Glyceroglycolipids, a novel class of platelet-activating factor antagonists from Kalimeris indica

Abstract The bioassay-guided purification of chloroform extracts of Kalimeris indica (Linn) Schultz-Bip led to the isolation of three diacylglycerols: 1- O -(9 Z ,12 Z ,15 Z -octadecatrienoyl)-2- O -hexadecanoylglycerol ( 1 ), 1- O -(9 Z ,12 Z ,15 Z -octadecatrienoyl)-2- O -hexadecanoyl-3- O -α-(6-sulfoquinovopyranosyl)glycerol ( 2 ), 1- O -(9 Z ,12 Z ,15 Z -octadecatrienoyl)-2- O -hexadecanoyl-3- O -[α- d -galactopyranosyl(1 → 6)- O -β- d -galactopyranosyl]glycerol ( 3 ). Their structures were established on the basis of spectral and chemical methods. The glyceroglycolipids 2 and 3 exhibited significant PAF receptor binding inhibitory activities. Our studies have identified diacylglycolipids as a novel class of potent PAF antagonist.