Sur une nouvelle série de réactifs du groupe carbonyle, leur utilisation à l'extraction des substances cétoniques et à la caractérisation microchimique des aldéhydes et cétones

A Simple Chemical Procedure for Distinguishing E From F Prostaglandins, With Application to Tissue Extracts

“…The reduced recovery of activity of PGE1 and PGE2 can be presumed to result from the expected combination with the reagent and retention of the product in the aqueous phase on subsequent partition with ether. Although Girard & Sandulesco (1936) mention that refluxing may be necessary for the reaction to occur, this seemed superfluous because satisfactory results were obtained under the milder conditions used by us at room temperature and even at 00 C. Girard & Sandulesco (1936) also mention that the hydrazones are more stable at low temperatures. This might explain the increased inactivation observed when the samples were frozen to -15°C after treatment for 1 hr at room temperature and thawed before partition; possibly the temperature at which these partitions were performed was lower than in our other experiments.…”

“…All these samples were stood for 1 hr either at room temperature (21°-25°C) or at 00 C and were then partitioned with ether after acidification; in a few experiments the partition was carried out after 0.5 hr. Because Girard & Sandulesco (1936) mention that the condensation product formed is more stable at low temperatures, the treated and control samples in some experiments were kept at room temperature for I hr and then stored overnight in a deep freeze (-150 C) and thawed next morning immediately before partition. For partition all samples were acidified to pH 3-4.3 with 0.1 N or 0.5 N HCl, the exact amount of acid having been predetermined by titration of an aliquot.…”

“…For partition all samples were acidified to pH 3-4.3 with 0.1 N or 0.5 N HCl, the exact amount of acid having been predetermined by titration of an aliquot. Treated and control samples were then immediately extracted twice with 1 volume of freshly distilled ether; delay was avoided after acidification, because Girard & Sandulesco (1936) state that the condensation reaction is rapidly reversed by " strong mineral acids." The separated ether phases were evaporated to dryness in a stream of nitrogen; these will be referred to as ether-purified residues.…”

“…To obtain this ketonic condensation we have used Girard's reagent T (trimethylammonium-acetohydrazide chloride, H2N.NH.CO.CH2.N(CH3)3C1), which is one of a series of reagents developed by Girard & Sandulesco (1936); these reagents are soluble in water and insoluble in non-hydroxylated organic solvents. The hydrazones formed from ketones and reagent T are also more water and less ether-soluble than the original ketones.…”

Analyse de l huile essentielle du ledum groenlandicum retzius

“…Les techniques envisageables varient de la séparation par réactivité en fonction des groupements chimiques (cétones, alcool .. .réf. 28,29,30) à celle de chacune des molécules par chromatographie (HPLC.. .réf.3i à 37 ). …”