Hydroxycinnamoyl: Coenzyme A Transferase Involved in the Biosynthesis of Kaempferol-3-(p-coumaroyl Triglucoside) in Pisum sativum

1977 ◽  
Vol 32 (9-10) ◽  
pp. 765-768 ◽  
Author(s):  
Marie H. Saylor ◽  
Richard L. Mansell

Abstract The major flavonoids of Pisum are derivatives of kaempferol and quercetin, including both tri-glucosides and acylated triglucosides in which the acyl group is p-coumaric acid. Although hydroxy-cinnamic acid esters of flavonoids are common pigments in many plants, neither the enzymes nor the precursors involved in their biosynthesis have been demonstrated. We report here that crude enzyme preparations extracted from peas catalyze the transfer of the p-coumaroyl moiety of p-coumaroyl: Coenzyme A to kaempferol-3-triglucoside forming kaempferol-3-(p-coumaroyl triglucoside) as the acylated product. The reaction product has been vigorously shown to be identical to the naturally occurring kaempferol-3-(p-coumaroyl triglucoside) in both chromatographic and chemical properties. The enzymatic formation of the acylated derivative occurred only minimally when incubated with the cofactors required for carboxyl group activation (ligase) and maximally when incubated with p-coumaroyl : Coenzyme A as the acyl donor.

2002 ◽  
Vol 67 (7) ◽  
pp. 473-480 ◽  
Author(s):  
Hulya Çelik

In this study, monoketo and monohydroxy eicosanoic acids and their methyl esters with the position of the substituent on odd numbered carbon atoms from 3 to 13 were synthesized with high purity. Furthermore, the semicarbazone and anilide derivatives of the obtained keto acids were prepared. They were characterized by TLC, IR and 1H-NMR spectroscopy and their physical and chemical properties were established.


1987 ◽  
Vol 42 (7-8) ◽  
pp. 885-890 ◽  
Author(s):  
Gernot Metschulat ◽  
Rainer Sütfeld

Naturally-occurring hydroxybutinylbithiophene derivatives were acylated by enzyme preparations of Tagetes patula seedlings in the presence of distinct acyl-Coenzyme A esters. The O-acyltransferase activity could only be detected after almost complete separation of the enzyme from counter-currently acting esterases which were present in the same extracts. This was achieved by affinity chromatography on Cibachron Blue A. During this procedure, the O-acyl-transferase was split, yielding two active fractions. Both had a Mr of 37,000 (±5,000), equal isoelectric properties, a pH optimum of pH 7.0, and were considerably inhibited in the presence of free Coenzyme A. Small differences existed in their affinities for their thiophenic substrates (3,4-dihydroxybutinylbithiophene and 4-hydroxybutinylbithiophene, respectively), as well as for various acyl-CoA esters as cosubstrates. With the preferred cosubstrate, acetyl-CoA, acylation took place at the 4-position of the butinyl side chain of the molecules, forming the naturally- occurring 4-acetoxybutinylbithiophene and 3-OH,4-OAc-butinylbithiophene, respectively. From the other acyl-CoA esters employed, only propionyl-CoA was likewise converted, forming the corresponding O-propionyl esters. The reactions observed are suggested to be catalyzed by two acetyl-CoA: 4-hydroxybutinylbithiophene O-acetyltransferase isoenzymes which exhibit different affinities for particular substrates and cosubstrates. The activities of both the isoenzymes changed drastically if plant material from different developmental stages was used as enzyme source. Therefore, it may be suggested that these isoenzymes play an important regulatory role in the metabolism of naturally-occurring hydroxy- and acetoxybutinylbithiophenes and their derivatives.


1992 ◽  
Vol 11 (8) ◽  
pp. 1015-1025 ◽  
Author(s):  
Danuta Piskorska ◽  
Janusz Sokolowski ◽  
Marlin Friesen ◽  
Gérard Descotes

Author(s):  
Afshan Saleem ◽  
Noureen Rafi ◽  
Sumara Qasim ◽  
Usama Ashraf ◽  
Nasir Hussain Virk

Picric acid and its derivatives are widely used in various applications/industries. The first synthetic dye was prepared in 1771 using picric acid. It was used to dye silk fabric into greenish-yellow color. In this study, Picric acid and their derivatives were synthesized and characterized by their physical and chemical properties. The derivatives of Picric acid which are considered in this research include Picramic acid and Sodium Picramate. The physical properties like melting point, colors, physical state and solubility of Picric acid and its derivatives were determined and confirmed using IR Spectra. IR spectra proved efficient in scanning and mapping.


2021 ◽  
pp. 50-56
Author(s):  
А. В. Хільковець

Nitrogen-containing heterocyclic compounds are widely represented in modern organic chemistry. A special place among the huge number of substances presented is occupied by derivatives of 1,2,4-triazole due to their uniqueness and prospects. In recent years, these derivatives have remained the object of close attention of both synthetic chemists and researchers engaged in the search for new biologically active substances of a wide spectrum of action, the synthesis of optical materials, dyes, corrosion inhibitors, veterinary drugs, etc. It is known from the literature that the combination of the aromatic heterocycle of thiophene and 1,2,4-triazole is a promising area for research. The result of such combinations is a number of compounds obtained with fairly high yields and a wide range of activities. Thus, further chemical modification of 1,2,4-triazole derivatives by additional administration of a typical thiophene pharmacophore is an urgent task. The aim of the study is to obtain new compounds in a number of S-substituted 5-thiophene-(3-ylmethyl)-4R-1,2,4-triazole-3-thiols and study their physico-chemical properties using complex analysis methods. The study of the physical and chemical properties of the compounds obtained was carried out according to methods that meet the standards of the state pharmacopoeia of Ukraine. The synthesis of new compounds was carried out according to generally accepted methods. The previously obtained 5-thiophene-(3-ylmethyl)-4h-1,2,4-triazole-3-thiol and 5-thiophene-(3-ylmethyl)-4-phenyl-1,2,4-triazole-3-thiol were used as starting compounds. Preparation of thioethanones was performed in an alkaline medium in the presence of methanol. The acids were obtained in an alcohol-alkaline medium with the addition of monochloroacetic acid. To obtain esters, two conventional methods were used. The first method is based on the alkylation in an alkaline-alcohol medium of the starting thiols with isopropyl ester of monochloroacetic acid. The second method is the classical esterification reaction. To confirm the structure and study of the physical and chemical properties, all the resulting compounds were crystallized. As a result, some new compounds that were not previously described were obtained, namely: thioethanones, thioacetamides, thioacetic acids, thioacetates, and a number of other thiopo-derivatives of these initial compounds. The structure and individuality of the obtained molecules were confirmed by elemental analysis (CHNS), IR and 1H NMR spectra. A number of new S-derivatives of 5-thiophene-(3-ylmethyl)-4R-1,2,4-triazole-3-thiols have been obtained. The physical and chemical properties of the obtained compounds are determined and their structure is confirmed using modern analysis methods. Some compounds will be transferred for further research.


The possibility of creating polymers with fluorescence, derivatives of poly (3-aminopropene) (PAP) by alkylation of amino groups with aromatic or heterocyclic aldehydes by Leykart-Wallach reaction with own fluorescence was investigated. Synthesis of N-alkylated PAP derivatives was performed by sequential conversion: acrylamide → PAA (Mν = 100 kDa) → PAP → alkylated PAP. Due to the impossibility of using LiAlH4 to reduce the amide groups of polyacrylamide to amine due to the low solubility of PAA in the non-aqueous (diethyl ether, tetrahydrofuran, etc.) solvents, the reduction of PAA by other reducing agents was optimized. It was found that the best conditions for the reduction of amide groups of PAA to amine - acetic acid - dioxane as a solvent and NaBH4 (suspended in anhydrous 1,4-dioxane) as a reducing agent. According to IR spectroscopy, the products obtained are copolymers of 3-aminopropene (the main amount of elementary units), acrylamide and acrylic acid. To modify the structure of the obtained polymer, the Leuckart-Wallach reaction was used, where the following aldehydes having luminescence were selected: pyrene-3-aldehyde, 2-hydroxy-1-naphthaldehyde, anthracene-9-carbaldehyde, and 3.5 phenyl-1-(4-formylphenyl)-2-pyrazoline. To obtain N-Ar/Het-methylene derivatives, a mixture of PAP, aldehyde and 98% formic acid was heated under harsh conditions (6 hours, glycerol bath), isolated and purified. The obtained modified samples of polymers are intensely fluorescent both in the solid state and in the form of solutions, which indicates the successful passage of the Leykart-Wallach reaction. Spectral characteristics were obtained for solutions in a mixed solvent – ethyl acetate – formic acid (9 : 1). For both the original aldehydes and the copolymers in the mixed solvent used, the spectral fluorescence curves lose their oscillatory structure, probably due to the specific effect of the mixed solvent on the phosphor molecules (for the original aldehydes) and the side methylamino-N-arylmethylene - […СН2-СН(СН2-NH-CH2-Ar)- …] and methylamino-N-getarylmethylene […-СН2-СН(СН2-NH-CH2-Het)-…] groups both in the ground and in the excited state, and for polymers of inhomogeneity of the medium with local polarity zones.


2021 ◽  
Vol 19 (9) ◽  
pp. 117-125
Author(s):  
Sabrean Farhan Jawad ◽  
Dr. Nagham Mahmood Aljamali

Cancerous tumors are considered a serious and fatal diseases for both sexes and for all ages, even fetuses before their birth. Therefore, it has become necessary to find an alternative treatment for radiation to be safer and less dangerous than chemical treatments. Therefore, derivatives of one of the amino acids, such as tyrosine, were prepared. Tyrosine or tyrosine is one of the well-known and important amino acids for humans, and it is present in most proteins; The human body uses it to produce several types of hormones such as noradrenaline and adrenaline. In this paper, we prepared new derivatives of tyrosine represented by (four, five, six)-membered ring, then all these new tyrosine derivatives investigated by several techniques (FT.IR, H.NMR)–spectrophotometric, other physical and chemical properties, with assaying for some new created derivatives as anti-cancer.


2021 ◽  
Vol 18 ◽  
Author(s):  
Wahid Bux Jatoi ◽  
Ashique Hussain Balouch ◽  
Mazhar Iqbal Khaskheli ◽  
Nafeesa Khatoon Shahani ◽  
Qurat-Ul-Ain Shaikh ◽  
...  

: Piperidine-based alkaloids are undoubtedly an important class of biologically active natural products. When a unique group like trifluoromethyl (Tfm) is added to an active compound, it significantly ameliorates its bioactivity, bioavailability, physical and chemical properties. Many fluorination and trifluoromethylation methods have been reported. In the present paper, we have shown that among all other trifluoromethylation pathways, Mannich reaction also has the great tendency to introduce a Tfm group in a saturated or aromatic heterocyclic compound. Applications of this reaction are elaborated in preparing several derivatives of piperidine base alkaloids with trifluoromethyl at α-position. Furthermore, the substitution at C-4 and C-6 was successfully achieved with variety of saturated and aromatic groups.


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