
O
Quaternine (179)
N
H
N O
HO
O
O
O-Deacetylpicraline (180)
N O
NH
H
O
O
H
H
Alstonal (181)
R
2
Fig. 14.36 Chemical structures of various alkaloids from A. macrophylla (174–181)
Table 14.13 SGLT
inhibitory activities of various
alkaloids from A.
macrophylla
Compound
% inhibition
a
SGLT1
SGLT2
150
89.9
101.4
174
60.3
85.9
175
65.2
103.8
177
95.8
102.6
178
53.0
87.3
a At 50 µM
14 Pharmaceutical Application of Bio-actives …
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