.
Structures of compounds
1–
5.
The fermented material was freeze-dried and extracted with methyl
ethyl ketone (3 × 500 mL), and the organic solvent was evaporated to
dryness under vacuum to afford 5.0 g of crude extract. The extract was
fractionated by silica gel column chromatography (5 × 40 cm) using CHCl
3–CH
3OH
gradient elution. The fraction (50 mg) that was eluted with 1% MeOH was
further separated by semipreparative reversed-phase HPLC (Kramosil C
18 column; 10-µm; 10 × 250 mm, 2 mL/min) to afford pestalafuranone B (
2; 1.9 mg,
tR 15.3 min; 50% MeOH in H
2O
over 2 min, 50–72% over 10 min, 72–74% over 13 min). The fraction (180
mg) that was eluted with 2% MeOH was then separated by Sephadex LH-20
column chromatography (CH
2Cl
2–
n-C
6H
14
= 4:1) to afford six fractions. Fraction 3 (60 mg) was successively
separated by semipreparative reversed-phase HPLC (32% MeOH in H
2O over 2 min, 32–55% over 60 min) afforded pestalafuranones A (
1; 1.6 mg,
tR 25.7 min), C (
3; 6.0 mg,
tR 26.6 min), D (
4; 1.5 mg,
tR 30.0 min), and E (
5; 3.5 mg,
tR 31.5 min).
Pestalafuranone A (
1): colorless oil; UV (CH
3OH) λ
max 272 (
ε 7800), 265 (
ε 6600) nm; IR (Neat)
νmax 2962, 1748, 1717, 1448, 1364 cm
−1;
1H- and
13C-NMR data, see and ; HRESIMS obsd.
m/z 217.0840 [M+Na]
+ (calcd for C
11H
14O
3Na, 217.0835).
Pestalafuranone B (
2): pale yellow oil; [
α]
D −16 (
c 0.05, CH
3OH); UV (CH
3OH) λ
max 270 (
ε 3300) nm; IR (Neat)
νmax 3403 (br), 2932, 1749, 1446 cm
−1;
1H- and
13C-NMR data, see and ; HRESIMS obsd.
m/z 217.0842 [M+Na]
+ (calcd for C
11H
14O
3Na, 217.0835).
Pestalafuranone C (
3): pale yellow oil; UV (CH
3OH) λ
max 265 (
ε 6600), 235 (
ε 4300) nm; IR (Neat)
νmax 2919, 1752, 1717, 1445, 1365 cm
−1;
1H- and
13C-NMR data, see and ; HRESIMS obsd.
m/z 219.0998 [M+Na]
+ (calcd for C
11H
16O
3Na, 219.0992).
Pestalafuranone D (
4): colorless oil; [
α]
D +32 (
c 0.05, CH
3OH); UV (CH
3OH) λ
max 275 (
ε 4460) nm; IR (Neat)
νmax 2963, 1751, 1450, 1381 cm
−1;
1H- and
13C-NMR data, see and ; HRESIMS obsd.
m/z 217.0846 [M+Na]
+ (calcd for C
11H
14O
3Na, 217.0835).
Pestalafuranone D (
5): colorless oil; [
α]
D +16 (
c 0.05, CH
3OH); UV (CH
3OH) λ
max 275 (
ε 6270) nm; IR (Neat)
νmax 2931, 1753, 1446, 1346 cm
−1;
1H- and
13C-NMR data, see and ; HRESIMS obsd.
m/z 219.0995 [M+Na]
+ (calcd for C
11H
16O
3Na, 219.0992).
New Furanones from the Plant Endophytic Fungus
Pestalotiopsis besseyi
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