ABSTRACT
Three new (1-3) and one known (4) bioactive terpenoids were isolated from the seeds of Silybum marianum based on the investigation to get new NO inhibitors. Their structures were determined by extensive NMR (1D and 2D NMR) and MS spectroscopic data, and the absolute configurations were identified by experimental and calculated ECD spectra. The NO inhibitory activities in murine microglial BV-2 cells and interactions with iNOS protein by molecular docking were evaluated for all compounds. The results showed that these compounds had potent NO inhibitory effects.
Subject(s)
Nitric Oxide Synthase Type II/metabolism , Nitric Oxide/metabolism , Silybum marianum/chemistry , Terpenes/chemistry , Animals , Binding Sites , Cell Line , Circular Dichroism , Lipopolysaccharides/toxicity , Magnetic Resonance Spectroscopy , Mass Spectrometry , Mice , Silybum marianum/metabolism , Molecular Conformation , Molecular Docking Simulation , Neurons/cytology , Neurons/drug effects , Neurons/metabolism , Nitric Oxide Synthase Type II/antagonists & inhibitors , Plant Extracts/chemistry , Protein Structure, Tertiary , Seeds/chemistry , Seeds/metabolism , Terpenes/isolation & purification , Terpenes/pharmacologyABSTRACT
Two new amide compounds, mariamides A and B (1-2), were obtained together with fourteen known compounds from the seeds of milk thistle (Silybum marianum). Their structures were established on the basis of extensive 1D and 2D NMR analyses, as well as HR-ESI-MS data. Most of the compounds showed significant antioxidant activities than positive control in ABTS and FRAP assays. However, only amide compounds 1-4 showed moderate DPPH radical scavenging activity and compounds 7 and 16 showed the most potent activity against DPPH. Most of the compounds showed moderate to stronger α-glucosidase inhibitory activities. Nevertheless, only flavonoids showed strong PTP1B inhibitory activities. These results indicate a use of milk thistle seed extracts as promising antioxidant and antidiabetic agents.