Astraoleanosides E-P, oleanane-type triterpenoid saponins from the aerial parts of Astragalus membranaceus Bunge and their ß-glucuronidase inhibitory activity.

Historically, Astragalus membranaceus Bunge has been used as a beneficial medicinal plant, particularly in the Asian traditional medical systems, for the treatment of various human diseases such as stomach ulcers, diarrhea, and respiratory issues associated with phlegm. In this study, a phytochemical characterization of the aerial parts of A. membranaceusled to the isolation of 29 oleanane-type triterpenoid saponins, including 11 new compounds named astraoleanosides E-P (6-9, 13, 14, 18-22), as well as 18 known ones. The structures of these compounds were elucidated using nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry. Among them, astraoleanoside H (9) and cloversaponin III (15) demonstrated the most potent ß-glucuronidase inhibitory activities, with IC50 values of 21.20 ± 0.75 and 9.05 ± 0.47 µM, respectively, compared to the positive control d-saccharic acid 1,4-lactone (IC50 = 20.62 ± 1.61 µM). Enzyme kinetics studies were then conducted to investigate the type of inhibition exhibited by these active compounds. In addition, the binding mechanism, key interactions, binding stability, and dynamic behavior of protein-ligand complexes were investigated through in silico approaches, such as molecular docking and molecular dynamics simulations. These findings highlight the promising potential of triterpenoid saponins from A. membranaceus as lead compounds for ß-glucuronidase inhibitors, offering new possibilities for the development of therapeutic agents targeting various diseases where ß-glucuronidase plays a crucial role.

Cytotoxic steroid derivatives from the Vietnamese soft coral Sinularia brassica.

Using various chromatographic separations, six ergostane-type steroids, including one new compound sinubrassione (1), and two pregnene-type steroid glycosides, including one new compound sinubrassioside (7), were isolated from methanol extract of the Vietnamese soft coral Sinularia brassica. The structure elucidation was confirmed by spectroscopic methods including 1D, 2D NMR and HR-ESI-MS. The cytotoxic activities of all the isolated compounds against three human cancer cell lines were also evaluated using MTT-based colorimetric assays.

The chemical constituents of ethanolic extract from Stauntonia hexaphylla leaves and their anti-inflammatory effects.

Stauntonia hexaphylla (Lardizabalaceae) is an important medicinal plant in Korea, Japan, and China. Its leaves are used to treat many diseases because of their analgesic, sedative, and diuretic effects; however, there are few reports on their chemical constituents and biological activities. This study divided an ethanol extract into dichloromethane (DCM), ethyl acetate (EtOAc), and water fractions. Bioassay-guided fractionation of the ethanol extracts led to the isolation of seven compounds (1-7). To our knowledge, this is the first report of 1-7 from S. hexaphylla. The anti-inflammatory effects were investigated by suppressing cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in Western blots. The ethanol extract (20 µg/mL), DCM fraction (20 µg/mL), and compound 1 (10 µM) decreased COX-2 and iNOS expression significantly in LPS-induced RAW264.7 cells. These results suggest that S. hexaphylla leaves and compound 1 are useful candidates for treating inflammatory and other diseases.