New acetylated flavone C-glycosides from Iris lactea

Abstract Chemical investigation of the aerial parts of Iris lactea afforded three new flavone C -glycosides including 4‴- O -acetyl-embinin ( 1 ), 2‴,4‴- O -diacetyl-embinin ( 2 ) and 6″,4‴- O -diacetyl-embinin ( 3 ) along with the known analogue embinin ( 4 ). Their structures were elucidated by 1D and 2D NMR spectroscopic analysis as well as by HRESIMS data. The sugars were characterized following acid hydrolysis of the respective glycosides and TLC analysis compared to known standards. Duplicated signals can be observed in the NMR spectra, indicating the presence of rotamers caused by rotational hindrance around the glycosyl-flavone C C linkage. All isolated compounds were tested for their antimicrobial and cytotoxic activities but found to be inactive.