phytosterols and gitogenin

Longipetalosides A-C (1-3); three new furostane steroidal saponins together with (25S)-5α-furastan-3β,22,26-triol (4) and gitogenin (5) were isolated from the methanolic extract of the whole plant of Tribulus longipetalus. The structures of these compounds (1-5) were established by using 1D ((1)H, (13)C) and 2D NMR (HMQC, HMBC, COSY, NOESY) spectroscopy, and mass spectrometry (ESIMS, HRESIMS), and in comparison with literature data reported for related compounds. Compounds 1-5 were evaluated for their inhibitory activities against enzymes α-glucosidase, lipoxygenase, acetylcholinesterase, and butyrylcholinesterase. Only the compounds 4 and 5 were found as the inhibitors of enzyme α-glucosidase with IC50 values of 33.5±0.22 and 37.2±0.18μM, respectively.

Topics: Acetylcholinesterase; alpha-Glucosidases; Butyrylcholinesterase; Enzyme Inhibitors; Glycoside Hydrolase Inhibitors; Lipoxygenase; Magnetic Resonance Spectroscopy; Phytosterols; Saponins; Spirostans; Steroids; Tribulus

An improved fast method for extraction of steroidal saponins in Tribulus terrestris based on the use of focus microwave-assisted extraction (FMAE) is proposed. Under optimized conditions, four steroidal saponins were extracted from Tribulus terrestris and identified by GC-MS, which are Tigogenin (TG), Gitogenin (GG), Hecogenin (HG) and Neohecogenin (NG). One of the most important steroidal saponins, namely TG was quantified finally. The recovery of TG was in the range of 86.7-91.9% with RSD<5.2%. The convention heating reflux extraction was also conducted in order to validate the reliability of this new FMAE method. The yield of total steroidal saponins was 90.3% in a one-step FMAE, while the yield of 65.0% was achieved during heating reflux extraction, and the extraction time was reduced from 3 h to 5 min by using less solvent. The method was successfully applied to analyze the steroidal saponins of Tribulus terrestris from different areas of occurrence. The difference in chromatographic characteristics of steroidal saponins was proved to be related to the different areas of occurrence. The results showed that FMAE-GC-MS is a simple, rapid, solvent-saving method for the extraction and determination of steroidal saponins in Tribulus terrestris.

Topics: Drugs, Chinese Herbal; Gas Chromatography-Mass Spectrometry; Microwaves; Phytosterols; Plants, Medicinal; Sapogenins; Saponins; Spirostans; Tribulus