Isolation and identification of two isomeric trihydroxy octadecenoic acids with prostaglandin E-like activity from onion bulbs (Allium cepa).
Two fractions with prostaglandin E-like activity were isolated from onion (Allium cepa) by using XAD-2 adsorption, silicic acid column chromatography and thin layer chromatography. The fractions were analyzed by gas chromatography/mass spectrometry and were characterized as isomeric mixtures of 9,10,13-trihydroxy-11-octadecenoic and 9,12,13-trihydroxy-10-octadecenoic acid, which are lipoxygenase metabolites of linoleic acid. Bio-assay, for which cascade superfusion was used and the rabbit coeliac and mesenteric arteries and the rat fundus strip were employed as assay organs, was utilized to monitor the bio-active profile throughout the isolation procedures. The activity of 1 microgram of the pharmacologically active fractions T1 and T2 was found to be equivalent to that of respectively 1.33 and 0.63 ng of prostaglandin E2.
D002850:Chromatography, Gel; D002855:Chromatography, Thin Layer; D005230:Fatty Acids, Nonesterified / Q000032:analysis; D007536:Isomerism; D013058:Mass Spectrometry; D009829:Oleic Acids / Q000032:analysis*; D010944:Plants / Q000032:analysis*; D011458:Prostaglandins E / Q000032:analysis*
D005230:Fatty Acids, Nonesterified; D009829:Oleic Acids; D011458:Prostaglandins E