Kaempferol triosides from Silphium perfoliatum

Abstract

Two apiose-containing kaempferol triosides, together with nine known flavonoids were isolated from the leaves of Silphium perfoliatum L. Their structures were elucidated by acid hydrolysis and spectroscopic methods including UV, LSI MS, FAB MS, CI MS, 1H, 13C and 2D-NMR, DEPT, HMQC and HMBC experiments. The two new compounds were identified as kaempferol 3- O-β- d-apiofuranoside 7- O-α- l-rhamnosyl-(1‴′→6‴)- O-β- d-galactopyranoside and kaempferol 3- O-β- d-apiofuranoside 7- O-α- l-rhamnosyl-(1 ⁗→ 6‴)- O-β- d (2‴- O- E-caffeoylgalactopyranoside).