Determination of Flavonoids from Four Energy Grasses

The total flavonoid contents in four common energy grasses (hybridPennisetum, switchgrass, giant reed, elephant grass) including whole strain, stems and leaves were quantified. The flavonoids were detected by LC-MS. For the whole strains, switchgrass has a flavonoids content of 6.84 mg quercetin equivalents/g dry weight, which is 59.8%, 20.1% and 11.2% higher than giant reed, hybridPennisetum and elephant grass. The content in leaves is 2.3 ~ 3.0 times to stems, the contents in hybridPennisetum leaves is 10.55 mg quercetin equivalents/g dry weight, which is the highest among all these samples. 14 flavonoid glycosides and 2 flavonols were identified in the extracts of four grasses. Quercetin, isorhamnetin and quercitrin are identified positively with standards. This research may provide a theoretical support for the value added phytochemicals extract from energy grass.