BIOSYNTHESIS OF MUSTARD OIL GLUCOSIDES: V. FORMATION OF GLUCONASTURTIIN FROM L-γ-PHENYLBUTYRINE-C14-N15 IN WATERCRESS

1965 ◽  
Vol 43 (2) ◽  
pp. 179-187 ◽  
Author(s):  
E. W. Underbill
Keyword(s):  
Sodium Acetate ◽  
Amino Nitrogen ◽  
Competition Experiment ◽  
Mustard Oil ◽  
Side Chain ◽  
Nasturtium Officinale ◽  
A Chain ◽  
Phenylbutyric Acid

C14-Labelled compounds were fed to watercress (Nasturtium officinale R. Br.) and their efficiency as precursors of the aglycone portion of gluconasturtiin compared. Phenylalanine-2- and -3-C14 and sodium acetate-2-C14 were efficient precursors of the aglycone but neither compound was as efficient a precursor as γ-phenylbutyrine (2-amino-4-phenylbutyric acid). Approximately 40% of the C14 from γ-phenylbutyrine-2- or -3-C14 was incorporated into the aglycone side chain. Results of studies with doubly labelled L-γ-phenylbutyrine-C14-N15 show that the amino nitrogen is incorporated directly into the thioglucoside. Evidence that indicates that D-γ-phenylbutyrine is converted to its L-isomer by the plant is also presented. The results of an isotope competition experiment provide some evidence for the existence of a chain-lengthening pathway (analogous to the formation of leucine from valine) for the biosynthesis of γ-phenylbutyrine from phenylalanine and acetate in watercress.

Chain Elongation of Aromatic Amino Acids: the Role of 2-Benzylmalic Acid in the Biosynthesis of a C6C4 Amino Acid and a C6C3 Mustard Oil Glucoside

1974 ◽  
Vol 52 (10) ◽  
pp. 916-921 ◽  
Author(s):  
D. Dörnemann ◽  
W. Löffelhardt ◽  
H. Kindl
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aromatic Amino Acids ◽  
Chain Elongation ◽  
Mustard Oil ◽  
Barbarea Vulgaris ◽  
Nasturtium Officinale ◽  
A Chain ◽  
Phenylbutyric Acid

A chemical synthesis of specifically 14C-labelled 2-benzylmalic acid, hitherto unknown, was developed. 4-Phenylacetoacetate obtained by condensation of phenylacetyl chloride-1-14C with ethyl acetoacetate yielded 2-benzylmalic acid-2-14C after cyanohydrin reaction and hydrolysis.2-Benzylmalic acid-2-14C, administered to shoots of Nasturtium officinale and Barbarea vulgaris, was shown to be an efficient precursor of the aglucone moiety of the mustard oil glucoside gluconasturtiin. The incorporation of radioactivity agreed well with the values reported for incorporation of 3-benzylmalic acid, but was considerably higher than that obtained after application of L-phenylalanine-U-14C. A conversion of 2-benzylmalic acid into 3-benzylmalic acid and 2-amino-4-phenylbutyric acid could also be demonstrated. These findings provide the final evidence for a chain-lengthening mechanism leading to homologous amino acids as proposed by Underbill and Wetter in 1966.

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

1968 ◽  
Vol 46 (5) ◽  
pp. 401-405 ◽  
Author(s):  
E. W. Underhill
Keyword(s):  
High Efficiency ◽  
Mustard Oil ◽  
Nasturtium Officinale ◽  
Acid Degradation ◽  
Phenylbutyric Acid

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.

Gausemycins A,B – Cyclic Lipoglycopeptides from Streptomyces Sp.

2020 ◽  
Author(s):  
Anton Tyurin ◽  
Vera Alferova ◽  
Alexander Paramonov ◽  
Maxim Shuvalov ◽  
Gulnara Kudryakova ◽  
...  
Keyword(s):  
Cyclic Peptides ◽  
Pore Formation ◽  
Structural Features ◽  
Side Chain ◽  
Peptide Antibiotic ◽  
Streptomyces Sp ◽  
Gram Positive Bacteria ◽  
Low Concentrations ◽  
Phenylbutyric Acid ◽  
Peptide Core

We report a novel family of natural lipoglycopeptides produced by Streptomyces sp. INA-Ac-5812. Two major components of the mixture, named gausemycins A and B, were isolated, and their structures were elucidated. The compounds are cyclic peptides with a unique peptide core and several remarkable structural features, including unusual positions of D-amino acids, lack of the Ca2+ -binding Asp-X-Asp-Gly (DXDG) motif, tyrosine glycosylation with arabinose, presence of 2-amino-4-hydroxy-4- phenylbutyric acid (Ahpb) and chlorinated kynurenine (ClKyn), N-acylation of the ornithine side chain. These major components of the peptide antibiotic family have pronounced activity against Gram-positive bacteria. The mechanism of action of gausemycins was explored by a number of methods, showing significant differences compared to glycopeptides and related lipopeptides. For example, gausemycins exhibit no Ca2+ -dependence of antimicrobial activity and induce no pore formation at low concentrations. Moreover, there is no detectable accumulation of cell wall biosynthesis precursors under treatment with gausemycins.

BIOSYNTHESIS OF MUSTARD OIL GLUCOSIDES: I. ADMINISTRATION OF C14-LABELLED COMPOUNDS TO HORSERADISH, NASTURTIUM, AND WATERCRESS

1962 ◽  
Vol 40 (1) ◽  
pp. 1505-1514 ◽  
Author(s):  
E. W. Underhill ◽  
M. D. Chisholm ◽  
L. R. Wetter
Keyword(s):  
Allyl Isothiocyanate ◽  
The Other ◽  
Mustard Oil ◽  
Methyl Carbon ◽  
Nasturtium Officinale ◽  
Other Hand ◽  
Tropaeolum Majus ◽  
Armoracia Lapathifolia ◽  
Carboxyl Carbon

Biosynthetic investigations with C14-labelled compounds indicate that the aromatic isothiocyanate moieties of mustard oil glucosides obtained from garden nasturtium (Tropaeolum majus L.) and watercress (Nasturtium officinale R.Br.) are derived from phenylalanine. Similar investigations on sinigrin, the mustard oil glucoside isolated from horseradish (Armoracia lapathifolia Gilib.) demonstrate that glycine is incorporated into allyl isothiocyanate. The methyl carbon of acetate was readily incorporated into sinigrin and gluconasturtium and was found almost exclusively in the 'isothiocyanate carbon'; on the other hand the carboxyl carbon is a poor precursor of sinigrin.

BIOSYNTHESIS OF MUSTARD OIL GLUCOSIDES: VI. BIOSYNTHESIS OF GLUCOBARBARIN IN RESEDA LUTEOLA L.

1965 ◽  
Vol 43 (2) ◽  
pp. 189-198 ◽  
Author(s):  
E. W. Underhill
Keyword(s):  
Specific Activity ◽  
Mustard Oil ◽  
Keto Acid ◽  
Carbon 14 ◽  
Acid Analogue ◽  
Phenylbutyric Acid ◽  
Carboxyl Carbon

A number of C14-labelled compounds were fed to Reseda luteola L.; after a 24-hour period of metabolism, the thioglucoside aglycone (5-phenyl-2-oxazolidinethione) was isolated and its specific activity determined. In some instances the aglycone was degraded to determine the distribution of C14.DL-γ-Phenylbutyrine (2-amino-4-phenylbutyric acid) was the most efficient precursor of the aglycone, followed by phenylalanine and acetate; the carboxyl carbon of these compounds was not incorporated into the thioglucoside aglycone. Little or no randomization of C14 in the aglycone resulted from feeding DL-γ-phenylbutyrine-2- and -3-C14, DL-phenylalanine-2- and -3-C14, and acetate-2-C14. The conversion of C14 from 10 additional compounds into the aglycone was less than that from D-glucose-G-C14. Isotope competition experiments suggest that β-benzylmalic acid also may be a precursor. It appears that the C6–C3 aglycone is formed from phenylalanine and acetate via C6–C5 and C6–C4 intermediates (including γ-phenylbutyrine or its keto acid analogue) in a manner analogous to the formation of gluconasturtiin in watercress. The carbon-14 and nitrogen-15 of L-phenylalanine-G-C14-N15 and of DL-γ-phenylbutyrine-2-C14-N15 were not incorporated as a unit into the aglycone of glucobarbarin.

The chemistry of thujone. XVII. The synthesis of ambergris fragrances and related analogues

1994 ◽  
Vol 72 (6) ◽  
pp. 1570-1581 ◽  
Author(s):  
James P. Kutney ◽  
Yong-Huang Chen
Keyword(s):  
Ring Opening ◽  
Sodium Acetate ◽  
Ring Closure ◽  
Side Chain ◽  
Synthetic Route ◽  
Acid Catalyzed ◽  
Robinson Annulation

A strategy to utilize the thujone-derived enone 1 for the development of a synthetic route to ambergris fragrances is presented. Thujone (8) is transformed to the tricyclic enone 9, via the Robinson annulation reaction, and the latter is then elaborated to the cis-fused tricyclic intermediates 10, 11, and 12. Extrusion of the isopropyl side chain in 12 is achieved through an initial ozonation reaction and the resulting ketone 14 is then treated with m-CPBA to afford 16. Cyclopropyl ring opening in 16 is performed via initial saponification to the alcohol 17 and the latter is then reacted with FeCl3 and sodium acetate to enone 1. The necessary elaboration of a tetrahydrofuran ring attached to ring B of 1 is achieved through reaction of 1 with vinylmagnesium bromide, alkylation, hydroboration, and final acid-catalyzed ring closure of the 1,5-diol 4. The route affords the opportunity of synthesizing a variety of analogues within the Ambrox series.

Limitation of cupric bromide for selective side-chain bromination of methyl aryl ketones

1968 ◽  
Vol 21 (1) ◽  
pp. 217 ◽  
Author(s):  
RW Jemison
Keyword(s):  
Sodium Acetate ◽  
Side Chain ◽  
Aryl Ketones

2-Hydroxy-4,6-dimethoxyacetophenone and its acetate undergo nuclear bromination with cupric bromide, and 2,3,4-trimethoxyacetophenone gave w-bromo-2-hydroxy-3,4-dimethoxyacetophenone accompanied by a small yield of 2-hydroxy-3,4-dimethoxyacetophenone and by w-bromo-2,3,4-trimethoxyacetophenone. Formation of the last compound was shown by isolation of w-acetoxy-2,3,4-trimethoxyacetophenone after treatment of the mixture of brominated products with sodium acetate in ethanol.

scholarly journals 4-Hydroxy-5-methoxy-N,1-dimethyl-2-oxo-N-[4-(trifluoromethyl)phenyl]-1,2-dihydroquinoline-3-carboxamide

2014 ◽  
Vol 70 (3) ◽  
pp. o297-o298
Author(s):  
Emmanuel S. Akinboye ◽  
Ray J. Butcher ◽  
Sema Ozturk Yildirim ◽  
John T. Isaacs
Keyword(s):  
Ring System ◽  
Proton Donor ◽  
Phase Iii ◽  
Side Chain ◽  
Carbonyl Groups ◽  
Intermolecular Contact ◽  
Phase Iii Clinical Trials ◽  
Compound C ◽  
A Chain ◽  
Intramolecular Hydrogen

The title compound, C20H17F3N2O4, named tasquinimod, is a second-generation oral quinoline-3-carboxamide analogue, which is currently in phase III clinical trials for the treatment of metastatic prostate cancer. The quinoline unit is almost planar (r.m.s. deviation of fitted atoms = 0.0075 Å). The carboxamide side chain, substituted at position 3, is tilted by 88.07 (7)° to the quinoline plane. Both the methyl and carbonyl groups of this carboxamide side chain are in asynconformation. The 4-(trifluoromethyl)phenyl plane is inclined at 50.62 (17)° to the plane of the carboxamide side chain, and at 87.14 (4)° to the plane of the quinoline ring system. The 4-hydroxy H atom acts as a double proton donor in an intramolecular hydrogen bond to the 5-position methoxy O atom and in an intermolecular contact to the 2-oxo group, generating a chain along [010] in the crystal structure.

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