• Title/Summary/Keyword: Amide-Esters

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Hydrolysis of Esters and Amides of 20R- and 20S-Dihydroprednisolonic Acid in Rat Serum and Liver Homogenate

  • Yeon, Kue-Jeng;Byun, Si-Myung;Lee, Henry J.;Lee, Sean-Hyang;Kim, Hyun-Pyo
    • Archives of Pharmacal Research
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    • v.12 no.2
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    • pp.68-72
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    • 1989
  • The hydrolysis rates of ester and amide derivatives of 20-dihydroprednisolonic acid were measured in rat serum and liver homogenate. The hydrolysis rate of the esters in serum was found to be faster than that in liver homogenate on the basis of blood volume and liver weight, while the amide derivatives showed much slower change. And it is also found that the size of substituents at C-21 and C-20 configuration expressed considerable effects on the hydrolysis rate of these derivatives.

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Liquid Chromatographic Resolution of Racemic $\alpha$-Amino Acid Derivatives on an Improved $\pi$-Acidic Chiral Stationary Phase Derived from (S)-Leucine

  • 현명호;이승준;류재정
    • Bulletin of the Korean Chemical Society
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    • v.19 no.10
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    • pp.1105-1109
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    • 1998
  • A chiral stationary phase derived from (S)-N-(3,5-dinitrobenzoyl)leucine N-phenyl N-alkyl amide (CSP 2) was applied in separating the two enantiomers of various π-basic aromatic derivatives of leucine N-propyl amide in order to evaluate π-basic aromatic groups as an effective derivatizing group for the resolution of a-amino acids. Subsequently N-(3,5-dimethoxybenzoyl) group was found to be very effective as a π-basic aromatic derivatizing group. Based on these results, N-(3,5-dimethoxybenzoyl) derivatives of various a-amino N-propyl amides, N,N-diethyl amides and esters were resolved on the CSP derived from (S)-N-(3,5-dinitrobenzoyl) leucine N-phenyl N-alkyl amide (CSP 2) and the resolution results were compared with those on the CSP derived from (S)-N-(3,5-dinitrobenzoyl)leucine N-alkyl amide (CSP 1). The enantioselectivities exerted by CSP 2 were much greater than those exerted by CSP 1. In addition, racemic N-(3,5-dimethoxybenzoyl)-a-mino N,Ndiethyl amides were resolved much better than the corresponding N-(3,5-dimethoxybenzoyl)-a-mino N-propyl amides and esters on both CSPs. Based on these results, a chiral recognition mechanism utilizing the π-π donor-acceptor interaction and the two hydrogen bondings between the CSP and the analyte was proposed.

Gd-complexes of DTPA-bis(amide) Conjugates of Phosphonated Tranexamic Esters as MRI Contrast Agents

  • Patel, Mehul A.;Kim, Hee-Kyung;Lee, Gang-Ho;Chang, Yong-Min;Kim, Tae-Jeong
    • Bulletin of the Korean Chemical Society
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    • v.32 no.3
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    • pp.1022-1026
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    • 2011
  • The syntheses of DTPA-bis(amide) conjugates of phosphonated cyclohexane moieties (5a-d) and their Gd(III) complexes of the type $[Gd(L)(H_2O)]{\cdot}nH_2O$ (6a-d; L = 5a-d) are described. All new compounds have been characterized by microanalysis and spectroscopic techniques. High $r_1$ relaxivities of aqueous solutions of 6a-d are observed to be in the range of $10.7-18.3\;mM^{-1}sec^{-1}$, which compare much better than that of $Omniscan^{(R)}$ ($r_1=3.90\;mM^{-1}sec^{-1}$).

The significant influence of residual feed intake on flavor precursors and biomolecules in slow-growing Korat chicken meat

  • Poompramun, Chotima;Molee, Wittawat;Thumanu, Kanjana;Molee, Amonrat
    • Animal Bioscience
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    • v.34 no.10
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    • pp.1684-1694
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    • 2021
  • Objective: This study investigated the association between feed efficiency, physicochemical properties, flavor precursors and biomolecules in the thigh meat of Korat (KR) chickens. Methods: The feed intake and body weight of individual male KR chickens were recorded from 1 to 10 weeks old to calculate the individual residual feed intake (RFI) of 75 birds. At 10 weeks of age, chickens with the 10 highest (HRFI) and lowest RFI (LRFI) were slaughtered to provide thigh meat samples. The physicochemical properties (ultimate pH, water holding capacity [WHC], drip loss) and flavor precursors (guanosine monophosphate, inosine monophosphate (IMP), adenosine monophosphate and inosine) were analyzed conventionally, and Fourier transform infrared spectroscopy was used to identify the composition of biomolecules (lipids, ester lipids, amide I, amide II, amide III, and carbohydrates) and the secondary structure of the proteins. A group t-test was used to determine significant differences between mean values and principal component analysis to classify thigh meat samples into LRFI and HRFI KR chickens. Results: The physicochemical properties of thigh meat samples from LRFI and HRFI KR chickens were not significantly different but the IMP content, ratios of lipid, lipid ester, protein (amide I, amide II) were significantly different (p<0.05). The correlation loading results showed that the LRFI group was correlated with high ratios of lipids, lipid esters, collagen content (amide III) and beta sheet protein (rg loading >0.5) while the HRFI group was positively correlated with protein (amide I, amide II), alpha helix protein, IMP content, carbohydrate, ultimate pH and WHC (rg loading >0.5). Conclusion: The thigh meat from chickens with different RFI differed in physiochemical properties affecting meat texture, and in the contents of flavor precursors and biomolecules affecting the nutritional value of meat. This information can help animal breeders to make genetic improvements by taking more account of traits related to RFI.

A Study on the Comparison of Surfactants(Sulfate and Sulfonate Salt4s) in their A4ctivi4ties (Sulfate염(鹽)과 Sulfonate염(鹽)의 활성능(活性能)에 관한 비교시험(比較試驗))

  • Choi, Young-Sook
    • Journal of Pharmaceutical Investigation
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    • v.10 no.3
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    • pp.46-50
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    • 1980
  • This study was performed to compare the activities of sulfate esters and sulfonate salts. (comparison of activities such as detergency, forming, permeation and patient of hard water). The one of the method is the combined use of nonionics and the other is the use of anionics alone. The results obtained are as follows: 1. The sulfonate salts are better soluble than the sulfate esters. 2. The lauryl system is better soluble than the sulfate esters. 3. The alkylol sulfate(CONH-OSO3H)that is induced amide radical to the fatty acid shows the excellent foaming power and detergency.

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Preparation of A New HPLC Chiral Stationary Phase from (S)-Naproxen and Application in Elucidating Chiral Recognition Models

  • 현명호;김광자;정경규
    • Bulletin of the Korean Chemical Society
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    • v.18 no.10
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    • pp.1085-1089
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    • 1997
  • A new HPLC chiral stationary phase (CSP 3) has been prepared by connecting N-phenyl N-propyl amide of (S)-naproxen to silica gel through the 6-methoxy-2-naphthyl group of (S)-naproxen. The new CSP has been applied in resolving a homologous series of N-(3,5-dinitrobenzoyl)-α-amino acid esters and a homologous series of N-(3,5-dinitrobenzoyl)-α-(4-alkylphenyl)alkylamines. The separation factors, α, for resolving a homologous series of N-(3,5-dinitrobenzoyl)-α-amino esters and a homologous series of N-(3,5-dinitrobenzoyl)-α-(4-alkylphenyl)alkylamines on the new CSP have been found to remain almost constant throughout the wide range of the length of the alkyl substituent of the analytes while those on the previously reported CSPs (CSP 1 and 2) which were prepared by connecting N-phenyl N-propyl amide of (S)-naproxen to silica gel through the N-propyl group increase or decrease continuously. These results are concluded to support the chiral recognition models which utilize the intercalation of the alkyl substituent of the racemic analytes between the adjacent strands of CSP 1 or 2 to rationalize the increasing or decreasing trends of separation factors.

Introduction of Heterocycles at the 2-Position of Indoline as Ester Bioisosteres

  • Lee, Sung-Kyung;Yi, Kyu-Yang;Yoo, Sung-Eun
    • Bulletin of the Korean Chemical Society
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    • v.25 no.2
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    • pp.207-212
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    • 2004
  • In this study, we attempted to prepare compounds with heterocyclic replacements for metabolically unstable esters of benzopyranyl indole-2-carboxylic esters, which showed good in vitro and in vivo cardioprotective efficacies possibly through the opening of mitochondrial ATP-sensitive potassium channel ($K_{ATP}$). Initially, we tried to construct indolin-2-yl-heterocycles using unprotected indoline-2-carboxylic acid, but the cyclization was proceeded with oxidation of the indoline ring to the indole, which didn't react with benzopyranyl epoxide. Thus we introduced N-Boc group to deplete the electron density of the indoline ring. We successfully prepared various indolin-2-yl-heterocycles by the cyclization of the building blocks including carboxamide, ${\beta}$-hydroxy amide, hydrazide, nitrile starting from N-Boc-indoline-2-carboxylic acid.

Synthesis of Vegetable-based Alkanol Amides for Improving Lubricating Properties of Diesel Fuel (경유의 윤활 성능 향상을 위한 식물유 기반 알칸올 아마이드의 합성)

  • Yuk, Jung-Suk;Kim, Young-Wun;Yoo, Seung-Hyun;Chung, Keun-Wo;Kim, Nam-Kyun;Lim, Dae-Jae
    • Applied Chemistry for Engineering
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    • v.23 no.4
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    • pp.421-427
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    • 2012
  • To improve the lubricity of ultra low sulfur diesel, vegetable oil-based alkanol amide derivatives were prepared and their lubricity properties were studied. To synthesize the alkanol amides, we conducted the amidation reaction of diethaolamine High Frequency Reciprocating Rig (HFRR) and the fatty acid methyl esters, obtained by the continuous transesterification of methanol and several vegetable oil, such as soybean oil, palm oil and coconut oil. The synthesized amides were soluble in ultra low sulfur diesel in the concentration range of ca. 1 wt%; the lubricating properties of ultra low sulfur diesel containing 120 ppm of amides were measured using an HFRR method. It was found that the wear scar diameter in the pure ultra low sulfur diesel decreased significantly from 581 ${\mu}m$ to 305~323 ${\mu}m$ upon the addition of the amides, indicating that lubricating properties of the diesel were improved. On the other hand, the types of vegetable oils did not affect the wear scar diameters, implying that lubricating properties of the diesel did not depend strongly on the structures of alkyl groups of alkanol amide derivatives. When we measured the lubricating properties of the one type of diesels containing various amounts of alkanol amide, we observed that the wear scar diameter decreased drastically with increasing the amide concentration, meaning that the lubricity improved with the amide concentration.

Synthesis and Anti-Inflammatory Testing of Some New Compounds Incorporating 5-Aminosalicylic Acid (5-ASA) as Potential Prodrugs

  • Abdel-Alim Abdel-Alim Mohamed;EI-Shorbagi Abdel-Nasser Ahmed;Abdel-Moty Samia Galal;Abdel-Allah Hajjaj Hassan Mohamed
    • Archives of Pharmacal Research
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    • v.28 no.6
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    • pp.637-647
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    • 2005
  • This work includes the synthesis of 15 final compounds (6a-h and 7b-h) as prod rugs of 5-ASA in the form of the acid itself, esters and amides linked by an amide linkage through a spacer to the endocyclic ring N of nicotinamide. Also, 15 new intermediate compounds were prepared. The target compounds (6b, 6f, 7b, and 7e-h) revealed potent analgesic and anti-inflammatory activities in comparison to sulfasalazine and 5-ASA. In addition, ulcerogenicity, $LD_{50}$, in vivo and in vitro metabolism of compound 7f were determined.