Sensitized phosphorescence excitation spectra of benzoic acid monomer and methyl benzoate and their complexes in supersonic jets

1985 ◽  
Vol 89 (17) ◽  
pp. 3636-3641 ◽  
Author(s):  
Shinichi Kamei ◽  
Haruo Abe ◽  
Naohiko Mikami ◽  
Mitsuo Ito
Keyword(s):  
Benzoic Acid ◽  
Supersonic Jets ◽  
Methyl Benzoate ◽  
Excitation Spectra ◽  
Sensitized Phosphorescence

Sensitized phosphorescence excitation spectra of biacetyl, benzaldehyde and benzophenone in supersonic jets

1984 ◽  
Vol 109 (3) ◽  
pp. 217-220 ◽  
Author(s):  
Haruo Abe ◽  
Shin-ichi Kamei ◽  
Naohiko Mikami ◽  
Mitsuo Ito
Keyword(s):  
Supersonic Jets ◽  
Excitation Spectra ◽  
Sensitized Phosphorescence

Aliphatic diazo compounds. X. The reaction of α-diazoacetophenone with methanolic sodium methoxide

1977 ◽  
Vol 55 (1) ◽  
pp. 145-152 ◽  
Author(s):  
Peter Yates ◽  
R. J. Mayfield
Keyword(s):  
Acrylic Acid ◽  
Benzoic Acid ◽  
Sodium Methoxide ◽  
Methyl Benzoate ◽  
Diazo Compounds ◽  
Dilute Solution ◽  
Cis And Trans

The reaction of α-diazoacetophenone (1) with methanolic sodium methoxide in dilute solution gives 3-benzoyl-5-hydroxy-4-phenylpyrazole (4), 3-benzoyl-4-hydroxy-5-phenyl-pyrazole (5), 3-benzoyl-5-methoxy-4-phenylpyrazole (9), 3-benzoyl-4-phenylpyrazole (6), 5-benzoyltetrazole (7), 3,6-dibenzoyldihydro-s-tetrazine (10), cis- and trans- β-benzoyl- α-phenyl-acrylic acid, acetophenone, methyl benzoate, and benzoic acid. The pyrazoles 4, 5, and 9 are considered to arise via reaction of 1 to give α-methoxyacetophenone followed by further reaction of the anion of the latter with 1. Evidence in accord with this view was obtained by a study of the products formed when 1 was treated with methanolic sodium methoxide in the presence of 2-methoxy-4′-methylacetophenone. Acetophenone is considered to arise by reduction of 1 via phenylglyoxal 2-monohydrazone (37); condensation of 1 with the enolate ion derived from acetophenone then can give the pyrazole 6, while condensation of 1 with 37 could give the tetrazole 7.

scholarly journals Coordinated and High-Level Expression of Biosynthetic Pathway Genes Is Responsible for the Production of a Major Floral Scent Compound Methyl Benzoate in Hedychium coronarium

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuechong Yue ◽  
Lan Wang ◽  
Rangcai Yu ◽  
Feng Chen ◽  
Jieling He ◽  
...  
Keyword(s):  
Gene Expression ◽  
Benzoic Acid ◽  
Methyl Salicylate ◽  
Biosynthetic Pathway ◽  
Floral Scent ◽  
Methyl Benzoate ◽  
High Level Expression ◽  
Developmentally Regulated ◽  
Hedychium Coronarium ◽  
High Level

Methyl benzoate is a constituent of floral scent profile of many flowering plants. However, its biosynthesis, particularly in monocots, is scarcely reported. The monocot Hedychium coronarium is a popular ornamental plant in tropical and subtropical regions partly for its intense and inviting fragrance, which is mainly determined by methyl benzoate and monoterpenes. Interestingly, several related Hedychium species lack floral scent. Here, we studied the molecular mechanism of methyl benzoate biosynthesis in H. coronarium. The emission of methyl benzoate in H. coronarium was found to be flower-specific and developmentally regulated. As such, seven candidate genes associated with methyl benzoate biosynthesis were identified from flower transcriptome of H. coronarium and isolated. Among them, HcBSMT1 and HcBSMT2 were demonstrated to catalyze the methylation of benzoic acid and salicylic acid to form methyl benzoate and methyl salicylate, respectively. Methyl salicylate is a minor constituent of H. coronarium floral scent. Kinetic analysis revealed that HcBSMT2 exhibits a 16.6-fold lower Km value for benzoic acid than HcBSMT1, indicating its dominant role for floral methyl benzoate formation. The seven genes associated with methyl benzoate biosynthesis exhibited flower-specific or flower-preferential expression that was developmentally regulated. The gene expression and correlation analysis suggests that HcCNL and HcBSMT2 play critical roles in the regulation of methyl benzoate biosynthesis. Comparison of emission and gene expression among four Hedychium species suggested that coordinated and high-level expression of biosynthetic pathway genes is responsible for the massive emission of floral methyl benzoate in H. coronarium. Our results provide new insights into the molecular mechanism for methyl benzoate biosynthesis in monocots and identify useful molecular targets for genetic modification of scent-related traits in Hedychium.

scholarly journals Singlet And Triplet n,π∗ Transitions of Jet-Cooled p-Benzoquinone

1994 ◽  
Vol 14 (1-3) ◽  
pp. 143-154 ◽  
Author(s):  
Isamu Suzuka ◽  
Masaomi Sanekata ◽  
Mitsuo Ito ◽  
Nobuhiro Ohta
Keyword(s):  
Excitation Spectrum ◽  
Excitation Spectra ◽  
Dispersed Fluorescence ◽  
Sensitized Phosphorescence ◽  
Vibronic Level ◽  
Phosphorescence Spectra

The fluorescence/phosphorescence excitation spectra, the dispersed fluorescence/phosphorescence spectra and the sensitized phosphorescence excitation spectrum have been measured for jet-cooled p-benzoquinone. The assignments of vibronic bands in the 1B1g(n-,π∗) ← 1Ag and 1Au(n+,π∗) ← 1Ag transitions have been definitely established. The phosphorescence spectra from vibronic levels of 3Au exhibit a feature of single vibronic level emission. The 3Au ← 1Ag transition was also vibrationally analyzed.

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