O-(2,3,4,5,6-Pentafluorophenyl)methylhydroxylamine hydrochloride: a versatile reagent for the determination of carbonyl-containing compounds

Cancilla, Devon A.; Hee, Shane S. Que

doi:10.1016/0021-9673(92)87181-7

Cited by 81 publications

(55 citation statements)

References 40 publications

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“…Because of the instability of acetoacetic acid to heat and/or acid, identification of acetoacetic acid was carried out after derivatization. It is known that 3-keto acids can react with O- (2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride to give stable oxime derivatives with benzyl chromophore (12). The Ayg1p reaction mixture was treated with O- (2,3,4,5,6-pentafluorobenzyl) Effect of Chemical Reagents on Ayg1p Activity-The effect of chemical reagents on Ayg1p activity was examined as shown in Table II.…”

Section: Resultsmentioning

confidence: 99%

Hydrolytic Polyketide Shortening by Ayg1p, a Novel Enzyme Involved in Fungal Melanin Biosynthesis

Fujii

Yasuoka

Tsai

et al. 2004

Journal of Biological Chemistry

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The pentaketide 1,3,6,8-tetrahydroxynaphthalene (T4HN) is a key precursor of 1,8-dihydroxynaphthalenemelanin, an important virulence factor in pathogenic fungi, where T4HN is believed to be the direct product of pentaketide synthases. We showed recently the involvement of a novel protein, Ayg1p, in the formation of T4HN from the heptaketide precursor YWA1 in Aspergillus fumigatus. To investigate the mechanism of its enzymatic function, Ayg1p was purified from an Aspergillus oryzae strain that overexpressed the ayg1 gene. The Ayg1p converted the naphthopyrone YWA1 to T4HN with a release of the acetoacetic acid. Although Ayg1p does not show significant homology with known enzymes, a serine protease-type hydrolytic motif is present in its sequence, and serine-specific inhibitors strongly inhibited the activity. To identify its catalytic residues, site-directed Ayg1p mutants were expressed in Escherichia coli, and their enzyme activities were examined. The single substitution mutations S257A, D352A, and H380A resulted in a complete loss of enzyme activity in Ayg1p. These results indicated that the catalytic triad Asp 352 -His 380 -Ser 257 constituted the active-site of Ayg1p. From a Dixon plot analysis, 2-acetyl-1,3,6,8-tetrahydroxynaphthalene was found to be a strong mixed-type inhibitor, suggesting the involvement of an acyl-enzyme intermediate. These studies support the mechanism in which the Ser 257 at the active site functions as a nucleophile to attack the YWA1 side-chain 1 -carbonyl and cleave the carbon-carbon bond between the naphthalene ring and the side chain. Acetoacetic acid is subsequently released from the Ser 257 -O-acetoacetylated Ayg1p by hydrolysis. An enzyme with activity similar to Ayg1p in melanin biosynthesis has not been reported in any other organism.

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Section: Resultsmentioning

confidence: 99%

Hydrolytic Polyketide Shortening by Ayg1p, a Novel Enzyme Involved in Fungal Melanin Biosynthesis

Fujii

Yasuoka

Tsai

et al. 2004

Journal of Biological Chemistry

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“…After extraction, the drop was retracted and injected into GC-MS for analysis. For each aldehyde, after derivatization with PFBHA, two isomers of Z-oxime and Eoxime can form [22]. Four analyses were done in replicate; the total peak area of the two isomers for each aldehdye was used for the determination of the optimal parameters.…”

Section: Optimization Of the Extraction Conditionsmentioning

confidence: 99%

“…Due to high volatility and reactivity, derivatization is required prior to analysis. In recent publications [22][23][24][25][26][27][28][29][30][31][32], O-2,3,4,5,6-(pentaflurobenzyl)hydroxylamine hydrochloride (PFBHA) has been shown to be the most efficient derivatization agent of aldehydes. In the study, aldehydes were used as the model compounds.…”

Section: Introductionmentioning

confidence: 99%

Headspace single‐drop microextraction with in‐drop derivatization for aldehyde analysis

Deng

Yao

et al. 2005

J of Separation Science

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A new technique, headspace single-drop microextraction (HS-SDME) with in-drop derivatization, was developed. Its feasibility was demonstrated by analysis of the model compounds, aldehydes in water. A hanging microliter drop of solvent containing the derivatization agent of O-2,3,4,5,6-(pentaflurobenzyl)hydroxylamine hydrochloride (PFBHA) was shown to be an excellent extraction, concentration, and derivatization medium for headspace analysis of aldehydes by GC-MS. Using the microdrop solvent with PFBHA, acetaldehyde, propanal, butanal, hexanal, and heptanal in water were headspace extracted and simultaneously derivatized. The formed oximes in the microdrop were analyzed by GC-MS. HS-SDME and in-drop derivatization parameters (extraction solvent, extraction temperature, extraction time, stirring rate microdrop volume, and the headspace volume) and the method validations (linearity, precision, detection limit, and recovery) were studied. Compared to liquid-liquid extraction and solid-phase microextraction, HS-SDME with in-drop derivatization is a simple, rapid, convenient, and inexpensive sample technique.

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“…53 A method to determine carbonyl compounds in the wine by GC/MS analysis of their O- (2,3,4,5,6-pentafluorobenzyl)-hydroxylamine (PFBOA) derivatives was developed. 54,55,56 To quantify carbonyl compounds at the low levels occurring in wine, the signal at m/z 181 was recorded in SIM mode. Carbonyl compounds react with PFBOA to form oxime derivatives, characterized as highly volatile, and by the loss of the m/z 181 fragment as base peak in mass spectra, corresponding to the pentafluorobenzyl ion.…”

Section: Carbonyl Compounds and Malolactic Fermentation Of Winementioning

confidence: 99%

Some advances in the knowledge of grape, wine and distillates chemistry as achieved by mass spectrometry

Flamini

2005

J. Mass Spectrom.

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Mass spectrometry plays a very important role in acquiring knowledge of the chemistry of grape and its derivative products. By liquid mass spectrometry, anthocyanins of grape were studied, and in hybrid grape extracts, delphinidin, cyanidin, petunidin and malvidin 3-O-(6-O-p-coumaroyl)-5-O-diglucosides were found. A semiquantitative procedure to estimate the amounts and percentages of monoglucoside and diglucoside anthocyanins without chromatography was developed. By gas chromatography mass spectrometry (GC/MS), aroma compounds of grape, wine and the distillate Italian grappa were studied, and molecular structures characterized. The representative aroma profile of Muscat grape was characterized by 23 terpenols, present in both free and bonded form, and direct correlation between aroma and genetic profile permitted to distinguish between different Muscat grape varieties. Aroma of Italian grappa resulted from and was characterized by several compounds linked to the grape variety, such as vitispiranes, terpenols, ethyl cinnamate, salicylic esters, benzaldehyde and farnesol. Synthesis of O-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine (PFBOA) derivatives and GC/MS analysis resulted in a sensitive and selective method to study carbonyl compounds at the low levels occurring in wine.

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O-(2,3,4,5,6-Pentafluorophenyl)methylhydroxylamine hydrochloride: a versatile reagent for the determination of carbonyl-containing compounds

Cited by 81 publications

References 40 publications

Hydrolytic Polyketide Shortening by Ayg1p, a Novel Enzyme Involved in Fungal Melanin Biosynthesis

Hydrolytic Polyketide Shortening by Ayg1p, a Novel Enzyme Involved in Fungal Melanin Biosynthesis

Headspace single‐drop microextraction with in‐drop derivatization for aldehyde analysis

Some advances in the knowledge of grape, wine and distillates chemistry as achieved by mass spectrometry

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