Acylated flavonol glycosides from the leaves of Eugenia jambolana

Eugenia jambolana is a traditional medicinal plant of low reaches of Kumaun Himalaya. The tribal inhabitants of Himalaya use the plant for curing diabetes and abdominal pain of peptic ulcers. The leaves of the plant were collected from Tarai regions of Himalaya. About 2 kg dried and powdered sample of the leaves was extracted with 50% aqueous methanol and extract obtained was concentrated under reduced pressure until only H2O layer remained. It was partitioned with dichloromethane and BuOH successively. The BuOH soluble of H2O – MeOH (1:1) extract of the leaves gave antioxidative activity. The BuOH soluble was fractionated with cellulose CC using various proportions of water and AcOH. On eluting column with 20% AcOH, a blue fluorescent band with UV light (365 nm) was observed on column between two major dark purple UV fluorescent bands. The blue UV fluorescent band was eluted and collected separately. The eluate of blue fluorescent band was concentrated and chromatographed on Sephadex LH-20 column using 40% Methanol as an eluent. Two blue fluorescent compounds were separated and identified as myricetin-3-methylether-5-O-(6"-transcaffeoyl)-β-D-glucoside and quercetin-3-methoxy-5-O-(6"-trans caffeoyl)-β-D-glucoside. The structural elucidation of the compounds was carried out by the help of UV, HNMR and MS studies, the anti-oxidative activity of the compounds were established against DPPH radical at 518 nm in UV-VIS spectrophotometer.