Original Papers
J = 13.5, 6.3 Hz, H-4′), 5.59 (m, H-5′), 5.04 (d, J = 9.2 Hz, H-6′),
22.84 (C-15″ and 17‴), 14.26 (C-16″ and 18‴), 29.20–29.90
(C-4″–13″, 4‴–7‴ and 12‴–15‴).
1
.64 (s, H-8′), 1.63 (s, H-9′), 1.79 (s, H-10′), 2.33 (m, H-2″), 1.61
m, H-3″), 2.15 (m, H-2‴), 1.52 (m, H-3‴), 0.88 (t, J = 6.8 Hz, H-
6″ and H-16‴), 1.24 (m, H-4″ – H-15″ and H-4‴ – H-15‴); 13C
NMR (125 MHz, CDCl ) δC 138.5 (C-1), 112.83 (C-2), 162.86 (C-
2
5
(
1
Hericene H (4): colorless oil, [α]
D
+ 1 (c 0.1, CH Cl );
2 2
UV (MeOH) λ (log ε) 228 (2.34), 294 (2.28) nm; CD (c
max
−
3
1.11 × 10 M, MeOH): no significant Cotton effects; IR (neat) ν
3
max
−
1
3
(
4
(
2
(
), 117.64 (C-4), 163.38 (C-5), 105.5 (C-6), 62.91 (C-7), 193.04
C-8), 55.89 (C-9), 21.43 (C-1′), 124.86 (C-2′), 131.28 (C-3′),
5.31 (C-4′), 69.65 (C-5′), 123.77 (C-6′), 136.69 (C-7′), 25.61
C-8′), 18.34 (C-9′), 16.47 (C-10′), 173.18 (C-1″), 34.23 (C-2″),
4.87 (C-3″), 173.07 (C-1‴), 34.54 (C-2‴), 24.99 (C-3‴), 31.93
C-14″ and 14‴), 22.74 (C-15″ and 15‴), 14.13 (C-16″ and 16‴),
3450, 2924, 2852, 1740, 1622, 1464, 1118 cm ; negative
HRTOFMS m/z 861.6597 [M
861.6608); H NMR (500 MHz, CDCl ) δ 6.51 (s, H-6), 5.31 (s,
–
H]− (calcd. for C55H89O7,
1
3
H
H-7), 10.10 (s, H-8), 3.90 (s, H-9), 12.34 (s, OH-3), 3.28 (dd,
J = 14.1, 7.2 Hz, H-1′), 3.33 (dd, J = 14.1, 7.2 Hz, H-1′), 5.19 (t,
J = 7.2 Hz, H-2′), 2.27 (dd, J = 13.5, 7.4 Hz, H-4′), 2.08 (dd,
J = 13.5, 6.3 Hz, H-4′), 5.59 (m, H-5′), 5.04 (d, J = 9.2 Hz, H-6′),
1.64 (s, H-8′), 1.63 (s, H-9′), 1.79 (s, H-10′), 2.33 (m, H-2″), 1.61
(m, H-3″), 2.15 (m, H-2‴), 1.52 (m, H-3‴), 2.04 (m, H-8‴ and
14‴), 5.34 (m, H-9‴, 10‴, 12‴ and 13‴), 2.76 (t, J = 6.8, H-11‴),
0.88 (m, H-18″ and 18‴), 1.24 (m, H-4″ – 17″, 4‴ – 7‴ and 15‴–
2
9.13–29.70 (C-4″–13″ and 4‴–13‴).
Hericene F (2): colorless oil, [α]
2
5
D
+ 2 (c 0.1, CH Cl );
2 2
UV (MeOH) λ
(log ε) 228 (2.34), 294 (2.28) nm; CD (c 7.1 ×
max
−
4
1
3
0 M, MeOH): no significant Cotton effects; IR (neat) ν
max
451, 2924, 2852, 1740, 1622, 1464, 1118 cm ; negative
−
1
HRTOFMS m/z 833.6285 [M
–
H]− (calcd. for C53H85O7,
17‴); 13C NMR (125 MHz, CDCl ) δC 138.65 (C-1), 112.98 (C-2),
3
1
8
33.6295); H NMR (500 MHz, CDCl ) δ 6.51 (s, H-6), 5.31 (s,
163.01 (C-3), 117.78 (C-4), 163.53 (C-5), 105.65 (C-6), 63.06 (C-
7), 193.19 (C-8), 56.04 (C-9), 21.57 (C-1′), 125.02 (C-2′), 131.42
(C-3′), 45.45 (C-4′), 69.85 (C-5′), 123.90 (C-6′), 136.85 (C-7′),
25.57 (C-8′), 18.49 (C-9′), 16.62 (C-10′), 173.32 (C-1″), 34.38
(C-2″), 25.02 (C-3″), 173.18 (C-1‴), 34.67 (C-2‴), 25.12 (C-3‴),
27.35 (C-8‴ and 14‴), 130.35, 130.22, 128.16, and 128.05 (C-
9‴, 10‴, 12‴ and 13‴), 25.63 (C-11‴), 31.67 and 32.08 (C-16″
and 16‴), 22.74 and 22.85 (C-15″ and 17‴), 14.28 and 14.23 (C-
18″ and 18‴), 29.23–29.85 (C-4″–15″, 4‴–7‴ and 15‴).
3
H
H-7), 10.10 (s, H-8), 3.90 (s, H-9), 12.34 (s, OH-3), 3.28 (dd,
J = 14.1, 7.2 Hz, H-1′), 3.33 (dd, J = 14.1, 7.2 Hz, H-1′), 5.19 (t,
J = 7.2 Hz, H-2′), 2.27 (dd, J = 13.5, 7.4 Hz, H-4′), 2.08 (dd,
J = 13.5, 6.3 Hz, H-4′), 5.59 (m, H-5′), 5.04 (d, J = 9.2 Hz, H-6′),
1
.64 (s, H-8′), 1.63 (s, H-9′), 1.79 (s, H-10′), 2.33 (m, H-2″), 1.61
(
m, H-3″), 2.15 (m, H-2‴), 1.52 (m, H-3‴), 2.04 (m, H-8‴ and
1
0
1
1
7
4‴), 5.34 (m, H-9‴, 10‴, 12‴ and 13‴), 2.76 (t, J = 6.8, H-11‴),
.88 (m, H-16″ and 18‴), 1.24 (m, H-4″ – 15″, 4‴ – 7‴ and 15‴ –
7‴); 13C NMR (125 MHz, CDCl ) δC 138.65 (C-1), 112.98 (C-2),
3
Alkaline hydrolysis reaction [31]
63.01 (C-3), 117.78 (C-4), 163.53 (C-5), 105.65 (C-6), 63.06 (C-
), 193.19 (C-8), 56.04 (C-9), 21.57 (C-1′), 125.02 (C-2′), 131.42
Each compound (1.0 mg) was dissolved in CH Cl and hydrolyzed
2
2
(
2
(
2
1
1
C-3′), 45.45 (C-4′), 69.85 (C-5′), 123.9 (C-6′), 136.85 (C-7′),
5.57 (C-8′), 18.49 (C-9′), 16.62 (C-10′), 173.32 (C-1″), 34.38
C-2″), 25.02 (C-3″), 173.18 (C-1‴), 34.67 (C-2‴), 25.12 (C-3‴),
7.35 (C-8‴ and 14‴), 130.35, 130.22, 128.16 and 128.05 (C-9‴,
0‴, 12‴ and 13‴), 25.63 (C-11‴), 31.67 and 32.08 (C-14″ and
6‴), 22.74 and 22.85 (C-15″ and 17‴), 14.28 and 14.23 (C-16″
with 2 M NaOH/MeOH (2 mL) for 3 h at room temperature. The re-
sulting mixture was then treated with 10 mL of HCl/MeOH under
stirring for overnight. The mixture containing methyl ester of fatty
acids was extracted with CH Cl for 2 times (10 mL × 2). The or-
2
2
ganic layer was evaporated to dryness under vacuum and then
dissolved in 1 mL chromatographically pure CH Cl2 followed by
2
and 18‴), 29.23–29.85 (C-4″–13″, 4‴–7‴ and 15‴).
GC‑MS analysis. The samples were analyzed in split injector mode
by using a fused silica capillary column Rtx-5MS (crosslinked 5%
diphenyl dimethyl polysiloxane, 30 m × 0.25 mm ID × 0.25 µm)
with helium (1 mL/min) as carrier. Oven temperature was pro-
grammed from 50°C to 325°C at a slope of 10°C per min and
then with 15 min hold. The MS was operated in EI mode (70 eV)
scanning from 40 to 500 amu. The retention time of methyl oleate
and methyl linoleate were at 18.80 and 18.83 min, separately.
2
5
Hericene G (3): colorless oil, [α]
D
+ 1 (c 0.1, CH Cl );
2 2
UV (MeOH) λ (log ε) 211 (2.34), 293 (2.28) nm; CD (c 8.4 ×
max
−
4
1
3
0 M, MeOH): no significant Cotton effects; IR (neat) ν
max
−
1
450, 2924, 2852, 1740, 1622, 1464, 1118 cm ; negative
HRTOFMS m/z 835.6464 [M
–
H]− (calcd. for C53H87O7,
1
8
35.6452); H NMR (500 MHz, CDCl ) δ 6.51 (s, H-6), 5.31 (s,
3
H
H-7), 10.10 (s, H-8), 3.90 (s, H-9), 12.34 (s, OH-3), 3.28 (dd,
J = 14.1, 7.2 Hz, H-1′), 3.33 (dd, J = 14.1, 7.2 Hz, H-1′), 5.19 (t,
J = 7.2 Hz, H-2′), 2.27 (dd, J = 13.5, 7.4 Hz, H-4′), 2.08 (dd,
J = 13.5, 6.3 Hz, H-4′), 5.59 (m, H-5′), 5.04 (d, J = 9.2 Hz, H-6′),
Inhibition assays against α-glucosidase and α-amylase
Crude enzyme was extracted from rat-intestinal mucosa as pre-
vious reported with slightly modification [32]. Rats were treated
according to recommendations in the Guide for the Care and Use
of Laboratory Animals approved by the Committee on the Ethics
of Animal Experiments of Institute of Microbiology, Chinese Acad-
emy of Sciences (IMCAS) (Permit No. APIMCAS2017023, permit
date, 10th Apr. 2017). A total of 1.0 g intestinal mucosa homoge-
nate obtained from 8-wk male SD rats was suspended in 3 mL of
0.9% saline, and the suspension was sonicated for 12 times (each
30 s) at 4°C. After centrifugation (10000 g) for 30 min at 4°C, the
resulting supernatant was used as the enzyme solution for the as-
say. Each compound or extracts dissolved in DMSO (1 µL) was
1
(
1
.64 (s, H-8′), 1.63 (s, H-9′), 1.79 (s, H-10′), 2.33 (m, H-2″), 1.61
m, H-3″), 2.15 (m, H-2‴), 1.52 (m, H-3‴), 2.04 (m, H-8‴ and
1‴), 5.34 (m, H-9‴ and 10‴), 0.88 (m, H-16″ and 18‴), 1.24 (m,
H-4″–15″, 4‴–7‴ and 12‴–17‴); 13C NMR (125 MHz, CDCl ) δC
3
1
38.67 (C-1), 113.04 (C-2), 163.03 (C-3), 117.81 (C-4), 163.55
(
(
C-5), 105.76 (C-6), 63.11 (C-7), 193.27 (C-8), 56.04 (C-9), 21.56
C-1′), 125.04 (C-2′), 131.44 (C-3′), 45.45 (C-4′), 69.92 (C-5′),
1
23.92 (C-6′), 136.85 (C-7′), 25.74 (C-8′), 18.48 (C-9′), 16.61
(
C-10′), 173.40 (C-1″), 34.36 (C-2″), 25.01 (C-3″), 173.36 (C-1‴),
3
1
4.67 (C-2‴), 25.11 (C-3‴), 27.36 (C-8‴ and 11‴), 130.18 (C-9‴),
27.88 (C-10‴), 32.05 and 32.07 (C-14″ and 16‴), 22.83 and
Chen B et al. Identification and α-Glucosidase… Planta Med 2020; 86: 571–578
5
76