Girard hydrazone

General structure of a fatty acid ester (R) of testosterone Girard hydrazone... 

Johnson substitutes trifluoroacetic acid (TFA) for acetic acid and conducts the de-rivatization at 75 C. Griffiths et al. [22] also report extensively on Girard hydrazone derivatives applied to LC-MS analysis of oxosteroids. 

Griffiths WJ, Alvelius G, Liu S, Sjovall J (2004) High-energy collision-induced dissociation of oxosteroids derivatised to Girard hydrazones. Eur J Mass Spectrom (Chichester, Eng) 10 63-88... 

L15. Lisboa, B. P., Formation and separation of Girard hydrazones on thin-layer chromatography by elatographic techniques. J. Chromatog. 24, 475-477 (1966). 

However, Prelog and Hafliger noticed that this mechanism did not explain all the observed facts, particularly the high value of AE / /ApH shift (85 mV/pH unit). Results consistent with these data were obtained by Young [112], who described splitting of waves for the Girard hydrazones in acidic medium. The reduction currents which he observed corresponded to a transfer of 0.6-1.4 electron. These... 

Steroid ketones Apply the sample solution followed by Girard s reagent (0 1% tnmethylacetyl hydrazide in 10% acetic acid) and allow to react for 15 h in an atmosphere of acetic acid Then dry at 80 °C for 10 mm and after cooling chromatograph the hydrazones that have been formed [81]... 

Other hydrazine derivatives frequently used to prepare the corresponding hydrazone are semicarbazide (NH2NHCONH2), in which case the hydrazone is called a semicarbazone, and Girard s reagents Tand P, in which case the hydrazone... 

Griffiths et al. [23] studied the ESI MS of sterols, and while they are not hormonal steroids, similar derivatization methods can be used. He converts 3/5-hydroxy-A5 sterols to - -4-ene sterols using cholesterol oxidase and follows this by preparation of Girard P hydrazones. This increases the sensitivity by 1000 in ESI. This technique would also be applicable to pregnenolone, dehydroepiandrosterone (DHEA) and similar A5 steroids, which can also be oxidized by cholesterol oxidase. 

The possibility of preliminary isolation of substances under analysis in the form of hydrazones is frequently utilized in the determination of ketosteroids in complex mixtures such as biological materials. In this form they are even sometimes subjected directly to GC analysis. Charransol et al. [378] determined androstanediol and testosterone in urine. After hydrolysis the sample was extracted with methylene chloride, evaporated and treated with Girard T reagent. Free hydroxysteroids were extracted with diethyl ether and... 

Trimethylaminoacetohydrazide chloride Trimethylammonium acetyl hydrazide chloride Trimethylammonium chloride acethydrazide. Reacts with ketones to form water-soluble hydrazones. Used in the isolation of ketosteroids. Girard s reagent P [1126-58-5], used in the same way, is 1-(2-hydrazino-2-oxoethyl)pyridinium chloride. Crystals mp = 192° soluble in H2O, polar organic solvents, insoluble in non-polar organic solvents. 

Water-soluble hydrazones are also provided by the Girard reagents P and T,524,929 which have proved their worth for separation of mixtures of natural products.930, 931 The condensation is usually effected in aqueous methanol buffered with acetate.524... 

Formation of a hydrazone with Girard s Reagent T introduces a permanent positive charge into the molecule. Na+ and K+ adducts are suppressed, thus ina-easing the sensitivity of detection (Naven and Harvey 1996). This reaction has been applied to CHOs but does not offer a major improvement in comparison with reductive amination (unpublished results from this laboratory). 

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