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.

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.

scholarly journals A Perspective of Diverse Synthetic Approaches and Biological Applications of Vitamin K

2021 ◽  
Author(s):  
Satyanarayana Battula
Keyword(s):  
Vitamin K ◽  
Shikimic Acid ◽  
Bone Mineralization ◽  
Growth Control ◽  
Vascular Diseases ◽  
Functional Health ◽  
Side Chain ◽  
Organometallic Reagents ◽  
Acid Pathway ◽  
Synthetic Approaches

Vitamin-K is a demanding multi-functional health product in the market and belongs to a class of isoprenoid molecules that comprises methylnaphthoquinone (MK) unit attached to an isoprene side chain. They are fat soluble and differ in the extent of side chain & obtained in the nature as vitamin K1 (phylloquinone), menaquinone/vitamin K2, and other lipoquinones. Owing to their owned polyprenyl side chain, they are hydrophobic/lipophilic in nature. Generally, the synthesis of vitamin K and its variants suffers with isomerization (for example 11 isomers were identified for cis/trans MK-7). Naturally, in bio-systems vitamin K produces through shikimic acid pathway and terpene biosynthetic pathway for the synthesis of menaquinone part & prenyl side chain parts respectively. Menadione or its auxiliaries are commonly being used as substrates to the synthesis of vitamin K variants through the involvement of condensation reactions, Friedel-Craft alkylation’s, Claisen rearrangement, Diels-Alder reactions and others. Importantly, organometallic reagents, such as Grignard, Gilman, organotelluride and other reagents could be the promising and consistent choice of substrate to the synthesis of various vitamin K’s. Vitamin K is well known for blood coagulation. As an antihaemorrhagic vitamin, it’s also being the current interest for the treatment of bone and vascular diseases. In addition, vitamin k is indispensable for the activation of vitamin K dependent (VKD) proteins and that are present almost in all tissues and responsible for hemostasis, bone mineralization, arterial calcification, apoptosis, phagocytosis, growth control, chemotaxis, and signal transduction. This chapter summarizes various synthetic approaches of vitamin K & derivatives and their biological functions.

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.

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.

Shikimic Acid Pathway

1998 ◽  
pp. 94-105 ◽  
Author(s):  
David S. Seigler
Keyword(s):  
Shikimic Acid ◽  
Shikimic Acid Pathway ◽  
Acid Pathway

A Review of the Analytical Methods Based on Chromatography for Analyzing Glyphosate in Foods

2020 ◽  
Author(s):  
Pasquale Avino ◽  
Ivan Notardonato ◽  
Mario Vincenzo Russo
Keyword(s):  
Water Solubility ◽  
Solid Phase ◽  
Shikimic Acid ◽  
Ion Exchange Chromatography ◽  
Liquid Extraction ◽  
Exchange Chromatography ◽  
Phase Extraction ◽  
Matrix Solid Phase Dispersion ◽  
Chromatographic Methods ◽  
Acid Pathway

Glyphosate is a pesticide widely used in agriculture, horticulture, and silviculture as well as around homes and gardens. It was introduced by Monsanto in the early 1970s, and it is a broad spectrum, nonselective, post-emergence herbicide that inhibits plants’ shikimic acid pathway. Glyphosate is considered as “difficult herbicide” in terms of trace analysis. It has low molecular weight, low volatility, thermal lability, and good water solubility. These properties cause problems in its extraction, purification, and detection. The determination often requires additional processes that may allow quantification by chromatographic methods. Several analytical procedures have been developed based on solid-phase extraction, ion-exchange chromatography, or matrix solid phase dispersion. Most published methods involve liquid extraction followed by clean-up. This review would like to revise the literature on this issue discussing the relevant chromatographic methods reported in the literature in terms of analytical parameters for analyzing such compound in food chain.

Regulation of Chloramphenicol Synthesis in Streptomyces sp. 3022a. 3-Deoxy-D-arabino-heptulosonate 7-Phosphate Synthetase

1971 ◽  
Vol 49 (4) ◽  
pp. 448-455 ◽  
Author(s):  
D. A. Lowe ◽  
D. W. S. Westlake
Keyword(s):  
Enzyme Activity ◽  
Shikimic Acid ◽  
Aromatic Amino Acids ◽  
Product Inhibition ◽  
Enzyme Synthesis ◽  
Synthetase Activity ◽  
Shikimic Acid Pathway ◽  
Sugar Phosphates ◽  
Acid Pathway ◽  
Single Enzyme

The repression and end-product inhibition of 3-deoxy-D-arabino-heptulosonate 7-phosphate (DAHP) synthetase were studied in a chloramphenicol-producing Streptomycetes. Synthesis of DAHP synthetase was repressed by p-hydroxybenzoate, and enzyme activity was inhibited competitively by sugar phosphates, especially D-ribose 5-phosphate. The presence of chloramphenicol, aromatic amino acids, or shikimic acid pathway intermediates did not repress enzyme synthesis nor inhibit enzyme activity. Chloramphenicol production by growing cultures was not affected by the intermediates or end products of the shikimic acid pathway nor by the repression of DAHP synthetase. Purification of DAHP synthetase activity indicated the presence of a single enzyme protein with a molecular weight of 88 000.

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