RESUMO
Activity-guided fractionation of the methanol extract of Daphnia pulex. (Leydig) using the MTT assay and P-388, A549, KB, and HT-29 cell lines permitted the isolation of four known glyceroglycolipid compounds: (2S.)-1-O.-(7Z.,10Z.,13Z.)-hexadecatrienoyl-2-O.-(7Z.,10Z.)-hexadecadienoyl-3-O.-ß.-D-galactopyranosyl-sn.-glycerol, (2S.)-1-O.-(7Z.,10Z.)-hexadecadienoyl-2-O.-(7Z.,10Z.)-hexadecadienoyl-3-O.-ß.-D-galactopyranosyl-sn.-glycerol, (2S.)-1-O.-(7Z.,10Z.)-hexadecadienolyl-2-O.-linolenoyl-3-O.-ß.-D-galactopyranosyl-sn.-glycerol, and (2S.)-1-O.-(9Z., 12Z.)-octadecadienoyl-2-O.-(7Z.,10Z.)-hexadecadienoyl-3-O.-(α.-D-galactopyranosyl(1-6)-ß.-D-galactopyranosyl-sn.-glycerol. All the isolates were found to be moderately cytotoxic (ED50 < 4 µg/ml) toward P-388, A549, KB, and HT-29 cell lines.