• Title/Summary/Keyword: Aromatic amino compounds

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Synthesis of Certain Mercapto and Aminopyrimidine Derivatives as Potential Antimicrobial Agents

  • El-Kerdawy, M.M.;Eisa, H.M.;El-Emam, A.A.;Massoud, M.A.;Nasr, M.N.
    • Archives of Pharmacal Research
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    • v.13 no.2
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    • pp.142-146
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    • 1990
  • Reaction of ethyl 4-chloro-2-phenylpyrimidine-4-carboxylate (4) with 5-chloro-2-methylthiophenol or 3-aryl-4-phenyl-1, 2, 4-triazole-5 thiol yielded the corresponding thioethers (5) and (8a, b), respectively. Careful alkaline hydrolysis of (5) yielded the corresponding carboxylic acid (6). Reaction of (4) with p-aminoacetophenone yielded compound (10) which was reacted with certain aromatic aldehyde to afford the$\alpha,\beta$-unsaturated ketones (11a-d). Condensation of (11a-d) with malononitrile or phenylhydrazine yielded the 2-amino-3-cyanopyridines (12a-f) or the 2-pyrazolines (13a, b) respectively. Seven representative compounds were tested for their in vitro antimicrobial activity against some pathogenic micro-organisms, some of them were proved to be active.

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Retraction: Changes in the volatile aromatic compounds and amino acid contents of distilled soju using co-fermentation by Saccharomyces cerevisiae and Hanseniaspora uvarum yeasts (Retraction: Saccharomyces cerevisiae 와 Hanseniaspora uvarum 효모 혼합발효를 이용한 증류식 소주의 휘발성 향기성분 및 아미노산 함량 변화)

Heterologous Expression of Novel Cytochrome P450 Hydroxylase Genes from Sebekia benihana

  • Park Nam-Sil;Park Hyun-Joo;Han Kyu-Boem;Kim Eung-Soo
    • Journal of Microbiology and Biotechnology
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    • v.16 no.2
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    • pp.295-298
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    • 2006
  • Actinomycetes are ubiquitous Gram-positive soil bacteria and a group of the most important industrial microorganisms for the biosynthesis of many valuable secondary metabolites as well as the source of various bioconversion enzymes. Cytochrome P450 hydroxylase (CYP), a hemebinding protein, is known to be involved in the modification of various natural compounds, including polyketides, fatty acids, steroids, and some aromatic compounds. Previously, six different novel CYP genes were isolated from a rare actinomycetes called Sebekia benihana, and they were completely sequenced, revealing significant amino acid similarities to previously known CYP genes involved in Streptomyces secondary metabolism. In the present study, these six CYP genes were functionally expressed in Streptomyces lividans, using an $ermE^{*}$ promoter-containing Streptomyces expression vector. Among six CYP genes, two S. benihana CYP genes (CYP503 and CYP504) showed strong hydroxylation activities toward 7-ethoxycoumarin. Furthermore, the recombinant S. lividans containing both the S. benihana CYP506-ferredoxin genes as well as the S. coelicolor feredoxin reductase gene also demonstrated cyclosporin A hydroxylation activity, suggesting potential application of actinomycetes CYPs for the biocatalysts of natural product bioconversion.

Synthesis and Biological Activities of Some New 3,6-Disubstituted 1,2,4-Triazolo[3,4-b]1,3,4-thiadiazole Derivatives

  • Rafiq, Muhammad;Saleem, Muhammad;Hanif, Muhammad;Maqsood, Muhammad Rizwan;Rama, Nasim Hasan;Lee, Ki-Hwan;Seo, Sung-Yum
    • Bulletin of the Korean Chemical Society
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    • v.33 no.12
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    • pp.3943-3949
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    • 2012
  • A series of aromatic hydrazides 3a-j were prepared by refluxing esters 2a-j with hydrazine hydrate in methanol, which were prepared by the esterification of 1a-j. Acetohydrazides 3a-j upon treatment with carbon disulfide and methanolic potassium hydroxide yielded potassium dithiocarbazate salts 4a-j, which on refluxing with hydrazine hydrate yielded substituted 4-amino-5-aryl-3H-1,2,4-triazole-3-thiones 5a-j. The target compounds 6a-j were synthesized by condensing furan-3-carboxylic acid in the presence of polyphosphoric acid under reflux. The structures of newly synthesized compounds were characterized by IR, $^1H$ NMR, $^{13}C$ NMR, elemental analysis and mass spectrometric studies. All the synthesized compounds were screened for their urease, acetylcholine esterase inhibition, antioxidant and alkaline phosphatase inhibition activity. Almost all of the compounds 6a-j showed good to excellent activities against urease and acetylcholine esterase more than the reference drugs. Compounds 6f and 6g were more potent scavenger of free radicals than the reference n-propyl gallate. Compound 6b and 6h showed excellent activities of alkaline phosphatase as compare to the reference $KH_2PO_4$.

Physicochemical attributes, oxidative stability, and microbial profile of boneless sirloin and bone-in T-bone steaks from Hanwoo steer with reference to dry-aging

  • Ali, Mahabbat;Nam, Ki-Chang
    • Journal of Animal Science and Technology
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    • v.63 no.5
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    • pp.1169-1181
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    • 2021
  • We investigated the comparative physicochemical attributes, oxidative stability, and microbial characteristics of 28 days dry-aged meat in between boneless sirloin (gluteus medius) and bone-in T-bone steaks (infraspinatus) muscles from Korean Native Hanwoo Steer (KNHS). Results reveal that regardless of the muscles, dry-aging increased protein content and water-holding capacity (WHC) (p < 0.05). Meat from infraspinatus-aged muscle led to darker meat with higher pH values than un-aged meat (p < 0.05). However, fat content, CIE a*, and CIE b* remained unchanged in both muscles at aging. At aged meat, thiobarbituric acid reactive substances (TBARS) values from bone-in infraspinatus muscle was 2.5-fold higher than boneless gluteus medius muscle (p < 0.05). Dry-aging led to an increase in the contents of total unsaturated fatty acids (UFAs), monounsaturated fatty acids (MUFAs), and UFA/saturated fatty acids (SFA) in both muscles (p < 0.05). Furthermore, gluteus medius aged muscle concentrated with olic acid (C18:1) compared to infraspinatus aged muscle. Irrespective of the muscles, dry-aging enhanced the total free amino acids (FAAs) as well as tasty, and bitter amino acid contents whereas decreased the tasty/bitter amino acids (p < 0.05). Aromatic amino acid, tryptophan that converted to serotonin was 2-fold higher in boneless gluteus medius muscle than bone-in infraspinatus muscle at pre and post aging processes (p < 0.05). Aged Infraspinatus muscle increased total bacteria (p < 0.05) while no salmonella spp. was detected in both muscles. Taken together, our study confirms that 28 days dry-aging profiling the quality characteristics of boneless sirloin (gluteus medius) and bone-in T-bone steaks (infraspinatus) distinctly while gluteus medius aged steak performs better owing to oxidative stability and functional compounds than infraspinatus aged steak.

Development of a Chemically Defined Minimal Medium for the Exponential Growth of Leuconostoc mesenteroides ATCC8293

  • Kim, Yu Jin;Eom, Hyun-Ju;Seo, Eun-Young;Lee, Dong Yup;Kim, Jeong Hwan;Han, Nam Soo
    • Journal of Microbiology and Biotechnology
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    • v.22 no.11
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    • pp.1518-1522
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    • 2012
  • Leuconostoc mesenteroides is a heterofermentative Grampositive bacterium that plays key roles in fermentation of foods such as kimchi, sauerkraut, and milk, leading to the production of various organic acids and aromatic compounds. To study the microbiological and genomic characteristics of L. mesenteroides, we have developed a new chemically defined minimal medium by using the single omission technique. During the exponential cell growth, this species required glutamine, methionine, valine, and nicotinic acid as essential nutrients and 8 amino acids (arginine, cysteine, histidine, leucine, phenylalanine, proline, threonine, and tryptophan), 5 vitamins (ascorbic acid, folic acid, inosine, calcium panthothenate, and thiamine), and others (manganese, magnesium, adenine, uracil, and Tween 80) as supplemental nutrients. This medium is useful to study the metabolic characteristics of L. mesenteroides and to explain its role in food fermentation.

Effects of Leaf Loading Quantity and Circulating Air Volume on the Physical and Chemical Characteristics during Curing in Flue-cured Tobacco Leaves. (열풍건조시 적입 및 송풍량에 따른 황색종 연초엽의 이화학성 변화)

  • 석영선;노재영
    • Journal of the Korean Society of Tobacco Science
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    • v.14 no.1
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    • pp.48-56
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    • 1992
  • This studies were carried out to investigate the effects of leaf loading quantity and circulating air volume during bulk curing on the variation of physical and chemical characteristics in flue-cured tobacco. The results are as follows : 1. The content of sugar in cured leaves was decreased with more circulating air volume and leaf loading quantity at bulk curing. 2. Total nitrogen and protein nitrogen were decreased with less circulating air volume and more leaf loading quantity, while amino nitrogen was increased. 3. The contents of linolenic acid and linoleic acid were increased with more leaf loading quantity and oxalic acid and citric acid had a tendency of being increased in case of high circulating air volume. 4. In general, major aromatic compounds were increased through flue-curing. Relatively high content of solanone in case of lower air volume and less leaf loading were observed, while megastig matrienone was increased when leaf loading was small. 5. The more circulation air volume with leaf loading quantity caused lowering equilibrium moisture content and higher shatter index, which resulted in poor quality of cured leaves based on quality index, nitrogen number, taste index phillips index, and sugar-nicotine ratio.

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Preparation of Radiopharmaceuticals through Arylthallium Ditrifluoroacetate Intermediate (Arylthallium ditrifluoroacetate를 중간체(中間體)로 하는 방사성의약품(放射性醫藥品)의 합성법(合成法))

  • Kim, You-Sun
    • The Korean Journal of Nuclear Medicine
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    • v.17 no.2
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    • pp.71-77
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    • 1983
  • Amino acids such as L-tyrosine, L-histidine, and tryptophan, which bear an aromatic ring in the molecule, could successfully be labelled by radioactive iodine through arylthallium ditrifluoroacetate intermediate. Generally, the labelling reaction could proceed in a short labelling time(ca, 20 minutes) and resulted in a high labelling yields and purity of the labelled product. This procedure has, therefore, been proved to be effective as the labelling method of short labelling time and high specific activity. Labelling proteins such as oval albumin and human albumin could also be achieved in $34\sim48%$ net labelling yield by thallating them at the low temperature $(0\sim10^{\circ}C)$, whereas the labelled products were mainly composed of various denatured products by thallating them at the high temperature$(35\sim40^{\circ}C)$, though the radioactivity was highly retained in the labelled products. Uracil and hippuric acid could also be labelled in a short labelling time though their thallation required a prolonged heating procedure. It was proved that this procedure may be effective to label these compounds by short lived radioisotopes. The labelling yields were, however, lower than 30%.

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Chemical Lithography by Surface-Induced Photoreaction of Nitro Compounds

  • Han, Sang-Woo;Lee, In-Hyung;Kim, Kwan
    • ETRI Journal
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    • v.26 no.1
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    • pp.38-44
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    • 2004
  • Searching for systems of self-assembled monolayers (SAMs) that can be used as templates for chemical lithography, we found that nitro groups on aromatic SAMs are selectively converted on Ag to amino groups by irradiation with a visible laser. 4-nitrobenzenethiol on Ag was thus converted to 4-aminobenzenethiol by irradiating it with an $Ar^+$ laser. This was evident from surface-enhanced Raman scattering (SERS) as well as from a coupling reaction forming amide bonds. The surface-induced photoreaction allowed us to prepare patterned binary monolayers on Ag that showed different chemical reactivities. Using the binary monolayers as a lithographic template, we induced site-specific chemical reactions, such as the selective growth of biominerals on either the nitro- or amine-terminated regions by adjusting the crystal-growth conditions. We also demonstrated that patterned, amine-terminated monolayers can be fabricated even on gold by using silver nanoparticles as photoreducing catalysts.

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Genome sequence of Caballeronia sordidicola strain PAMC 26592 isolated from an arctic lichen species (북극 지의류에서 분리한 Caballeronia sordidicola균주 PAMC 26592의 유전체 서열 분석)

  • Kim, Junghee;Kwon, Kae Kyoung;Kim, Byung Kwon;Hong, Soon Gyu;Oh, Hyun-Myung
    • Korean Journal of Microbiology
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    • v.53 no.1
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    • pp.64-66
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    • 2017
  • Caballeronia sordidicola strain PAMC 26592 was isolated from Umbilicaria sp., a lichen material collected from Svalbard Archipelago in the Arctic Ocean. We report the draft genome sequence of the strain PAMC 26592, a metabolic generalist. As we have observed in previous genomic studies in the genus Caballeronia draft genomic sequences of PAMC 26592 had an assortment of genes of ecological importance and of bio-technical potentials, which include diverse metabolic genes for carbohydrates, aromatic compounds, amino acids, and vitamins, and genes for nitrogen / sulfur metabolisms, stress responses, membrane transporters, antibiotic resistance, and heavy metal resistance.