A new alkaloid, 2-(furan-2-yl)-6-(2
S,3
S,4-trihydroxybutyl)pyrazine (
1), along with 12 known compounds, 2-(furan-2-yl)-5-(2
S,3
S,4-trihydroxybutyl)pyrazine (
2), (
S)-4-isobutyl-3-oxo-3,4-dihydro-1
H-pyrrolo[2,1-
c][1,4]oxazine-6-carbaldehyde (
3), (
S)-4-isopropyl-3-oxo-3,4-dihydro-1
H-pyrrolo[2,1-
c][1,4]oxazine-6-carbaldehyde (
4
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A new alkaloid, 2-(furan-2-yl)-6-(2
S,3
S,4-trihydroxybutyl)pyrazine (
1), along with 12 known compounds, 2-(furan-2-yl)-5-(2
S,3
S,4-trihydroxybutyl)pyrazine (
2), (
S)-4-isobutyl-3-oxo-3,4-dihydro-1
H-pyrrolo[2,1-
c][1,4]oxazine-6-carbaldehyde (
3), (
S)-4-isopropyl-3-oxo-3,4-dihydro-1
H-pyrrolo[2,1-
c][1,4]oxazine-6-carbaldehyde (
4), (4
S)-4-(2-methylbutyl)-3-oxo-3,4-dihydro-1
H-pyrrolo[2,1-
c][1,4]oxazine-6-carbaldehyde (
5), (
S)-4-benzyl-3-oxo-3,4-dihydro-1
H-pyrrolo[2,1-
c][1,4]oxazine-6-carbaldehyde (
6), flazin (
7), perlolyrine (
8), 1-hydroxy-β-carboline (
9), lumichrome (
10), 1
H-indole-3-carboxaldehyde (
11), 2-hydroxy-1-(1
H-indol-3-yl)ethanone (
12), and 5-(methoxymethyl)-1
H-pyrrole-2-carbaldehyde (
13), were isolated and identified from the fermentation broth of an endophytic actinomycetes,
Jishengella endophytica 161111. The new structure
1 and the absolute configurations of
2–
6 were determined by spectroscopic methods,
J-based configuration analysis (JBCA) method, lactone sector rule, and electronic circular dichroism (ECD) calculations. Compounds
8–
11 were active against the influenza A virus subtype H1N1 with
IC50 and selectivity index
(
SI) values of 38.3(±1.2)/25.0(±3.6)/ 39.7(±5.6)/45.9(±2.1) μg/mL and 3.0/16.1/3.1/11.4, respectively. The
IC50 and
SI values of positive control, ribavirin, were 23.1(±1.7) μg/mL and 32.2, respectively. The results showed that compound
9 could be a promising new hit for anti-H1N1 drugs. The absolute configurations of
2–
5,
13C nuclear magnetic resonance (NMR) data and the specific rotations of
3–
6 were also reported here for the first time.
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