A new acylated avicularin, namely avicularin 200-(4000-O-n- pentanoyl)- gallate ( 1) along with 12 metabolites have been isolated from the ethyl acetate extract of the aerial parts of Jussiaea repens L. ( Onagraceae). Their structures were established as trifolin 2"-O-gallate ( 2), quercetrin ( 3), guaijaverin ( 4), reynoutrin ( 5), juglanin ( 6), avicularin ( 7), hyperin ( 8), trifolin ( 9), hyperin 2"-O-gallate ( 10), rutin ( 11), kaempferol ( 12) and quercetin ( 13) on the basis of their chromatographic properties, chemical and spectroscopic evidences. The investigated ethyl acetate extract was found to be non-toxic (LD50 up to the maximum soluble dose 4 g kg(-1) body wt.) and had significant antioxidant, hepatoprotective, anti-inflammatory and antidiabetic activities. Also some of the isolated flavonoids showed cytotoxic activity against Ehrlich ascitis carcinoma cells.