SUPPLEMENTARY MATERIAL
Isolation of -glucosidase inhibitors including a new flavonol glycoside
from Dendrobium devonianum
Jing Suna,b, Fudong Zhangc, Miao Yanga, Lijun Chena, Rui Zhana, Ling
Lic,*, Yegao Chena,*
a
School of Chemistry and Chemical Engineering, Yunnan Normal University,
Kunming 650500, China
b
Qujing Medical College, Qujing 655000, China
c
Research Center for Biomedical Engineering, Kunming Medical University,
Kunming 650500, China
*Corresponding authors. Tel: 86-871-65941089; Email: ygchen48@126.com
(Y.Chen), kmli62@163.com (L.Li)
Isolation of -glucosidase inhibitors including a new flavonol glycoside
from Dendrobium devonianum
From the whole plant of Dendrobium devonianum, a new flavonol glycoside,
5-hydroxy-3-methoxy-flavone-7-O-[β-D-apiosyl(1→6)]-β-D-glucoside, as well
as thirteen known compounds was isolated. Their structures were identified
based on extensive spectroscopic studies including HREIMS, 1H,
13
C NMR,
DEPT, H-H COSY, HSQC, HMBC and NOESY spectra. The new compound
and gigantol were evaluated for their -glucosidase inhibitory activity, and
both displayed more potent -glucosidase inhibitory activity than acarbose, one
of the most potent -glucosidase inhibitor drugs, with the inhibition rate of
43.4% and 36.7% respectively in the concentration of 437.5 mol/L.
Keywords: Dendrobium devonianum; Orchidaceae; flavonol glycoside
Supporting information
Spectroscopic data of the known compounds 2-14.
Figure S1. Selective HMBC (H→C) correlations for compound 1.
Original spectra of compound 1.
1
H NMR Spectrum (500 MHz, DMSO-d6)
13
C NMR Spectrum (125 MHz, DMSO-d6)
COSY Spectrum
HSQC Spectrum
HMBC Spectrum
HREIMS
EIMS
Spectroscopic data of the known compounds 2-14.
gigantol (2)
Red gum, C16H18O4, MW: 274; 1H NMR [(CD3)2CO, 500 MHz]:  6.78 (1H, d, J= 2.0
Hz, H-2’), 6.76 (1H, d, J= 8.0 Hz, H-5’), 6.67 (1H, dd, J= 8.0, 2.0 Hz, H-6’ ), 6.35
(1H, dd, J= 2.0, 2.0 Hz, H-6), 6.31 (1H, d, J= 2.0, 2.0 Hz, H-4), 6.29 (H, dd, J= 2.0,
2.0 Hz, H-2), 3.77 (3H, s, 5-OMe), 3.69 (3H, s, 3’-OMe), 2.77 (4H, m, H-α, H-α’);
C NMR [(CD3)2CO, 125 MHz]:  161.6 (C-5), 159.0 (C-3), 147.8 (C-1), 145.2
13
(C-3’), 145.0 (C-4’), 134.0 (C-1’), 121.5 (C-6’), 115.4 (C-2’), 112.7 (C-5’), 108.8
(C-2), 106.2 (C-6), 99.6 (C-4), 56.0 (5-OMe), 55.2 (3’-OMe), 38.8 (C-α), 37.8 (C-α’).
(-)-syringaresinol (3)
Colorless powder, C22H26O8, MW: 418; 1H NMR [(CD3)2CO, 400 MHz]:  7.17 (2H,
brs, 4-OH), 6.67 (4H, s, H-2, 2’, 6, 6’), 4.66 (2H, d, J= 4.0 Hz, H-7, 7’), 4.23 (2H, m,
H-9a, 9a’), 3.86 (2H, m, H-9b, 9b’), 3.81 (12H, s, 3,3’,5,5’-OCH3), 3.10 (2H, m, H-8,
8’);
13
C NMR[(CD3)2CO, 100 MHz]:  148.6 (C-3, 3’, 5, 5’), 136.1 (C-4, 4’), 133.1
(C-1, 1’), 104.3 (C-2, 2’, 6, 6’), 86.8 (C-7, 7’), 72.3 (C-9, 9’), 56.6 (3, 3’, 5, 5’-OCH3),
55.3 (C-8, 8’).
N-trans-feruloyl tyramine (4)
White powder, C18H19NO4, MW: 313; 1H NMR (CD3OD, 400 MHz):  7.45 (1H, d,
J= 15.7 Hz, H-8), 7.06 (1H, d, J= 8.5 Hz, H-3’, 5’), 7.02 (1H, d, J= 8.5 Hz, H-2’, 6’),
6.79 (1H, d, J= 8.2 Hz, H-5), 6.72 (1H, dd, J= 8.5, 1.8 Hz, H-6), 6.70 (1H, d, J= 1.8
Hz, H-2), 6.41 (1H, d, J= 15.7 Hz, H-7), 3.87 (3H, s, 3-OCH3 ), 3.48 (2H, t, J= 7.5 Hz,
H-8’ ), 2.76 (2H, t, J= 7.5 Hz, H-7’ ); 13C NMR (CD3OD, 100 MHz):  169.2 (C-9)，
156.9 (C-4’) , 150.3 (C-3), 149.4 (C-4), 142.1 (C-7), 131.2 (C-1’), 130.7 (C-3’, 5’),
128.0 (C-1), 123.3 (C-8), 118.5 (C-5), 116.6 (C-2), 116.3 (C-2’, 6’), 111.4 (C-6), 56.3
(3-OCH3), 42.4 (C-8’), 35.6 (C-7’).
paprazine (5)
Colorless powder, C17H17NO3, MW: 283; 1H NMR (CD3OD, 400 MHz):  7.46 (1H,
d, J= 15.7 Hz, H-8), 7.41 (2H, d, J= 8.6 Hz, H-2, 6), 7.07 (2H, d, J= 8.6 Hz, H-3, 5),
6.80 (2H, d, J= 8.6 Hz, H-3’, 5’), 6.72 (2H, d, J= 8.6 Hz, H-2’, 6’), 6.40 (1H, d, J=
15.7 Hz, H-7), 3.48 (2H, t, J= 7.6 Hz, H-8’), 2.77 (2H, t, J= 7.6 Hz, H-7’); 13 C NMR
(CD3OD, 100 MHz):  169.2 (C-9), 160.5 (C-4), 156.9 (C-4’), 141.8 (C-8), 131.3
(C-1’), 130.7 (C-3’, 5’), 130.5 (C-3, 5), 127.7 (C-1), 118.4 (C-7), 116.7 (C-2, 6),
116.2 (C-2’, 6’), 42.6 (C-8’), 35.8 (C-7’).
vanillic acid (6)
Colorless powder, C8H8O4, MW: 168; 1H NMR (CD3OD, 400 MHz):  7.59 (1H, dd,
J= 8.2, 1.8 Hz, H-6), 7.55 (1H, d, J= 1.8 Hz, H-2), 6.91 (1H, d, J= 8.0 Hz, H-5), 3.89
(3H, s, 3-OCH3);
13
C NMR (CD3OD, 100 MHz):  170.9 (C-7), 151.9 (C-3), 148.0
(C-4), 124.8 (C-6), 122.8 (C-1), 115.4 (C-5), 113.3 (C-2), 56.2 (3-OCH3).
p-hydroxybenzoic acid (7)
White neddles, C7H6O3, MW: 138; 1H NMR (CD3OD, 500 MHz):  7.86 (2H, d, J=
8.7 Hz, H-2, 6), 6.81 (2H, d, J= 8.5 Hz, H-3, 5);
C NMR (CD3OD, 125 MHz): 
13
170.2 (C-7), 163.3 (C-4), 133.0 (C-3, 5), 122.8 ( C-1), 116.0 (C-2, 6).
p-hydroxybenzaldehyde (8)
White neddles, C7H6O2, MW: 122; 1H NMR (CD3OD, 400 MHz):  9.76 (1H, s),
(7.79 (2H, dd, J= 8.4, 2.0 Hz), 6.92 (2H, d, J= 8.1 Hz), 4.91 (1H, s);5)13C NMR
(CD3OD, 100 MHz):  192.8 (C-7), 165.1 (C-4), 133.4 (C-2, 6), 130.2 (C-1), 116.9
(C-3, 5).
oleanolic acid (9)
White powder, C30H48O3, MW: 456; 1H NMR (C5D5N, 400 MHz):  5.49 (1H, s,
H-12), 3.47 (1H, t, J= 7.0 Hz, H-3), 1.04, 1.00, 0.99, 0.95, 0.93, 0.87, 0.84, 0.83 (21H,
s, 7×CH3); 13C NMR (C5D5N, 100 MHz):  180.0 (C-28), 139.3 (C-13), 125.7 (C-12),
78.2 (C-3), 55.8 (C-5), 48.2 (C-17), 48.1 (C-9), 46.2 (C-19), 42.5 (C-14), 41.6 (C-18),
40.0 (C-8), 39.5 (C-4), 39.4 (C-1), 37.5 (C-10), 34.0 (C-21), 33.4 (C-7), 33.0 (C-22),
31.1 (C-20), 28.9 (C-23), 28.2 (C-15), 28.4 (C-2), 24.0 (C-30), 23.9 (C-16), 23.7
(C-11), 23.5 (C-30), 21.5 (C-29), 19.1 (C-6), 18.8 (C-27), 17.5 (C-26), 16.6 (C-24),
15.7 (C-25).
vomifoliol (10)
White powder, C13H20O3, MW: 224; 1H NMR [(CD3)2CO, 400 MHz]:  5.88 (1H, d,
J= 16.0 Hz, H-1’), 5.83 (1H, dd, J= 16.0, 5.0 Hz, H-2’), 5.78 (1H, s, H-2), 4.33 (1H,
m, H-3’), 2.46 (1H, d, J= 16.0 Hz, H-6a), 2.10 (2H, d, J= 16.0 Hz, H-6b), 1.80 (3H, s,
3-CH3), 1.30 (3H, d, J= 7.0 Hz, 4’-CH3), 0.96 (3H, s, 5α-CH3), 0.88 (3H, s, 5β-CH3);
C NMR [(CD3)2CO, 100 MHz]:  197.5 (C-1), 164.5 (C-3), 137.1 (C-2’), 129.4
13
(C-1’), 126.9 (C-2), 79.0 (C-4), 67.9 (C-3’), 50.4 (C-6), 41.8 (C-5), 24.4 (C-4’), 24.2
(5β-CH3), 23.4 (5α-CH3), 19.2 (3-CH3).
7-oxo--sitosterol (11)
Colorless neddles, C29H48O2, MW: 428; 1H NMR (CDCl3, 400 MHz):  5.68 (1H, d,
J= 1.8 Hz, H-6), 3.70 (1H, m, H-3), 2.52 (1H, ddd, J = 13.0, 5.0, 1.8 Hz, H-4α), 2.40
(1H, ddt, J= 13.0, 11.0, 1.8 Hz, H-4α’), 2.24 (1H, m, H-8), 1.97 (1H, dt, J= 12.7, 4.0
Hz, H-12), 1.20 (3H, s, H-19), 0.93 (3H, d, J= 6.8 Hz, H-21), 0.86 (3H, d, J= 6.8 Hz,
H-27), 0.82 (3H, t, J= 6.8 Hz, H-29), 0.81 (3H, d, J= 6.8 Hz, H-26), 0.64 (3H, s,
H-18);
13
C NMR (CDCl3, 100 MHz):  202.3 (C-7), 165.1 (C-5), 126.1 (C-6), 70.5
(C-3), 54.6 (C-17), 49.9 (C-9, C-14), 45.8 (C-8), 45.4 (C-24), 43.1 (C-13), 41.8 (C-4),
38.6 (C-12), 38.3 (C-10), 36.3 (C-1), 36.0 (C-20), 33.9 (C-22), 31.1 (C-2), 29.1
(C-25), 28.5 (C-16), 26.3 (C-15), 26.1 (C-23), 23.0 (C-28), 21.2 (C-11), 19.8 (C-27),
19.0 (C-26), 18.9 (C-21), 17.3 (C-19), 11.9 (C-18, C-29).
3β-hydroxy-5α,8α-epidioxyergosta-6,9,22-triene (12)
White powder, C28H42O3, MW: 426; 1H NMR [(CD3)2CO, 500 MHz]:  6.63 (1H, d,
J= 8.5 Hz, H-7), 6.30 (1H, d, J= 8.5 Hz, H-6), 5.30 (1H, dd, J= 15.5, 7.5 Hz, H-23),
5.21 (1H, dd, J= 15.4, 8.0 Hz, H-22), 1.08 (3H, s, H-19), 1.03 (3H, d, J= 6.7 Hz,
H-21), 0.93 (3H, d, J= 6.8 Hz, H-28), 0.86 (3H, d, J= 7.0 Hz, H-26), 0.84 (3H, d, J=
6.9 Hz, H-27), 0.77 (3H, s, H-18).
13
C NMR [(CD3)2CO, 125 MHz]:  144.6 (C-9),
136.7 (C-6), 136.4 (C-22), 133.0 (C-23), 131.2 (C-7), 119.4 (C-11), 78.5 (C-8), 83.1
(C-5), 66.1 (C-3), 56.6 (C-17), 49.2 (C-14), 43.7 (C-13), 43.0 (C-24), 42.0 (C-12),
40.7 (C-20), 38.6 (C-10), 37.6 (C-4), 33.8 (C-1), 33.5 (C-25), 31.7 (C-2), 29.3 (C-16),
25.8 (C-19), 21.5 (C-15), 21.1 (C-21), 20.3 (C-26), 19.8 (C-27), 18.0 (C-28), 13.2
(C-18).
-sitosterol (13)
Colorless neddles, identified by co-TLC and comparison of 1H NMR,
13
C NMR and
EIMS with those of authentic samples.
daucosterol (14)
White powder, identified by co-TLC and comparison of 1H NMR,
EIMS with those of authentic samples.
13
C NMR and
Figure S1. Selective HMBC (H→C) correlations for compound 1
OH
HO
HO
O
HO
H
HO
HO
H
H
O
OH
H
O
O
OCH3
OH
1
O
Original spectra of compound 1.
HNMR:
Original spectra of compound 1.
13
CNMR：
Original spectra of compound 1.
H-H COSY：
Original spectra of compound 1.
HSQC：
Original spectra of compound 1.
HMBC：
Original spectra of compound 1.
HREIMS
Original spectra of compound 1.
EIMS