In the study, ultraperformance
liquid chromatography–quadrupole
time-of-flight–mass spectrometry analysis of
Leucosidea sericea
leaf and stem extracts led to
the identification of various classes of compounds. Further chromatographic
purifications resulted in the isolation of 22 compounds that consisted
of a new triterpenoid named leucosidic acid A (
1
), an
acetophenone derivative
2
, a phloroglucinol derivative
3
, three chromones
4–6
, seven pentacyclic
triterpenoids
7–13
, a phytosterol glucoside
14
, a flavonoid
15
, and seven flavonoid glycosides
16–22
. Nineteen of these compounds including the previously
undescribed triterpenoid
1
are isolated for the first
time from
L. sericea
. The structures
of the isolated compounds were assigned based on their high-resolution
mass spectrometry and nuclear magnetic resonance data. Some of the
isolated triterpenoids were evaluated for inhibitory activity against
α-amylase, α-glucosidase, and pancreatic lipase. Of the
tested compounds, 1-hydroxy-2-oxopomolic acid (
7
) and
pomolic acid (
13
) showed higher potency on α-glucosidase
than acarbose, which is used as a positive control in this study.
The two compounds inhibited α-glucosidase with IC
50
values of 192.1 ± 13.81 and 85.5 ± 6.87 μM, respectively.