Biosynthesis Of Glucosides Research Articles

Studies on Monoterpene Glucosides and Related Natural Products. XVII. The Intermediacy of 7-Desoxyloganic Acid and Loganin in the Biosynthesis of Several Iridoid Glucosides

Administration experiments of labelled compounds into several plants revealed that 7-desoxyloganic acid is the intermediate in the biosynthesis of iridoid glucosides such as verbenalin (2), loganin (4), geniposide (5), asperuloside (6), and aucubin (10). Tracer experiments on asperuloside (6) proved that loganin (4) (or loganic acid (3)) locates biosynthetically between 7-desoxyloganic acid (1) and the glucosides formed after geniposide (5).

Oximes, nitriles and 2-hydroxynitriles as precursors in the biosynthesis of cyanogenic glucosides.

The biosynthesis of the cyanogenic glucosides, linamarin and prunasin, was investigated in linen-flax, peach and cherry-laurel shoots. It was shown that related 2-oximino acids, aldoximes, nitriles and 2-hydroxynitriles were generally good precursors of the aglycone moiety. Studies with double-labelled compounds confirmed the retention of the oximino nitrogen atom from 2-oximinoisovaleric acid and isobutyraldoxime in the biosynthesis of linamarin. A general pathway from amino acids to cyanogenic glucosides involving N-hydroxyamino acids, aldoximes, nitriles and 2-hydroxynitriles is proposed.

The biosynthesis of steryl glucosides in plants.

Mitochondrial preparations from pea root (Pisum sativum L. var. Alaska) cauliflower inflorescence (Brassica cauliflora Gars.) and avocado inner mesocarp (Persea americana Mill. var. Fuerte), and chloroplast preparations from spinach leaf (Spinacia oleracea L. var. Bloomsdale) incorporate glucose into steryl glucoside and acylated steryl glucoside when either uridine diphosphate-glucose or uridine diphosphate-galactose is supplied as precursor. In the case of pea root mitochondria, galactosyl diglycerides are not formed from either nucleotide sugar. In the case of spinach chloroplasts only 3% of the metabolized uridine diphosphate-galactose is found as steryl glycosides. Time course experiments indicate that the steryl glucoside is the precursor of the acylated steryl glucoside. The effect of pH on the over-all reaction and analysis of the reaction products suggest that the glucosylation of the sterol has a pH optimum of 8 to 9, and the pH optimum for the acylation of the steryl glucoside is 6.5 to 7. The synthesis of steryl glucoside and acylated steryl glucoside, catalyzed by acetone powders of pea root mitochondria, is stimuated by added sitosterol and stigmasterol.

Biosynthesis of Mustard Oil Glucosides: Sodium Phenylacetothiohydroximate and Desulfobenzylglucosinolate, Precursors of Benzylglucosinolate in Tropaeolum majus

The biosynthesis of the mustard oil glucoside, benzylglucosinolate, was studied in Tropaeolum majus L. A number of labeled compounds were administered to plant shoots and the incorporation of tracer into benzylglucosinolate, isolated as the crystalline tetramethyl-ammonium salt, was measured. In order of decreasing efficiency of conversion into benzyl-glucosinolate the compounds fed were S-(beta-d-glucopyranosyl)phenylacetothiohydroximic acid (desulfobenzylglucosinolate), sodium phenylacetothiohydroximate, dl-phenylalanine, d-glucose, and sodium-d-1-glucopyranosyl mercaptide (1-thioglucose). The results are consistent with the hypothesis that the thioglucosyl group of benzylglucosinolate is derived by glucosylation of phenylacetothiohydroximate and not from 1-thioglucose. The results also suggest that benzylglucosinolate is formed by sulfation of desulfobenzylglucosinolate as the final step in its biosynthesis.A method for the isolation of a number of glucosinolates (mustard oil glucosides) is described which utilizes anion exchange chromatography on diethylaminoethyl (DEAE) cellulose. Potassium allylglucosinolate, tetramethylammonium benzylglucosinolate, potassium 2-hydroxy-2-phenylethylglucosinolate and potassium 2-phenylethylglucosinolate were obtained on recrystallization of the glucosinolate fraction eluted from the column.

Biosynthesis of mustard oil glucosides: 3-benzylmalic acid, a precursor of 2-amino-4-phenylbutyric acid and of gluconasturtiin.

2-Amino-4-phenylbutyric acid was isolated from Nasturtium officinale R. Br. (watercress) and identified by gas–liquid and paper chromatography.Various 14C-labelled compounds, including 3-benzylmalic-1,2-14C acid, were fed to N. officinale and their efficiencies as precursors of the aglycone moiety of gluconasturtiin and of 2-amino-4-phenylbutyric acid were determined. The efficiency of conversion of 14C from 3-benzylmalic-1,2-14C acid into gluconasturtiin aglycone was greater than that from DL-phenylalanine-2-14C or -3-14C, acetate-2-14C, shikimic-G-14C acid, and D-glucose-G-14C, but was less than that from DL-2-ammo-4-phenylbutyric-2-14C acid. Degradation of the aglycone obtained from plants fed 3-benzylmalic-1,2-14C acid revealed the tracer had been incorporated specifically into the isothiocyanate carbon and it was concluded that the acid was converted to gluconasturtiin with the loss of C-1. As was reported previously, the carboxyl carbons of acetate and phenylalanine were not incorporated into gluconasturtiin aglycone.The 14C from DL-phenylalanine-2-14C, acetate-1-14C, acetate-2-14C, and from 3-benzylmalic-1,2-14C acid was incorporated into 2-amino-4-phenylbutyric acid with high efficiency. The results support the view that 2-amino-4-phenylbutyric acid is formed from phenylalanine and acetate via 3-benzylmalic acid.

Biosynthesis of mustard oil glucosides: N-Hydroxyphenylalanine, a precursor of glucotropaeolin and a substrate for the enzymatic and nonenzymatic formation of phenylacetaldehyde oxime

The incorporation of DL- N-hydroxyphenylalanine-2- 14C into the mustard oil glucoside glucotropaeolin was demonstrated by plant feeding experiments. The efficiency of conversion of 14C from this acid into the aglycone moiety of glucotropaeolin was higher than that from DL-phenylalanine-2- 14C or -3- 14C, and was comparable with that observed previously from phenylacetaldehyde oxime-1- 14C. These results support the reaction sequence: phenylalanine → N-hydroxyphcnylalanine → phenylacetaldehyde oxime → glucotropaeolin. Enzyme preparations were obtained from Sinapis alba L., Tropoeolum majus L. and Nasturtium officinale R.Br. which catalyze the transformation of N-hydroxyphenylalanine to phenylacetaldehyde oxime. Although no absolute requirement for cofactors could be found, an increase in the rate of formation of the aldehyde oxime and consumption of oxygen was observed using FMN and enzyme preparations from T. majus and S. alba. Using the enzyme from T. majus it was demonstrated that the μmoles of phenylacetaldehyde oxime formed and of oxygen consumed were equivalent. In this case FMN appeared to be the prosthetic group and oxygen the physiological hydrogen acceptor. In addition to this enzymatic conversion, an unspecific and nonenzymatic oxidation of the N-hydroxyamino acid to phenylacetaldehyde oxime and phenylacetonitrile was observed.

Biosynthesis of mustard oil glucosides: conversion of phenylacetaldehyde oxime and 3-phenylpropionaldehyde oxime to glucotropaeolin and gluconasturtiin.

Apart from certain amino acids none of the nitrogenous intermediates involved in the biosynthesis of mustard oil glucosides have, untl now, been determined. Results consistent with the hypothesis — amino acids → aldehyde oximes → mustard oil glucosides — are presented for glucotropaeolin and gluconasturtin.Administration of dl‐[2‐14C]phenylalanine and [1‐14C]phenylacetaldehyde oxime to Tropaeolum majus L. shoots resulted in a greater incorporation of the tracer from the latter into the aglycone moiety of glucotropaeolin; incorporation of 14C from phenylacetaldehyde oxime into the aglycone was without randomization. Radioactive phenylacetaldehyde oxime was isolated from T. majus shoots which were fed dl‐[2‐14C]phenylalanine.The extent of conversion of 14C into the aglycone of gluconasturtin was similar when 3‐phenyl[1‐14C]propionaldehyde oxime and dl‐2‐amino‐4‐phenyl[2‐14C]butyric acid were fed to Nasturtium officinale R. Br. There was no randomization of labelled carbon in gluconasturtin aglycone derived from 3‐phenylpropionaldehyde oxime.

Biosynthesis of mustard oil glucosides. II. The administration of sulphur-35 compounds to horse-radish leaves

Sulphur-35 from labelled sulphate, sulphide, thiosulphate and methionine was incorporated into sinigrin isolated from mature horse-radish leaves. Sulphate-S was more readily incorporated than was that from sulphide, thiosulphate or methionine. When inorganic sulphur-35 was supplied, about 80 per cent of the radioactivity of sinigrin was in the bisulphate moiety and 20 per cent in the isothiocyanate. However, with methionine- 35S as the tracer the isothiocyanate portion contained 90 per cent of the radioactivity. The data suggest that methionine sulphur is incorporated into sinigrin by a different pathway than are the various forms of inorganic sulphur.

Biosynthesis of mustard oil glucosides III. Formation of glucotropaeolin from L-phenylalanine-C 14-N 15

Biosynthesis of mustard oil glucosides III. Formation of glucotropaeolin from L-phenylalanine-C 14-N 15

The biosynthesis of phenolic glucosides in plants

Research Article| April 01 1963 The biosynthesis of phenolic glucosides in plants JB Pridham; JB Pridham 1Department of Chemistry, Royal Holloway College (University of London), Englefield Green, Surrey Search for other works by this author on: This Site PubMed Google Scholar MJ Saltmarsh MJ Saltmarsh 1Department of Chemistry, Royal Holloway College (University of London), Englefield Green, Surrey Search for other works by this author on: This Site PubMed Google Scholar Biochem J (1963) 87 (1): 218–224. https://doi.org/10.1042/bj0870218 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Cite Icon Cite Get Permissions Citation JB Pridham, MJ Saltmarsh; The biosynthesis of phenolic glucosides in plants. Biochem J 1 April 1963; 87 (1): 218–224. doi: https://doi.org/10.1042/bj0870218 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Journal Search Advanced Search This content is only available as a PDF. © 1963 The Biochemical Society1963 Article PDF first page preview Close Modal You do not currently have access to this content.

Adenosine diphosphate glucose and glucoside biosynthesis.

URIDINE diphosphate glucose (UDPG) has been found to act as glucose donor in a number of enzymatic reactions, such as glucoside formation in plants1 and in locust2, sucrose and starch synthesis in plants3,4 and glycogen formation in mammals5.