Flavonoids from Scutellaria likiangensis Diels and their antimalarial activities.

Two new flavonoid glycosides scutelikiosides A and B (13 and 23), along with twenty-one known compounds from the 75% ethanol extract of roots of Scutellaria likiangensis Diels. Their structures were determined by the comprehensive analyses of the spectroscopic data (1D NMR, 2D NMR, HRESIMS, and CD) and physicochemical properties. Compounds 4-14, 17-19, 21, and 22 were evaluated for their in vivo antimalarial activities against Plasmodium yoelii BY265RFP in mice. Compound 17 exhibited significant activity close to artemisinin with an inhibition ratio of 29.2%, and compounds 6, 9-12, 14, 18, 19, and 22 exhibited moderate antimalarial activities with inhibition ratios ranging from 10.2% to 20.0% at a dose of 25 mg/kg/day. In addition, a summary of preliminary structure-activity relationship of isolated flavonoids for in vivo antimalarial activity was described.

Phloridzin Highly Accumulated in Malus rockii Rehder and Its Structure Revision and Hypolipidemic Activity.

Phloridzin is a lead compound of the prestigious antidiabetic gliflozins. The present study found that phloridzin highly accumulated in Malus rockii Rehder. The content of phloridzin in M. rockii was the highest among wild plants, with the percentage of 15.54% in the dry leaves. The structure of phloridzin was revised by proton exchange experiments and extensive 2D NMR spectra. Phloridzin exhibited significant hypolipidemic activity in golden Syrian hamsters maybe by increasing the expression of CYP7A1, at the doses of 50 mg/kg and 200 mg/kg. The total performance of anti-hyperlipidemic effect of phloridzin may be superior to that of lovastatin, though lovastatin was more active than phloridzin. In addition, phloridzin exhibited moderate antimalarial activity with inhibition ratio of 31.3 ± 10.9% at a dose of 25 mg/kg/day, and showed moderate analgesic activity with 28.0% inhibition at a dose of 50 mg/kg.