Flavonoids from Pseudotsuga menziesii

Four O-acylated flavonol glycosides, new in the plant kingdom, were isolated from the needles of Pseudotsuga menziesii. Their structures were established by 1D and 2D NMR and MS data as: daglesioside I [kaempferol 3-O-[2",5"-O-(4''',4(IV)-dihydroxy)-beta-truxinoyl]-alpha-L-arabinofuranoside] (1), daglesioside II [kaempferol 3-O-[2",5"-O-(4"'-hydroxy)-beta-truxinoyl]-alpha-L-arabinofuranoside] (2), daglesioside III [kaempferol 3-O-[2",5"-di-O-(E)-p-coumaroyl]-alpha-L-arabinofuranoside] (3), and daglesioside IV [kaempferol 3-O-[3",6"-di-O-(E)-cinnamoyl]-beta-D-glucopyranoside] (4). In addition, the known flavonoids (E)-tiliroside, (E)-ditiliroside, astragalin (kaempferol 3-O-beta-D-glucopyranoside), isorhamnetin, kaempferol, and quercetin were identified. The cytotoxic activity of compounds 1 and 3 was evaluated towards the HL-60, HeLa, and MDA-MB468 cell lines.