Interaction of Microsomal Cytochrome P-450 s and N-Phenylcarbamates that Induce Flowering in Asparagus Seedlings

1993 ◽  
Vol 48 (11-12) ◽  
pp. 879-885 ◽  
Author(s):  
Fumiaki Tanigaki ◽  
Atsushi Ishihara ◽  
Kazuichi Yoshida ◽  
Takane Hara ◽  
Masateru Shinozaki ◽  
...  
Keyword(s):  
Cinnamic Acid ◽  
Shikimic Acid ◽  
Asparagus Officinalis ◽  
Phenylpropanoid Metabolism ◽  
Coumaric Acid ◽  
Site Of Action ◽  
Nadh Cytochrome ◽  
Acid Pathway ◽  
Cytochrome P 450 ◽  
Stem Segments

n-Propyl N-(3,4-dichlorophenyl)carbamate, which induces flowering while it inhibits a step or steps in the phenylpropanoid metabolism in Asparagus officinalis L. seedlings, was found to retard the conversion of t-cinnamic acid to p-coumaric acid by high-pressure liquid chromatography of the metabolites in the shikimic acid pathway. The concentrations of the metabolites preceding t-cinnamic acid on the pathway in treated and untreated seedlings were the same, but those of p-coumaric acid and later metabolites were significantly lower in treated plants. The carbamate inhibited phenylpropanoid metabolism when used to treat stem segments that included a shoot apex primordium, where flowers are induced, and when added to a 100,000 × g microsomal fraction prepared from such segments. NADPH-cytochrome P-450 and NADH-cytochrome b5 reductases in the 100,000 × g fraction were not inhibited by the carbamate. The results showed that this compound has its site of action on the endoplasmic reticulum and that it inhibits cytochrome P-450s, including t-cinnamic acid 4-hydroxylase. We examined the flower-inducing activity of known cytochrome P-450 inhibitors, and found that piperonyl butoxide also causes flowering.

BIOSYNTHESIS OF THE COUMARINS. TRACER STUDIES ON COUMARIN FORMATION IN HIEROCHLOË ODORATA AND MELILOTUS OFFICINALIS

1960 ◽  
Vol 38 (2) ◽  
pp. 143-156 ◽  
Author(s):  
Stewart A. Brown ◽  
G. H. N. Towers ◽  
D. Wright
Keyword(s):  
Cinnamic Acid ◽  
Shikimic Acid ◽  
Perennial Grass ◽  
Coumaric Acid ◽  
Sweet Clover ◽  
Tracer Studies ◽  
Melilotus Officinalis ◽  
Specific Activities ◽  
Acid Pathway ◽  
Hierochloe Odorata

Coumarin formation has been studied with C14in the perennial grass, Hierochloë odorata, and in yellow sweet clover, Melilotus officinalis. In general the latter species yielded inconsistent data. In Hierochloë, o-coumaric, cinnamic, and shikimic acids and L-phenylalanine were the best of 10 compounds tested as coumarin precursors, the first two at least being incorporated with little randomization of C14. Acetate was more poorly utilized. It was concluded that the aromatic ring of coumarin arises via the shikimic acid pathway in preference to acetate condensation. When the time of metabolism was varied, o-coumaryl glucoside and free o-coumaric acid rapidly acquired high specific activities from cinnamic acid-C14, but coumarin and melilotic acid became active much more slowly. A lag in the acquisition of C14by coumarin for the first 6 to 8 hours was followed by a rectilinear increase until at least 24 hours. Much the greatest accumulation of C14was found in o-coumaryl glucoside during this entire period. Furthermore, this compound when fed to Hierochloë is comparable to cinnamic acid as a coumarin precursor. These findings suggest a possible function for o-coumaryl glucoside or a derivative in coumarin biosynthesis.

BIOSYNTHESIS OF THE COUMARINS. TRACER STUDIES ON COUMARIN FORMATION IN HIEROCHLOË ODORATA AND MELILOTUS OFFICINALIS

1960 ◽  
Vol 38 (1) ◽  
pp. 143-156 ◽  
Author(s):  
Stewart A. Brown ◽  
G. H. N. Towers ◽  
D. Wright
Keyword(s):  
Cinnamic Acid ◽  
Shikimic Acid ◽  
Perennial Grass ◽  
Coumaric Acid ◽  
Sweet Clover ◽  
Tracer Studies ◽  
Melilotus Officinalis ◽  
Specific Activities ◽  
Acid Pathway ◽  
Hierochloe Odorata

Coumarin formation has been studied with C14in the perennial grass, Hierochloë odorata, and in yellow sweet clover, Melilotus officinalis. In general the latter species yielded inconsistent data. In Hierochloë, o-coumaric, cinnamic, and shikimic acids and L-phenylalanine were the best of 10 compounds tested as coumarin precursors, the first two at least being incorporated with little randomization of C14. Acetate was more poorly utilized. It was concluded that the aromatic ring of coumarin arises via the shikimic acid pathway in preference to acetate condensation. When the time of metabolism was varied, o-coumaryl glucoside and free o-coumaric acid rapidly acquired high specific activities from cinnamic acid-C14, but coumarin and melilotic acid became active much more slowly. A lag in the acquisition of C14by coumarin for the first 6 to 8 hours was followed by a rectilinear increase until at least 24 hours. Much the greatest accumulation of C14was found in o-coumaryl glucoside during this entire period. Furthermore, this compound when fed to Hierochloë is comparable to cinnamic acid as a coumarin precursor. These findings suggest a possible function for o-coumaryl glucoside or a derivative in coumarin biosynthesis.

METABOLISM OF PHENYLPROPANOID COMPOUNDS IN SALVIA: II. BIOSYNTHESIS OF PHENOLIC CINNAMIC ACIDS

1959 ◽  
Vol 37 (1) ◽  
pp. 537-547 ◽  
Author(s):  
D. R. McCalla ◽  
A. C. Neish
Keyword(s):  
Caffeic Acid ◽  
Phenolic Acids ◽  
Cinnamic Acid ◽  
Shikimic Acid ◽  
Sinapic Acid ◽  
Coumaric Acid ◽  
Cinnamic Acids ◽  
Phenyllactic Acid ◽  
Salvia Splendens ◽  
Specific Activities

p-Coumaric, caffeic, ferulic, and sinapic acids were found to occur in Salvia splendens Sello in alkali-labile compounds of unknown constitution. A number of C14-labelled compounds were administered to leafy cuttings of salvia and these phenolic acids were isolated after a metabolic period of several hours and their specific activities measured. Cinnamic acid, dihydrocinnamic acid, L-phenylalanine, and (−)-phenyllactic acid were found to be good precursors of the phenolic acids. D-Phenylalanine, L-tyrosine, and (+)-phenyllactic acid were poor precursors. A kinetic study of the formation of the phenolic acids from L-phenylalanine-C14 gave data consistent with the view that p-coumaric acid → caffeic acid → ferulic acid → sinapic acid, and that these compounds can act as intermediates in lignification. Feeding of C14-labelled members of this series showed that salvia could convert any one to a more complex member of the series but not so readily to a simpler member. Caffeic acid-β-C14 was obtained from salvia after the feeding of L-phenylalanine-β-C14 or cinnamic acid-β-C14, and caffeic acid labelled only in the ring was obtained after feeding generally labelled shikimic acid.

BIOSYNTHESIS OF PUNGENIN FROM C14-LABELLED COMPOUNDS BY COLORADO SPRUCE

1959 ◽  
Vol 37 (5) ◽  
pp. 1085-1100 ◽  
Author(s):  
A. C. Neish
Keyword(s):  
Cinnamic Acid ◽  
Mandelic Acid ◽  
Protocatechuic Acid ◽  
Phenylacetic Acid ◽  
Shikimic Acid ◽  
Coumaric Acid ◽  
Carbonyl Carbon ◽  
Phenyllactic Acid ◽  
Methyl Group ◽  
Picea Pungens

A number of C14-labelled compounds were fed to detached leafy twigs of Colorado spruce (Picea pungens Engelm.), and after a metabolic period of 24 hours the pungenin was isolated and the specified activities of the glucose moiety and the aglycone (3,4-dihydroxyacetophenone) were determined. In some instances the aglycone was degraded further to determine the C14 in the methyl and carbonyl carbons separately.Caffeic acid and L-phenylalanine were the best precursors of the aglycone; cinnamic acid, p-coumaric acid, phenyllactic acid, and shikimic acid were quite good. Sodium acetate was a poor precursor, and was converted to glucose more readily than to the aglycone. Compounds found to be very poor precursors include tyrosine, 3,4-dihydroxyphenylalanine, 3-hydroxytyramine, phenylacetic acid, mandelic acid, p-hydroxyphenylpyruvic acid, p-hydroxyphenyllactic acid, p-hydroxybenzoic acid, and protocatechuic acid. Cinnamic acid-α-C14 gave 3,4-dihydroxyacetophenone labelled chiefly in the methyl group, while cinnamic acid-β-C14, L-phenylalanine-β-C14, p-coumaric acid-β-C14, and caffeic acid-β-C14 formed 3,4-dihydroxyacetophenone labelled mainly in the carbonyl carbon. It appears that a phenylethanoid compound is formed by a process involving the loss of the terminal carbon of a phenylpropanoid compound.3,4-Dihydroxyacetophenone-carbonyl-C14 was fed to spruce twigs bearing new terminal growth; up to 20% was converted to pungenin but most of it formed unidentified compounds. It was a poor precursor of lignin, compared with cinnamic acid, and a poor precursor of glutamic acid, relative to acetate.

scholarly journals Observations on the biosynthesis of phytoterpenoid quinone and chromanol nuclei

1967 ◽  
Vol 105 (1) ◽  
pp. 145-154 ◽  
Author(s):  
G R Whistance ◽  
D R Threlfall ◽  
T W Goodwin
Keyword(s):  
Rhodospirillum Rubrum ◽  
Shikimic Acid ◽  
French Bean ◽  
Side Chain ◽  
Pulse Labelling ◽  
Coumaric Acid ◽  
Ochromonas Danica ◽  
Maize Roots ◽  
Labelling Experiment ◽  
Acid Pathway

1. p-Hydroxy[U−14C]benzoic acid, except for loss of the carboxyl group, is effectively incorporated into the nucleus of ubiquinone and an unidentified prenylphenol by maize roots, maize shoots, french-bean leaves, french-bean cotyledons and Ochromonas danica. Plastoquinone, α-tocopherol, γ-tocopherol and α-tocopherolquinone are all unlabelled from this substrate. The high radioactivity of the prenylphenol and its behaviour in a pulse-labelling experiment with maize shoots suggested that it may be a ubiquinone precursor. 2. Members of the 2-polyprenylphenol and 6-methoxy-2-polyprenylphenol series, compounds that are known ubiquinone precursors in Rhodospirillum rubrum, could not be detected in maize tissues, but possibly they may occur as their glycosides. 3. [G−14C]Shikimic acid is incorporated into the nuclei of phylloquinone, plastoquinone, α-tocopherolquinone, γ-tocopherol, α-tocopherol and ubiquinone in maize shoots, showing that in plant tissues the nuclei of these compounds arise via the shikimic acid pathway of aromatic biosynthesis. 4. l-[U−14C]Phenylalanine and l-[U−14C]tyrosine are incorporated into plastoquinone, γ-tocopherol, α-tocopherolquinone and ubiquinone. α-Tocopherol, which is absent from shoots incubated with l-[U−14C]tyrosine, is also labelled from l-[U−14C]phenylalanine. Degradation studies showed that there is little 14C radioactivity in the terpenoid portions of the molecules and from this it is concluded that the aromatic portions of these amino acids are giving rise to the quinone and chromanol nuclei. 5. It is proposed that in maize the nucleus of ubiquinone can be formed from either phenylalanine or tyrosine by a pathway involving p-coumaric acid and p-hydroxybenzoic acid. Plastoquinone, tocopherols and tocopherolquinones are formed from tyrosine by some pathway in which the aromatic ring and C-3 of the side chain of this amino acid gives rise to the nucleus and one methyl substituent respectively of these compounds.

METABOLISM OF PHENYLPROPANOID COMPOUNDS IN SALVIA: II. BIOSYNTHESIS OF PHENOLIC CINNAMIC ACIDS

1959 ◽  
Vol 37 (4) ◽  
pp. 537-547 ◽  
Author(s):  
D. R. McCalla ◽  
A. C. Neish
Keyword(s):  
Caffeic Acid ◽  
Phenolic Acids ◽  
Cinnamic Acid ◽  
Shikimic Acid ◽  
Sinapic Acid ◽  
Coumaric Acid ◽  
Cinnamic Acids ◽  
Phenyllactic Acid ◽  
Salvia Splendens ◽  
Specific Activities

p-Coumaric, caffeic, ferulic, and sinapic acids were found to occur in Salvia splendens Sello in alkali-labile compounds of unknown constitution. A number of C14-labelled compounds were administered to leafy cuttings of salvia and these phenolic acids were isolated after a metabolic period of several hours and their specific activities measured. Cinnamic acid, dihydrocinnamic acid, L-phenylalanine, and (−)-phenyllactic acid were found to be good precursors of the phenolic acids. D-Phenylalanine, L-tyrosine, and (+)-phenyllactic acid were poor precursors. A kinetic study of the formation of the phenolic acids from L-phenylalanine-C14 gave data consistent with the view that p-coumaric acid → caffeic acid → ferulic acid → sinapic acid, and that these compounds can act as intermediates in lignification. Feeding of C14-labelled members of this series showed that salvia could convert any one to a more complex member of the series but not so readily to a simpler member. Caffeic acid-β-C14 was obtained from salvia after the feeding of L-phenylalanine-β-C14 or cinnamic acid-β-C14, and caffeic acid labelled only in the ring was obtained after feeding generally labelled shikimic acid.

scholarly journals Identification of the Tyrosine- and Phenylalanine-Derived Soluble Metabolomes of Sorghum

2021 ◽  
Vol 12 ◽  
Author(s):  
Jeffrey P. Simpson ◽  
Jacob Olson ◽  
Brian Dilkes ◽  
Clint Chapple
Keyword(s):  
Amino Acids ◽  
Cinnamic Acid ◽  
Aromatic Amino Acids ◽  
Flavonoid Glycosides ◽  
Coumaric Acid ◽  
Biotic And Abiotic Stress ◽  
Proportional Contribution ◽  
Negative Ionization ◽  
Derivatives Of

The synthesis of small organic molecules, known as specialized or secondary metabolites, is one mechanism by which plants resist and tolerate biotic and abiotic stress. Many specialized metabolites are derived from the aromatic amino acids phenylalanine (Phe) and tyrosine (Tyr). In addition, the improved characterization of compounds derived from these amino acids could inform strategies for developing crops with greater resilience and improved traits for the biorefinery. Sorghum and other grasses possess phenylalanine ammonia-lyase (PAL) enzymes that generate cinnamic acid from Phe and bifunctional phenylalanine/tyrosine ammonia-lyase (PTAL) enzymes that generate cinnamic acid and p-coumaric acid from Phe and Tyr, respectively. Cinnamic acid can, in turn, be converted into p-coumaric acid by cinnamate 4-hydroxylase. Thus, Phe and Tyr are both precursors of common downstream products. Not all derivatives of Phe and Tyr are shared, however, and each can act as a precursor for unique metabolites. In this study, 13C isotopic-labeled precursors and the recently developed Precursor of Origin Determination in Untargeted Metabolomics (PODIUM) mass spectrometry (MS) analytical pipeline were used to identify over 600 MS features derived from Phe and Tyr in sorghum. These features comprised 20% of the MS signal collected by reverse-phase chromatography and detected through negative-ionization. Ninety percent of the labeled mass features were derived from both Phe and Tyr, although the proportional contribution of each precursor varied. In addition, the relative incorporation of Phe and Tyr varied between metabolites and tissues, suggesting the existence of multiple pools of p-coumaric acid that are fed by the two amino acids. Furthermore, Phe incorporation was greater for many known hydroxycinnamate esters and flavonoid glycosides. In contrast, mass features derived exclusively from Tyr were the most abundant in every tissue. The Phe- and Tyr-derived metabolite library was also utilized to retrospectively annotate soluble MS features in two brown midrib mutants (bmr6 and bmr12) identifying several MS features that change significantly in each mutant.

scholarly journals NADPH: cytochrome P-450 reductase in olfactory epithelium Relevance to cytochrome P-450-dependent reactions

1986 ◽  
Vol 240 (2) ◽  
pp. 585-592 ◽  
Author(s):  
C J Reed ◽  
E A Lock ◽  
F De Matteis
Keyword(s):  
Olfactory Epithelium ◽  
Direct Evidence ◽  
Reductase Activity ◽  
Electron Flow ◽  
Male Rats ◽  
Male And Female ◽  
Marked Activity ◽  
Nadh Cytochrome ◽  
Olfactory Tissue ◽  
Cytochrome P 450

The presence of a very active cytochrome P-450-dependent drug-metabolizing system in the olfactory epithelium has been confirmed by using 7-ethoxycoumarin, 7-ethoxyresorufin, hexobarbitone and aniline as substrates, and the reasons for the marked activity of the cytochrome P-450 in this tissue have been investigated. The spectral interaction of hexobarbitone and aniline with hepatic and olfactory microsomes has been examined. By this criterion there was no evidence for marked differences in the spin state of the cytochromes of the two tissues, or for the olfactory epithelium containing a greater amount of cytochrome capable of binding hexobarbitone, a very actively metabolized substrate. Rates of NADPH and NADH: cytochrome c reductase activity were found to be higher in the olfactory epithelium than in the liver, and direct evidence was obtained for a greater amount of the NADPH-dependent flavoprotein in the olfactory microsomes. Investigation of male rats and male and female mice, as well as male hamsters, demonstrated that, in all cases, the cytochrome P-450 levels of the olfactory epithelium were lower than those of the liver, while the 7-ethoxycoumarin de-ethylase and NADPH:cytochrome c reductase activities were higher. A correlation was found between 7-ethoxycoumarin de-ethylase and NADPH:cytochrome c reductase activities for both tissues in all species examined. The ratio of reductase to cytochrome P-450 was found to be considerably higher in the olfactory epithelium (1:2-1:3) than in the liver (1:11-1:15), regardless of the species examined, suggesting that facilitated electron flow may contribute significantly to the cytochrome P-450 catalytic turnover in the olfactory tissue.

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