Acetic Acid → 17711-13-6

A mixture of heneicosa-8c, 11c,14c-trienoic acid (24 mg), glutathione (120 mg), hydroquinone (12 mg) and protein (600 mg) from the particulate enzyme fraction of the vesicular glands of sheep (obtained as described by Struyk et al., loc.cit.) suspended in aqueous 0.2 M tris(hydroxymethyl)aminomethane hydrochloride buffer solution, pH 8.0, to a total volume of 300 ml, was incubated aerobically by stirring the mixture in a large beaker open to the air at 30° for 20 minutes. The enzymic reaction was then terminated by acidification with citric acid to pH 4 and the mixture was extracted with two portions of ether (300 ml). The residue from evaporation of the extract was dissolved in chloroform and the solution chromatographed on a column of silica gel (25 g) using as successive eluants chloroform (150 ml), chloroform containing 3% methanol (150 ml), and chloroform containing 5% methanol (150 ml), and 10 ml fractions of eluate were collected. Small samples of the fractions (0.1 ml) were tested for the presence of a prostaglandin by treatment with 0.5 ml 3N potassium hydroxide in 75% aqueous methanol and examination for an ultraviolet absorption peak at 278 nm. The last fractions of the 3% methanol eluant and the first fractions of the 5% methanol eluant were found to contain the substance required: they were evaporated to give 12 mg of product. This was then purified further by RPPC using as support a diatomaceous earth (2.5 g) that had been made water-repellent by the action of a methylchlorosilane, as stationary phase a mixture (1.8 ml) of equal volumes of iso-octanol and chloroform, and as eluant aqueous methanol containing 9 volumes of methanol to 10 of water, and collecting 2 ml fractions. All those fractions shown to give the alkali reaction referred to above, except the first and the last, were combined and evaporated and the residue recrystallised from a mixture of ether and light petroleum to give 1α-(6-carboxyhexyl)-4α-hydroxy-5β-(3S-hydroxynon-1t-enyl)cyclopentan-2-one (ω-homo-PGE1, 7.2 mg), m.p. 92°-3°, showing an optical rotation in methanol (1 g/liter) at 20° of -69°. Comparison with PGE1 by TLC on silica gel using a mixture of chloroform, methanol, acetic acid and water in the respective proportions by volume 90:8:1:0.75, gave an Rf value for ω-homo-PGE1 of 0.34 as compared with 0.32 for PGE1, the two substances being just separated.

1. customat 20°
2. customof -69°

ORD record

ord-e7b2715a712b45e9b6c71b2947a37645

Source dataset

uspto-grants-1979_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04163108