Diterpenoids as PPARγ agonists from Siegesbeckia pubescens and their anti-inflammatory effects in vitro / 中国中药杂志

This study aims to investigate the PPARγ agonists isolated from the aqueous extract of Siegesbeckia pubescens( SPA) and their anti-inflammatory activities in vitro. The 293 T cells transfected transiently with PPARγ recombinant plasmid were used as a screening model to guide the isolation of PPARγ activitating components,and then PPARγ activities were measured by double luciferase reporter gene assay. The chemical structures were identified by chromatography or spectroscopic techniques. Furthermore,a UC inflammatory model in vitro was established on HT-29 cells by stimulating with TNF-α． The mRNA levels and secretion of proinflammatory cytokines on HT-29 cells,such as IL-1β,TNF-α,IL-8,were detected by RT-PCR and ELISA. The results showed that five diterpenoids were obtained from the fraction D_(50) with the strongest PPARγ activity among others in SPA,and determined as kirenol( 1),darutigenol( 2),enantiomeric-2-ketone-15,16,19-three hydroxypinomane-8( 14)-ene-19-O-β-D-glucoside( 3),darutoside( 4),enantiomeric-2-β,15,16,19-four hydroxypinomane-8( 14)-ene-19-O-β-D-glucoside( 5),respectively. All the compounds exhibited active effects on PPARγ in a concentration-dependent manner( P<0. 01). In addition,compound 1 significantly inhibited the expression of IL-1β mRNA and secretion of IL-8 on HT-29 cells inflammation model( P<0. 001); both compounds 2 and 3 effectively inhibited the expression of IL-1β,TNF-α,IL-8 mRNA and secretion of IL-8( P<0. 01 or P<0. 001),although at different extent; compound 4 significantly inhibited the expression of IL-1β and TNF-α mRNA( P<0. 01 or P<0. 001),while compound 5 inhibited the expression of IL-1β mRNA obviously( P<0. 001). In conclusion,the diterpenoids 1-5 isolated from S. pubescens have the PPARγ activation activities and potential effects of anti-UC in vitro.

Saponins from roots of Stephanotis mucronata / 中国中药杂志

<p><b>OBJECTIVE</b>To study the chemical constituents from n-BuOH fraction of the roots of Stephanotis mucronata.</p><p><b>METHOD</b>The compounds were separated by chromatographic methods. A combination of UV, MS, and NMR spectroscopic methods was applied to identify structure of these compounds.</p><p><b>RESULT</b>Four oleane saponins were isolated and identified as sitakisoside VII (1), sitakisoside VI (2), sitakisoside II (3), and sitakisoside I (4).</p><p><b>CONCLUSION</b>These four compounds were obtained for the first time from this plant.</p>