In peptide synthesis, hydrazides are important intermediates for the azide coupling method. A hydrazide is converted to the corresponding azide in the presence of an acid and a nitrite. When acetic acid (or formic acid) is used as the acid, partial acetylation (or formylation) of the hydrazide occurs as a side reaction. Formylation of the hydrazide is much faster than acetylation. Removal of th...

Treatment of polycytidylic acid with hydroxylamine produces an inactivation of its template properties as measured by incorporation of guanosine 5’-phosphate. Partial recovery of the guanosine 5’-phosphate incorporation can be obtained by the addition of adenosine 5’-triphosphate, but not @dine 5’4riphosphate or uridine 5’4riphosphate. Nearest neighbor studies showed that the adenosine 5’-phosp...

Reaction of 4-oxo-3,4-dihydroquinazoline-2-carbaldehyde with hydroxylamine hydrochloride (1.1 equiv) in the presence K2CO3 (1 gave (E)-4-oxo-3,4-dihydroquinazoline-2-carbaldehyde oxime (8) 58% yield. The compound was fully characterized and conformation supported by single crystal x-ray diffractometry.

Nitrones undergo dynamic exchange in chloroform at room temperature through two mechanisms-hydrolysis and recombination or hydroxylamine addition/elimination; this dynamic exchange is harnessed to select a nitrone-based bis(amidopyridine) receptor for diacids from a group of four nitrones through its binding to a glutaric acid-based target.

According to the nomenclature rules of IUPAC the dihedral angle describing the relative orienta­ tions of the two ends of the molecule should be de­ fined as 0° in 1 a and as 180° in lb [3], We refer to l a as the syn conformer and to lb as anti. A mi­ crowave study of gaseous hydroxylamine has shown that the predominant conformer is syn [4]. A microwave study of O-methyl hydroxylamine [5], and...

Accompanying the autoxidation of hydroxylamine at pH 10.2, nitroblue tetrazolium was reduced and nitrite was produced in the presence of EDTA. The rate of at&oxidation was negligible below pH 8.0, but sharply increased with increasing pH. The reduction of nitroblue tetrazolium was inhibited by euperoxide dismutaee, indicating the participation of superoxide anion radical in the autoxidation. Hy...

Purpose Methods to assess the authenticity and traceability of wines have been extensively studied as enhancers food quality, allowing producers obtain market recognition premium prices. Among analytical techniques, volatilome profile attained by gas chromatography coupled with mass spectrometry is acquiring more attention scientific community, together use chemometrics Design/methodology/appro...