Hydrazino derivatization

Der Ersatz einer Benzylthio-Gruppe in N-Heterocyclen wie z. B. Purin-Derivaten kann durch Erhitzen in waBrigem Hydrazin (- 6-Hydrazino-Derivat, 88%) und anschlieBendes Kochen in Wasser in Gegenwart von Raney-Nickel erfolgen (70%)1 z. B. ... 

Coupling of hydrazino-derivatized ligands to aldehyde functionalized liposomes by hydrazone formation (Fig. Ic) has been described by Bonnet et al. [20], who... 

Figure 14 Representative fluorescence derivatization reagents used for PO-CL detection. DNS-CI, dansyl chloride DBD-F, 4-(A,A-dimethylaminosulphonyl-7-fluoro-2,l, 3-benzoxadiazole NDA, naphthalene-2,3-dicarboxaldehyde DNS-H, dansyl hydrazine DBD-H, 4-(iV,iV-dimethylaminosulphonyl-7-hydrazino-2,l,3-benzoxadiazole).

Durch Reduktion von 2-Nitrosamino-l,3,4-oxadiazolenkannman 2-Hydrazino-1,3,4-oxadiazole652 herstellen bzw. als Benzyliden-Derivat isolieren428,653 (andere Methode vgl. S. 602). 

Higashi and coworkers [28] used 2-hydrazino-l-methylpyridine (HMP) derivatization to introduce a positively charged moiety in testosterone and dihydrotestosterone (DHT) to achieve a sensitivity improvement of 70- to 1600-fold compared to underivatized molecules in ESI. However, they found the derivative was unsuitable for di-keto steroids such as androstenedione and progesterone, so this form of derivatization is unlikely to be widely accepted. Separable syn- and anti- (E and Z) stereoisomers are formed using this derivative. Preparation is as follows a solution of 10 pg HMP in 50 pi ethanol containing 25 pg TFA was added to the steroid dissolved in 30 pi ethanol. After heating for 1 h at 60 C, the solvents can be removed and sample injected. 

Higashi T, Yamauchi A, Shimada (2005b) 2-Hydrazino-l-methylpyridine a highly sensitive derivatization reagent for oxosteroids in liquid chromatography-electrospray ionization-mass spectrometry. J Chromatogr 825 214-222... 

Several reagents for derivatization of carbonyl groups are also available. Dansylhydrazine reacts with carbonyl groups in the presence of trichloroacetic acid, yielding highly fluorescent dansylhydrazones that exhibit, however, limited stability. In addition, fluorescent hydrazones can be produced from carbonyl-containing compounds after their reaction with 4-hydrazino-2-oxa-l,3-diazole or... 

Ono M, Arano Y, Mukai T, et al. (2001). Plasma protein binding of Tc-labeled hydrazino nicotinamide derivatized polypeptides and peptides. Nucl. Med. Biol. 28(2) 155-164. 

Babich J W, Fischman A J (1995). Effect of co-ligand on the biodistribntion of Tc-labeled hydrazino nicotinic acid derivatized chemotactic peptides. Nucl. Med. Biol. 22 25-30. 

Hydrazino compounds can react with carboxy compounds in aqueous medium to form hydrazide. For the reaction to proceed under mild conditions, N-ethyl-N -(3-dimethylaminopropyl) carbodiimide (EDC) is required as a condensing reagent. Fatty acids are determined with 2-nitrophenylhydrazine hydrochloride (NPH) by LC-UV detection. The detection limits for long chain fatty acids are 2.5-5 pmol per injection. As FL derivatization reagents, 6,7-dimethoxy-l-memyl-2( lH)-quinoxalinone-3-propionyl carboxylic... 

Human prostate (10 mg tissue) extraction (70% methanol) PR-SPE derivatization with 2-hydrazino-l-methylpyridine... 

T IS ds-T Rat brain (100 mg) extraction (methanol-acetic acid) RP-SPE preparative NP-HPLC derivatization with 2-hydrazino-l-methylpyridine Rat serum (50 p,l) deproteinization (methanol-acetic acid) RP-SPE derivatization with 2-hydrazino-l-methylpyridine J sphere ODS H-80 (150 X 2.0 mm I.D., YMC), acetonitrile-methanol-10 mM ammonium formate and 0.2 ml/min API 2000 (Applied Biosystems), positive ESI, SRM ([M]+ residual [M]+) LOQ 0.06 ng/g tissue (brain) and 0.06 ng/ml (serum) [37]... 

Detection Methods. - The use of purpald (4-amino-3-hydrazino-5-nicrcsq)to-l,2,4-triazole) as a reagent for post-column derivatization of neutral nwnosaccharides has been repented. ... 

---