Chemical Constituents of Nelumbo nucifera Gaertn Leaf Extract Exhibiting Hypolipidemia Activity

The purpose of this study was to investigate and isolate compounds from ethanolic extract of lotus leaves ( Nelumbo nucifera Gaertn) exhibiting inhibitory activity against pancreatic lipase or HMG-CoA reductase. From a previous study, it was found that the partially purified portion of the ethanolic extract of lotus leaves (Nn-E3) showed the best inhibitory activity against pancreatic lipase enzyme, with IC50 at 36.80 μg/ml, using orlistat as a positive control. In addition, the crude extract at the concentration of 10 μg/ml showed moderate inhibitory activity (65.87%) against HMG-CoA reductase, using pravastatin as a positive control. Therefore, it was interesting to further isolate the constituents from Nn-E3. As a result, two flavonoid compounds (A, B) were purified using column chromatography and their chemical structures were elucidated using NMR and MS spectroscopic techniques. These compounds were identified as quercetin 3- O -beta- D -glucuronide (miquelianin) and rutin respectively. Key words: Nelumbo nucifera Gaertn. leaf, miquelianin, quercetin 3- O -beta- D -glucuronide, rutin