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1

40 CFR 721.3100 - Oligomeric silicic acid ester compound with a hy-droxyl-al-kyla-mine.  

Code of Federal Regulations, 2011 CFR

...false Oligomeric silicic acid ester compound with a hy-droxyl-al-kyla-mine...3100 Oligomeric silicic acid ester compound with a hy-droxyl-al-kyla-mine...generically as oligomeric silicic acid ester compound with a hydroxylalkylamine (PMN...

2011-07-01

2

40 CFR 721.3100 - Oligomeric silicic acid ester compound with a hy-droxyl-al-kyla-mine.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Oligomeric silicic acid ester compound with a hy-droxyl-al-kyla-mine. 721.3100 Section 721.3100... § 721.3100 Oligomeric silicic acid ester compound with a hy-droxyl-al-kyla-mine. (a) Chemical substance...

2010-07-01

3

40 CFR 721.3635 - Octadecanoic acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4).  

Code of Federal Regulations, 2012 CFR

... 2012-07-01 false Octadecanoic acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4). 721.3635 Section 721...Substances § 721.3635 Octadecanoic acid, ester with 1,2-propanediol,...

2012-07-01

4

40 CFR 721.3635 - Octadecanoic acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4).  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Octadecanoic acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4). 721.3635 Section 721...Substances § 721.3635 Octadecanoic acid, ester with 1,2-propanediol,...

2010-07-01

5

40 CFR 721.3635 - Octadecanoic acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4).  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Octadecanoic acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4). 721.3635 Section 721...Substances § 721.3635 Octadecanoic acid, ester with 1,2-propanediol,...

2013-07-01

6

40 CFR 721.3635 - Octadecanoic acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4).  

Code of Federal Regulations, 2011 CFR

... 2011-07-01 false Octadecanoic acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4). 721.3635 Section 721...Substances § 721.3635 Octadecanoic acid, ester with 1,2-propanediol,...

2011-07-01

7

Omega-3-acid Ethyl Esters  

MedlinePLUS

Omega-3-acid ethyl esters are used together with lifestyle changes (diet, weight-loss, exercise) to reduce the ... triglycerides (a fat-like substance) in your blood. Omega-3-acid ethyl esters are in a class of ...

8

Synthesis of pyromellitic acid esters  

NASA Technical Reports Server (NTRS)

The ester acids necessary for studyng the thermochemical properties of pyromellitic acid (PMK)-based peroxides were investigated. Obtaining a tetramethyl ester of a PMK was described. The mechanism of an esterification reaction is discussed, as is the complete esterification of PMK with primary alcohol.

Fedorova, V. A.; Donchak, V. A.; Martynyuk-Lototskaya, A. N.

1985-01-01

9

Adsorption kinetics of silicic acid on akaganeite.  

PubMed

As part of a series of studies on the interaction between ferric ions and silicic acid in the hydrosphere, the adsorption of silicic acid on akaganeite was investigated kinetically at various pH values. The adsorption of silicic acid increased with increasing pH over an initial pH range of 4-11.5. In the kinetic experiment, the Cl(-) was released from akaganeite much faster than silicic acid was adsorbed. From this result, we concluded that chloride ions bound on the surface of akaganeite are released and Fe-OH or Fe-O(-) sites are formed, which then acts as an adsorption site for silicic acid. The uptake mechanism of silicic acid by akaganeite is significantly different from that by schwertmannite, despite the presence of the same tunnel structure. PMID:23538050

Naren, Gaowa; Ohashi, Hironori; Okaue, Yoshihiro; Yokoyama, Takushi

2013-06-01

10

40 CFR 721.4215 - Hexanedioic acid, diethenyl ester.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Hexanedioic acid, diethenyl ester. 721.4215... § 721.4215 Hexanedioic acid, diethenyl ester. (a...substance identified as hexanedioic acid, diethenyl ester (PMN...worker in the following state(s): Open liquid...

2014-07-01

11

40 CFR 721.4215 - Hexanedioic acid, diethenyl ester.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Hexanedioic acid, diethenyl ester. 721.4215... § 721.4215 Hexanedioic acid, diethenyl ester. (a...substance identified as hexanedioic acid, diethenyl ester (PMN...worker in the following state(s): Open liquid...

2012-07-01

12

40 CFR 721.4215 - Hexanedioic acid, diethenyl ester.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Hexanedioic acid, diethenyl ester. 721.4215... § 721.4215 Hexanedioic acid, diethenyl ester. (a...substance identified as hexanedioic acid, diethenyl ester (PMN...worker in the following state(s): Open liquid...

2013-07-01

13

40 CFR 721.4215 - Hexanedioic acid, diethenyl ester.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Hexanedioic acid, diethenyl ester. 721.4215... § 721.4215 Hexanedioic acid, diethenyl ester. (a...substance identified as hexanedioic acid, diethenyl ester (PMN...worker in the following state(s): Open liquid...

2011-07-01

14

Quantitative separations of higher fatty acid methyl esters by adsorption chromatography on silica impregnated with silver nitrate  

Microsoft Academic Search

A chromatographic adsorbent has been developed for the separation of geometric isomers of fatty acid methyl esters. The adsorbent\\u000a consists of silicic acid impregnated with silver nitrate.\\u000a \\u000a Quantitative separations of saturated,cis-, andtrans-monoenoic and polyenoic methyl esters in 30 to 100 mg quantities are reported.

B. De Vries

1963-01-01

15

40 CFR 721.10679 - Carboxylic acid, substituted alkylstannylene ester, reaction products with inorganic acid tetra...  

Code of Federal Regulations, 2014 CFR

... 2014-07-01 false Carboxylic acid, substituted alkylstannylene ester, reaction products with inorganic acid tetra alkyl ester (generic). 721...Substances § 721.10679 Carboxylic acid, substituted alkylstannylene...

2014-07-01

16

Esters of valerenic acid as potential prodrugs.  

PubMed

Valerenic acid (VA) is a ?2/3 subunit-specific modulator of ?-aminobutyric acid (GABA) type A (GABAA) receptors inducing anxiolysis. Here we analyze if VA-esters can serve as prodrugs and if different ester structures have different in vitro/in vivo effects. Modulation of GABAA receptors expressed in Xenopus oocytes was studied with 2-microelectrode-voltage-clamp. Anxiolytic effects of the VA-esters were studied on male C57BL/6N mice by means of the elevated plus maze-test; anticonvulsant properties were deduced from changes in seizure threshold upon pentylenetetrazole infusion. VA was detected in plasma confirming hydrolysis of the esters and release of VA in vivo. Esterification significantly reduced the positive allosteric modulation of GABAA (?1?3?2S) receptors in vitro. in vivo, the studied VA-ester derivatives induced similar or even stronger anxiolytic and anticonvulsant action than VA. While methylation and propylation of VA resulted in faster onset of anxiolysis, the action of VA-ethylester was longer lasting, but occurred with a significant delay. The later finding is in line with the longer lasting anticonvulsant effects of this compound. The estimated VA plasma concentrations provided first insight into the release kinetics from different VA-esters. This might be an important step for its future clinical application as a potential non-sedative anxiolytic and anticonvulsant. PMID:24680924

Hintersteiner, Juliane; Haider, Maximilian; Luger, Denise; Schwarzer, Christoph; Reznicek, Gottfried; Jäger, Walter; Khom, Sophia; Mihovilovic, Marko D; Hering, Steffen

2014-07-15

17

Esters of valerenic acid as potential prodrugs  

PubMed Central

Valerenic acid (VA) is a ?2/3 subunit-specific modulator of ?-aminobutyric acid (GABA) type A (GABAA) receptors inducing anxiolysis. Here we analyze if VA-esters can serve as prodrugs and if different ester structures have different in vitro/in vivo effects. Modulation of GABAA receptors expressed in Xenopus oocytes was studied with 2-microelectrode-voltage-clamp. Anxiolytic effects of the VA-esters were studied on male C57BL/6N mice by means of the elevated plus maze-test; anticonvulsant properties were deduced from changes in seizure threshold upon pentylenetetrazole infusion. VA was detected in plasma confirming hydrolysis of the esters and release of VA in vivo. Esterification significantly reduced the positive allosteric modulation of GABAA (?1?3?2S) receptors in vitro. in vivo, the studied VA-ester derivatives induced similar or even stronger anxiolytic and anticonvulsant action than VA. While methylation and propylation of VA resulted in faster onset of anxiolysis, the action of VA-ethylester was longer lasting, but occurred with a significant delay. The later finding is in line with the longer lasting anticonvulsant effects of this compound. The estimated VA plasma concentrations provided first insight into the release kinetics from different VA-esters. This might be an important step for its future clinical application as a potential non-sedative anxiolytic and anticonvulsant. PMID:24680924

Hintersteiner, Juliane; Haider, Maximilian; Luger, Denise; Schwarzer, Christoph; Reznicek, Gottfried; Jäger, Walter; Khom, Sophia; Mihovilovic, Marko D.; Hering, Steffen

2014-01-01

18

40 CFR 721.7770 - Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt.  

Code of Federal Regulations, 2011 CFR

...Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt...Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt...alkyl phenoxypoly(oxyethylene) sulfuric acid ester, substituted amine...

2011-07-01

19

40 CFR 721.7770 - Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt.  

Code of Federal Regulations, 2013 CFR

...Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt...Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt...alkyl phenoxypoly(oxyethylene) sulfuric acid ester, substituted amine...

2013-07-01

20

40 CFR 721.7770 - Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt.  

Code of Federal Regulations, 2014 CFR

...Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt...Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt...alkyl phenoxypoly(oxyethylene) sulfuric acid ester, substituted amine...

2014-07-01

21

Thermoset polymer-layered silicic acid nanocomposites  

NASA Astrophysics Data System (ADS)

Nanocomposites are formed when phase mixing occurs on a nanometer length scale. Due to the improved phase morphology and interfacial properties, nanocomposites exhibit mechanical properties superior to conventional composites. Toyota researchers first demonstrated that organoclay could be exfoliated in a nylon-6 matrix to greatly improve the thermal and mechanical properties of the polymer, which has resulted in a practical application in the automobile industry. A great deal of research has been conducted on organic-inorganic hybrid composites in which smectite clays are used as reinforcement agents. However, little work has been devoted to derivatives of other layered inorganic solids. In the present work, the first examples of organic polymer-layered silicic acid nanocomposites have been prepared by formation of a cured epoxy polymer network in the presence of organo cation exchange forms of magadiite. The exfoliation of silicate nanolayers in the epoxy matrix was achieved by in-situ intragallery polymerization during the thermosetting process. In general, the tensile properties, solvent resistance, barrier properties and chemical stability of the polymer matrix are greatly improved by the embedded silicate nanolayers when the matrix is flexible (sub-ambient Tg). The improvement of properties are dependent on the silicate loading, the degree of nanolayer separation and interfacial properties. Interestingly, the exfoliation also affects the polymer elasticity in a favorable way. The mechanism leading to nanocomposite formation is proposed. One exfoliated epoxy-magadiite nanocomposite/composition possessed unique transparent optical properties. The exfoliation chemistry was successfully extended to the other members of the layered silicic acid family. A new approach also was developed to prepare thermoset epoxy polymer-layered silicate nanocomposites in which curing agents can be directly intercalated into the intragallery without the need for alkylammonium ions on the exchange sites. This new development has resulted in a greater improvement in the overall properties of thermoset polymer-clay nanocomposites. The exfoliation chemistry was extended further to other thermoset silicone polymer systems. The new polysiloxane-layered silicic acid nanocomposites were prepared with promising mechanical properties. Some fundamental chemistry and physics issues regarding nanocomposite formation were elucidated by this research work, particularly with regard to the relationship of microstructure and interfacial factors to the mechanical properties of the nanocomposites.

Wang, Zhen

22

40 CFR 721.6200 - Fatty acid polyamine condensate, phosphoric acid ester salts.  

Code of Federal Regulations, 2010 CFR

...polyamine condensate, phosphoric acid ester salts. 721.6200 Section 721.6200 ...polyamine condensate, phosphoric acid ester salts. (a) Chemical substances and significant...acid polyamine condensate, phosphate ester salts (PMNs P-90-1984 and...

2010-07-01

23

40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...  

Code of Federal Regulations, 2014 CFR

... 2014-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...

2014-07-01

24

40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...

2010-07-01

25

40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...  

Code of Federal Regulations, 2012 CFR

... 2012-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...

2012-07-01

26

40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...

2013-07-01

27

40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...  

Code of Federal Regulations, 2011 CFR

... 2011-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...

2011-07-01

28

40 CFR 721.5310 - Neononanoic acid, ethenyl ester.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Neononanoic acid, ethenyl ester. 721.5310... § 721.5310 Neononanoic acid, ethenyl ester. (a) Chemical...substance identified as neononanoic acid, ethenyl ester (PMN P-92-129...worker in the following state(s): Open liquid...

2011-07-01

29

40 CFR 721.5310 - Neononanoic acid, ethenyl ester.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Neononanoic acid, ethenyl ester. 721.5310... § 721.5310 Neononanoic acid, ethenyl ester. (a) Chemical...substance identified as neononanoic acid, ethenyl ester (PMN P-92-129...worker in the following state(s): Open liquid...

2013-07-01

30

40 CFR 721.10255 - Vinyl carboxylic acid ester (generic).  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Vinyl carboxylic acid ester (generic). 721.10255...721.10255 Vinyl carboxylic acid ester (generic). (a...generically as vinyl carboxylic acid ester (PMN P-09-400...as specified in § 721.80(s) (100,000 kilograms)....

2012-07-01

31

40 CFR 721.5310 - Neononanoic acid, ethenyl ester.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Neononanoic acid, ethenyl ester. 721.5310... § 721.5310 Neononanoic acid, ethenyl ester. (a) Chemical...substance identified as neononanoic acid, ethenyl ester (PMN P-92-129...worker in the following state(s): Open liquid...

2012-07-01

32

40 CFR 721.10255 - Vinyl carboxylic acid ester (generic).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Vinyl carboxylic acid ester (generic). 721.10255...721.10255 Vinyl carboxylic acid ester (generic). (a...generically as vinyl carboxylic acid ester (PMN P-09-400...as specified in § 721.80(s) (100,000 kilograms)....

2013-07-01

33

40 CFR 721.10715 - Carbonic acid, dialkyl ester (generic).  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Carbonic acid, dialkyl ester (generic...Substances § 721.10715 Carbonic acid, dialkyl ester (generic...identified generically as carbonic acid, dialkyl ester (PMN P-13-346...721.80(f), (j), and (s) (100,000 kilograms)....

2014-07-01

34

40 CFR 721.5310 - Neononanoic acid, ethenyl ester.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Neononanoic acid, ethenyl ester. 721.5310... § 721.5310 Neononanoic acid, ethenyl ester. (a) Chemical...substance identified as neononanoic acid, ethenyl ester (PMN P-92-129...worker in the following state(s): Open liquid...

2014-07-01

35

40 CFR 721.10255 - Vinyl carboxylic acid ester (generic).  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Vinyl carboxylic acid ester (generic). 721.10255...721.10255 Vinyl carboxylic acid ester (generic). (a...generically as vinyl carboxylic acid ester (PMN P-09-400...as specified in § 721.80(s) (100,000 kilograms)....

2014-07-01

36

Caffeic Acid Phenethyl Ester and Therapeutic Potentials  

PubMed Central

Caffeic acid phenethyl ester (CAPE) is a bioactive compound of propolis extract. The literature search elaborates that CAPE possesses antimicrobial, antioxidant, anti-inflammatory, and cytotoxic properties. The principal objective of this review article is to sum up and critically assess the existing data about therapeutic effects of CAPE in different disorders. The findings elaborate that CAPE is a versatile therapeutically active polyphenol and an effective adjuvant of chemotherapy for enhancing therapeutic efficacy and diminishing chemotherapy-induced toxicities. PMID:24971312

Karim, Sabiha; Akram, Muhammad Rouf; Khan, Shujaat Ali; Azhar, Saira; Mumtaz, Amara; Bin Asad, Muhammad Hassham Hassan

2014-01-01

37

40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...  

Code of Federal Regulations, 2011 CFR

...description of the neutralization of sulfuric acid esters and sulfonic acids subcategory...SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory...description of the neutralization of sulfuric acid esters and sulfonic acids...

2011-07-01

38

40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...  

Code of Federal Regulations, 2010 CFR

...description of the neutralization of sulfuric acid esters and sulfonic acids subcategory...SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory...description of the neutralization of sulfuric acid esters and sulfonic acids...

2010-07-01

39

40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...  

Code of Federal Regulations, 2012 CFR

...description of the neutralization of sulfuric acid esters and sulfonic acids subcategory...SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory...description of the neutralization of sulfuric acid esters and sulfonic acids...

2012-07-01

40

40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...  

Code of Federal Regulations, 2014 CFR

...description of the neutralization of sulfuric acid esters and sulfonic acids subcategory...SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory...description of the neutralization of sulfuric acid esters and sulfonic acids...

2014-07-01

41

40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...  

Code of Federal Regulations, 2013 CFR

...description of the neutralization of sulfuric acid esters and sulfonic acids subcategory...SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory...description of the neutralization of sulfuric acid esters and sulfonic acids...

2013-07-01

42

Plant-mediated stereoselective biotransformation of phenylglyoxylic acid esters.  

PubMed

Enantioselective reduction of the carbonyl group of three phenylglyoxylic acid esters (methyl, ethyl, and n-propyl esters, 2-4) was conducted using blended plant materials (roots of carrot, beetroot, celeriac and parsley; apple). All used biocatalysts transformed these esters to the corresponding mandelic acid esters with high yield, preferably into the respective R-enantiomer. Butanedione addition improved the enantioselectivity of the reaction. PMID:25265851

Maczka, Wanda Krystyna; Grabarczyk, Ma?gorzata; Wi?ska, Katarzyna; Anio?, Miros?aw

2014-01-01

43

Complexes of Alkyl Esters of Ethylidenediphosphonic Acids with Lanthanide Nitrates  

Microsoft Academic Search

The lanthanide complexes LnL2(NO3)33a?c and 5a?c, where Ln is La, Ce and Sm and L are tetraethyl esters of ethylidenediphosphonic acid 1 (for complexes 3) and tetraisopropyl esters of ethylidenediphosphonic acid 4 (for complexes 5) were synthesized and characterized by elemental analysis, IR and NMR spectroscopy. The crystal structure of DyL2(NO3)37 (L is tetraisopropyl ester of methylenediphosphonic acid) was determined

Vladislav Arabadzhiev; Jordanka Petrova; Erhard T. K. Haupt; Jürgen Kopf; Isabelle Nevoigt

2008-01-01

44

Antitumor activity of unsaturated fatty acid esters of 4'-demethyldeoxypodophyllotoxin.  

PubMed

Unsaturated fatty acid esters of 4'-demethyldeoxypodophyllotoxin (DDPT) were prepared and tested for antitumor activity. The esters showed increased in vivo antitumor activity despite the lower in vitro activity than DDPT. Especially, the ester (DFE12) of all-cis-11,14-eicosadienoic acid was much better (IR, 83%) than VP-16 (IR, 60%) without loss of body weight. Unsaturated fatty acids could be evaluated to be good carrier vehicles of DDPT. PMID:12873481

You, Young-Jae; Kim, Yong; Nam, Nguyen-Hai; Ahn, Byung-Zun

2003-08-18

45

Preparation of .alpha.,.beta.-unsaturated carboxylic acids and esters  

DOEpatents

Disclosed is a process for the preparation of .alpha.,.beta.-unsaturated carboxylic acids and esters thereof which comprises contacting formaldehyde or a source of formaldehyde with a carboxylic acid, ester or anhydride in the presence of a catalyst comprising an oxide of niobium.

Gogate, Makarand Ratnakar (Durham, NC); Spivey, James Jerry (Cary, NC); Zoeller, Joseph Robert (Kingsport, TN)

1998-01-01

46

Preparation of {alpha},{beta}-unsaturated carboxylic acids and esters  

DOEpatents

Disclosed is a process for the preparation of {alpha},{beta}-unsaturated carboxylic acids and esters thereof which comprises contacting formaldehyde or a source of formaldehyde with a carboxylic acid, ester or anhydride in the presence of a catalyst comprising an oxide of niobium.

Gogate, M.R.; Spivey, J.J.; Zoeller, J.R.

1998-09-15

47

MICROBIAL TRANSFORMATION OF ESTERS OF CHLORINATED CARBOXYLIC ACIDS  

EPA Science Inventory

Two groups of compounds were selected for microbial transformation studies. In the first group were carboxylic acid esters having a fixed aromatic moiety and an increasing length of the alkyl component. Ethyl esters of chlorine-substituted carboxylic acids were in the second grou...

48

40 CFR 721.7770 - Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt.  

Code of Federal Regulations, 2012 CFR

...sulfuric acid ester, substituted amine salt. 721.7770 Section 721.7770 ...sulfuric acid ester, substituted amine salt. (a) Chemical substance and significant...sulfuric acid ester, substituted amine salt (PMN P-92-396) is subject to...

2012-07-01

49

40 CFR 721.7770 - Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt.  

Code of Federal Regulations, 2010 CFR

...sulfuric acid ester, substituted amine salt. 721.7770 Section 721.7770 ...sulfuric acid ester, substituted amine salt. (a) Chemical substance and significant...sulfuric acid ester, substituted amine salt (PMN P-92-396) is subject to...

2010-07-01

50

21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.  

Code of Federal Regulations, 2011 CFR

...false Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260...260 Partial phosphoric acid esters of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section...

2011-04-01

51

Highly efficient tetradentate ruthenium catalyst for ester reduction: especially for hydrogenation of Fatty Acid esters.  

PubMed

A new tetradentate ruthenium complex has been developed for hydrogenation of esters. The catalyst's structure features a pyridinemethanamino group and three tight chelating five-membered rings. The structure character is believed to be responsible for its high stability and high carbonylation-resistant properties. Thus, this catalyst shows outstanding performance in the catalytic hydrogenation of a variety of esters, especially for fatty acid esters, which may be used in practical applications. New insight on designing hydrogenation catalyst for reducing esters to alcohols has been provided through theoretical calculations. PMID:25582610

Tan, Xuefeng; Wang, Yan; Liu, Yuanhua; Wang, Fangyuan; Shi, Liyang; Lee, Ka-Ho; Lin, Zhenyang; Lv, Hui; Zhang, Xumu

2015-02-01

52

Epoxidation of Fatty Acid Methyl Esters derived from Jatropha oil  

Microsoft Academic Search

Fatty Acid Methyl Esters (FAMEs) from transesterification of Jatropha oil were obtained by both acid and base catalyzed transesterification reactions. These FAMEs were epoxidized in or without solvent by either peroxyformic acid or peroxyacetic acid, formed in situ by 30% hydrogen peroxide. n-hexane was used as solvent. Detailed study regarding effects of type and concentration of organic acid used in

Muhammad Mushtaq; Isa B. Tan; Cecilia Devi; Saeed Majidaie; Muhammad Nadeem; Susan Lee

2011-01-01

53

Synthesis and Physical Properties of Estolide Ester Using Saturated Fatty Acid and Ricinoleic Acid  

PubMed Central

A study was conveyed to produce estolide ester using ricinoleic acid as the backbone. The ricinoleic acid reacted with saturated fatty acid from C8–C18. These reactions were conducted under vacuum at 60°C for 24?h without solvent. The reaction used acid catalyst, sulphuric acid. The new saturate ricinoleic estolide esters show superior low-temperature properties (?52 ± 0.08°C) and high flash point (>300°C). The yield of the neat estolide esters ranged from 52% to 96%. The viscosity range was 51 ± 0.08 to 86 ± 0.01?cp. These new saturated estolide esters were also compared with saturated branched estolide esters. PMID:22007150

Salimon, Jumat; Nallathamby, Neeranjini; Salih, Nadia; Abdullah, Bashar Mudhaffar

2011-01-01

54

ESTIMATION OF CARBOXYLIC ACID ESTER HYDROLYSIS RATE CONSTANTS  

EPA Science Inventory

SPARC chemical reactivity models were extended to calculate hydrolysis rate constants for carboxylic acid esters from molecular structure. The energy differences between the initial state and the transition state for a molecule of interest are factored into internal and external...

55

Enzymatic synthesis of wax esters from rapeseed fatty acid methyl esters and a fatty alcohol  

Microsoft Academic Search

Wax esters were transesterified from fatty acid methyl esters of rapeseed and a fatty alcohol (1-hexadecanol, 16:0). The amounts\\u000a of both the substrates were fixed to 0.1 mmol and an immobilized enzyme, Lipozyme, was used as catalyst. The experiment was\\u000a performed following a statistic central composite design with five variables. The enzyme\\/lipid ratio was varied between 0.3–0.9\\u000a of the substrate

Marianne Lilja Hallberg; Daobin Wang; Magnus Härröd

1999-01-01

56

21 CFR 172.852 - Glyceryl-lacto esters of fatty acids.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false Glyceryl-lacto esters of fatty acids. 172.852 Section 172.852 Food and...172.852 Glyceryl-lacto esters of fatty acids. Glyceryl-lacto esters of fatty acids (the lactic acid esters of mono- and...

2012-04-01

57

21 CFR 172.852 - Glyceryl-lacto esters of fatty acids.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Glyceryl-lacto esters of fatty acids. 172.852 Section 172.852 Food and...172.852 Glyceryl-lacto esters of fatty acids. Glyceryl-lacto esters of fatty acids (the lactic acid esters of mono- and...

2013-04-01

58

21 CFR 172.852 - Glyceryl-lacto esters of fatty acids.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false Glyceryl-lacto esters of fatty acids. 172.852 Section 172.852 Food and...172.852 Glyceryl-lacto esters of fatty acids. Glyceryl-lacto esters of fatty acids (the lactic acid esters of mono- and...

2011-04-01

59

21 CFR 172.852 - Glyceryl-lacto esters of fatty acids.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 false Glyceryl-lacto esters of fatty acids. 172.852 Section 172.852 Food and...172.852 Glyceryl-lacto esters of fatty acids. Glyceryl-lacto esters of fatty acids (the lactic acid esters of mono- and...

2014-04-01

60

Adsorption studies of phthalic acid esters in aqueous solutions  

E-print Network

ADSORPTION STUDIES OF PHTHALIC ACID ESTERS IN AQUEOUS SOLUTIONS A Thesis by KEVIN FRANCIS SULLIVAN Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE... August 1980 Major Subject: Chemistry ADSORPTION STUDIES OF PHTHALIC ACID ESTERS IN AQUEOUS SOLUTIONS A Thesis by KEVIN FRANCIS SULLIVAN Approved as to style and content by: (Chairman of Committ e) (Head of Department) (Member) (Member)( August...

Sullivan, Kevin Francis

2012-06-07

61

Fluorophilicity of alkyl and polyfluoroalkyl nicotinic acid ester prodrugs  

Microsoft Academic Search

The fluorophilicity of a series of hydrocarbon and fluorocarbon-functionalized nicotinic acid esters (nicotinates) is measured from their partitioning behavior (logKp) in the biphasic solvent system of perfluoro(methylcyclohexane) (PFMC) and toluene. The chain length of the hydrocarbon or fluorocarbon alkyl group of the ester ranges from one to twelve carbon atoms. Knowledge of the fluorophilicity of these solutes is relevant to

Vivian Ojogun; Barbara L. Knutson; Sandhya Vyas; Hans-Joachim Lehmler

2010-01-01

62

21 CFR 573.640 - Methyl esters of higher fatty acids.  

Code of Federal Regulations, 2013 CFR

...of higher fatty acids. The food additive methyl esters of...prescribed conditions: (a) The food additive is manufactured...of the following straight-chain monocarboxylic acids: Docosahexanoic...associated acid esters. (b) The food additive meets the...

2013-04-01

63

21 CFR 573.640 - Methyl esters of higher fatty acids.  

Code of Federal Regulations, 2014 CFR

...of higher fatty acids. The food additive methyl esters of...prescribed conditions: (a) The food additive is manufactured...of the following straight-chain monocarboxylic acids: Docosahexanoic...associated acid esters. (b) The food additive meets the...

2014-04-01

64

21 CFR 573.640 - Methyl esters of higher fatty acids.  

Code of Federal Regulations, 2011 CFR

...of higher fatty acids. The food additive methyl esters of...prescribed conditions: (a) The food additive is manufactured...of the following straight-chain monocarboxylic acids: Docosahexanoic...associated acid esters. (b) The food additive meets the...

2011-04-01

65

21 CFR 573.640 - Methyl esters of higher fatty acids.  

Code of Federal Regulations, 2012 CFR

...of higher fatty acids. The food additive methyl esters of...prescribed conditions: (a) The food additive is manufactured...of the following straight-chain monocarboxylic acids: Docosahexanoic...associated acid esters. (b) The food additive meets the...

2012-04-01

66

40 CFR 721.1728 - Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester.  

Code of Federal Regulations, 2010 CFR

... false Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...721.1728 Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...identified as benzoic acid, 2-(3-phenylbutylidene)amino-, methyl...

2010-07-01

67

40 CFR 721.1728 - Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester.  

Code of Federal Regulations, 2013 CFR

... false Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...721.1728 Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...identified as benzoic acid, 2-(3-phenylbutylidene)amino-, methyl...

2013-07-01

68

40 CFR 721.1728 - Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester.  

Code of Federal Regulations, 2012 CFR

... false Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...721.1728 Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...identified as benzoic acid, 2-(3-phenylbutylidene)amino-, methyl...

2012-07-01

69

40 CFR 721.1728 - Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester.  

Code of Federal Regulations, 2011 CFR

... false Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...721.1728 Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...identified as benzoic acid, 2-(3-phenylbutylidene)amino-, methyl...

2011-07-01

70

40 CFR 721.1728 - Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester.  

Code of Federal Regulations, 2014 CFR

... false Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...721.1728 Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...identified as benzoic acid, 2-(3-phenylbutylidene)amino-, methyl...

2014-07-01

71

Effects of high-melting methyl esters on crystallization properties of fatty acid methyl ester mixtures  

Technology Transfer Automated Retrieval System (TEKTRAN)

Biodiesel is a renewable alternative diesel fuel made from vegetable oils and animal fats. The most common form of biodiesel in the United States are fatty acid methyl esters (FAME) from soybean, canola, and used cooking oils, waste greases, and tallow. Cold flow properties of biodiesel depend on th...

72

Biological and therapeutic effects of ortho-silicic acid and some ortho-silicic acid-releasing compounds: New perspectives for therapy  

PubMed Central

Silicon (Si) is the most abundant element present in the Earth's crust besides oxygen. However, the exact biological roles of silicon remain unknown. Moreover, the ortho-silicic acid (H4SiO4), as a major form of bioavailable silicon for both humans and animals, has not been given adequate attention so far. Silicon has already been associated with bone mineralization, collagen synthesis, skin, hair and nails health atherosclerosis, Alzheimer disease, immune system enhancement, and with some other disorders or pharmacological effects. Beside the ortho-silicic acid and its stabilized formulations such as choline chloride-stabilized ortho-silicic acid and sodium or potassium silicates (e.g. M2SiO3; M= Na,K), the most important sources that release ortho-silicic acid as a bioavailable form of silicon are: colloidal silicic acid (hydrated silica gel), silica gel (amorphous silicon dioxide), and zeolites. Although all these compounds are characterized by substantial water insolubility, they release small, but significant, equilibrium concentration of ortho-silicic acid (H4SiO4) in contact with water and physiological fluids. Even though certain pharmacological effects of these compounds might be attributed to specific structural characteristics that result in profound adsorption and absorption properties, they all exhibit similar pharmacological profiles readily comparable to ortho-silicic acid effects. The most unusual ortho-silicic acid-releasing agents are certain types of zeolites, a class of aluminosilicates with well described ion(cation)-exchange properties. Numerous biological activities of some types of zeolites documented so far might probably be attributable to the ortho-silicic acid-releasing property. In this review, we therefore discuss biological and potential therapeutic effects of ortho-silicic acid and ortho-silicic acid -releasing silicon compounds as its major natural sources. PMID:23298332

2013-01-01

73

Preparation and physical properties of chitin fatty acids esters.  

PubMed

Trifluoroacetic anhydride is an effective promoter for the preparation of chitin single- and mixed-acid esters. Complete dissolution is achieved within 30 min when powdered chitin is heated at 70 degrees C in a mixed solution of carboxylic acid(s) and trifluoroacetic anhydride. Chitin esters prepared are chitin acetate, chitin butyrate, chitin hexanoate and chitin octanoate, chitin co-acetate/butyrate, chitin co-acetate/hexanoate, chitin co-acetate/octanoate, chitin co-acetate/palmitate, each from a solution of the respective reactants. The products have degrees of O-acyl substitution in a range of DS 1-2 depending on the nature of acyl group, as analyzed by gas-liquid and high-pressure liquid chromatography. Acetic acid as a mutual component for the mixed-acid esters increases the total degree of substitution, and the acetyl substitution is close to the relative distribution in the reaction mixture for chitin co-acetate/butyrate. It is favored over hexanoate, octanoate, and palmitate. The parent molecules, as calculated by the composition of the chitin esters and their molecular weights by light-scattering spectroscopy, are 30 kDa for the smallest and 150-151 kDa for the largest. Films of these chitin derivatives when cast from solution are strong and flexible with limited extensibility. By dynamic mechanical analysis of the ester film, it was found that both the glass transition temperature (T(g)) and the tensile modulus (E' at 25 degrees C) are highest for chitin acetate (218 degrees C and 5.8 GPa), and lowest for chitin octanoate (182 degrees C and 1.5 GPa). For the other esters, these values lie between the above-cited values, where the T(g) and the E' decrease with an increase in the chain length of the acyl constituent. PMID:19091309

Yang, Byung Y; Ding, Qiong; Montgomery, Rex

2009-02-17

74

Electron driven processes in chlorodifluoroacetic acid methyl ester  

NASA Astrophysics Data System (ADS)

Dissociative electron attachment to gas phase 2-chloro-2,2-difluoroacetic acid methyl ester (CClF2COOCH3) is studied by means of a crossed beams apparatus. Effective cleavage of the C-Cl bond is observed within a broad resonance in the energy range 0-1 eV and visible via the appearance of the light fragment Cl-. In chlorodifluoroacetic acid cleavage of the C-Cl bond was observed not only via the Cl- anion formation but predominantly via expulsion of the neutral chlorine atom leading to the formation of the (M-Cl)- anion. Similar to the previously studied esters CF3COOCH3 and CF3COOC2H5[I. Martin, J. Langer, E. Illenberger, Z. Phys. Chem. 222, 1185 (2008)], we observe reaction due to the cleavage of the ester bond resulting in the formation of the closed shell (M-CH3)- anion.

Kopyra, Janina

2014-07-01

75

21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.  

Code of Federal Regulations, 2013 CFR

21 Food and Drugs 3 2013-04-01...alcohol esters of long chain monobasic acids. ...Section 178.3780 Food and Drugs FOOD AND...CONTINUED) INDIRECT FOOD ADDITIVES: ADJUVANTS...alcohol esters of long chain monobasic acids....

2013-04-01

76

21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.  

Code of Federal Regulations, 2012 CFR

21 Food and Drugs 3 2012-04-01...alcohol esters of long chain monobasic acids. ...Section 178.3780 Food and Drugs FOOD AND...CONTINUED) INDIRECT FOOD ADDITIVES: ADJUVANTS...alcohol esters of long chain monobasic acids....

2012-04-01

77

21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.  

Code of Federal Regulations, 2014 CFR

21 Food and Drugs 3 2014-04-01...alcohol esters of long chain monobasic acids. ...Section 178.3780 Food and Drugs FOOD AND...CONTINUED) INDIRECT FOOD ADDITIVES: ADJUVANTS...alcohol esters of long chain monobasic acids....

2014-04-01

78

Synthesis of 14Hydroxy8-Azaprostanoic Acids Methyl Ester  

Microsoft Academic Search

Studies from a number of laboratories have led to the synthesis of aza-prostaglandin analogs with interesting physiological activity. We now describe a new approach to the 8-azaprostanoic skeleton utilizing as a key intermediate the 3,5-disubstituted isoxazole acid (6), quantitatively obtained by alkaline hydrolysis of the corresponding ester(5).

A. Barco; S. Benetti; G. P. Pollini; B. Veronesi; P. G. Baraldi; M. Guarneris; C. B. Vicentini

1978-01-01

79

Diffusion of phosphoric acid triethyl ester (1); air (2)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) phosphoric acid triethyl ester; (2) air

Winkelmann, J.

80

Diffusion of phosphorous acid tributyl ester (1); air (2)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) phosphorous acid tributyl ester; (2) air

Winkelmann, J.

81

Gas chromatographic analysis of fatty acid methyl esters  

Microsoft Academic Search

The full process of fatty acid methyl ester (FAME) analysis consists of esterification of lipids, and of injection, separation, identification and quantitation of the FAMEs. In order for the required accuracy and precision to be attained, each of these steps has to be optimized.Esterification of lipids can be carried out with several reagents based on acid-catalysed or base-catalysed reactions. The

K. Eder

1995-01-01

82

40 CFR 721.10412 - Phosphonic acid ester (generic) (P-07-706).  

Code of Federal Regulations, 2014 CFR

...false Phosphonic acid ester (generic) (P-07-706). 721.10412 Section 721...10412 Phosphonic acid ester (generic) (P-07-706). (a) Chemical substance...generically as phosphonic acid ester (PMN P-07-706) is subject to...

2014-07-01

83

40 CFR 721.10412 - Phosphonic acid ester (generic) (P-07-706).  

Code of Federal Regulations, 2013 CFR

...false Phosphonic acid ester (generic) (P-07-706). 721.10412 Section 721...10412 Phosphonic acid ester (generic) (P-07-706). (a) Chemical substance...generically as phosphonic acid ester (PMN P-07-706) is subject to...

2013-07-01

84

40 CFR 721.10412 - Phosphonic acid ester (generic) (P-07-706).  

Code of Federal Regulations, 2012 CFR

...false Phosphonic acid ester (generic) (P-07-706). 721.10412 Section 721...10412 Phosphonic acid ester (generic) (P-07-706). (a) Chemical substance...generically as phosphonic acid ester (PMN P-07-706) is subject to...

2012-07-01

85

40 CFR 721.3680 - Ethylene oxide adduct of fatty acid ester with pentaerythritol.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Ethylene oxide adduct of fatty acid ester with pentaerythritol...Chemical Substances § 721.3680 Ethylene oxide adduct of fatty acid ester with pentaerythritol...substance identified generically as ethylene oxide adduct of fatty acid ester with...

2010-07-01

86

40 CFR 721.3680 - Ethylene oxide adduct of fatty acid ester with pentaerythritol.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Ethylene oxide adduct of fatty acid ester with pentaerythritol...Chemical Substances § 721.3680 Ethylene oxide adduct of fatty acid ester with pentaerythritol...substance identified generically as ethylene oxide adduct of fatty acid ester with...

2013-07-01

87

40 CFR 721.6110 - Alkyldi(alkyloxyhydroxypropyl) derivative, phosphoric acid esters, potassium salts.  

Code of Federal Regulations, 2012 CFR

...derivative, phosphoric acid esters, potassium salts. 721.6110 Section 721.6110 Protection...derivative, phosphoric acid esters, potassium salts. (a) Chemical substance and significant...derivative, phosphoric acid esters, potassium salts (PMN P-91-818) is subject to...

2012-07-01

88

40 CFR 721.6110 - Alkyldi(alkyloxyhydroxypropyl) derivative, phosphoric acid esters, potassium salts.  

Code of Federal Regulations, 2010 CFR

...derivative, phosphoric acid esters, potassium salts. 721.6110 Section 721.6110 Protection...derivative, phosphoric acid esters, potassium salts. (a) Chemical substance and significant...derivative, phosphoric acid esters, potassium salts (PMN P-91-818) is subject to...

2010-07-01

89

40 CFR 721.6110 - Alkyldi(alkyloxyhydroxypropyl) derivative, phosphoric acid esters, potassium salts.  

Code of Federal Regulations, 2013 CFR

...derivative, phosphoric acid esters, potassium salts. 721.6110 Section 721.6110 Protection...derivative, phosphoric acid esters, potassium salts. (a) Chemical substance and significant...derivative, phosphoric acid esters, potassium salts (PMN P-91-818) is subject to...

2013-07-01

90

40 CFR 721.6110 - Alkyldi(alkyloxyhydroxypropyl) derivative, phosphoric acid esters, potassium salts.  

Code of Federal Regulations, 2014 CFR

...derivative, phosphoric acid esters, potassium salts. 721.6110 Section 721.6110 Protection...derivative, phosphoric acid esters, potassium salts. (a) Chemical substance and significant...derivative, phosphoric acid esters, potassium salts (PMN P-91-818) is subject to...

2014-07-01

91

Encapsulating fatty acid esters of bioactive compounds in starch  

NASA Astrophysics Data System (ADS)

Interest in the use of many bioactive compounds in foods is growing in large part because of the apparent health benefits of these molecules. However, many of these compounds can be easily degraded during processing, storage, or their passage through the gastrointestinal tract before reaching the target site. In addition, they can be bitter, acrid, or astringent, which may negatively affect the sensory properties of the product. Encapsulation of these molecules may increase their stability during processing, storage, and in the gastrointestinal tract, while providing controlled release properties. The ability of amylose to form inclusion complexes and spherulites while entrapping certain compounds has been suggested as a potential method for encapsulation of certain molecules. However, complex formation and spherulitic crystallization are greatly affected by the type of inclusion molecules, type of starch, and processing conditions. The objectives of the present investigation were to: (a) study the effect of amylose, amylopectin, and intermediate material on spherulite formation and its microstructure; (b) investigate the formation of amylose and high amylose starch inclusion complexes with ascorbyl palmitate, retinyl palmitate, and phytosterol esters; (c) evaluate the ability of spherulites to form in the presence of fatty acid esters and to entrap ascorbyl palmitate, retinyl palmitate, and phytosterol esters; and (d) evaluate the effect of processing conditions on spherulite formation and fatty acid ester entrapment. Higher ratios of linear to branched molecules resulted in the formation of more and rounder spherulites with higher heat stability. In addition to the presence of branches, it appears that spherulitic crystallization is also affected by other factors, such as degree of branching, chain length, and chain length distribution. Amylose and Hylon VII starch formed inclusion complexes with fatty acid esters of ascorbic acid, retinol, or phytosterols. However, only retinyl palmitate formed a complex with amylopectin. In general, ascorbyl palmitate resulted in the highest complexation, followed by retinyl palmitate and phytosterol ester. The presence of native lipids in Hylon VII starch did not inhibit complex formation. On the contrary, native lipids appear to increase the complexation yield and thermal stability of the starch-fatty acid ester inclusion complexes, possibly due to the formation of ternary complexes. From the three fatty acid esters studied, only ascorbyl palmitate was entrapped in starch spherulites. Various structures including round spherulites, various sizes of torus-shape spherulites, non-spherulitic birefringent and non-birefringent particles, "balloon" morphologies, and gel-like material were formed depending on processing conditions. However, only the torus-shape spherulites, and some non-spherulitic birefringent and non-birefringent particles showed ascorbyl palmitate entrapment. The % yield of the precipitate increased with higher % of added Hylon VII, and decreased with higher heating temperature and faster cooling rates. The amount of entrapped ascorbyl palmitate in the starch precipitate seems to be governed by the amount of this compound added during processing. This study showed that starch can form inclusion complexes with fatty acid esters which may be used for the delivery of certain bioactive molecules. In addition, encapsulation of fatty acid esters in starch spherulites may be a good potential delivery system for water soluble bioactive molecules. However, further research is necessary to gain a better understanding of the type of molecules that can be entrapped in starch spherulites, and the factors affecting spherulitic crystallization and bioactive compound entrapment.

Lay Ma, Ursula Vanesa

92

4-Dimenthylaminopyridine or Acid-Catalyzed Synthesis of Esters: A Comparison  

ERIC Educational Resources Information Center

A set of highly atom-economic experiments was developed to highlight the differences between acid- and base-catalyzed ester syntheses and to introduce the principles of atom economy. The hydrochloric acid-catalyzed formation of an ester was compared with the 4-dimethylaminopyradine-catalyzed ester synthesis.

van den Berg, Annemieke W. C.; Hanefeld, Ulf

2006-01-01

93

Comparison Of Asymmetric Hydrogenations Of Unsaturated- Carboxylic Acids And -Esters  

PubMed Central

As methodology development matures it can be difficult to discern the most effective ways of performing certain transformations from the rest. This review summarizes the most important contributions leading to asymmetric hydrogenations of simple unsaturated-acid and ester substrates, with the objective of highlighting at least the best types of catalysts for each. Achievements in the area are described and these reveal situations where further efforts should be worthwhile, and ones where more research is only likely to give diminishing returns. In general, our conclusions are that the most useful types of catalysts for unsaturated-acids and -esters tend to be somewhat different, simple substrates have been studied extensively, and the field is poised to address more complex reactions. These could be ones involving alternative, particularly cyclic, structures, chemoselectivity issues, and more complex substrate stereochemistries. PMID:24729943

Khumsubdee, Sakunchai; Burgess, Kevin

2013-01-01

94

Caffeic acid phenethyl ester prevents intestinal reperfusion injury in rats  

Microsoft Academic Search

Background\\/Purpose: Ischemia-reperfusion injury is encountered frequently in conditions that diminish intestinal blood flow. Caffeic acid phenethyl ester (CAPE), which is a specific component of the honeybee hive product propolis, exhibits potential antioxidant properties. This experimental study was designed to determine the effect of CAPE on ischemia-reperfusion injury in rat intestine.Methods: Fifty rats were divided into 5 groups; sham (SH), saline

U?ur Koltuksuz; Süleyman Özen; Efkan Uz; Mustafa Aydinç; Abdurrahman Karaman; Ahmet Gültek; Ömer Akyol; M. Harun Gürsoy; Engin Aydin

1999-01-01

95

Fatty acid methyl ester profiles of bat wing surface lipids.  

PubMed

Sebocytes are specialized epithelial cells that rupture to secrete sebaceous lipids (sebum) across the mammalian integument. Sebum protects the integument from UV radiation, and maintains host microbial communities among other functions. Native glandular sebum is composed primarily of triacylglycerides (TAG) and wax esters (WE). Upon secretion (mature sebum), these lipids combine with minor cellular membrane components comprising total surface lipids. TAG and WE are further cleaved to smaller molecules through oxidation or host enzymatic digestion, resulting in a complex mixture of glycerolipids (e.g., TAG), sterols, unesterified fatty acids (FFA), WE, cholesteryl esters, and squalene comprising surface lipid. We are interested if fatty acid methyl ester (FAME) profiling of bat surface lipid could predict species specificity to the cutaneous fungal disease, white nose syndrome (WNS). We collected sebaceous secretions from 13 bat spp. using Sebutape(®) and converted them to FAME with an acid catalyzed transesterification. We found that Sebutape(®) adhesive patches removed ~6× more total lipid than Sebutape(®) indicator strips. Juvenile eastern red bats (Lasiurus borealis) had significantly higher 18:1 than adults, but 14:0, 16:1, and 20:0 were higher in adults. FAME profiles among several bat species were similar. We concluded that bat surface lipid FAME profiling does not provide a robust model predicting species susceptibility to WNS. However, these results provide baseline data that can be used for lipid roles in future ecological studies, such as life history, diet, or migration. PMID:25227993

Pannkuk, Evan L; Fuller, Nathan W; Moore, Patrick R; Gilmore, David F; Savary, Brett J; Risch, Thomas S

2014-11-01

96

21 CFR 178.3450 - Esters of stearic and palmitic acids.  

Code of Federal Regulations, 2010 CFR

...Adjuvants and Production Aids § 178.3450 Esters of stearic and palmitic acids. The ester stearyl palmitate or palmityl stearate or mixtures thereof may be safely used as adjuvants in food-packaging materials when used in accordance with the...

2010-04-01

97

Synthesis of coenzyme A ester of retinoic acid: intermediate in vitamin A metabolism.  

PubMed Central

Coenzyme A esters of all-trans- and 13-cis-retinoic acid were synthesized for use in studying vitamin A metabolism. The esters were obtained by two different synthetic methods starting from retinoic acids, which were converted to activated succinimidyl esters or anhydrides. These in turn were coupled with coenzyme A to form their respective thioesters. The retinoyl coenzyme A esters were purified by reverse-phase high performance liquid chromatography. PMID:3462726

Kutner, A; Renstrom, B; Schnoes, H K; DeLuca, H F

1986-01-01

98

Fluorophilicity of Alkyl and Polyfluoroalkyl 1 Nicotinic Acid Ester Prodrugs  

PubMed Central

The fluorophilicity of a series of hydrocarbon and fluorocarbon-functionalized nicotinic acid esters (nicotinates) is measured from their partitioning behavior (log KP) in the biphasic solvent system of perfluoro(methylcyclohexane) (PFMC) and toluene. The chain length of the hydrocarbon or fluorocarbon alkyl group of the ester ranges from one to twelve carbon atoms. Knowledge of the fluorophilicity of these solutes is relevant to the design of these prodrugs for fluorocarbon-based drug delivery. The experimental log Kp values range from ?1.72 to ?3.40 for the hydrocarbon nicotinates and ?1.64 to 0.13 for the fluorinated nicotinates, where only the prodrug with the longest fluorinated chain (2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluorooctyl nicotinic acid ester) partitions preferentially into the fluorinated phase (log Kp = 0.13). Predictions of the partition coefficients using solubility parameters calculated from group contribution techniques or molecular dynamics simulation are in reasonable agreement for the perhydrocarbon nicotinates and short chained perfluorinated nicotinates (? 0.3%-39% deviation). Significant deviations from experimental partition coefficients (greater than 100%) are observed for the longest chain perfluoroalkyl nicotinates. PMID:20567608

Ojogun, Vivian; Knutson, Barbara L; Vyas, Sandhya; Lehmler, Hans-Joachim

2010-01-01

99

Silicic acid competes for dimethylarsinic acid (DMA) immobilization by the iron hydroxide plaque mineral goethite.  

PubMed

A surface complexation modeling approach was used to extend the knowledge about processes that affect the availability of dimethylarsinic acid (DMA) in the soil rhizosphere in presence of a strong sorbent, e.g., Fe plaques on rice roots. Published spectroscopic and molecular modeling information suggest for the organoarsenical agent to form bidentate-binuclear inner-sphere surface complexes with Fe hydroxides similar to the inorganic As oxyanions. However, since also the ubiquitous silicic acid oxyanion form the same bidentate binuclear surface complexes, our hypothesis was that it may have an effect on the adsorption of DMA by Fe hydroxides in soil. Our experimental batch equilibrium data show that DMA is strongly adsorbed in the acidic pH range, with a steep adsorption edge in the circumneutral pH region between the DMA acidity constant (pKa=6.3) and the point of zero charge value of the goethite adsorbent (pHpzc=8.6). A 1-pK CD-MUSIC surface complexation model was chosen to fit the experimental adsorption vs. pH data. The same was done for silicic acid batch equilibrium data with our goethite adsorbent. Both model parameters for individual DMA and silicic acid adsorption were then merged into one CD-MUSIC model to predict the binary DMA+Si adsorption behavior. Silicic acid (500?M) was thus predicted by the model to strongly compete for DMA with up to 60% mobilization of the latter at a pH6. This model result could be verified subsequently by experimental batch equilibrium data with zero adjustable parameters. The thus quantified antagonistic relation between DMA and silicic acid is discussed as one of factors to explain the increase of the DMA proportion in rice grains as observed upon silica fertilization of rice fields. PMID:25478657

Kersten, Michael; Daus, Birgit

2015-03-01

100

21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.  

Code of Federal Regulations, 2011 CFR

...esters of fatty acids produced from edible fats and oils. 172.225 Section 172...esters of fatty acids produced from edible fats and oils. Methyl esters and ethyl esters of fatty acids produced from edible fats and oils may be safely used in...

2011-04-01

101

Alternative fuel properties of tall oil fatty acid methyl ester–diesel fuel blends  

Microsoft Academic Search

In this experimental work, tall oil methyl ester–diesel fuel blends as alternative fuels for diesel engines were studied. Tall oil methyl ester was produced by reacting tall oil fatty acids with methyl alcohol under optimum conditions. The blends of tall oil methyl ester–diesel fuel were tested in a direct injection diesel engine at full load condition. The effects of the

Duran Alt?parmak; Ali Keskin; Atilla Koca; Metin Gürü

2007-01-01

102

ESTIMATION OF HYDROLYSIS RATE CONSTANTS OF CARBOXYLIC ACID ESTER AND PHOSPHATE ESTER COMPOUNDS IN AQUEOUS SYSTEMS FROM MOLECULAR STRUCTURE BY SPARC  

EPA Science Inventory

SPARC (SPARC Performs Automated Reasoning in Chemistry) chemical reactivity models were extended to calculate hydrolysis rate constants for carboxylic acid ester and phosphate ester compounds in aqueous non- aqueous and systems strictly from molecular structure. The energy diffe...

103

Jojoba oil wax esters and derived fatty acids and alcohols: Gas chromatographic analyses  

Microsoft Academic Search

HCl-catalyzed ethanolysis followed by saponification readily surmounts the resistance of long chain wax esters to direct hydrolysis\\u000a by alkali. Additionally, choosing ethyl instead of methyl esters allows baseline separations between long-chain alcohols and\\u000a corresponding esters in gas liquid chromatographic (GLC) analysis of total alcohol and acid components before saponification.\\u000a Liquid wax esters were analyzed on a temperature-programmed 3% OV-1 silicone

Thomas K. Miwa

1971-01-01

104

Autoxidation rates of various esters of safflower oil and linoleic acid  

Microsoft Academic Search

Autoxidation rates of five types of safflower oil esters increased in the following order: monoacylglycerol (MG), methyl ester\\u000a (ME), diacylglycerol (DG), triacylglycerol (TG) and sucrose ester (SE). The differences in autoxidation rate were confirmed\\u000a by measuring autoxidation of similar esters of linoleic acid. The order of the oxidation rates corresponded to the number\\u000a of acyl groups per molecule. This relationship

Kazuo Miyashita; Toru Takagi

1988-01-01

105

Efficient synthesis of fatty monoglyceride sulfates from fatty acids and fatty acid methyl esters  

Microsoft Academic Search

An efficient high yield synthesis of fatty monoglyceride sulfates from fatty acids or fatty acid methyl esters, glycerine\\u000a and chlorosulfuric acid in chloroform using stoichiometric amounts of reagents was developed. Sodium coco monoglyceride sulfate\\u000a was prepared in 79% yield with 93% purity from coco fatty acids. Similarly, sodium palm kernel monoglyceride sulfate in 57%\\u000a yield and sodium palm monoglyceride sulfate

Fahim U. Ahmed

1990-01-01

106

Effect of formic acid and benzoic acid esters on grass preservation  

E-print Network

Effect of formic acid and benzoic acid esters on grass preservation A Rauramaa A Tommila J- meadow-fescue grass from the third sward of the summer 1994. Chopped grass (1 kg) was treated and placed deterioration of silages were followed by measuring temperature. The grass treatments were : no additive (NO

Paris-Sud XI, Université de

107

THE USE OF FATTY ACID-ESTERS TO ENHANCE FREE ACID SOPHOROLIPID SYNTHESIS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Fatty acid esters were prepared by transesterification of soy oil with methanol (methyl-soyate, Me-Soy), ethanol (ethyl-soyate, Et-Soy) and propanol (propyl-soyate, Pro-Soy) and used with glycerol as fermentation substrates to enhance production of free-acid sophorolipids (SLs). Fed-batch fermentat...

108

40 CFR 721.8160 - Propanoic acid, 2,2-dimethyl-, ethenyl ester.  

Code of Federal Regulations, 2012 CFR

...721.8160 Propanoic acid, 2,2-dimethyl...identified as propanoic acid, 2,2-dimethyl...method, the company's personal protective...in the following state(s): Open liquid...substances hexanedioic acid, diethenyl ester,...

2012-07-01

109

40 CFR 721.8160 - Propanoic acid, 2,2-dimethyl-, ethenyl ester.  

Code of Federal Regulations, 2014 CFR

...721.8160 Propanoic acid, 2,2-dimethyl...identified as propanoic acid, 2,2-dimethyl...method, the company's personal protective...in the following state(s): Open liquid...substances hexanedioic acid, diethenyl ester,...

2014-07-01

110

21 CFR 184.1101 - Diacetyl tartaric acid esters of mono- and diglycerides.  

Code of Federal Regulations, 2012 CFR

...diglycerides. (a) Diacetyl tartaric acid esters of mono- and diglycerides...been esterified by diacetyl tartaric acid and by fatty acids. The ingredient is prepared by...reference in accordance with 5 U.S.C. 552(a). Copies...

2012-04-01

111

40 CFR 721.8160 - Propanoic acid, 2,2-dimethyl-, ethenyl ester.  

Code of Federal Regulations, 2011 CFR

...721.8160 Propanoic acid, 2,2-dimethyl...identified as propanoic acid, 2,2-dimethyl...method, the company's personal protective...in the following state(s): Open liquid...substances hexanedioic acid, diethenyl ester,...

2011-07-01

112

21 CFR 184.1101 - Diacetyl tartaric acid esters of mono- and diglycerides.  

Code of Federal Regulations, 2011 CFR

...diglycerides. (a) Diacetyl tartaric acid esters of mono- and diglycerides...been esterified by diacetyl tartaric acid and by fatty acids. The ingredient is prepared by...reference in accordance with 5 U.S.C. 552(a). Copies...

2011-04-01

113

21 CFR 184.1101 - Diacetyl tartaric acid esters of mono- and diglycerides.  

Code of Federal Regulations, 2014 CFR

...diglycerides. (a) Diacetyl tartaric acid esters of mono- and diglycerides...been esterified by diacetyl tartaric acid and by fatty acids. The ingredient is prepared by...reference in accordance with 5 U.S.C. 552(a). Copies...

2014-04-01

114

21 CFR 184.1101 - Diacetyl tartaric acid esters of mono- and diglycerides.  

Code of Federal Regulations, 2013 CFR

...diglycerides. (a) Diacetyl tartaric acid esters of mono- and diglycerides...been esterified by diacetyl tartaric acid and by fatty acids. The ingredient is prepared by...reference in accordance with 5 U.S.C. 552(a). Copies...

2013-04-01

115

40 CFR 721.8160 - Propanoic acid, 2,2-dimethyl-, ethenyl ester.  

Code of Federal Regulations, 2013 CFR

...721.8160 Propanoic acid, 2,2-dimethyl...identified as propanoic acid, 2,2-dimethyl...method, the company's personal protective...in the following state(s): Open liquid...substances hexanedioic acid, diethenyl ester,...

2013-07-01

116

40 CFR 721.4250 - Hexanoic acid, 2-ethyl-, ethenyl ester.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Hexanoic acid, 2-ethyl-, ethenyl ester...Substances § 721.4250 Hexanoic acid, 2-ethyl-, ethenyl ester...substance identified as hexanoic acid, 2-ethyl-, ethenyl...worker in the following state(s): Open liquid...

2012-07-01

117

40 CFR 721.4250 - Hexanoic acid, 2-ethyl-, ethenyl ester.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Hexanoic acid, 2-ethyl-, ethenyl ester...Substances § 721.4250 Hexanoic acid, 2-ethyl-, ethenyl ester...substance identified as hexanoic acid, 2-ethyl-, ethenyl...worker in the following state(s): Open liquid...

2013-07-01

118

40 CFR 721.4250 - Hexanoic acid, 2-ethyl-, ethenyl ester.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Hexanoic acid, 2-ethyl-, ethenyl ester...Substances § 721.4250 Hexanoic acid, 2-ethyl-, ethenyl ester...substance identified as hexanoic acid, 2-ethyl-, ethenyl...worker in the following state(s): Open liquid...

2014-07-01

119

40 CFR 721.4250 - Hexanoic acid, 2-ethyl-, ethenyl ester.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Hexanoic acid, 2-ethyl-, ethenyl ester...Substances § 721.4250 Hexanoic acid, 2-ethyl-, ethenyl ester...substance identified as hexanoic acid, 2-ethyl-, ethenyl...worker in the following state(s): Open liquid...

2011-07-01

120

21 CFR 184.1101 - Diacetyl tartaric acid esters of mono- and diglycerides.  

Code of Federal Regulations, 2010 CFR

...acid esters of mono- and diglycerides, also know as DATEM, are composed of mixed esters of glycerin in which one or more of the hydroxyl groups of glycerin has been esterified by diacetyl tartaric acid and by fatty acids. The ingredient is...

2010-04-01

121

STUDIES ON THE APPLICATION OF ALKYL PHOSPHORIC ACID ESTER IN THE FLOTATION OF WOLFRAMITE  

Microsoft Academic Search

The application of alkyl phosphoric acid ester for the flotation of wolframite was investigated. The studies include flotation of pure wolframite as a function of pulp pH, surfactant concentration, and particle size. The response contours were explained on the basis of solution properties of alkyl phosphoric acid ester. The performance of alkyl phosphoric acid collector has been compared with other

K. SRINIVAS; T. SREENIVAS; N. P. H. PADMANABHAN; R. VENUGOPAL

2004-01-01

122

Heterotrophic production of eicosapentaenoid acid by the diatom Nitzschia laevis : effects of silicate and glucose  

Microsoft Academic Search

  The effects of silicate and glucose on growth and eicosapentaenoic acid (EPA) production by the diatom Nitzschia laevis were studied. By alternately altering the concentrations of silicate (2.7–64 mg l?1) and glucose (1–40 g l?1) in the medium, the highest cell dry weight (ca. 5.5 g l?1) was obtained at 20 g l?1 glucose and 32 mg l?1 silicate, while

Z-Y Wen; F Chen

2000-01-01

123

Divergent effects of eicosapentaenoic and docosahexaenoic acid ethyl esters, and fish oil on hepatic fatty acid oxidation in the rat.  

PubMed

The physiological activity of fish oil, and ethyl esters of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) affecting hepatic fatty acid oxidation was compared in rats. Five groups of rats were fed various experimental diets for 15 days. A group fed a diet containing 9.4% palm oil almost devoid of n-3 fatty acids served as a control. The test diets contained 4% n-3 fatty acids mainly as EPA and DHA in the form of triacylglycerol (9.4% fish oil) or ethyl esters (diets containing 4% EPA ethyl ester, 4% DHA ethyl ester, and 1% EPA plus 3% DHA ethyl esters). The lipid content of diets containing EPA and DHA ethyl esters was adjusted to 9.4% by adding palm oil. The fish oil diet and ethyl ester diets, compared to the control diet containing 9.4% palm oil, increased activity and mRNA levels of hepatic mitochondrial and peroxisomal fatty acid oxidation enzymes, though not 3-hydroxyacyl-CoA dehydrogenase activity. The extent of the increase was, however, much greater with the fish oil than with EPA and DHA ethyl esters. EPA and DHA ethyl esters, compared to the control diet, increased 3-hydroxyacyl-CoA dehydrogenase activity, but fish oil strongly reduced it. It is apparent that EPA and DHA in the form of ethyl esters cannot mimic the physiological activity of fish oil at least in affecting hepatic fatty acid oxidation in rat. PMID:14642774

Hong, Dang Diem; Takahashi, Yoko; Kushiro, Masay; Ide, Takashi

2003-11-30

124

Novel fatty acid methyl esters from the actinomycete Micromonospora aurantiaca  

PubMed Central

Summary The volatiles released by Micromonospora aurantiaca were collected by means of a closed-loop stripping apparatus (CLSA) and analysed by GC–MS. The headspace extracts contained more than 90 compounds from different classes. Fatty acid methyl esters (FAMEs) comprised the major compound class including saturated unbranched, monomethyl and dimethyl branched FAMEs in diverse structural variants: Unbranched, ?-branched, ?-branched, (??1)-branched, (??2)-branched, ?- and (??1)-branched, ?- and (??1)-branched, ?- and (??2)-branched, and ?- and (??3)-branched FAMEs. FAMEs of the last three types have not been described from natural sources before. The structures for all FAMEs have been suggested based on their mass spectra and on a retention index increment system and verified by the synthesis of key reference compounds. In addition, the structures of two FAMEs, methyl 4,8-dimethyldodecanoate and the ethyl-branched compound methyl 8-ethyl-4-methyldodecanoate were deduced from their mass spectra. Feeding experiments with isotopically labelled [2H10]leucine, [2H10]isoleucine, [2H8]valine, [2H5]sodium propionate, and [methyl-2H3]methionine demonstrated that the responsible fatty acid synthase (FAS) can use different branched and unbranched starter units and is able to incorporate methylmalonyl-CoA elongation units for internal methyl branches in various chain positions, while the methyl ester function is derived from S-adenosyl methionine (SAM). PMID:22238549

Bruns, Hilke; Riclea, Ramona

2011-01-01

125

Synthesis, Evaluation of Anticancer Activity and QSAR Study of Heterocyclic Esters of Caffeic Acid  

PubMed Central

Caffeic acid phenethyl ester (CAPE) suppresses the growth of transformed cells such as human breast cancer cells, hepatocarcinoma , myeloid leukemia, colorectal cancer cells, fibrosarcoma, glioma and melanoma. A group of heterocyclic esters of caffeic acid was synthesized using Mitsunobu reaction and the esters were subjected to further structural modification by electrooxidation of the catechol ring of caffeic acid esters in the presence of sodium benzenesulfinate and sodium toluensulfinate as nucleophiles. Both heterocyclic esters of caffeic acid and their arylsulfonyl derivatives were evaluated for their cytotoxic activity against HeLa, SK-OV-3, and HT-29 cancer cell lines. HeLa cells showed the highest sensitivity to the compounds and heterocyclic esters with no substituent on catechol ring showed better activity compared to their substituted counterparts. QSAR studies reemphasized the importance of molecular shape of the compounds for their cytotoxic activity. PMID:24523750

Hajmohamad Ebrahim Ketabforoosh, Shima; Amini, Mohsen; Vosooghi, Mohsen; Shafiee, Abbas; Azizi, Ebrahim; Kobarfard, Farzad

2013-01-01

126

Synthesis, evaluation of anticancer activity and QSAR study of heterocyclic esters of caffeic Acid.  

PubMed

Caffeic acid phenethyl ester (CAPE) suppresses the growth of transformed cells such as human breast cancer cells, hepatocarcinoma , myeloid leukemia, colorectal cancer cells, fibrosarcoma, glioma and melanoma. A group of heterocyclic esters of caffeic acid was synthesized using Mitsunobu reaction and the esters were subjected to further structural modification by electrooxidation of the catechol ring of caffeic acid esters in the presence of sodium benzenesulfinate and sodium toluensulfinate as nucleophiles. Both heterocyclic esters of caffeic acid and their arylsulfonyl derivatives were evaluated for their cytotoxic activity against HeLa, SK-OV-3, and HT-29 cancer cell lines. HeLa cells showed the highest sensitivity to the compounds and heterocyclic esters with no substituent on catechol ring showed better activity compared to their substituted counterparts. QSAR studies reemphasized the importance of molecular shape of the compounds for their cytotoxic activity. PMID:24523750

Hajmohamad Ebrahim Ketabforoosh, Shima; Amini, Mohsen; Vosooghi, Mohsen; Shafiee, Abbas; Azizi, Ebrahim; Kobarfard, Farzad

2013-01-01

127

Derivatives of Some 2-Chloroethylphosphonic Acid Esters, with Plant Growth Regulating Activity  

Microsoft Academic Search

A method for the synthesis of esters of 2-(dimethylsulfonium)ethylphos-phonic acid and the results of some trials showing the plant growth regulating activity of these compounds are presented. For the synthesis of the mentioned compounds, dimethyl sulphide is reacted with 2-chloroethylphosphonic acid esters; these esters are obtained through the complex[1] of AlCl3, PCl3 and 1,2-dichloroethan (1). Using the optimum reaction conditions,

Gheorghe Ilia

1999-01-01

128

Preparation of fatty acid methyl esters and dimethylacetals from lipids with boron fluoride-methanol  

Microsoft Academic Search

SUMMARY Fatty acid methyl esters and dimethylacetals suitable for gas chromatographic analysis were prepared by treatment of lipids with boron fluoride-methanol (140 g BFI per liter of methanol). This reagent is stable and easy to handle. Reaction conditions were investigated for triglycerides, di- glycerides, monoglycerides, free fatty acids, sterol esters, phos- phatidyl ethanolamines, phosphatidyl serines, phosphatidyl 'cholines, monophosphoinositides, monogalactosyl glycerides,

WILLIAM R. MORRISON; LLOYD M. SMITH

129

Analysis of phytostanyl fatty acid esters in enriched foods via UHPLC-APCI-MS.  

PubMed

A method for the analysis of phytostanyl fatty acid esters, the functional ingredients of cholesterol-lowering enriched foods, was developed. The procedure is based on (i) separation of the intact esters via reversed-phase ultrahigh-performance liquid chromatography; (ii) detection by atmospheric pressure chemical ionization-mass spectrometry; and (iii) quantitation using selected ion monitoring (SIM) mode. Employing a C8 column, phytostanyl fatty acid esters sharing the same stanol nucleus could be separated according to the esterified fatty acids while esters with different stanol moieties could be distinguished via SIM based on the formation of an intense fragment ion [M - fatty acid + H](+). The suitability of the approach was demonstrated using different types of enriched foods reflecting the diversity in potential matrices (skimmed milk drinking yogurt, margarine, and soft-cheese-style spread). The developed methodology extends the analytical basis for authenticity and quality assessments of functional foods enriched with phytostanyl fatty acid esters. PMID:24766184

Scholz, Birgit; Barnsteiner, Andreas; Feist, Katharina; Schmid, Wolfgang; Engel, Karl-Heinz

2014-05-14

130

Thermodynamic analysis of fatty acid esterification for fatty acid alkyl esters production  

Microsoft Academic Search

The development of renewable energy source alternatives has become a planet need because of the unavoidable fossil fuel scarcity and for that reason biodiesel production has attracted growing interest over the last decade. The reaction yield for obtaining fatty acid alkyl esters varies significantly according to the operating conditions such as temperature and the feed reactants ratio and thus investigation

Fernando A. P. Voll; Camila da Silva; Carla C. R. S. Rossi; Reginaldo Guirardello; Fernanda de Castilhos; J. Vladimir Oliveira; Lúcio Cardozo-Filho

2011-01-01

131

Methyl esters from vegetable oils with hydroxy fatty acids: Comparison of lesquerella and castor methyl esters  

Technology Transfer Automated Retrieval System (TEKTRAN)

The search for alternative feedstocks for biodiesel as partial replacement for petrodiesel has recently extended to castor oil. In this work, the castor oil methyl esters were prepared and their properties determined in comparison to the methyl esters of lesquerella oil, which in turn is seen as alt...

132

Energy-rich glyceric acid oxygen esters - Implications for the origin of glycolysis  

NASA Technical Reports Server (NTRS)

The apparent Gibbs free energy change (GFEC) of hydrolysis (pH 7) of the 2- and 3-O-glyceroyl esters of 2- and 3-O-L-glyceroyl-L-glyceric acid methyl ester were measured at 25 C. The 2- and 3-glyceroyl esters were found to be 'energy-rich' with GFEC values of -9.1 kcal/mol and -7.8 kcal/mol, respectively. This result indicates that the analogous 2- and 3-glyceroyl esters of polyglyceric acid are also energy-rich and, therefore, could have acted as an energy source for primitive phosphoanhydride synthesis.

Weber, Arthur L.; Hsu, Victor

1990-01-01

133

Fractionation of fats, oils, and waxes on thin layers of silicic acid  

Microsoft Academic Search

Summary  Adsorption chromatography on thin layers of silicic acid or alumina provides a new and highly efficient analytical tool for\\u000a the rapid separation of lipids according to classes of compounds.

Helmut K. Mangold; Donald C. Malins

1960-01-01

134

[Enzymatic synthesis of saccharide and saccharide alcohol fatty acid esters].  

PubMed

Conditions for esterification in tert-butanol using fatty acid as acy1 donor and saccharides or saccharide alcohols as acy1 acceptors, immobilized lipase from Candida sp. 1619 as biocatalyst were investigated. Optimal temperature and pH for esterication were 40 degrees C-45 degrees C and 5.5-7.5, respectively. Among the 13 acy1 donors compared, the best ones are the linoleic acid and oleic acid. The similar conversion degree was obtained when using saturated fatty acids with carbon chain length from C8 to C22. Among the 23 saccharides and saccharide alcohols compared, D-fructose, D-Xylose, trehalose, D-sorbitol, xylitol, mannitol isopropyidoneglucofruranose and alpha-methylglucopyranoside showed much higher esterification degree than other acy1 acceptors. In addition, the reaction degree of saccharide alcohols were substantially higher than that of the corresponding saccharides. The conversion was enhanced greatly when the molar ratio of acy1 donor to acy1 acceptor was higher than 2 to 1. In the case of using sorbitol and loeic acid as substrates, the reaction was carried out in 100 ml conical flask and the reaction system consisted of 3.0 mmol oleic acid(0.85 g), 0.2 mmol sorbitol(0.036 g), 3 mL tert-butanol, 30 mg immobilized lipase(600 u), shaken at 40 degrees C. After reaction for 48 h, more than 90% of sorbitol was esterified based on equal molar of substrates. The products were identified TLC as monoester and diester. PMID:12548944

Kou, X; Xu, J

2000-04-01

135

Fundamental Study on Temperature Dependence of Deposition Rate of Silicic Acid - 13270  

SciTech Connect

The dynamic behavior of the silicic acid is one of the key factors to estimate the condition of the repository system after the backfill. This study experimentally examined the temperature dependence of dynamic behavior of supersaturated silicic acid in the co-presence of solid phase, considering Na ions around the repository, and evaluated the deposition rate constant, k, of silicic acid by using the first-order reaction equation considering the specific surface area. The values of k were in the range of 1.0x10{sup -11} to 1.0x10{sup -9} m/s in the temperature range of 288 K to 323 K. The deposition rate became larger with increments of temperature under the Na ion free condition. Besides, in the case of Na ions 0.6 M, colloidal silicic acid decreased dramatically at a certain time. This means that the diameter of the colloidal silicic acid became larger than the pore size of filter (0.45 ?m) due to bridging of colloidal silicic acid. Furthermore, this study estimated the range of altering area and the aperture of flow-path in various value of k corresponding to temperature by using advection-dispersion model. The concentration in the flow-path became lower with increments of temperature, and when the value of k is larger than 1.0x10{sup -11} m/s, the deposition range of supersaturated silicic acid was estimated to be less than 20 m around the repository. In addition, the deposition of supersaturated silicic acid led the decrement of flow-path aperture, which was remarkable under the condition of relatively high temperature. Such a clogging in flow paths is expected as a retardation effect of radionuclides. (authors)

Shinmura, Hayata; Niibori, Yuichi; Mimura, Hitoshi [Dept. of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, 6-6-01-2 Aobayama, Aoba-ku, Sendai 980-8579 (Japan)] [Dept. of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, 6-6-01-2 Aobayama, Aoba-ku, Sendai 980-8579 (Japan)

2013-07-01

136

Synthesis and properties of fatty acid starch esters.  

PubMed

Being completely bio-based, fatty acid starch esters (FASEs) are attractive materials that represent an alternative to crude oil-based plastics. In this study, two synthesis methods were compared in terms of their efficiency, toxicity and, especially, product solubility with starch laurate (C12) as model compound. Laurates (DS>2) were obtained through transesterification of fatty acid vinylesters in DMSO or reaction with fatty acid chlorides in pyridine. The latter lead to higher DS-values in a shorter reaction time. But due to the much better solubility of the products compared to lauroyl chloride esterified ones, vinylester-transesterification was preferred to optimize reaction parameters, where reaction time could be shortened to 2h. FASEs C6-C18 were also successfully prepared via transesterification. To determine the DS of the resulting starch laurates, the efficient ATR-IR method was compared with common methods (elementary analysis, (1)H NMR). Molar masses (Mw) of the highly soluble starch laurates were analyzed using SEC-MALLS (THF). High recovery rates (>80%) attest to the outstanding solubility of products obtained through transesterification, caused by a slight disintegration during synthesis. Particle size distributions (DLS) demonstrated stable dissolutions in CHCl3 of vinyl laurate esterified - contrary to lauroyl chloride esterified starch. For all highly soluble FASEs (C6-C18), formation of concentrated solutions (10 wt%) is feasible. PMID:23987337

Winkler, Henning; Vorwerg, Waltraud; Wetzel, Hendrik

2013-10-15

137

Optimized enzymatic synthesis of caffeic acid phenethyl ester by RSM.  

PubMed

In this study, optimization of enzymatic synthesis of caffeic acid phenethyl ester (CAPE), catalyzed by immobilized lipase (Novozym 435) from Candida antarctica was investigated. Novozym 435 was used to catalyze caffeic acid and 2-phenylethanol in an isooctane system. Response surface methodology (RSM) and 5-level-4-factor central-composite rotatable design (CCRD) were employed to evaluate the effects of synthesis parameters, such as reaction temperature (30-70 degrees C), reaction time (24-72 hours), substrate molar ratio of caffeic acid to 2-phenylethanol (1:10-1:90) and enzyme amounts (100-500 PLU) on percentage conversion of CAPE by direct esterification. Reaction temperature and time had significant effects on percent conversion. On the basis of ridge max analysis, the optimum conditions for synthesis were: reaction time 59 hours, reaction temperature 69 degrees C, substrate molar ratio 1:72 and enzyme amount 351 PLU. The molar conversion of predicted values and actual experimental values were 91.86+/-5.35% and 91.65+/-0.66%, respectively. PMID:20018263

Chen, Hsiao-Ching; Ju, Hen-Yi; Twu, Yawo-Kuo; Chen, Jiann-Hwa; Chang, Chieh-Ming J; Liu, Yung-Chuan; Chang, Cheng; Shieh, Chwen-Jen

2010-02-28

138

40 CFR 721.10369 - Carbonic acid, diphenyl ester, polymer with diphenyl P-methylphosphonate and 4,4?-(1...  

Code of Federal Regulations, 2012 CFR

...acid, diphenyl ester, polymer with diphenyl P-methylphosphonate and 4,4â²-(1-methylethylidene...acid, diphenyl ester, polymer with diphenyl P-methylphosphonate and 4,4?-(1-methylethylidene...acid, diphenyl ester, polymer with diphenyl P-methylphosphonate and...

2012-07-01

139

40 CFR 721.10369 - Carbonic acid, diphenyl ester, polymer with diphenyl P-methylphosphonate and 4,4?-(1...  

Code of Federal Regulations, 2014 CFR

...acid, diphenyl ester, polymer with diphenyl P-methylphosphonate and 4,4â²-(1-methylethylidene...acid, diphenyl ester, polymer with diphenyl P-methylphosphonate and 4,4?-(1-methylethylidene...acid, diphenyl ester, polymer with diphenyl P-methylphosphonate and...

2014-07-01

140

40 CFR 721.10369 - Carbonic acid, diphenyl ester, polymer with diphenyl P-methylphosphonate and 4,4?-(1...  

Code of Federal Regulations, 2013 CFR

...acid, diphenyl ester, polymer with diphenyl P-methylphosphonate and 4,4â²-(1-methylethylidene...acid, diphenyl ester, polymer with diphenyl P-methylphosphonate and 4,4?-(1-methylethylidene...acid, diphenyl ester, polymer with diphenyl P-methylphosphonate and...

2013-07-01

141

40 CFR 721.9400 - Reaction product of phenolic pentaerythritol tetraesters with fatty acid esters and oils, and...  

Code of Federal Regulations, 2010 CFR

...pentaerythritol tetraesters with fatty acid esters and oils, and glyceride...pentaerythritol tetraesters with fatty acid esters and oils, and glyceride...pentaerythritol tetraesters with fatty acid esters and oils, and glyceride...processed, or used in the employer's workplace, the employer...

2010-07-01

142

40 CFR 721.9400 - Reaction product of phenolic pentaerythritol tetraesters with fatty acid esters and oils, and...  

Code of Federal Regulations, 2011 CFR

...pentaerythritol tetraesters with fatty acid esters and oils, and glyceride...pentaerythritol tetraesters with fatty acid esters and oils, and glyceride...pentaerythritol tetraesters with fatty acid esters and oils, and glyceride...processed, or used in the employer's workplace, the employer...

2011-07-01

143

40 CFR 721.9400 - Reaction product of phenolic pentaerythritol tetraesters with fatty acid esters and oils, and...  

Code of Federal Regulations, 2013 CFR

...pentaerythritol tetraesters with fatty acid esters and oils, and glyceride...pentaerythritol tetraesters with fatty acid esters and oils, and glyceride...pentaerythritol tetraesters with fatty acid esters and oils, and glyceride...processed, or used in the employer's workplace, the employer...

2013-07-01

144

40 CFR 721.9400 - Reaction product of phenolic pentaerythritol tetraesters with fatty acid esters and oils, and...  

Code of Federal Regulations, 2014 CFR

...pentaerythritol tetraesters with fatty acid esters and oils, and glyceride...pentaerythritol tetraesters with fatty acid esters and oils, and glyceride...pentaerythritol tetraesters with fatty acid esters and oils, and glyceride...processed, or used in the employer's workplace, the employer...

2014-07-01

145

40 CFR 721.9400 - Reaction product of phenolic pentaerythritol tetraesters with fatty acid esters and oils, and...  

Code of Federal Regulations, 2012 CFR

...pentaerythritol tetraesters with fatty acid esters and oils, and glyceride...pentaerythritol tetraesters with fatty acid esters and oils, and glyceride...pentaerythritol tetraesters with fatty acid esters and oils, and glyceride...processed, or used in the employer's workplace, the employer...

2012-07-01

146

The content and composition of sterols and sterol esters in low erucic acid rapeseed ( Brassica napus )  

Microsoft Academic Search

The low temperature crystallization technique for the enrichment of “minor” components, such as sterols and sterol esters,\\u000a from vegetable oils was applied to low erucic acid rapeseed oils. The recovery of free sterols and sterol esters was estimated\\u000a by use of14C-cholesterol and14C-cholesterol oleate. 80% of the free sterols and 45% of the sterol esters were recovered in the liquid fraction,

Anna Johansson; Lars-Åke Appelqvist

1978-01-01

147

An Investigation of Ester Group Steric Effects on Metal Ion Extraction by Symmetrically Substituted Methylenediphosphonic Acids  

Microsoft Academic Search

Symmetrically substituted partial alkyl?esters of methylenediphosphonic acid are powerful metal ion extractants for actinides in all oxidation states. A preliminary study of calcium and americium(III) extraction by the n?octyl and 2?ethylhexyl di?substituted esters of methylenediphosphonic acid revealed the distribution ratios and the nitric acid dependency behaviors for the two extractants to be very similar, with the extraction efficiency for the

D. C. Stepinski; D. R. McAlister; P. R. Zalupski; R. Chiarizia; A. W. Herlinger

2004-01-01

148

Sugar fatty acid esters inhibit biofilm formation by food-borne pathogenic bacteria  

PubMed Central

Effects of food additives on biofilm formation by food-borne pathogenic bacteria were investigated. Thirty-three potential food additives and 3 related compounds were added to the culture medium at concentrations from 0.001 to 0.1% (w/w), followed by inoculation and cultivation of five biofilm-forming bacterial strains for the evaluation of biofilm formation. Among the tested food additives, 21 showed inhibitory effects of biofilm formation by Staphylococcus aureus and Escherichia coli, and in particular, sugar fatty acid esters showed significant anti-biofilm activity. Sugar fatty acid esters with long chain fatty acid residues (C14-16) exerted their inhibitory effect at the concentration of 0.001%(w/w), but bacterial growth was not affected at this low concentration. Activities of the sugar fatty acid esters positively correlated with the increase of the chain length of the fatty acid residues. Sugar fatty acid esters inhibited the initial attachment of the Staphylococcus aureus cells to the abiotic surface. Sugar fatty acid esters with long chain fatty acid residues (C14-16) also inhibited biofilm formation by Streptococcus mutans and Listeria monocytogenes at 0.01%(w/w), while the inhibition of biofilm formation by Pseudomonas aeruginosa required the addition of a far higher concentration (0.1%(w/w)) of the sugar fatty acid esters. PMID:20089325

Furukawa, Soichi; Akiyoshi, Yuko; O’Toole, George A.; Ogihara, Hirokazu; Morinaga, Yasushi

2010-01-01

149

Four aristolochic acid esters of rearranged ent-elemane sesquiterpenes from aristolochia heterophylla  

PubMed

Four aristolochic acid esters of ent-elemane type sesquiterpene having a new carbon skeleton, aristophyllides A (1), B (2), C (3), and D (4), were isolated from the stems and roots of Aristolochia heterophylla. The esters were characterized by NMR and MS methods and included is a study of absolute configurations using the CD exciton chirality method. PMID:10075784

Wu; Chan; Leu; Wu; Li; Mori

1999-02-01

150

A convenient enantioselective decarboxylative aldol reaction to access chiral ?-hydroxy esters using ?-keto acids  

PubMed Central

Summary We show a convenient decarboxylative aldol process using a scandium catalyst and a PYBOX ligand to generate a series of highly functionalized chiral ?-hydroxy esters. The protocol tolerates a broad range of ?-keto acids with inactivated aromatic and aliphatic ?-keto esters. The possible mechanism is rationalized. PMID:24991246

Duan, Zhiqiang; Han, Jianlin; Qian, Ping; Zhang, Zirui; Pan, Yi

2014-01-01

151

The effect of benzoic acid or its ethyl ester on rumen fermentation parameters  

E-print Network

The effect of benzoic acid or its ethyl ester on rumen fermentation parameters J Nousiainen Valio response of BA or its ethyl ester (EB) on the rumen fermentation parameters in the continuous culture to represent the maximum amount in vivo. The fermentation apparatus and the design of trials as well

Paris-Sud XI, Université de

152

Synthesis of Branched Methyl Hydroxy Stearates Including an Ester from Bio-Based Levulinic Acid  

Technology Transfer Automated Retrieval System (TEKTRAN)

We report the synthesis of 5 useful branched methyl alpha-hydroxy oleate esters from commercially available methyl oleate and common organic acids. Of special interest is the synthesis utilizing the natural byproduct, levulinic acid. The other common organic acids used herein were propionic acid, ...

153

Direct Determination of MCPD Fatty Acid Esters and Glycidyl Fatty Acid Esters in Vegetable Oils by LC–TOFMS  

PubMed Central

Analysis of MCPD esters and glycidyl esters in vegetable oils using the indirect method proposed by the DGF gave inconsistent results when salting out conditions were varied. Subsequent investigation showed that the method was destroying and reforming MCPD during the analysis. An LC time of flight MS method was developed for direct analysis of both MCPD esters and glycidyl esters in vegetable oils. The results of the LC–TOFMS method were compared with the DGF method. The DGF method consistently gave results that were greater than the LC–TOFMS method. The levels of MCPD esters and glycidyl esters found in a variety of vegetable oils are reported. MCPD monoesters were not found in any oil samples. MCPD diesters were found only in samples containing palm oil, and were not present in all palm oil samples. Glycidyl esters were found in a wide variety of oils. Some processing conditions that influence the concentration of MCPD esters and glycidyl esters are discussed. PMID:21350591

Haines, Troy D.; Adlaf, Kevin J.; Pierceall, Robert M.; Lee, Inmok; Venkitasubramanian, Padmesh

2010-01-01

154

Fatty acid alkyl esters: perspectives for production of alternative biofuels.  

PubMed

The global economy heads for a severe energy crisis: whereas the energy demand is going to rise, easily accessible sources of crude oil are expected to be depleted in only 10-20 years. Since a serious decline of oil supply and an associated collapse of the economy might be reality very soon, alternative energies and also biofuels that replace fossil fuels must be established. In addition, these alternatives should not further impair the environment and climate. About 90% of the biofuel market is currently captured by bioethanol and biodiesel. Biodiesel is composed of fatty acid alkyl esters (FAAE) and can be synthesized by chemical, enzymatic, or in vivo catalysis mainly from renewable resources. Biodiesel is already established as it is compatible with the existing fuel infrastructure, non-toxic, and has superior combustion characteristics than fossil diesel; and in 2008, the global production was 12.2 million tons. The biotechnological production of FAAE from low cost and abundant feedstocks like biomass will enable an appreciable substitution of petroleum diesel. To overcome high costs for immobilized enzymes, the in vivo synthesis of FAAE using bacteria represents a promising approach. This article points to the potential of different FAAE as alternative biofuels, e.g., by comparing their fuel properties. In addition to conventional production processes, this review presents natural and genetically engineered biological systems capable of in vivo FAAE synthesis. PMID:20033403

Röttig, Annika; Wenning, Leonie; Bröker, Daniel; Steinbüchel, Alexander

2010-02-01

155

Spectroscopic and quantum chemical analysis of Isonicotinic acid methyl ester  

NASA Astrophysics Data System (ADS)

In this present study, an organic compound Isonicotinic acid methyl ester (INAME) was structurally characterized by FTIR, FT-Raman, and NMR and UV spectroscopy. The optimized geometrical parameters and energies of all different and possible conformers of INAME are obtained from Density Functional Theory (DFT) by B3LYP/6-311++G(d,p) method. There are three conformers (SI, SII-1, and SII-2) for this molecule (ground state). The most stable conformer of INAME is SI conformer. The molecular geometry and vibrational frequencies of INAME in the ground state have been calculated by using HF and density functional method (B3LYP) 6-311++G (d,p) basis set. Detailed vibrational spectral analysis has been carried out and assignments of the observed fundamental bands have been proposed on the basis of peak positions and relative intensities. The computed vibrational frequencies were compared with the experimental frequencies, which yield good agreement between observed and calculated frequencies. A study on the electronic properties, such as HOMO and LUMO energies were performed by time independent DFT approach. Besides, molecular electrostatic potential (MEP) and thermodynamic properties were performed. The electric dipole moment (?) and first hyper polarizability (?) values of the investigated molecule were computed using ab initio quantum mechanical calculations. The calculated results show that the INAME molecule may have microscopic nonlinear optical (NLO) behavior with non zero values. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by gauge independent atomic orbital (GIAO) method.

Shoba, D.; Periandy, S.; Govindarajan, M.; Gayathri, P.

2015-02-01

156

Comparative Oxidative Stability of Fatty Acid Alkyl Esters by Accelerated Methods  

Technology Transfer Automated Retrieval System (TEKTRAN)

Several fatty acid alkyl esters were subjected to accelerated methods of oxidation, including EN 14112 (Rancimat method) and pressurized differential scanning calorimetry (PDSC). Structural trends elucidated from both methods that improved oxidative stability included decreasing the number of doubl...

157

21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.  

Code of Federal Regulations, 2012 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADHESIVES AND COMPONENTS OF COATINGS Substances for Use as Components of Coatings § 175.260 Partial phosphoric acid esters...

2012-04-01

158

21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.  

Code of Federal Regulations, 2014 CFR

...and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT FOOD ADDITIVES: ADHESIVES AND COMPONENTS OF COATINGS Substances for Use as Components of Coatings § 175.260 Partial phosphoric acid esters...

2014-04-01

159

21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.  

Code of Federal Regulations, 2013 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADHESIVES AND COMPONENTS OF COATINGS Substances for Use as Components of Coatings § 175.260 Partial phosphoric acid esters...

2013-04-01

160

Isolation and characterization of esters of indole-3-acetic acid from the liquid endosperm of the horse chestnut (Aesculus species)  

NASA Technical Reports Server (NTRS)

Esters of indole-3-acetic acid were extracted and purified from the liquid endosperm of immature fruits of various species of the horse chestnut (Aesculus parviflora, A. baumanni, A. pavia rubra, and A. pavia humulis). The liquid endosperm contained, at least 12 chromatographically distinct esters. One of these compounds was purified and characterized as an ester of indole-3-acetic acid and myo-inositol. A second compound was found to be an ester of indole-3-acetic acid and the disaccharide rutinose (glucosyl-rhamnose). A third compound was partially characterized as an ester of indole-3-acetic acid and a desoxyaminohexose.

Domagalski, W.; Schulze, A.; Bandurski, R. S.

1987-01-01

161

Omega-3 fatty acids increase the arachidonic acid content of liver cholesterol ester and plasma triacylglycerol fractions in the rat.  

PubMed Central

Recent studies have demonstrated that dietary fish oils rich in eicosapentaenoic acid (C20:5,omega 3) lower the content of arachidonic acid and its metabolites in plasma and tissue phospholipids. The present study examined the fatty acid composition of cholesterol ester and triacylglycerol fractions from plasma and livers of rats fed diets enriched with saturated fatty acids (beef tallow), alpha-linolenic acid (linseed oil) or eicosapentaenoic acid (fish oil). Feeding diets containing linseed oil or fish oil for 28 days increased arachidonic acid (C20:4,omega 6) levels in the cholesterol ester fraction of liver and in the triacylglycerol fraction of the plasma lipids. Plasma cholesterol esters were depleted of C20:4,omega 6 after feeding of the diet containing either linseed oil or fish oil. The changes in C20:4,omega 6 content cannot be explained by alterations in cholesterol ester or triacylglycerol pools of plasma and liver. These results suggest that the decrease in phospholipid C20:4,omega 6 content generally observed after fish oil consumption may be partly due to a shift of C20:4,omega 6 from phospholipid to the triacylglycerol and/or cholesterol ester pools in the same tissue. Triacylglycerols and cholesterol esters may therefore play a buffering role in the homeostatic maintenance of tissue phospholipid levels of arachidonic acid. Images Fig. 1. PMID:2775198

Garg, M L; Wierzbicki, A A; Thomson, A B; Clandinin, M T

1989-01-01

162

Estimating the average carbon chain length of saturated fatty acid esters by infrared spectroscopy  

Microsoft Academic Search

The average carbon chain length of saturated fatty acid esters can be determined by comparing absorption intensities in the\\u000a 3.3 and 5.75 ? infrared regions. Data are presented for triglycerides, monoglycerides, and methyl esters. The method was used\\u000a to follow the fractionation of hydrogenated milk fat from acetone, and the average values for fatty acid chain length were\\u000a in good

P. G. Keeney

1962-01-01

163

Synthesis of an acid addition salt of delta-aminolevulinic acid from 5-bromo levulinic acid esters  

DOEpatents

A process of preparing an acid addition salt of delta-aminolevulinic acid comprising: dissolving a lower alkyl 5-bromolevulinate and an alkali metal diformylamide in an organic solvent selected from the group consisting of acetonitrile, methanol, tetrahydrofuran, 2-methyltetrahydrofuran and methylformate or mixtures thereof to form a suspension of an alkyl 5-(N,N-diformylamino) levulinate ester; and hydrolyzing said alkyl 5-(N,N-diformylamino) levulinate with an inorganic acid to form an acid addition salt of delta-amino levulinic acid.

Moens, Luc (Lakewood, CO)

1999-01-01

164

Fatty Acid Phytyl Ester Synthesis in Chloroplasts of Arabidopsis[W  

PubMed Central

During stress or senescence, thylakoid membranes in chloroplasts are disintegrated, and chlorophyll and galactolipid are broken down, resulting in the accumulation of toxic intermediates, i.e., tetrapyrroles, free phytol, and free fatty acids. Chlorophyll degradation has been studied in detail, but the catabolic pathways for phytol and fatty acids remain unclear. A large proportion of phytol and fatty acids is converted into fatty acid phytyl esters and triacylglycerol during stress or senescence in chloroplasts. We isolated two genes (PHYTYL ESTER SYNTHASE1 [PES1] and PES2) of the esterase/lipase/thioesterase family of acyltransferases from Arabidopsis thaliana that are involved in fatty acid phytyl ester synthesis in chloroplasts. The two proteins are highly expressed during senescence and nitrogen deprivation. Heterologous expression in yeast revealed that PES1 and PES2 have phytyl ester synthesis and diacylglycerol acyltransferase activities. The enzymes show broad substrate specificities and can employ acyl-CoAs, acyl carrier proteins, and galactolipids as acyl donors. Double mutant plants (pes1 pes2) grow normally but show reduced phytyl ester and triacylglycerol accumulation. These results demonstrate that PES1 and PES2 are involved in the deposition of free phytol and free fatty acids in the form of phytyl esters in chloroplasts, a process involved in maintaining the integrity of the photosynthetic membrane during abiotic stress and senescence. PMID:22623494

Lippold, Felix; vom Dorp, Katharina; Abraham, Marion; Hölzl, Georg; Wewer, Vera; Yilmaz, Jenny Lindberg; Lager, Ida; Montandon, Cyrille; Besagni, Céline; Kessler, Felix; Stymne, Sten; Dörmann, Peter

2012-01-01

165

Branched Chain Amino Acid Metabolism in the Biosynthesis of Lycopersicon pennellii Glucose Esters 1  

PubMed Central

Lycopersicon pennellii Corr. (D'Arcy) an insect-resistant, wild tomato possesses high densities of glandular trichomes which exude a mixture of 2,3,4-tri-O-acylated glucose esters that function as a physical impediment and feeding deterrent to small arthropod pests. The acyl moieties are branched C4 and C5 acids, and branched and straight chain C10, C11, and C12 acids. The structure of the branched acyl constituents suggests that the branched chain amino acid biosynthetic pathway participates in their biosynthesis. [14C]Valine and deuterated branched chain amino acids (and their oxo-acid derivatives) were incorporated into branched C4 and C5 acid groups of glucose esters by a process of transamination, oxidative decarboxylation and subsequent acylation. C4 and C5 branched acids were elongated by two carbon units to produce the branched C10-C12 groups. Norvaline, norleucine, allylglycine, and methionine also were processed into acyl moieties and secreted from the trichomes as glucose esters. Changes in the acyl composition of the glucose esters following sulfonylurea herbicide administration support the participation of acetohydroxyacid synthetase and the other enzymes of branched amino acid biosynthesis in the production of glucose esters. PMID:16667654

Walters, Donald S.; Steffens, John C.

1990-01-01

166

Spectroscopic and quantum chemical analysis of Isonicotinic acid methyl ester.  

PubMed

In this present study, an organic compound Isonicotinic acid methyl ester (INAME) was structurally characterized by FTIR, FT-Raman, and NMR and UV spectroscopy. The optimized geometrical parameters and energies of all different and possible conformers of INAME are obtained from Density Functional Theory (DFT) by B3LYP/6-311++G(d,p) method. There are three conformers (SI, SII-1, and SII-2) for this molecule (ground state). The most stable conformer of INAME is SI conformer. The molecular geometry and vibrational frequencies of INAME in the ground state have been calculated by using HF and density functional method (B3LYP) 6-311++G (d,p) basis set. Detailed vibrational spectral analysis has been carried out and assignments of the observed fundamental bands have been proposed on the basis of peak positions and relative intensities. The computed vibrational frequencies were compared with the experimental frequencies, which yield good agreement between observed and calculated frequencies. A study on the electronic properties, such as HOMO and LUMO energies were performed by time independent DFT approach. Besides, molecular electrostatic potential (MEP) and thermodynamic properties were performed. The electric dipole moment (?) and first hyper polarizability (?) values of the investigated molecule were computed using ab initio quantum mechanical calculations. The calculated results show that the INAME molecule may have microscopic nonlinear optical (NLO) behavior with non zero values. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by gauge independent atomic orbital (GIAO) method. PMID:25459608

Shoba, D; Periandy, S; Govindarajan, M; Gayathri, P

2015-02-01

167

Kinematic viscosity of fatty acid methyl esters: Prediction, calculated viscosity contribution of esters with unavailable data, and carbon-oxygen equivalents  

Technology Transfer Automated Retrieval System (TEKTRAN)

Many properties of biodiesel, the mono-alkyl esters of vegetable oils, animal fats or other triacylglycerol-containing feedstocks, are largely determined by its major components, the fatty acid alkyl esters. Therefore, information on the properties of individual components and their interaction is ...

168

Amides and esters of phenylpropenoic acids from the aerial parts of Trifolium pallidum.  

PubMed

Two new derivatives of phenylpropenoic acids, N-trans-feruloyl-L-DOPA and O-trans-caffeoyl-malic acid dimethyl ester, along with four known N-trans-caffeoyl-L-DOPA (clovamide), N-trans-caffeoyl-L-DOPA-methyl ester, O-trans-caffeoyl-malic acid, O-trans-feruloyl-malic acid and quercetin 3-O-beta-D-glucopyranoside were isolated from the aerial parts of Trifolium pallidum. Their structures were elucidated by extensive spectroscopic methods including 1D- (1H, 13C) and 2D-NMR (DQF-COSY, HSQC, HMBC) experiments as well as mass spectrometry analysis. PMID:21941901

Szajwaj, Barbara; Moldoch, Jaroslaw; Masullo, Milena; Piacente, Sonia; Oleszek, Wieslaw; Stochmal, Anna

2011-09-01

169

Polymers from amino acids: development of dual ester-urethane melt condensation approach and mechanistic aspects.  

PubMed

A new dual ester-urethane melt condensation methodology for biological monomers-amino acids was developed to synthesize new classes of thermoplastic polymers under eco-friendly and solvent-free polymerization approach. Naturally abundant L-amino acids were converted into dual functional ester-urethane monomers by tailor-made synthetic approach. Direct polycondensation of these amino acid monomers with commercial diols under melt condition produced high molecular weight poly(ester-urethane)s. The occurrence of the dual ester-urethane process and the structure of the new poly(ester-urethane)s were confirmed by (1)H and (13)C NMR. The new dual ester-urethane condensation approach was demonstrated for variety of amino acids: glycine, ?-alanine, L-alanine, L-leucine, L-valine, and L-phenylalanine. MALDI-TOF-MS end group analysis confirmed that the amino acid monomers were thermally stable under the melt polymerization condition. The mechanism of melt process and the kinetics of the polycondensation were studied by model reactions and it was found that the amino acid monomer was very special in the sense that their ester and urethane functionality could be selectively reacted by polymerization temperature or catalyst. The new polymers were self-organized as ?-sheet in aqueous or organic solvents and their thermal properties such as glass transition temperature and crystallinity could be readily varied using different l-amino acid monomers or diols in the feed. Thus, the current investigation opens up new platform of research activates for making thermally stable and renewable engineering thermoplastics from natural resource amino acids. PMID:22713137

Anantharaj, S; Jayakannan, M

2012-08-13

170

Gas-Liquid Chromatographic Analysis of Indole-3-acetic Acid Myoinositol Esters in Maize Kernels 1  

PubMed Central

An improved method of fractionating the myoinositol esters of indoleacetic acid (IAA) from maize kernels by gas-liquid chromatography has been developed. Mass spectrometry was employed as an aid in identification of the esters. Maize kernels contain three groups of esters of IAA: (a) IAA myoinositols, (b) IAA myoinositol arabinosides, and (c) IAA myoinositol galactosides. Each group has three chromatographically distinguishable isomers. The glycosylinositols described are unique in that carbon 1 of the sugar is attached to the hydroxyl at C-5 of the myoinositol. PMID:16657535

Ueda, Minoru; Ehmann, Axel; Bandurski, Robert S.

1970-01-01

171

Effect of caffeic acid phenethyl ester on myringosclerosis development in the tympanic membrane of rat.  

PubMed

Myringosclerosis is hyalinization and calcification of certain areas of the tympanic membrane, especially the fibrous lamina propria layer and appears as white sclerotic lesions. Ventilation tube insertion is one of the most performed operations in the pediatric otorhinolaryngology practice to treat chronic otitis media with effusion. Myringosclerosis is a very common sequela of ventilation tube insertion. In this experimental study, our aim was to show the histopathological effects of caffeic acid phenethyl ester on myringosclerosis development in rat tympanic membrane after myringotomy. The rats were randomly categorized into four experimental groups including the comparison group (n = 4), non-treated group (n = 7), the saline (control) group (n = 7), the caffeic acid phenethyl ester group (n = 7). Non-treated group did not receive any treatment for 15 days. Saline (2.5 mL/kg, intraperitoneal) was administered to the third group once a day for 15 days. Fourth group received caffeic acid phenethyl ester intraperitoneally once a day at a dose of 10 ?mol/kg for 15 days. Myringotomy was performed on the right tympanic membrane of all rats except comparison group using a sterile pick with the help of an operating microscope. Histopathological examination of myringosclerosis formation was done by a pathologist under light microscope. In histopathological analysis of groups, the severity of inflammation was milder in caffeic acid phenethyl ester group compared to non-treated and saline groups (p < 0.05). There was less myringosclerotic plaques in caffeic acid phenethyl ester group than in non-treated and saline groups (p < 0.05). TM thickness measurements were very close to each other in non-treated and saline groups. The tympanic membrane thickness of caffeic acid phenethyl ester group was much thinner than the other two groups (p < 0.05). Caffeic acid phenethyl ester decreases inflammation severity and the formation of myringosclerotic plaques. These two effects resulted in thinner tympanic membranes of rats which were treated with caffeic acid phenethyl ester. As a result, caffeic acid phenethyl ester has potential preventive effects on myringosclerosis development after myringotomy and ventilation tube insertion. PMID:24281567

Kinis, Vefa; Ozbay, Musa; Alabalik, Ulas; Gul, Aylin; Yilmaz, Beyhan; Ozkurt, Fazi Emre; Sengul, Engin; Topcu, Ismail

2015-01-01

172

40 CFR 721.3130 - Sulfuric acid, mono-C9-11-alkyl esters, sodium salts.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Sulfuric acid, mono-C9-11-alkyl esters...Chemical Substances § 721.3130 Sulfuric acid, mono-C9-11 -alkyl esters...chemical substance identified as sulfuric acid, mono-C9-11...

2012-07-01

173

40 CFR 721.3130 - Sulfuric acid, mono-C9-11-alkyl esters, sodium salts.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Sulfuric acid, mono-C9-11-alkyl esters...Chemical Substances § 721.3130 Sulfuric acid, mono-C9- 11-alkyl esters...chemical substance identified as sulfuric acid, mono-C9-11...

2011-07-01

174

40 CFR 721.3130 - Sulfuric acid, mono-C9-11-alkyl esters, sodium salts.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Sulfuric acid, mono-C9-11-alkyl esters...Chemical Substances § 721.3130 Sulfuric acid, mono-C9-11 -alkyl esters...chemical substance identified as sulfuric acid, mono-C9-11...

2014-07-01

175

40 CFR 721.10457 - 1,2-Benzenedicarboxylic acid, mixed esters with benzyl alc., cyclohexanol, 2-ethyl-1-hexanol...  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false 1,2-Benzenedicarboxylic acid, mixed esters with benzyl alc., cyclohexanol, 2-ethyl-1-hexanol, fumaric acid and propylene glycol. 721.10457 ...721.10457 1,2-Benzenedicarboxylic acid, mixed esters with benzyl alc.,...

2013-07-01

176

Diurnal heterogeneity in silicic acid fluxes in shallow coastal sites: Causes and implications  

Microsoft Academic Search

In shallow coastal areas the amplitude and range of benthic silicic acid fluxes can have a significant influence on benthic–pelagic coupling and the functioning of the pelagic system. To explore the oscillation in fluxes over the diurnal cycle and in particular the influence of microphytobenthos (MPB), an experiment was carried out in a shallow subtidal site in the Bay of

Sorcha Ní Longphuirt; Olivier Ragueneau; Laurent Chauvaud; Sophie Martin; Frédéric Jean; Gérard Thouzeau; Aude Leynaert

2009-01-01

177

Inhibitory Effects of Caffeic Acid Phenethyl Ester Derivatives on Replication of Hepatitis C Virus  

PubMed Central

Caffeic acid phenethyl ester (CAPE) has been reported as a multifunctional compound. In this report, we tested the effect of CAPE and its derivatives on hepatitis C virus (HCV) replication in order to develop an effective anti-HCV compound. CAPE and CAPE derivatives exhibited anti-HCV activity against an HCV replicon cell line of genotype 1b with EC50 values in a range from 1.0 to 109.6 µM. Analyses of chemical structure and antiviral activity suggested that the length of the n-alkyl side chain and catechol moiety are responsible for the anti-HCV activity of these compounds. Caffeic acid n-octyl ester exhibited the highest anti-HCV activity among the tested derivatives with an EC50 value of 1.0 µM and an SI value of 63.1 by using the replicon cell line derived from genotype 1b strain Con1. Treatment with caffeic acid n-octyl ester inhibited HCV replication of genotype 2a at a similar level to that of genotype 1b irrespectively of interferon signaling. Caffeic acid n-octyl ester could synergistically enhance the anti-HCV activities of interferon-alpha 2b, daclatasvir, and VX-222, but neither telaprevir nor danoprevir. These results suggest that caffeic acid n-octyl ester is a potential candidate for novel anti-HCV chemotherapy drugs. PMID:24358168

Shen, Hui; Yamashita, Atsuya; Nakakoshi, Masamichi; Yokoe, Hiromasa; Sudo, Masashi; Kasai, Hirotake; Tanaka, Tomohisa; Fujimoto, Yuusuke; Ikeda, Masanori; Kato, Nobuyuki; Sakamoto, Naoya; Shindo, Hiroko; Maekawa, Shinya; Enomoto, Nobuyuki; Tsubuki, Masayoshi; Moriishi, Kohji

2013-01-01

178

The use of fatty acid esters to enhance free acid sophorolipid synthesis.  

PubMed

Fatty acid esters were prepared by transesterification of soy oil with methanol (methyl-soyate, Me-Soy), ethanol (ethyl-soyate, Et-Soy) and propanol (propyl-soyate, Pro-Soy) and used with glycerol as fermentation substrates to enhance production of free-acid sophorolipids (SLs). Fed-batch fermentations of Candida bombicola resulted in SL yields of 46 +/- 4 g/l, 42 +/- 7 g/l and 18 +/- 6 g/l from Me-Soy, Et-Soy, and Pro-Soy, respectively. Liquid chromatography with atmospheric pressure ionization mass spectrometry (LC/API-MS) showed that Me-Soy resulted in 71% open-chain SLs with 59% of those molecules remaining esterified at the carboxyl end of the fatty acids. Et-Soy and Pro-Soy resulted in 43% and 80% open-chain free-acid SLs, respectively (containing linoleic acid and oleic acid as the principal fatty acid species linked to the sophorose sugar at the omega-1 position), with no evidence of residual esterification. PMID:16555009

Ashby, Richard D; Solaiman, Daniel K Y; Foglia, Thomas A

2006-02-01

179

21 CFR 573.637 - Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic...  

Code of Federal Regulations, 2013 CFR

... Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic acids). 573.637 Section 573.637 Food... Methyl esters of conjugated linoleic acid (cis-9, trans-11 and...

2013-04-01

180

21 CFR 573.637 - Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic...  

Code of Federal Regulations, 2012 CFR

... Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic acids). 573.637 Section 573.637 Food... Methyl esters of conjugated linoleic acid (cis-9, trans-11 and...

2012-04-01

181

21 CFR 573.637 - Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic...  

Code of Federal Regulations, 2010 CFR

... Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic acids). 573.637 Section 573.637 Food... Methyl esters of conjugated linoleic acid (cis-9, trans-11 and...

2010-04-01

182

21 CFR 573.637 - Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic...  

Code of Federal Regulations, 2014 CFR

... Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic acids). 573.637 Section 573.637 Food... Methyl esters of conjugated linoleic acid (cis-9, trans-11 and...

2014-04-01

183

21 CFR 573.637 - Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic...  

Code of Federal Regulations, 2011 CFR

... Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic acids). 573.637 Section 573.637 Food... Methyl esters of conjugated linoleic acid (cis-9, trans-11 and...

2011-04-01

184

Fatty acid methyl ester (FAME) profiles as measures of soil microbial community structure  

Microsoft Academic Search

Analysis of fatty acid methyl ester (FAME) profiles extracted from soils is a rapid and inexpensive procedure that holds great promise in describing soil microbial community structure without traditional reliance on selective culturing, which seems to severely underestimate community diversity. Interpretation of FAME profiles from environmental samples can be difficult because many fatty acids are common to different microorganisms and

Michel A. Cavigelli; G. Philip Robertson; Michael J. Klug

1995-01-01

185

Coriander Seed Oil Methyl Esters as Biodiesel Fuel: Unique Fatty Acid Composition and Excellent Oxidative Stability  

Technology Transfer Automated Retrieval System (TEKTRAN)

Coriander (Coriandrum sativum L.) seed oil methyl esters were prepared and evaluated as an alternative biodiesel fuel and contained an unusual fatty acid (FA) hitherto unreported as the principle component in biodiesel fuels: petroselinic (6Z-octadecenoic; 68.5 wt %) acid. Most of the remaining FA...

186

Inactive Methyl Indole-3-Acetic Acid Ester Can Be Hydrolyzed and Activated by Several Esterases Belonging  

E-print Network

-acetic acid (IAA), also known as auxin, is a plant hormone involved in many aspects of plant growth on the growth of wild-type roots when applied exogenously. However, the roots of Arabidopsis plants carrying TInactive Methyl Indole-3-Acetic Acid Ester Can Be Hydrolyzed and Activated by Several Esterases

Pichersky, Eran

187

Fuel and lubricant additives from acid treated mixtures of vegetable oil derived amides and esters  

SciTech Connect

Vegetable oils such as corn oil, peanut oil, and soy oil are reacted with polyamines to form a mixture containing amides, imides, half esters, and glycerol with subsequent treatment with a strong acid such as sulfonic acid to produce a product mix that has good detergent properties in fuels and lubricants.

Bonazza, B.R.; Devault, A.N.

1981-05-26

188

Amino acids and glycine ethyl ester as new crystallization reagents for lysozyme  

PubMed Central

Several amino acids and their derivatives are prominent additives in the field of protein chemistry. This study reports the use of charged amino acids and glycine ethyl ester as precipitants in protein crystallization, using hen egg-white lysozyme (HEWL) as a model. A discussion of the crystallization of HEWL using these reagents as precipitating agents is given. PMID:20516616

Ito, Len; Shiraki, Kentaro; Yamaguchi, Hiroshi

2010-01-01

189

Partitioning of homologous nicotinic acid ester prodrugs (nicotinates) into dipalmitoylphosphatidylcholine (DPPC) membrane bilayers  

Microsoft Academic Search

The partitioning behavior of a series of perhydrocarbon nicotinic acid esters (nicotinates) between aqueous solution and dipalmitoylphosphatidylcholine (DPPC) membrane bilayers is investigated as a function of increasing alkyl chain length. The hydrocarbon nicotinates represent putative prodrugs, derivatives of the polar drug nicotinic acid, whose functionalization provides the hydrophobic character necessary for pulmonary delivery in a hydrophobic, fluorocarbon solvent, such as

Vivian Ojogun; Sandhya M. Vyas; Hans-Joachim Lehmler; Barbara L. Knutson

2010-01-01

190

Structural analysis and antitussive evaluation of five novel esters of verticinone and bile acids.  

PubMed

Shedan-Chuanbei powder, a complex of traditional Chinese medicine preparation, which consists of Snake Bile (Chinese name "Shedan") and Fritillariae Cirrhosae (Chinese name "Chuanbei"), is the most popular antitussive and expectorant formulation in Chinese communities. However, the clinical application of Shedan-Chuanbei powder is now stringently limited because of the shortage of the two crude medicinal materials, especially for the sake of animal protection. In addition, the inherent defects of the most of the complex of traditional Chinese medicine such as the indistinct basal pharmacodynamic materials and the difficulties in quality control had blocked them heading into the international medicinal market. So we attempted to seek new substitute for Shedan-Chuanbei powder for antitussive drugs. In order to gain some new compounds with better bioactivity and attenuated toxicity, we tried to combine two kinds of drugs through ester bond. Enlightened with "combination principle" in drug discovery, we synthesized five novel esters of verticinone and bile acids, both of which are the major bioactive components in Shedan-Chuanbei powder. We then evaluated the antitussive activity and the acute toxicity of the five ester-linked compounds. The five ester-linked compounds had much more potent antitussive activity and expectorant activity than single bile acids at the same doses, and had equivalent antitussive activity and expectorant activity in comparison with about double moles dose of the monomer verticinone. Especially, cholic acid-verticinone ester had much more potent antitussive effects than the monomer verticinone or cholic acid at the same dose. A further acute toxicity study showed that the LD(50) values of the five ester-linked compounds exceeded 3.5g/kg by intraperitoneal injection in mice. Based on the studies of pharmacology and acute toxicity, the five ester-linked compounds have synergic pharmacodynamic action and attenuated toxicity compared with single verticinone and single bile acids. PMID:19154752

Zhang, Jiu-Liang; Wang, Hui; Pi, Hui-Fang; Ruan, Han-Li; Zhang, Peng; Wu, Ji-Zhou

2009-01-01

191

Kinetics of sulfuric acid leaching of low-grade zinc silicate ore  

Microsoft Academic Search

The results of a leaching kinetics study of low-grade zinc silicate ore with sulfuric acid are presented. Effect of ore particle size, reaction temperature, and acid concentration on zinc dissolution rate were determined. The results obtained show that leaching of about 94% of zinc is achieved using ?200+270 mesh ore particle size at a reaction temperature of 70°C for 180

E. A Abdel-Aal

2000-01-01

192

40 CFR 721.9511 - Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium and europium-doped.  

Code of Federal Regulations, 2011 CFR

... false Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium...9511 Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium...as silicic acid (H6 SiO2 O7 ) magnesium, strontium...

2011-07-01

193

40 CFR 721.9511 - Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium and europium-doped.  

Code of Federal Regulations, 2012 CFR

... false Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium... Silicic acid (H6 SiO2 O7 ), magnesium, strontium salt(1:1:2), dysprosium...as silicic acid (H6 SiO2 O7 ) magnesium, strontium...

2012-07-01

194

40 CFR 721.9511 - Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium and europium-doped.  

Code of Federal Regulations, 2010 CFR

... false Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium...9511 Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium...as silicic acid (H6 SiO2 O7 ) magnesium, strontium...

2010-07-01

195

On the neutralization of acid rock drainage by carbonate and silicate minerals  

NASA Astrophysics Data System (ADS)

The net result of acid-generating and-neutralizing reactions within mining wastes is termed acid rock drainage (ARD). The oxidation of sulfide minerals is the major contributor to acid generation. Dissolution and alteration of various minerals can contribute to the neutralization of acid. Definitions of alkalinity, acidity, and buffer capacity are reviewed, and a detailed discussion of the dissolution and neutralizing capacity of carbonate and silicate minerals related to equilibium conditions, dissolution mechanism, and kinetics is provided. Factors that determine neutralization rate by carbonate and silicate minerals include: pH, PCO 2, equilibrium conditions, temperature, mineral composition and structure, redox conditions, and the presence of “foreign” ions. Similar factors affect sulfide oxidation. Comparison of rates shows sulfides react fastest, followed by carbonates and silicates. The differences in the reaction mechanisms and kinetics of neutralization have important implications in the prediction, control, and regulation of ARD. Current static and kinetic prediction methods upon which mine permitting, ARD control, and mine closure plans are based do not consider sample mineralogy or the kinetics of the acid-generating and-neutralizing reactions. Erroneous test interpretations and predictions can result. The importance of considering mineralogy for site-specific interpretation is highlighted. Uncertainty in prediction leads to difficulties for the mine operator in developing satisfactory and cost-effective control and remediation measures. Thus, the application of regulations and guidelines for waste management planning need to beflexible.

Sherlock, E. J.; Lawrence, R. W.; Poulin, R.

1995-02-01

196

Alternative fuel properties of tall oil fatty acid methyl ester-diesel fuel blends.  

PubMed

In this experimental work, tall oil methyl ester-diesel fuel blends as alternative fuels for diesel engines were studied. Tall oil methyl ester was produced by reacting tall oil fatty acids with methyl alcohol under optimum conditions. The blends of tall oil methyl ester-diesel fuel were tested in a direct injection diesel engine at full load condition. The effects of the new fuel blends on the engine performance and exhaust emission were tested. It was observed that the engine torque and power output with tall oil methyl ester-diesel fuel blends increased up to 6.1% and 5.9%, respectively. It was also seen that CO emissions decreased to 38.9% and NO(x) emissions increased up to 30% with the new fuel blends. The smoke opacity did not vary significantly. PMID:16524723

Altiparmak, Duran; Keskin, Ali; Koca, Atilla; Gürü, Metin

2007-01-01

197

Comparison of phospholipid fatty acid (PLFA) and total soil fatty acid methyl esters (TSFAME) for characterizing soil microbial communities  

Microsoft Academic Search

Phospholipid fatty acid (PLFA) and total soil fatty acid methyl esters (TSFAME), both lipid-based approaches used to characterize microbial communities, were compared with respect to their reliable detection limits, extraction precision, and ability to differentiate agricultural soils. Two sets of soil samples, representing seven crop types from California's Central Valley, were extracted using PLFA and TSFAME procedures. PLFA analysis required

Rebecca E. Drenovsky; Geoff N. Elliott; Kenneth J. Graham; Kate M. Scow

2004-01-01

198

Characterization of modified calcium-silicate cements exposed to acidic environment  

SciTech Connect

Portland cement which is used as a binder in concrete in the construction industry has been developed into a biomaterial. It is marketed as mineral trioxide aggregate and is used in dentistry. This material has been reported to be very biocompatible and thus its use has diversified. The extended use of this material has led to developments of newer versions with improved physical properties. The aim of this study was to evaluate the effect of acidic environments found in the oral cavity on fast setting calcium silicate cements with improved physical properties using a combination of techniques. Two fast setting calcium silicate cements (CSA and CFA) and two cement composites (CSAG and CFAG) were assessed by subjecting the materials to lactic acid/sodium lactate buffer gel for a period of 28 days. At weekly intervals the materials were viewed under the tandem scanning confocal microscope (TSM), and scanning electron microscope (SEM). The two prototype cements exhibited changes in their internal chemistry with no changes in surface characteristics. Since the changes observed were mostly sub-surface evaluation of surface characteristics of cement may not be sufficient in the determination of chemical changes occurring. - Research Highlights: {yields} An acidic environment affects modified fast setting calcium silicate-based cements. {yields} No surface changes are observed in acidic environment. {yields} An acidic environment causes sub-surface changes in the material chemistry which are only visible in fractured specimens. {yields} A combination of techniques is necessary in order to evaluate the chemical changes occurring.

Camilleri, Josette, E-mail: josette.camilleri@um.edu.mt

2011-01-15

199

Conjugated linoleic acid modulation of phorbol ester-induced events in murine keratinocytes  

Microsoft Academic Search

Recent work in our lab has shown that the chemoprotective fatty acid, conjugated linoleic acid (CLA), inhibits phorbol ester\\u000a skin tumor promotion in mice. Because little is known about the deposition of CLA into tissues as well as its biological activity,\\u000a this study compared the incorporation and biological activity of CLA to linoleic acid (LA; 18:2, c9, c12) and arachidonic

Kai-Li Liu; Martha A. Belury

1997-01-01

200

Coriander seed oil methyl esters as biodiesel fuel: Unique fatty acid composition and excellent oxidative stability  

Microsoft Academic Search

Coriander (Coriandrum sativum L.) seed oil methyl esters were prepared and evaluated as an alternative biodiesel fuel and contained an unusual fatty acid hitherto unreported as the principle component in biodiesel fuels: petroselinic (6Z-octadecenoic; 68.5wt%) acid. Most of the remaining fatty acid profile consisted of common 18 carbon constituents such as linoleic (9Z,12Z-octadeca-dienoic; 13.0wt%), oleic (9Z-octadecenoic; 7.6wt%) and stearic (octadecanoic;

Bryan R. Moser; Steven F. Vaughn

2010-01-01

201

Separation of fatty acid methyl esters from tall oil by selective adsorption  

Microsoft Academic Search

Fatty acid methyl esters (FAME) and resin acids (RA) were separated from tall oil by selective adsorption. Commercial nonmodified\\u000a molecular sieve 13X was used as adsorbent. The adsorption isotherms of fatty acids (FA), FAME, and RA on molecular sieve 13X\\u000a at 25°C were determined using various solvents. The solvents were methanol, ethanol, isopropanol, acetone, benzene, hexane,\\u000a isooctane, petroleum ether (40–60°C),

Güldem Üstün

1996-01-01

202

Molecular Basis of Prodrug Activation by Human Valacyclovirase, an [alpha]-Amino Acid Ester Hydrolase  

SciTech Connect

Chemical modification to improve biopharmaceutical properties, especially oral absorption and bioavailability, is a common strategy employed by pharmaceutical chemists. The approach often employs a simple structural modification and utilizes ubiquitous endogenous esterases as activation enzymes, although such enzymes are often unidentified. This report describes the crystal structure and specificity of a novel activating enzyme for valacyclovir and valganciclovir. Our structural insights show that human valacyclovirase has a unique binding mode and specificity for amino acid esters. Biochemical data demonstrate that the enzyme hydrolyzes esters of {alpha}-amino acids exclusively and displays a broad specificity spectrum for the aminoacyl moiety similar to tricorn-interacting aminopeptidase F1. Crystal structures of the enzyme, two mechanistic mutants, and a complex with a product analogue, when combined with biochemical analysis, reveal the key determinants for substrate recognition; that is, a flexible and mostly hydrophobic acyl pocket, a localized negative electrostatic potential, a large open leaving group-accommodating groove, and a pivotal acidic residue, Asp-123, after the nucleophile Ser-122. This is the first time that a residue immediately after the nucleophile has been found to have its side chain directed into the substrate binding pocket and play an essential role in substrate discrimination in serine hydrolases. These results as well as a phylogenetic analysis establish that the enzyme functions as a specific {alpha}-amino acid ester hydrolase. Valacyclovirase is a valuable target for amino acid ester prodrug-based oral drug delivery enhancement strategies.

Lai, Longsheng; Xu, Zhaohui; Zhou, Jiahai; Lee, Kyung-Dall; Amidon, Gordon L. (Michigan)

2008-07-08

203

Molecular Basis of Prodrug Activation by Human Valacyclovirase, an ?-Amino Acid Ester Hydrolase*S?  

PubMed Central

Chemical modification to improve biopharmaceutical properties, especially oral absorption and bioavailability, is a common strategy employed by pharmaceutical chemists. The approach often employs a simple structural modification and utilizes ubiquitous endogenous esterases as activation enzymes, although such enzymes are often unidentified. This report describes the crystal structure and specificity of a novel activating enzyme for valacyclovir and valganciclovir. Our structural insights show that human valacyclovirase has a unique binding mode and specificity for amino acid esters. Biochemical data demonstrate that the enzyme hydrolyzes esters of ?-amino acids exclusively and displays a broad specificity spectrum for the aminoacyl moiety similar to tricorn-interacting aminopeptidase F1. Crystal structures of the enzyme, two mechanistic mutants, and a complex with a product analogue, when combined with biochemical analysis, reveal the key determinants for substrate recognition; that is, a flexible and mostly hydrophobic acyl pocket, a localized negative electrostatic potential, a large open leaving group-accommodating groove, and a pivotal acidic residue, Asp-123, after the nucleophile Ser-122. This is the first time that a residue immediately after the nucleophile has been found to have its side chain directed into the substrate binding pocket and play an essential role in substrate discrimination in serine hydrolases. These results as well as a phylogenetic analysis establish that the enzyme functions as a specific ?-amino acid ester hydrolase. Valacyclovirase is a valuable target for amino acid ester prodrug-based oral drug delivery enhancement strategies. PMID:18256025

Lai, Longsheng; Xu, Zhaohui; Zhou, Jiahai; Lee, Kyung-Dall; Amidon, Gordon L.

2008-01-01

204

Process for the generation of .alpha., .beta.-unsaturated carboxylic acids and esters using niobium catalyst  

DOEpatents

A process using a niobium catalyst includes the step of reacting an ester or carboxylic acid with oxygen and an alcohol in the presence a niobium catalyst to respectively produce an .alpha.,.beta.-unsaturated ester or carboxylic acid. Methanol may be used as the alcohol, and the ester or carboxylic acid may be passed over the niobium catalyst in a vapor stream containing oxygen and methanol. Alternatively, the process using a niobium catalyst may involve the step of reacting an ester and oxygen in the presence the niobium catalyst to produce an .alpha.,.beta.-unsaturated carboxylic acid. In this case the ester may be a methyl ester. In either case, niobium oxide may be used as the niobium catalyst with the niobium oxide being present on a support. The support may be an oxide selected from the group consisting of silicon oxide, aluminum oxide, titanium oxide and mixtures thereof. The catalyst may be formed by reacting niobium fluoride with the oxide serving as the support. The niobium catalyst may contain elemental niobium within the range of 1 wt % to 70 wt %, and more preferably within the range of 10 wt % to 30 wt %. The process may be operated at a temperature from 150 to 450.degree. C. and preferably from 250 to 350.degree. C. The process may be operated at a pressure from 0.1 to 15 atm. absolute and preferably from 0.5-5 atm. absolute. The flow rate of reactants may be from 10 to 10,000 L/kg.sub.(cat) /h, and preferably from 100 to 1,000 L/kg.sub.(cat) /h.

Gogate, Makarand Ratnakav (Durham, NC); Spivey, James Jerome (Cary, NC); Zoeller, Joseph Robert (Kingsport, TN)

1999-01-01

205

Synthesis and evaluation of odour-active methionyl esters of fatty acids via esterification and transesterification of butter oil.  

PubMed

Methionol-derived fatty acid esters were synthesised by both chemical and lipase catalysed esterification between fatty acids and methionol. Beneficial effects of both methods were compared qualitatively and quantitatively by GC-MS/GC-FID results. And the high acid and heat stability of our designed methionyl esters meet the requirement of the food industry. Most importantly, the sensory test showed that fatty acid carbon-chain length had an important effect on the flavour attributes of methionyl esters. Moreover, through Lipozyme TL IM-mediated transesterification, valuable methionol-derived esters were synthesised from the readily available natural material butter oil as the fatty acid source. The conversion of methionol and yield of each methionyl ester were also elucidated by GC-MS-FID. PMID:24128547

Li, Cheng; Sun, Jingcan; Fu, Caili; Yu, Bin; Liu, Shao Quan; Li, Tianhu; Huang, Dejian

2014-02-15

206

Beyond fatty acid methyl esters: Expanding the renewable carbon profile with alkenones from Isochrysis sp.  

Technology Transfer Automated Retrieval System (TEKTRAN)

In addition to characteristic fatty acid methyl esters (FAMEs), biodiesel produced from Isochrysis sp. contains a significant amount (14% dry weight) of predominantly C37 and C38 longchain alkenones. These compounds are members of a class of lipids known collectively as polyunsaturated long-chain al...

207

Novel sustained-release dosage forms of proteins using polyglycerol esters of fatty acids  

Microsoft Academic Search

In order to develop a novel delivery system for proteins based on polyglycerol esters of fatty acids (PGEFs), we studied a model system using interferon-? (IFN-?) as the test protein. A cylindrical matrix was prepared by a heat extrusion technique using a lyophilized powder of the protein and 11 different types of synthetic PGEFs, which varied in degree of glycerol

Yutaka Yamagata; Katsumi Iga; Yasuaki Ogawa

2000-01-01

208

Supercritical hydrogenolysis of fatty acid methyl esters: Phase equilibrium measurements on selected binary and ternary systems  

Microsoft Academic Search

Fatty alcohols (FOH) are industrially obtained by heterogeneous catalytic hydrogenolysis of fatty acid methyl esters (FAME). Reaction rates are strongly dependent on hydrogen concentration at the catalyst surface, which is limited by the low solubility of hydrogen and high mass-transport resistance of the liquid substrate. The addition of a supercritical solvent can bring the reactive mixture into a single phase,

L. J. Rovetto; S. B. Bottini; E. A. Brignole; C. J. Peters

2005-01-01

209

Contamination of vegetable oils marketed in Italy by phthalic acid esters  

Microsoft Academic Search

More than 90% of the phthalic acid esters (PAEs) produced in Europe is used to plasticize polyvinyl chloride (PVC). Animal studies have shown that some PAEs can damage the liver and interfere with the endocrine system, whereas data on the toxic effects on humans are inconsistent. For the general population, the diet is believed to be the main source of

Natalia Nanni; Katell Fiselier; Koni Grob; Mauro Di Pasquale; Laura Fabrizi; Paolo Aureli; Ettore Coni

2011-01-01

210

SEPARATION OF T-MAZ ETHOXYLATED SORBITAN FATTY ACID ESTERS BY SUPERCRITICAL FLUID CHROMATOGRAPHY  

EPA Science Inventory

The application of supercritical fluid chromatography (SFC) to the analysis of T-MAZ ethoxylated sorbitan fatty acid esters is described. FC separation methods utilize a density programming technique and a 50 um I.D. capillary column. his work demonstrates that capillary column S...

211

Performance and Emission Analysis of Diesel engine using of Single Composition Fatty Acid Methyl Esters  

Microsoft Academic Search

Biodiesel is also called as Fatty acid Methyl ester. It is an alternative fuel for diesel engines that can be manufactured from vegetable oils, animal fats and used cooking oils. It offers many advantages such as it is renewable, energy efficient, nontoxic, sulfur free and biodegradable, and also it usually takes cleaner combustion and reduces global warming gas emissions from

T. Hari; K. Hema Chandra Reddy; M. Muralidhara Rao

212

SEPARATION OF T-MAZ ETHOXYLATED SORBITAN FATTY ACID ESTERS BY REVERSE PHASE CHROMATOGRAPHY  

EPA Science Inventory

The method for determination of T-MAZ ethoxylated sorbitan fatty acid esters is described. This work demonstrates that with a less retentive C8 alkyl bonded phase packing, reverse phase chromatography can be used to analyze nonionic polymer mixtures with a molecular weight range ...

213

Esterification and transesterification of greases to fatty acid methyl esters with highly active diphanylammonium salts  

Technology Transfer Automated Retrieval System (TEKTRAN)

We have conducted an investigation designed to identify alternate catalysts for the production of fatty acid methyl esters (FAME) to be used as biodiesel. Diphenylammonium sulfate (DPAS) and diphenylammonium chloride (DPA-HCl) salts were found to be highly active homogeneous catalysts for the simu...

214

Antithyroid effect of a food or drug preservative: 4-hydroxybenzoic acid methyl ester  

Microsoft Academic Search

Summary 4-hydroxybenzoic acid methyl ester (methylparaben) inhibits organification of iodide by isolated hog thyroid cells. The concentration which produces a 50% inhibition was about 2.0×10?4M. A similar inhibition was observed in nonstimulated and TSH- or dibutyryl cyclic AMP-stimulated cells. Neither iodide uptake nor cyclic AMP generation were altered by methylparaben.

B. Rousset

1981-01-01

215

Esterification and Transesterification of greases to fatty acid methyl esters with highly active diphenylamine salts  

Technology Transfer Automated Retrieval System (TEKTRAN)

Diphenylamine sulfate (DPAS) and diphenylamine hydrochloride (DPACl) salts were found to be highly active catalysts for esterification and transesterification of inexpensive greases to fatty acid methyl esters (FAME). In the presence of catalytic amounts of DPAS or DPACl and excess methanol, the fr...

216

Identification of foodborne bacteria by infrared spectroscopy using cellular fatty acid methyl esters  

Microsoft Academic Search

Identification of bacterial species by profiling fatty acid methyl esters (FAMEs) has commonly been carried out by using a 20-min capillary gas chromatographic procedure followed by library matching of FAME profiles using commercial MIDI databases and proprietary pattern recognition software. Fast GC (5 min) FAME procedures and mass spectrometric methodologies that require no lipid separation have also been reported. In

P Whittaker; M. M Mossoba; S Al-Khaldi; F. S Fry; V. C Dunkel; B. D Tall; M. P Yurawecz

2003-01-01

217

ESTIMATION OF PHOSPHATE ESTER HYDROLYSIS RATE CONSTANTS. II. ACID AND GENERAL BASE CATALYZED HYDROLYSIS  

EPA Science Inventory

SPARC (SPARC Performs Automated Reasoning in Chemistry) chemical reactivity models were extended to calculate acid and neutral hydrolysis rate constants of phosphate esters in water. The rate is calculated from the energy difference between the initial and transition states of a ...

218

Catalytic synthesis of fatty acid methyl esters from extremely low quality greases  

Technology Transfer Automated Retrieval System (TEKTRAN)

Biodiesel (BD) is a renewable fuel for compression ignition engines that is composed of the simple alkyl esters, usually methyl-, of fatty acids (FAME). It is typically produced via base-catalyzed transesterification between refined vegetable oil or animal fat (e.g., soybean oil, tallow) and an alc...

219

Synthesis and biological evaluation of caffeic acid 3,4-dihydroxyphenethyl ester.  

PubMed

A high-yield synthesis of caffeic acid 3,4-dihydroxyphenethyl ester (1) has been achieved through Knoevenagel condensation of 3,4-dihydroxybenzaldehyde and 3,4-dihydroxyphenethyl monomalonate as the key step. Compound 1 was tested against a 56-cell-line cytotoxicity panel and for its free-radical-scavenging activity in the DPPH test. PMID:20092326

Zhang, Zhizhen; Xiao, Binghua; Chen, Qi; Lian, Xiao-Yuan

2010-02-26

220

Synthesis and bioactivity of novel caffeic acid esters from Zuccagnia punctata.  

PubMed

Synthesis of novel caffeic acid esters (1 and 2) was accomplished starting from appropriately substituted benzaldehydes (3 and 9). While compound 2 exhibited potent anti-oxidative activity in both the nitroblue tetrazolium and 1,1-diphenyl-2-picrylhydrazyl radical-scavenging models, compound 1 showed moderate 5-lipoxygenase inhibitory activity. PMID:17145655

Ramachandra, M S; Subbaraju, G V

2006-12-01

221

A quantitation problem in the open tubular gas chromatography of fatty acid esters from cod liver lipids  

Microsoft Academic Search

Methyl esters of fatty acids of marine origin contain large amounts of highly unsaturated long-chain fatty acids. It is shown\\u000a that, although esters of saturated and monounsaturated fatty acids can be quantitatively analyzed on open tubular columns\\u000a with a flame ionization detector there are serious losses of the long-chain highly unsaturated fatty acids of marine oils\\u000a on the column. Through

R. G. Ackman; J. C. Sipos; P. M. Jangaard

1967-01-01

222

Desorption of arsenic from clay and humic acid-coated clay by dissolved phosphate and silicate  

NASA Astrophysics Data System (ADS)

Arsenic (As) contaminated aquifers contain iron minerals and clays that strongly bind As at their surfaces. It was suggested that As mobilization is driven by natural organic matter (including fulvic acids (FA) and humic acids (HA)) present in the aquifers either via providing reducing equivalents for reductive dissolution of Fe(III) (hydr)oxides or via competitive desorption of As from the mineral surfaces. In the present study we quantified sorption of As(III) and As(V) to Ca 2+-homoionized illite (IL) and to kaolinite (Kao) as well as to HA-coated clays, i.e., illite-HA (IL-HA) and kaolinite-HA (Kao-HA) at neutral pH. Clay-HA complexes sorbed 28-50% more As than clay-only systems upon addition of 100 ?M As(III)/As(V) to 0.5 g of clay or HA-clay with Ca 2+ probably playing an important role for HA binding to the clay surface and As binding to the HA. When comparing sorption of As(V) and As(III) to clay and HA-clay complexes, As(V) sorption was generally higher by 15-32% than sorption of As(III) to the same complexes. IL and IL-HA sorbed 11-28% and 6-11% more As compared to Kao and Kao-HA, respectively. In a second step, we then followed desorption of As from Kao, Kao-HA, IL and IL-HA by 100 and 500 ?M phosphate or silicate both at high (0.41-0.77 ?mol As/g clay), and low (0.04 to 0.05 ?mol As/g clay) As loadings. Phosphate desorbed As to a larger extent than silicate regardless of the amount of As loaded to clay minerals, both in the presence and absence of HA, and both for illite and kaolinite. At high loadings of As, the desorption of both redox species of As from clay-HA complexes by phosphate/silicate ranged from 32 to 72% compared to 2-54% in clay only systems meaning that As was desorbed to a larger extent from HA-coated clays compared to clay only systems. When comparing As(III) desorption by phosphate/silicate to As(V) desorption in high As-loading systems, there was no clear trend for which As species is desorbed to a higher extent in the four clay systems meaning that both As species behave similarly regarding desorption from clay surfaces by phosphate/silicate. Similarly, no significant differences were found in high As-loading systems in the amount of As desorbed by phosphate/silicate when comparing Kao vs. IL and Kao-HA vs IL-HA systems meaning that both clay types behave similarly regarding desorption of As by phosphate/silicate. At low As loadings, up to 80% of As was desorbed by phosphate and silicate with no noticeable differences being observed between different As species, different types of clay, clay vs clay-HA or the type of desorbant (phosphate and silicate). The results of this study showed that HA sorption to Ca 2+-homoionized clay minerals can increase As binding to the clay although the As sorbed to the clay-HA is also released to a greater extent by competing ions such as phosphate and silicate. Desorption of As depended on the initial loadings of As onto the clay/clay-HA. Based on our results, the effect of humic substances on sorption of As and on desorption of As by phosphate and silicate has to be considered in order to fully understand and evaluate the environmental behavior of As in natural environments.

Sharma, Prasesh; Kappler, Andreas

2011-11-01

223

Novel sustained-release dosage forms of proteins using polyglycerol esters of fatty acids.  

PubMed

In order to develop a novel delivery system for proteins based on polyglycerol esters of fatty acids (PGEFs), we studied a model system using interferon-alpha (IFN-alpha) as the test protein. A cylindrical matrix was prepared by a heat extrusion technique using a lyophilized powder of the protein and 11 different types of synthetic PGEFs, which varied in degree of glycerol polymerization (di- and tetra-), chain length of fatty acids (myristate, palmitate and stearate) and degree of fatty acid esterification (mono-, di- and tri-). In an in-vitro release study using an enzyme-linked immunosorbent assay (ELISA) as a detection method, the matrices prepared from a monoglyceride (used for comparison) and from diglycerol esters exhibited a biphasic release pattern with a large initial burst followed by slow release. In contrast, the matrices prepared from tetraglycerol esters showed a steady rate of release without a large initial burst. In an in vivo release study, initial bursts of IFN-alpha release were, also, dramatically reduced when the matrices were prepared from the tetraglycerol esters of palmitate and stearate, and the mean residence time (MRT) of IFN-alpha was prolonged, whereas the matrices prepared from monoglyceride and from diglycerol esters showed large initial bursts of IFN-alpha release. Since the release rates from the matrices prepared from the tetraglycerol esters of palmitate and stearate were governed by Jander's equation modified for a cylindrical matrix, the release from those matrices was concluded to be a diffusion-controlled process. The bioavailability of IFN-alpha after implantation of the matrix formulation prepared using all types of PGEFs, except for tetraglycerol triesters, was almost equivalent to that after injection of IFN-alpha solution; consequently, IFN-alpha in these matrices appears to remain stable during the release period. PMID:10601727

Yamagata, Y; Iga, K; Ogawa, Y

2000-02-01

224

SYNTHESIS AND STRUCTURE OF THE COMPLEXES OF ESTERS OF SOME PHOSPHONIC ACIDS AND AMIDES WITH MOLYBDENUM DIOXODICHLORIDE  

Microsoft Academic Search

The complexes L?MoO2Cl2 (2), L?·MoO2Cl2 (4), L??·MoO2Cl2 (6) and L????MoO2Cl2 (8) were obtained by the reaction of MoO2Cl2 and the ligands: L=diethyl ester of 2-dimethylamino-2-oxoethylphosphonic acid (1), L?=diethyl ester of 2-amino-2-oxoethylphosphonic acid (3), L??=tetraethyl ester of methylenediphosphonic acid (5) and L???=tetraethylester of ethylenediphosphonic acid (7). They were characterized by elemental analyses, IR and NMR spectroscopy. The crystal structure of the

E. T. K. Haupt; J. Kopf; J. Petrova; S. Momchilova

2002-01-01

225

40 CFR 721.2140 - Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt.  

Code of Federal Regulations, 2010 CFR

...azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. 721.2140 Section 721.2140 Protection...azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. (a) Chemical substance and significant...azo-al-kyl-a-mino-al-kyl-car-bo-mon-o-cyc-lic ester, halogen acid salt (PMN P-88-1682) is subject to...

2010-07-01

226

40 CFR 721.2140 - Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt.  

Code of Federal Regulations, 2014 CFR

...azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. 721.2140 Section 721.2140 Protection...azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. (a) Chemical substance and significant...azo-al-kyl-a-mino-al-kyl-car-bo-mon-o-cyc-lic ester, halogen acid salt (PMN P-88-1682) is subject to...

2014-07-01

227

Antioxidant activity of brocchlin carboxylic acid and its methyl ester from Chrozophora brocchiana.  

PubMed

The analogue of brevifolin carboxylic acid and its methyl ester were isolated and identified from the aqueous ethanolic extract of the leaves of Chrzophora brocchiana in addition to eight known compounds identified as gallic acid, methyl and ethyl gallate, ellagic acid, monomethoxy and methylenedioxy ellagic acid, apigenin 7-O-glucoside and luteolin 7-O-glucoside. The structures were determined primarily by ESI-MS and NMR spectroscopy. The assignment of NMR signals was preformed by means of 1H-H COSY, HMQC and HMBC experiments. The antioxidant activity of the new compounds was determined by checking the scavenging activity against DPPH free radical. PMID:17613821

Hawas, Usama W

2007-06-01

228

Effects of metadoxine on cellular formation of fatty acid ethyl esters in ethanol treated rats.  

PubMed

Free fatty acids (FFA) and fatty acid ethyl esters (FAEE) were extracted from different organs of rats administered ethanol, which was found to have induced FAEE formation, which reached its highest levels in the heart, followed by kidney, brain and liver; the ethanol administration resulted also in a marked increase of total FFA content, particularly in brain, kidney, heart and liver. Pretreatment of animals with Metadoxine one hour before ethanol administration inhibited significantly both FAEE and FFA accumulation in all organs examined. These effects were concomitant with the decreased levels of ethanol in blood found in alcohol-intoxicated rats pretreated with Metadoxine. Our results point to the role of fatty acid ethyl esters as possible mediators in the production of alcohol-dependent syndromes, especially in organs lacking oxidative pathways. Administration of Metadoxine, through an increment in alcohol metabolism and turnover, greatly reduces this metabolic abnormality, warranting its potential usefulness as a pharmacological tool in alcoholism management. PMID:8867649

Calabrese, V; Calderone, A; Ragusa, N; Rizza, V

1995-01-01

229

Water chemical ionization mass spectrometry of aldehydes, ketones esters, and carboxylic acids  

SciTech Connect

Chemical ionization mass spectrometry (CI) of aliphatic and aromatic carbonyl compounds using water as the reagent gas provides intense pseudomolecular ions and class-specific fragmentation patterns that can be used to identify aliphatic aldehydes, ketones, carboxylic acids, and esters. The length of ester acyl and alkyl groups can easily be determined on the basis of loss of alcohols from the protonated parent. Water CI provides for an approximately 200:1 selectivity of carbonyl species over alkanes. No reagent ions are detected above 55 amu, allowing species as small as acetone, propanal, acetic acid, and methyl formate to be identified. When deuterate water was used as the reagent, only the carboxylic acids and ..beta..-diketones showed significant H/D exchange. The use of water CI to identify carbonyl compounds in a wastewater from the supercritical water extraction of lignite coal, in lemon oil, and in whiskey volatiles is discussed.

Hawthorne, S.B.; Miller, D.J.

1986-11-01

230

Carotenoids and their fatty acid esters of spiny lobster Panulirus japonicus.  

PubMed

Carotenoids and their fatty acid esters in the carapace of the spiny lobster Panulirus japonicus were investigated. Fatty acid esters of astaxanthin, adonixanthin, and pectenolone were characterized by (1)H-NMR and FAB-MS. The acylated position of adonixanthin and pectenolone monoesters was determined to be a hydroxy group at C-3' by (1)H-NMR. The fatty acids esterified with these carotenoids were identified as C22:6, C20:4, C20:5, C18:0, C18:1, C17:0, C16:0, C16:1, C14:0, and C12:0 from FAB-MS spectral data. Furthermore, 2,3-didehydrocanthaxanthin (4) was first identified as a natural product. PMID:18270463

Maoka, Takashi; Akimoto, Naoshige

2008-01-01

231

Caffeic acid phenethyl ester (CAPE): synthesis and X-ray crystallographic analysis.  

PubMed

The structure of caffeic acid phenethyl ester [2-propenoic acid, 3-(3,4-dihydroxyphenyl)-, 2-phenethyl ester] (I), C17H16O4 x 1/2C6H6, synthesized by base-catalyzed alkylation of caffeic acid salt with beta-bromoethylbenzene in HMPA (hexamethylphosphoramide) and recrystallized from benzene, was confirmed by single crystal X-ray diffraction. The crystals are triclinic, space group P1, Z=2, unit cell dimension a=5.8129 (9) A, b=11.122 (2) A, c=13.226 (2) A, alpha=97.080 (3) degrees, beta=101.467 (3) degrees, gamma=95.405 (3) degrees , V=825.4 (2) A3, Dcalc=1.301 g/cm3, F(000)=342. The packing of the molecule is stabilized by intermolecular O1H...O4 (2.69 A) and O1...HO2 (2.82 A) hydrogen bonds. PMID:11217116

Son, S; Lobkowsky, E B; Lewis, B A

2001-02-01

232

Comparison of infrared spectrophotometric and lead salt-alcohol methods for determination of trans octadecenoic acids and esters  

Microsoft Academic Search

Summary  The scope and limitations of the lead salt-alcohol method (11, 19) have been defined as a result of observations in the authors'\\u000a laboratories and in others. Trans octadecenoic acids and esters are not determined specifically by this method, and when large\\u000a amounts of cis acids or esters are present, they are also isolated with the solid acid fraction.\\u000a \\u000a The infrared

Daniel Swern; H. B. Knight; O. D. Shreve; M. R. Heether

1950-01-01

233

21 CFR 172.854 - Polyglycerol esters of fatty acids.  

Code of Federal Regulations, 2011 CFR

...prescribed conditions: (a) They are prepared from corn oil, cottonseed oil, lard, palm oil from fruit, peanut oil, safflower oil, sesame oil, soybean oil, and tallow and the fatty acids derived from these substances (hydrogenated and...

2011-04-01

234

21 CFR 172.854 - Polyglycerol esters of fatty acids.  

Code of Federal Regulations, 2012 CFR

...prescribed conditions: (a) They are prepared from corn oil, cottonseed oil, lard, palm oil from fruit, peanut oil, safflower oil, sesame oil, soybean oil, and tallow and the fatty acids derived from these substances (hydrogenated and...

2012-04-01

235

21 CFR 172.854 - Polyglycerol esters of fatty acids.  

Code of Federal Regulations, 2013 CFR

...prescribed conditions: (a) They are prepared from corn oil, cottonseed oil, lard, palm oil from fruit, peanut oil, safflower oil, sesame oil, soybean oil, and tallow and the fatty acids derived from these substances (hydrogenated and...

2013-04-01

236

21 CFR 172.854 - Polyglycerol esters of fatty acids.  

Code of Federal Regulations, 2010 CFR

...prescribed conditions: (a) They are prepared from corn oil, cottonseed oil, lard, palm oil from fruit, peanut oil, safflower oil, sesame oil, soybean oil, and tallow and the fatty acids derived from these substances (hydrogenated and...

2010-04-01

237

21 CFR 172.854 - Polyglycerol esters of fatty acids.  

Code of Federal Regulations, 2014 CFR

...prescribed conditions: (a) They are prepared from corn oil, cottonseed oil, lard, palm oil from fruit, peanut oil, safflower oil, sesame oil, soybean oil, and tallow and the fatty acids derived from these substances (hydrogenated and...

2014-04-01

238

Enzymatic esterification of tapioca maltodextrin fatty acid ester.  

PubMed

In this work new types of hydrophobically modified maltodextrin were prepared by enzyme-catalyzed reaction of maltodextrin and three fatty acids: decanoic acid (C-10), lauric acid (C-12) and palmitic acid (C-16). Lipase obtained from Thermomyces lanuginosus was found to be a useful biocatalyst in the maltodextrin esterification. Esterified maltodextrin with a degree of substitution (DS) 0.015-0.084 was prepared at the optimum conditions of 60 °C for 4 h. The DS was found to be at its highest when maltodextrin and fatty acids were taken in the ratio 1:0.5. The functional properties of these esterified maltodextrin were investigated. All esterified maltodextrin did not completely dissolve in water. Esterified maltodextrin at a concentration of 25% (w/w) exhibited Newtonian flow behavior similar to that of native maltodextrin. Esterified maltodextrin had a higher viscosity compare to native maltodextrin. X-ray diffraction pattern of esterified maltodextrin indicated crystallization of the fatty acid side chains. The thermal stability of esterified maltodextrin was checked by differential scanning calorimetry (DSC). Esterified maltodextrin was then used as an emulsifier to make n-hexadecane O/W emulsions. The emulsions were characterized according to their oil droplet characteristics and emulsification index. PMID:24274521

Udomrati, Sunsanee; Gohtani, Shoichi

2014-01-01

239

Utilization of crude karanj (Pongamia pinnata) oil as a potential feedstock for the synthesis of fatty acid methyl esters.  

PubMed

Methyl esters were synthesized from crude karanj oil (CKO) by single step esterification with methanol using sulfuric acid (H(2)SO(4)) and phosphoric acid (H(3)PO(4)) as catalysts in a homogeneous batch process. H(3)PO(4) was less active than H(2)SO(4) during the process as it presented very low ester yields (<20%) for the various molar ratios of fatty acid to alcohol studied. With H(2)SO(4) as catalyst, the yield was as high as 89.8% at 65°C after 5h. The fatty acids profile of the oil (palmitic acid: ? 12%; stearic acid: ? 8%; oleic acid: ? 52% and linolenic acid of 17%) and the different reactivities of the acids were responsible for the observed differences in conversion to methyl esters. The findings attained with this study might contribute to the economic utilization of a non-edible feedstock. PMID:22405756

Khayoon, M S; Olutoye, M A; Hameed, B H

2012-05-01

240

Synthesis and antiradical/antioxidant activities of caffeic acid phenethyl ester and its related propionic, acetic, and benzoic acid analogues.  

PubMed

Caffeic acid phenethyl ester (CAPE) is a bioactive component isolated from propolis. A series of CAPE analogues was synthesized and their antiradical/antioxidant effects analyzed. The effect of the presence of the double bond and of the conjugated system on the antioxidant effect is evaluated with the analogues obtained from 3-(3,4-dihydroxyphenyl) propanoic acid. Those obtained from 2-(3,4-dihydroxyphenyl) acetic acid and 3,4-dihydroxybenzoic acid allow the evaluation of the effect of the presence of two carbons between the carbonyl and aromatic system. PMID:23222926

LeBlanc, Luc M; Paré, Aurélie F; Jean-François, Jacques; Hébert, Martin J G; Surette, Marc E; Touaibia, Mohamed

2012-01-01

241

n-Hexyl laurate and fourteen related fatty acid esters: new secretory compounds from the julid millipede, Anaulaciulus sp.  

PubMed

A total of fifteen saturated fatty acid esters were newly identified from the secretions of an unidentified Anaulaciulus sp. (Julida: Julidae). The fatty acid components of the esters were composed of normal chain acids (from C(10) to C(14)) and of branched chain acids (from iso-C(12) to iso-C(15) and anteiso-C(15)). The alcohol moieties were all composed of normal chain alcohols varying from n-butanol to n-octanol. The most abundant component found in the total esters was n-hexyl laurate (64.7%). Novel compounds identified from the millipede secretion extracts include six branched iso- and anteiso-fatty esters, an odd-numbered C(11)-fatty acid ester, a C(13)-fatty acid ester, and a C(7)-alcohol ester, all of which were previously undescribed natural products. In addition, a characteristic mixture of benzoquinones, such as 2-methyl-1,4-benzoquinone, 2-methoxy-3-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, 2-methoxy-6-methyl-1,4-benzoquinone, and 2,3-dimethoxy-5-methyl-1,4-benzoquinone were identified from the secretions, together with trace amounts of 1,4-benzoquinone. PMID:22252536

Shimizu, Nobuhiro; Kuwahara, Yasumasa; Yakumaru, Ryota; Tanabe, Tsutomu

2012-01-01

242

Alcohol to Ester 21 ALCOHOL TO ESTER  

E-print Network

Alcohol to Ester 21 ALCOHOL TO ESTER Acid-Catalyzed Esterification of an Unknown Alcohol Summary: You will be given an unknown alcohol, you will convert it to an ester, and you will identify both the original alcohol and the derived ester using boiling point and H-NMR. Some Learning Goals: 1. Observe

Jasperse, Craig P.

243

Metabolic pathway engineering for fatty acid ethyl ester production in Saccharomyces cerevisiae using stable chromosomal integration.  

PubMed

Fatty acid ethyl esters are fatty acid derived molecules similar to first generation biodiesel (fatty acid methyl esters; FAMEs) which can be produced in a microbial cell factory. Saccharomyces cerevisiae is a suitable candidate for microbial large scale and long term cultivations, which is the typical industrial production setting for biofuels. It is crucial to conserve the metabolic design of the cell factory during industrial cultivation conditions that require extensive propagation. Genetic modifications therefore have to be introduced in a stable manner. Here, several metabolic engineering strategies for improved production of fatty acid ethyl esters in S. cerevisiae were combined and the genes were stably expressed from the organisms' chromosomes. A wax ester synthase (ws2) was expressed in different yeast strains with an engineered acetyl-CoA and fatty acid metabolism. Thus, we compared expression of ws2 with and without overexpression of alcohol dehydrogenase (ADH2), acetaldehyde dehydrogenase (ALD6) and acetyl-CoA synthetase (acs SE (L641P) ) and further evaluated additional overexpression of a mutant version of acetyl-CoA decarboxylase (ACC1 (S1157A,S659A) ) and the acyl-CoA binding protein (ACB1). The combined engineering efforts of the implementation of ws2, ADH2, ALD6 and acs SE (L641P) , ACC1 (S1157A,S659A) and ACB1 in a S. cerevisiae strain lacking storage lipid formation (are1?, are2?, dga1? and lro1?) and ?-oxidation (pox1?) resulted in a 4.1-fold improvement compared with sole expression of ws2 in S. cerevisiae. PMID:25422103

de Jong, Bouke Wim; Shi, Shuobo; Valle-Rodríguez, Juan Octavio; Siewers, Verena; Nielsen, Jens

2015-03-01

244

Condensation of anhydrides or dicarboxylic acids with compounds containing active methylene groups. Part 1: Condensation of phthalic anhydride with acetoacetic and malonic ester  

NASA Technical Reports Server (NTRS)

Phthalic anhydride was condensed with acetoacetic ester in acetic anhydride and triethylamine solution, and when phthalyl chloride was reacted with sodium acetoacetic ester compounds were formed of the phthalide and indandione series: phthalylacetoacetic ester and a derivative of indan-1,3-dione which after boiling with hydrochloric acid yielded indan-1,3-dione. Phthalylmalonic ester was obtained from phthalic anhydride and malonic ester in the presence of triethylamine.

Oshkaya, V. P.; Vanag, G. Y.

1985-01-01

245

Fatty Acid Esters of Phloridzin Induce Apoptosis of Human Liver Cancer Cells through Altered Gene Expression  

PubMed Central

Phloridzin (phlorizin or phloretin 2?-O-glucoside) is known for blocking intestinal glucose absorption. We have investigated the anticarcinogenic effect of phloridzin and its novel derivatives using human cancer cell lines. We have synthesised novel acylated derivatives of phloridzin with six different long chain fatty acids by regioselective enzymatic acylation using Candida Antarctica lipase B. The antiproliferative effects of the new compounds were investigated in comparison with the parent compounds, phloridzin, aglycone phloretin, the six free fatty acids and chemotherapeutic drugs (sorafenib, doxorubicin and daunorubicin) using human hepatocellular carcinoma HepG2 cells, human breast adenocarcinoma MDA-MB-231 cells and acute monocytic leukemia THP-1 cells along with normal human and rat hepatocytes. The fatty acid esters of phloridzin inhibited significantly the growth of the two carcinoma and leukemia cells while similar treatment doses were not toxic to normal human or rat hepatocytes. The antiproliferative potency of fatty esters of phloridzin was comparable to the potency of the chemotherapeutic drugs. The fatty acid esters of phloridzin inhibited DNA topoisomerases II? activity that might induce G0/G1 phase arrest, induced apoptosis via activation of caspase-3, and decreased ATP level and mitochondrial membrane potential in HepG2 cells. Based on the high selectivity on cancer cells, decosahexaenoic acid (DHA) ester of phloridzin was selected for gene expression analysis using RT2PCR human cancer drug target array. Antiproliferative effect of DHA ester of phloridzin could be related to the down regulation of anti-apoptotic gene (BCL2), growth factor receptors (EBFR family, IGF1R/IGF2, PDGFR) and its downstream signalling partners (PI3k/AKT/mTOR, Ras/Raf/MAPK), cell cycle machinery (CDKs, TERT, TOP2A, TOP2B) as well as epigenetics regulators (HDACs). These results suggest that fatty esters of phloridzin have potential chemotherapeutic effects mediated through the attenuated expression of several key proteins involved in cell cycle regulation, DNA topoisomerases II? activity and epigenetic mechanisms followed by cell cycle arrest and apoptosis. PMID:25229655

Nair, Sandhya V. G.; Ziaullah; Rupasinghe, H. P. Vasantha

2014-01-01

246

Calculations of phase equilibria for mixtures of triglycerides, fatty acids, and their esters in lower alcohols  

NASA Astrophysics Data System (ADS)

The objects of study were mixtures containing triglycerides and lower alcohols and also the products of the transesterification of triglycerides, glycerol and fatty acid esters. The Redlich-Kwong-Soave equation of state was used as a thermodynamic model for the phase state of the selected mixtures over wide temperature, pressure, and composition ranges. Group methods were applied to determine the critical parameters of pure substances and their acentric factors. The parameters obtained were used to calculate the phase diagrams and critical parameters of mixtures containing triglycerides and lower alcohols and the products of the transesterification of triglycerides, glycerol and fatty acid esters, at various alcohol/oil ratios. The conditions of triglyceride transesterification in various lower alcohols providing the supercritical state of reaction mixtures were selected.

Stepanov, D. A.; Ermakova, A.; Anikeev, V. I.

2011-01-01

247

A Convenient Synthesis of Triacetic Acid Methyl Ester  

Microsoft Academic Search

Poly-?-keto compounds play an important role in the biogenesis of natural products such as poly hydroxy phenols and lactones as stated by Birch's “Acetate Hypothesis”. Poly-?-keto compounds and their derivatives (poly-ketides) have been used as intermediates in the biogenetic type synthesis of these natural products by several workers but they are relatively inaccessible. Triacetic acid lactone I is used mostly

J. G. Batelaan

1976-01-01

248

Evaluation of eye irritation by S-(-)-10,11-dihydroxyfarnesic acid methyl ester secreted by Beauveria bassiana CS1029  

PubMed Central

The aim of this study was to investigate whether S-(-)-10,11-dihydroxyfarnesic acid methyl ester produced by cell subtype Beauveria bassiana CS1029 causes acute toxicity when used for cosmetic purposes by performing an eye irritation test. New Zealand white (NZW) rabbits were treated with a 100 mg/dose of S-(-)-10,11-dihydroxyfarnesic acid methyl ester according to standard procedure guidelines. No significant changes in terms of ocular lesions of the cornea, turbidity of the cornea, swelling of the eyelid or ocular discharge were observed in the methyl ester-treated groups, while sodium dioctyl sulfosuccinate, a positive control, caused severe toxicity. The anatomical and pathological observations indicate that the methyl ester produced by Beauveria bassiana CS1029 did not induce eye irritation in the lenses of the rabbits. The data suggest that the methyl ester evaluated in this study has promising potential as a cosmetic ingredient that does not irritate the eye. PMID:24137288

SON, HYEONG-U; LEE, SANG-HAN

2013-01-01

249

Sesquiterpene esters of aristolochic acid from the root and stem of Aristolochia heterophylla.  

PubMed

Three novel sesquiterpene esters of aristolochic acid, aristoloterpenate-II (2), -III (3), and-IV (4), together with known aristoloterpenate-I (1), were isolated and characterized from the root and stem of Aristolochia heterophylla. Their structures were elucidated by spectroscopic methods. The absolute configuration of these compounds at C-4' was determined as R by circular dichroic studies. These compounds showed cytotoxicity against hepatoma G2, 2, 2, 15 cells. PMID:10096848

Wu, T S; Chan, Y Y; Leu, Y L; Chen, Z T

1999-03-01

250

Low chain esters of stearic acid as phase change materials for thermal energy storage in buildings  

Microsoft Academic Search

Esterification of different commercial mixtures of stearic and palmitic acid with methyl, butyl and propyl alcohols was undertaken at the laboratory scale and the thermal properties of the esters were determined by Differential Scanning Calorimetry (DSC).Twelve products were obtained with melting points in the interval of 17–34°C and freezing points in the range of 20–32°C. About half of them are

D. Feldman; D. Banu; D. Hawes

1995-01-01

251

Internal rotation barriers in esters of N,N-dimethyldithiocarbamic acid  

Microsoft Academic Search

The method of a complete analysis of the shape of the lines was used to determine the activation parameters of hindered rotation around the N-C bond in the molecules of N,N-dimethyldithiocarbamic acid esters. The value of the barrier in these compounds is lower than in the thioamides, and depends on the electronic and steric nature of the substituent on the

I. D. Kalikhman; N. A. Kryukova; V. A. Pestunovich; N. I. Ivanova; S. V. Amosova; B. A. Trofimov

1976-01-01

252

Bioactivity and chemical synthesis of caffeic acid phenethyl ester and its derivatives.  

PubMed

Caffeic acid phenethyl ester (CAPE), as one of the main active ingredients of the natural product propolis, shows the unique biological activities such as anti-tumor, anti-oxidation, anti-inflammatory, immune regulation, and so on. These have attracted the attention of many researchers to explore the compound with potent biological activities. This review aims to summarize its bioactivities, synthetic methods and derivatives, which will be helpful for further study and development of CAPE and its derivatives. PMID:25314606

Zhang, Pengxuan; Tang, Yuping; Li, Nian-Guang; Zhu, Yue; Duan, Jin-Ao

2014-01-01

253

The interaction of aluminum with silicic acid in dilute solution and its biological relevance  

SciTech Connect

The affinity of silicic acid, Si(OH){sub 4}, for aluminum is a unique one in chemistry, owing to ionic size, charge, and coordination geometry of the species involved. The chemistry of aluminosilicates generally has been concerned with the solid state (minerals such as clays, feldspars and zeolites), and relatively little attention has been given to the species which exist in solution since aluminosilicates are highly insoluble near neutral pH. However, under dilute conditions the kinetics of colloid formation can be quite slow and the soluble precursors to a solid phase may be reasonably metastable. When equilibrium is approached, the solubility levels are typically 0.05-0.28 {mu}mol/L Al and 18-210 {mu}mol/L Si. These soluble species are usually regarded as simple hydroxyaluminum ions and silicic acid, although it remains arguable as to whether these species may be associated with each other. The formation of a stable soluble specie would allow for molecular aluminosilicates to exist at below saturation levels. So at concentrations above saturation stable aluminosilicates do form (as a part of an insoluble phase), and they may possibly exist at below saturation (as a stable soluble specie). This interaction is then relevant to biology, where human plasma levels (0.06-0.54 {mu}mol/L Al, 14-39 {mu}mol/L Si) (6,7) fall among saturation values. There is a growing concern over the toxic effects of aluminum, but its chemistry with silicic acid has not been addressed. This chemistry is the topic of this study.

Chappell, J.S.; Birchall, J.D. (Imperial Chemicals Industries plc, Cheshire (England))

1988-09-01

254

Omacor (prescription omega-3-acid ethyl esters 90): From severe rhythm disorders to hypertriglyceridemia.  

PubMed

Despite progress made in post-myocardial infarction (MI) revascularization and background therapy for the failing heart, the prevention of adverse cardiac remodeling associated with severe rhythm disorders remains an important drug target. Part of the remodeling can be counteracted by modulating the activity of ion channels and exchangers by omega-3 acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). In the GISSI-Prevenzione and GISSI-HF trials, omega-3 fatty acids were administered as ethyl esters (Omacor Solvay Pharmaceuticals) and not as triglycerides present in fish oil. Ethyl esters result in a sustained intestinal absorption of EPA and DHA and require various purification steps during production, thereby minimizing the content of environmental toxins. Also the rather high (38%) DHA content of Omacor should not be ignored since in rats with low dose intake of omega-3 acids, DHA but not EPA inhibited ischemia-induced arrhythmias. In patients on multiple tablets, 840 mg EPA+DHA in one capsule is preferred to increase compliance. It is not justified to refer to Omacor as "n-3 polyunsaturated fatty acid supplementation" or even "fish oil" and, based on controlled clinical trials, there is no evidence that fish oil could be a substitute of Omacor. To avoid further confusion, guidelines should be precise and refer to the medication, eg, as in NICE guideline CG48: "Omega-3-acid ethyl esters treatment licensed for secondary prevention post-MI." The anti-arrhythmogenic action of Omacor should be seen in the context of implantable cardioverter-defibrillator trials (DINAMIT, IRIS) where non-sudden death was increased and total mortality unaltered. However, Omacor administered in the GISSI-HF trial reduced the incidence of severe arrhythmic events and mortality. Also in the GISSI-Prevenzione trial, arrhythmic death and mortality were reduced. At higher dosages (daily, 3-4 g) Omacor exhibits more pronounced cardiovascular benefits and, as a licensed indication, improves hypertriglyceridemia and related lipid parameters. PMID:19629408

Rupp, Heinz

2009-07-01

255

Electron paramagnetic resonance studies of gamma-irradiated DL-alanine ethyl ester hydrochloride, L-theanine and L-glutamic acid dimethyl ester hydrochloride  

NASA Astrophysics Data System (ADS)

The electron paramagnetic resonance (EPR) of gamma irradiated powders of DL-alanine ethyl ester hydrochloride, L-theanine and L-glutamic acid dimethyl ester hydrochloride were investigated at room temperature. The observed paramagnetic species were attributed to the CH3?HCOOC2H5, -CH2?HCOOH and -CH2?HCOOCH3 radicals, respectively. Hyperfine structure constants and g-values were determined for these three radicals. Some spectroscopic properties and suggestions concerning the possible structure of the radicals were also discussed.

Ba?kan, M. Halim; Ayd?n, Murat

2013-08-01

256

Electron paramagnetic resonance studies of gamma-irradiated DL-alanine ethyl ester hydrochloride, L-theanine and L-glutamic acid dimethyl ester hydrochloride.  

PubMed

The electron paramagnetic resonance (EPR) of gamma irradiated powders of DL-alanine ethyl ester hydrochloride, L-theanine and L-glutamic acid dimethyl ester hydrochloride were investigated at room temperature. The observed paramagnetic species were attributed to the CH3?HCOOC2H5, -CH2?HCOOH and -CH2?HCOOCH3 radicals, respectively. Hyperfine structure constants and g-values were determined for these three radicals. Some spectroscopic properties and suggestions concerning the possible structure of the radicals were also discussed. PMID:23680512

Ba?kan, M Halim; Ayd?n, Murat

2013-08-01

257

GC-based analysis of plant stanyl fatty acid esters in enriched foods.  

PubMed

Approaches for the capillary gas chromatographic (GC) based analysis of intact plant stanyl esters in enriched foods were developed. Reference compounds were synthesized by enzyme-catalyzed transesterifications. Their identities were confirmed by means of mass spectrometry. Using a medium polar trifluoropropylmethyl polysiloxane stationary phase, long-chain plant stanyl esters could be separated according to their stanol moieties and their fatty acid chains. Thermal degradation during GC analysis was compensated by determining response factors; calibrations were performed for ten individual plant stanyl esters. For the analysis of low-fat products (skimmed milk drinking yogurts), the GC separation was combined with a "fast extraction" under acidic conditions. For fat-based foods (margarines), online coupled LC-GC offered an elegant and efficient way to avoid time-consuming sample preparation steps. The robust and rapid methods allow conclusions on both, the stanol profiles and the fatty acid moieties, and thus provide a basis for the authentication of this type of functional food ingredients. PMID:21486072

Barnsteiner, Andreas; Lubinus, Tim; di Gianvito, Angelica; Schmid, Wolfgang; Engel, Karl-Heinz

2011-05-25

258

Amino acid esters substituted phosphorylated emtricitabine and didanosine derivatives as antiviral and anticancer agents.  

PubMed

Owing to the promising antiviral activity of amino acid ester-substituted phosphorylated nucleosides in the present study, a series of phosphorylated derivatives of emtricitabine and didanosine substituted with bioactive amino acid esters at P-atom were synthesized. Initially, molecular docking studies were screened to predict their molecular interactions with hemagglutinin-neuraminidase protein of Newcastle disease virus and E2 protein of human papillomavirus. The title compounds were screened for their antiviral ability against Newcastle disease virus (NDV) by their in ovo study in embryonated chicken eggs. Compounds 5g and 9c exposed well mode of interactions with HN protein and also exhibited potential growth of NDV inhibition. The remaining compounds exhibited better growth of NDV inhibition than their parent molecules, i.e., emtricitabine (FTC) and didanosine (ddI). In addition, the in vitro anticancer activity of all the title compounds were screenedagainst HeLa cell lines at 10 and 100 ?g/mL concentrations. The compounds 5g and 9c showed an effective anticancer activity than that of the remaining title compounds with IC50 values of 40 and 60 ?g/mL, respectively. The present in silico and in ovo antiviral and in vitro anticancer results of the title compounds are suggesting that the amino acid ester-substituted phosphorylated FTC and ddI derivatives, especially 5g and 9c, can be used as NDV inhibitors and anticancer agents for the control and management of viral diseases with cancerous condition. PMID:24789416

Sekhar, Kuruva Chandra; Janardhan, Avilala; Kumar, Yellapu Nanda; Narasimha, Golla; Raju, Chamarthi Naga; Ghosh, S K

2014-07-01

259

Why are esters and amides weaker carbon acids than ketones and Acid fluorides? Contributions by resonance and inductive effects.  

PubMed

Two computational methodologies-a vinylogue extrapolation methodology and a block localized wave function (BLW) methodology-were employed to determine the contributions by resonance and inductive effects toward the gas-phase deprotonation enthalpies at the alpha carbons of acetone, acetamide, acetic acid, and acetyl fluoride, which were taken to be model compounds for ketones, amides, esters, and acid fluorides, respectively. Results from the vinylogue methodology suggest that resonance serves to enhance the gas-phase deprotonation enthalpy of a ketone by 34.3 kcal/mol, an amide by 26.2 kcal/mol, an ester by 30.5 kcal/mol, and an acid fluoride by 30.8 kcal/mol. Comparably, the BLW methodology suggests those numbers to be 42.3, 31.2, 36.1, and 39.7 kcal/mol, respectively. Results from the vinylogue methodology suggest that inductive effects serve to enhance the gas-phase deprotonation enthalpy of a ketone by 11.8 kcal/mol, an amide by 12.7 kcal/mol, an ester by 15.5 kcal/mol, and an acid fluoride by 26.0 kcal/mol, and in the same order, those numbers suggested by the BLW methodology are 3.0, 6.2, 8.5, and 16.3 kcal/mol. PMID:19736922

Fersner, Alexandra; Karty, Joel M; Mo, Yirong

2009-10-01

260

Determination of enthalpy of formation of methyl and ethyl esters of fatty acids.  

PubMed

Biofuels composed by fatty acid methyl esters are widely used as partly substituting fuels for diesel fossil fuels. Additionally, it is expected that the diesel biofuel norms will be extended to ethyl esters produced from bioethanol in the upcoming years. A precise knowledge of the standard enthalpy of formation is necessary for the calculation of some parameters useful for the analysis of the combustion process and emissions of a diesel engine operating with different fuels, such as the heating value, the adiabatic flame temperature or the kinetic mechanisms. However, experimental data for this property are scarce, and only available for short-chain, saturated methyl esters. In this work, four estimation methods for the calculation of the enthalpy of formation are examined and compared. Three of them are simple methods based on groups or bonds contribution, and another one is a computational method (with Gaussian 03 software). After presenting the implementation rules for each of them, conclusions are stated based on the results attained. Gaussian and Benson-Groups methods seem to be more accurate in predicting the actual values of the enthalpy of formation, both methods considering the separation between double bonds and the edge effects in the molecule. However, only the Gaussian method considers the effect of the position of the double bond in the molecule for all the unsaturated esters. PMID:19917272

Lapuerta, Magín; Rodríguez-Fernández, José; Oliva, Fermín

2010-02-01

261

Caffeic acid phenethyl ester prevents apoptotic cell death in the developing rat brain after pentylenetetrazole-induced status epilepticus.  

PubMed

Population-based studies suggest that seizure incidence is highest during the first year of life, and early-life seizures frequently result in the development of epilepsy and behavioral alterations later in life. The early-life insults like status epilepticus often lead to epileptogenesis, a process in which initial brain injury triggers cascades of molecular, cellular, and network changes and eventually spontaneous seizures. Caffeic acid phenethyl ester is an active component of propolis obtained from honeybees and has neuroprotective properties. The aim of this study was to investigate whether caffeic acid phenethyl ester exerts neuroprotective effects on the developing rat brain after status epilepticus. Twenty-one dams reared Wistar male rats, and 21-day-old rats were divided into three groups: control group, pentylenetetrazole-induced status epilepticus group, and caffeic acid phenethyl ester-treated group. Status epilepticus was induced on the first day of experiment. Caffeic acid phenethyl ester injections (30 mg/kg intraperitoneally) started 40 min after the tonic phase of status epilepticus was reached, and the injections of caffeic acid phenethyl ester were repeated over 5 days. Rats were sacrificed, and brain tissues were collected on the 5th day of experiment after the last injection of caffeic acid phenethyl ester. Apoptotic cell death was evaluated. Histopathological examination showed that caffeic acid phenethyl ester significantly preserved the number of neurons in the CA1, CA3, and dentate gyrus regions of the hippocampus and the prefrontal cortex. It also diminished apoptosis in the hippocampus and the prefrontal cortex. In conclusion, this experimental study suggests that caffeic acid phenethyl ester administration may be neuroprotective in status epilepticus in the developing rat brain. PMID:24012504

Yi?, Uluç; Topçu, Yasemin; Özbal, Seda; Tu?yan, Kaz?m; Bayram, Erhan; Karakaya, Pakize; Yilmaz, Osman; Kurul, Semra H?z

2013-11-01

262

The isolation of omega-3 polyunsaturated fatty acids and methyl esters of fish oils by silver resin chromatography  

Microsoft Academic Search

Multigram quantities of the highly unsaturated ?3 component from samples of fish oil fatty acids and esters were isolated\\u000a by silver resin chromatography. An XN1010 resin column saturated with silver ions was utilized. Polyunsaturated fatty acid\\u000a (PUFA) esters from fish oil concentrate (FOC) were fractionated based on the number of double bonds by using solvent programming\\u000a (acetonitrile in methanol). Larger

R. O. Adlof; E. A. Emken

1985-01-01

263

Antioxidant activity of propolis: role of caffeic acid phenethyl ester and galangin.  

PubMed

Propolis, a natural product produced by the honeybee, has been used for thousands of years in folk medicine for several purposes. The extract contains amino acids, phenolic acids, phenolic acid esters, flavonoids, cinnamic acid, terpenes and caffeic acid. It possesses several biological activities such as antiinflammatory, immunostimulatory, antiviral and antibacterial. The exact mode of physiological or biochemical mechanisms responsible for the medical effects, however, is yet to be determined. In this work, we have investigated the antioxidant activity of a propolis extract deprived of caffeic acid phenethyl ester (CAPE). In addition, the activity of CAPE and galangin was also examined. Propolis extract (with and without CAPE) and its active components showed a dose-dependent free radical scavenging effect, a significant inhibition of xanthine oxidase activity, and an antilipoperoxidative capacity. Propolis extract with CAPE was more active than propolis extract without CAPE. CAPE, used alone, exhibited a strong antioxidant activity, higher than galangin. The experimental evidence, therefore, suggests that CAPE plays an important role in the antioxidant activity of propolis. PMID:12495706

Russo, A; Longo, R; Vanella, A

2002-11-01

264

Developing intestine is injured during absorption of oleic acid but not its ethyl ester.  

PubMed Central

Although lipids are essential nutrients in the mammalian diet, we have shown that fatty acids are injurious to epithelial cells of developing piglet intestine during luminal perfusion. Furthermore, the intestine of young animals sustains greater injury than that of older piglets. In an effort to understand the mechanism for this developmental injury, we investigated whether changes in the chemical configuration of oleic acid would alter this damage. Mucosal permeability, as quantitated by the plasma-to-lumen clearance of 51chromium EDTA, was evaluated during luminal perfusion with oleic acid as compared with its ethyl (ethyl oleate) and glyceryl (glycerol-1-mono-oleate) esters, solubilized with taurocholic acid, in jejunum of 1-d-, 3-d-, 2-wk-, and 1-mo-old piglets. 51Chromium EDTA clearance increased significantly during oleic acid and glycerol-1-mono-oleate perfusion, but did not increase during perfusion with ethyl oleate or saline. This result was not secondary to failure of absorption of ethyl oleate, as [14C]oleic acid and ethyl [1-14C]oleate were absorbed to a similar extent. Furthermore, developing intestine was able to remove the ethyl group and then re-esterify the fatty acid to form triacyglycerol. These studies indicate that oleic acid-induced mucosal injury can be abolished when the carboxylic group of the fatty acid is esterified with an ethyl, but not a glycerol, group. Since the ethyl ester is also absorbed and metabolized similarly to the free fatty acid, this may provide a means of supplying long-chain fatty acids to developing intestine without causing mucosal damage. Images PMID:8113387

Velasquez, O R; Place, A R; Tso, P; Crissinger, K D

1994-01-01

265

Electrochemical behaviour of new dimeric esters and amides derived from caffeic acid in dimethylsulfoxide.  

PubMed

The electrochemical oxidation in DMSO of four new derivatives of caffeic acid (CA), two dimeric amides and two dimeric esters, is reported in this article. Although all of them contain two caffeoyl electroactive moieties in their structures, small differences in the connectors result in interesting changes in the electrochemical behaviour of this type of compound. Voltammograms of both esters do not show appreciable differences between them; however, an electrografting process occurs during the electrochemical oxidation of one of them, which suggests that the identity of the connector has an influence on the ability of the diesters to interact with the electrode surface. On the other hand, voltammograms of dimeric amides were more complex than those corresponding to dimeric esters. Electronic effects of diamine connectors seem to be related to the fact that caffeoyl moieties suffer from separate oxidation processes in both compounds. In contrast to their ferulic acid (FA) analogues, which have been studied by our group before, CA dimeric amides do not interact in an appreciable way with the electrode surface. In addition, a relationship between the oxidation potential and the inhibition percentage of the DPPH (2,2'-diphenyl-1-picrylhydrazyl) radical was not observed for the symmetrical CA derivatives studied here. However, the molecular flexibility seems to play a very important role in the Free Radical Scavenging Activity (FRSA) of this type of compound. PMID:24988384

Sánchez, Analilia; Martínez-Mora, Omar; Martínez-Benavidez, Evelin; Hernández, Javier; Domínguez, Zaira; Salas-Reyes, Magali

2014-08-21

266

Catalytic, Enantioselective Alkylation of r-Imino Esters: The Synthesis of Nonnatural r-Amino Acid Derivatives  

E-print Network

Catalytic, Enantioselective Alkylation of r-Imino Esters: The Synthesis of Nonnatural r-Amino Acid, 2001 Abstract: Methodology for the practical synthesis of nonnatural amino acids has been developed (up to 25:1/anti:syn), are protected nonnatural amino acids that represent potential precursors

Lectka, Thomas

267

Influence of fatty acid on lipase-catalyzed synthesis of ascorbyl esters and their free radical scavenging capacity.  

PubMed

Fatty acid ascorbyl esters are recently emerging food, cosmetic, and pharmaceutical additives, which can be prepared in eco-friendly way by using lipases as catalysts. Since they are amphiphilic molecules which possess high free radical scavenging capacity, they can be applied as liposoluble antioxidants, as well as emulsifiers and biosurfactants. In this study, the influence of a wide range of acyl donors on ester yield in lipase-catalyzed synthesis and ester antioxidant activity was examined. Among saturated acyl donors, higher yields and antioxidant activities of esters were achieved when short chain fatty acids were used. Oleic acid gave the highest yield overall and its ester exhibited high antioxidant activity. Optimization of experimental factors showed that the highest conversion (60.5%) in acetone was achieved with 5 g L(-1) of lipase, 50 mM of vitamin C, ten-fold molar excess of oleic acid, and 0.7 mL L(-1) of initial water. Obtained results showed that even short and medium chain ascorbyl esters could be synthesized with high yields and retained (or even exceeded) free radical scavenging capacity of L-ascorbic acid, indicating prospects of broadening their application in emulsions and liposomes. This article is protected by copyright. All rights reserved. PMID:25224149

Stojanovi?, Marija; Carevi?, Milica; Mihailovi?, Mladen; Veli?kovi?, Dušan; Dimitrijevi?, Aleksandra; Milosavi?, Nenad; Bezbradica, Dejan

2014-09-15

268

21 CFR 582.4101 - Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat...  

Code of Federal Regulations, 2011 CFR

...tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat-forming fatty acids. 582.4101 Section 582...tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat-forming fatty acids....

2011-04-01

269

Biodegradable Coumaric Acid-based Poly(anhydride-ester) Synthesis and Subsequent Controlled Release  

PubMed Central

p-Coumaric acid (pCA), a naturally occurring bioactive, has been chemically incorporated into a poly(anhydride-ester) backbone through solution polymerization following a Knoevenagel synthetic approach to overcome drug delivery issues associated with its short half-life in vivo. Nuclear magnetic resonance and Fourier transform infrared spectroscopies indicated that pCA was successfully incorporated without noticeable alterations in structural integrity. The weight-average molecular weight and thermal properties were determined for the polymer, which exhibited a molecular weight of over 26,000 Da and a glass transition temperature of 57 °C. In addition, in vitro pCA release via hydrolytic anhydride and ester bond cleavage demonstrated pCA release over 30 days and maintained its antioxidant activity, demonstrating its potential as a controlled release system. PMID:23836606

Ouimet, Michelle A.; Stebbins, Nicholas D.; Uhrich, Kathryn E.

2013-01-01

270

Poly(ortho ester amides): Acid-labile Temperature-responsive Copolymers for Potential Biomedical Applications  

PubMed Central

A new, convenient pathway is developed to synthesize highly hydrolytically labile poly(ortho ester amide) (POEA) copolymers that overcomes some of the major weaknesses of the traditional methods of synthesizing poly(ortho esters) and their derivatives. A diamine monomer containing a built-in, stabilized ortho ester group was synthesized and was used for polycondensation with diacid esters, giving rise to a series of POEA copolymers with unique stimuli-responsive properties. The POEA undergoes temperature-responsive, reversible sol-gel phase transition in water. Phase diagrams of the POEA/H2O mixture reveal the concentration-dependent existence of different phases, including hydrogel and opaque or clear solution. Such behavior may be attributed to the temperature-dependent hydrogen-bonding involving the amide groups in the POEA backbone and hydrophobic interactions between POEA chains, and it is tunable by selecting diacid monomers with different chemical structures. The kinetics of POEA mass loss in physiological aqueous buffers and release of a model macromolecular drug, fluorescently labeled dextran, are nearly zero-order, suggesting predominantly surface-restricted polymer erosion. The rates of polymer erosion and drug release are much faster at pH 5.0 than pH 7.4. No cytotoxicity was found for the polymer extracts and the polymer degradation products at concentrations as high as 1 mg/ml. The normal morphology of fibroblasts cultured directly in contact with POEA films was not altered. These novel acid-labile temperature-responsive POEA copolymers may be potentially useful for a wide range of biomedical applications such as minimal invasive delivery of controlled-release drug formulations that respond to biological temperature and acidic-pH environments in cells and tissues. PMID:19281150

Tang, Rupei; Palumbo, R. Noelle; Ji, Weihang; Wang, Chun

2009-01-01

271

Studies of the acidic components of the Colorado Green River formation oil shale-Mass spectrometric identification of the methyl esters of extractable acids.  

NASA Technical Reports Server (NTRS)

Study of solvent extractable acidic constituents of oil shale from the Colorado Green River Formation. Identification of individual components is based on gas chromatographic and mass spectrometric data obtained for their respective methyl esters. Normal acids, isoprenoidal acids, alpha, omega-dicarboxylic acids, mono-alpha-methyl dicarboxylic acids and methyl ketoacids were identified. In addition, the presence of monocyclic, benzoic, phenylalkanoic and naphthyl-carboxylic acids, as well as cycloaromatic acids, is demonstrated by partial identification.

Haug, P.; Schnoes, H. K.; Burlingame, A. L.

1971-01-01

272

Optimizing Reaction Conditions for the Isomerization of Fatty Acids and Fatty Acid Methyl Esters to Their Branch Chain Products  

Microsoft Academic Search

In order to improve the oxidative stability and cold flow properties of oleic acid or methyl oleate, branch chain isomerization\\u000a was conducted using a beta zeolite catalyst. Reaction conditions of temperature (200–300 °C), pressure (0.1–3.0 MPa), and\\u000a co-catalyst (0–2 wt%) were optimized based on branch chain conversion and the cloud point of the ester following the isomerization\\u000a reaction of oleic acid or

Stephen J. Reaume; Naoko Ellis

2011-01-01

273

Characterization of benthic microbial community structure by high-resolution gas chromatography of fatty acid methyl esters  

SciTech Connect

Fatty acids are a widely studied group of lipids of sufficient taxonomic diversity to be useful in defining microbial community structure. The gas-liquid chromatographic analyses are both reproducible and highly sensitive, and the recovery of fatty acids is quantitative. The analyses can be automated, and the diagnostic technique of mass spectral fragmentation analysis can be readily applied. Reciprocal mixtures of bacteria and fungi, when extracted and analyzed, showed progressive changes of distinctive fatty acid methyl esters derived from the lipids. By manipulating the environment of an estuarine detrital microbial community with antibiotics and culture conditions, it was possible to produce a community greatly enriched in eucaryotic fungi, as evidenced by scanning electron microscopic morphology. The fatty acid methyl C/sub 18/ dienoic and the C/sub 18/ and C/sub 20/ polyenoic esters. Manipulation of the detrital microbiota that increased the procaryotic population resulted in an absence of large structures typical of fungal mycelia or diatoms, as evidenced by scanning electron microscopy, and a significantly larger proportion of anteiso and isobranched C/sub 15/ fatty acid esters, C/sub 17/ cyclopropane fatty acid esters, and the cisvaccenic isomer of the C/sub 18/ monoenoic fatty acid esters. As determined by these techniques, a marine settling community showed greater differences in bacterial as contrasted to microeucaryotic populations when compared with the microbial communities of benthic cores.

Bobbie, R.J.; White, D.C.

1980-06-01

274

Effect of caffeic acid esters on carcinogen-induced mutagenicity and human colon adenocarcinoma cell growth.  

PubMed

Propolis, a honey bee hive product, is thought to exhibit a broad spectrum of activities including antibiotic, antiviral, anti-inflammatory and tumor growth inhibition; some of the observed biological activities may be due to caffeic acid (cinnamic acid) esters that are present in propolis. In the present study we synthesized three caffeic acid esters, namely methyl caffeate (MC), phenylethyl caffeate (PEC) and phenylethyl dimethylcaffeate (PEDMC) and tested them against the 3,2'-dimethyl-4-aminobiphenyl, (DMAB, a colon and mammary carcinogen)-induced mutagenicity in Salmonella typhimurium strains TA 98 and TA 100. Also, the effect of these agents on the growth of human colon adenocarcinoma, HT-29 cells and activities of ornithine decarboxylase (ODC) and protein tyrosine kinase (PTK) was studied. Mutagenicity was induced in Salmonella typhimurium strains TA 98 and TA 100 plus S9 activation using 5 and 10 micrograms DMAB and antimutagenic activities of 0-150 microM MC, 0-60 microM PEC and 0-80 microM PEDMC were determined. The results indicate that MC, PEC and PEDMC were not mutagenic in the Salmonella tester system. DMAB-induced mutagenicity was significantly inhibited with 150 microM MC, 40-60 microM PEC and 40-80 microM PEDMC in both tester systems. Treatment of HT-29 colon adenocarcinoma cells with > 150 microM MC, 30 microM PEC and 20 microM PEDMC significantly inhibited the cell growth and syntheses of RNA, DNA and protein. ODC and PTK activities were also inhibited in HT-29 cells treated with different concentrations of MC, PEC and PEDMC. These results demonstrate that caffeic acid esters which are present in Propolis possess chemopreventive properties when tested in short-term assay systems. PMID:1423745

Rao, C V; Desai, D; Kaul, B; Amin, S; Reddy, B S

1992-11-16

275

Synthesis and Biological Evaluation of Novel Mono Acid Esters Derived from the Constituents of Urtica pilulifera  

PubMed Central

New mono acid esters have been synthesized from the reaction of benzoic acid and mono-hydroxybenzoic acids with 2-phenoxyethanol separated from Urtica pilulifera, characterized, and screened for possible antioxidant, antifungal, antimicrobial and anticancer activities. These phenolic acid esters gave various degrees of free radical scavenging, but the values were lower than that of ?-tocopherol. The concentrations of the tested compounds needed to reduce DPPH absorption by 50% at 517 nm were nearly in the range of 900-1100 µg/mL. While for ?-tocopherol was 40 µg /mL. The compounds were tested in-vitro against six bacterial species which are known to cause dermic and mucosal infections in human. 2-phenoxyethyl benzoate showed significant activity in the range of 30% against P. aeruginosa to 70% against E. coli compared with the activity of Streptomycin. On the other hand 2-phenoxyethyl 2-hydroxybenzoate reveals 70% of gentamicin against K. pneumoniae. The tested compounds also showed complete inhibition at a concentration less than 37.5 µg/mL against M. canis and less than 50 µg/mL against T. rubrum. 2-phenoxyethyl 4-hydroxybenzoate showed considerable activity against MCF-7 with IC50 is less than 62.5 µg/mL.

I. Husein, Ahmad; J. Jondi, Waheed; A. Zatar, Nidal; S. Ali-Shtayeh, Mohammed

2014-01-01

276

Prediction of gas chromatographic retention times of esters of long chain alcohols and fatty acids.  

PubMed

The linear free energy of solution (DeltaG) relationship (DeltaG=DeltaGo+zdeltaG) for compounds of different carbon atoms (z) in the same homologous series is expanded and modified to cover compounds with two different hydrocarbon side chains. The expanded equation is successfully used to predict the retention times (tR) of standard esters of long chain alcohols and fatty acids of different chain lengths in both isothermal and temperature-programmed gas chromatography (TPGC). Approximately 90% of the 125 predicted tR values have a difference of less than 1.00% from the actual tR and the highest difference is 1.26%. Two different temperature gradients in TPGC are tested. The expanded equation can be used to forecast the tR of TPGC with good accuracy. The highest difference is +/-1.40% and +/-1.00% for the temperature gradients of 2 degrees C and 4 degrees C/min, respectively. However, the increments in free energy per carbon atom (zdeltaG) of the alcohol and acid are approximately equal but have slightly different temperature sensitivities. Therefore, it is very difficult to separate esters of different acid and alcohol chain length but with the same total carbon numbers. Furthermore, the difference in temperature sensitivities for the acid and alcohol side chains renders them to be inversely eluted at different temperatures. PMID:16620510

Katsuwon, Karuna; Aryusuk, Kornkanok; Krisnangkura, Kanit

2006-03-01

277

40 CFR 721.3700 - Fatty acid, ester with styrenated phenol, ethylene oxide adduct.  

Code of Federal Regulations, 2010 CFR

...ester with styrenated phenol, ethylene oxide adduct. 721.3700 Section 721.3700...ester with styrenated phenol, ethylene oxide adduct. (a) Chemical substances and...ester with styrenated phenol, ethylene oxide adduct (P-90-364) is subject...

2010-07-01

278

40 CFR 721.3800 - Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene...  

Code of Federal Regulations, 2014 CFR

...ester with styrenated phenol, ethylene oxide adduct. 721.3800 Section 721.3800...ester with styrenated phenol, ethylene oxide adduct. (a) Chemical substances and...ester with styrenated phenol, ethylene oxide adduct (PMN P-90-360) is...

2014-07-01

279

40 CFR 721.3800 - Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene...  

Code of Federal Regulations, 2012 CFR

...ester with styrenated phenol, ethylene oxide adduct. 721.3800 Section 721.3800...ester with styrenated phenol, ethylene oxide adduct. (a) Chemical substances and...ester with styrenated phenol, ethylene oxide adduct (PMN P-90-360) is...

2012-07-01

280

40 CFR 721.3800 - Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene...  

Code of Federal Regulations, 2011 CFR

...ester with styrenated phenol, ethylene oxide adduct. 721.3800 Section 721.3800...ester with styrenated phenol, ethylene oxide adduct. (a) Chemical substances and...ester with styrenated phenol, ethylene oxide adduct (PMN P-90-360) is...

2011-07-01

281

40 CFR 721.3700 - Fatty acid, ester with styrenated phenol, ethylene oxide adduct.  

Code of Federal Regulations, 2014 CFR

...ester with styrenated phenol, ethylene oxide adduct. 721.3700 Section 721.3700...ester with styrenated phenol, ethylene oxide adduct. (a) Chemical substances and...ester with styrenated phenol, ethylene oxide adduct (P-90-364) is subject...

2014-07-01

282

40 CFR 721.3700 - Fatty acid, ester with styrenated phenol, ethylene oxide adduct.  

Code of Federal Regulations, 2011 CFR

...ester with styrenated phenol, ethylene oxide adduct. 721.3700 Section 721.3700...ester with styrenated phenol, ethylene oxide adduct. (a) Chemical substances and...ester with styrenated phenol, ethylene oxide adduct (P-90-364) is subject...

2011-07-01

283

40 CFR 721.3700 - Fatty acid, ester with styrenated phenol, ethylene oxide adduct.  

Code of Federal Regulations, 2012 CFR

...ester with styrenated phenol, ethylene oxide adduct. 721.3700 Section 721.3700...ester with styrenated phenol, ethylene oxide adduct. (a) Chemical substances and...ester with styrenated phenol, ethylene oxide adduct (P-90-364) is subject...

2012-07-01

284

40 CFR 721.3700 - Fatty acid, ester with styrenated phenol, ethylene oxide adduct.  

Code of Federal Regulations, 2013 CFR

...ester with styrenated phenol, ethylene oxide adduct. 721.3700 Section 721.3700...ester with styrenated phenol, ethylene oxide adduct. (a) Chemical substances and...ester with styrenated phenol, ethylene oxide adduct (P-90-364) is subject...

2013-07-01

285

Antiandrogenic activity of anthranilic acid ester derivatives as novel lead structures to inhibit prostate cancer cell proliferation.  

PubMed

A plant extract from the fruits of saw palmetto, which is currently used to treat the androgen-dependent benign prostatic hyperplasia and PCa, served as source for new structure variants. We investigated the antiandrogenic potential of an ethanolic total extract and one of its main aromatic components anthranilic acid. An androgen receptor-antagonistic (antiandrogenic) effect of the extract was evident, and although anthranilic acid itself revealed no remarkable effect, its methyl ester, methyl anthranilate, exhibited antiandrogenic potential. Based on this chemical structure, we synthesized and investigated the antiandrogenic activity of four AnA ester derivatives, which were either novel or only little described in literature. These AnA esters inhibit the androgen-dependent transactivation of both the wild-type (wt) androgen receptor and the androgen receptor point mutant T877A, which often occurs in refractory PCa. Moreover, they inhibit the androgen receptor-induced expression of the endogenous prostate-specific antigen. Importantly, AnA esters repress the growth of human PCa cells. Deletion analyses of androgen receptor propose that the antiandrogenic effect of anthranilic acid esters is mediated by the ligand-binding domain, most likely through direct binding, without affecting androgen receptor protein levels. Taken together, the data suggest antiandrogenic potential of anthranilic acid ester derivatives, which can serve as lead structures for novel antiandrogens. PMID:21439024

Roell, Daniela; Rösler, Thomas W; Degen, Stephanie; Matusch, Rudolf; Baniahmad, Aria

2011-06-01

286

Development of biodegradable flexible films of starch and poly(lactic acid) plasticized with adipate or citrate esters.  

PubMed

Biodegradable films were produced from blends contained a high amount of thermoplastic starch (TPS) and poly(lactic acid) (PLA) plasticized with different adipate or citrate esters. It was not possible to obtain pellets for the production of films using only glycerol as a plasticizer. The plasticization of the PLA with the esters and mixture stages added through extrusion was critical to achieve a blend capable of producing films by blow extrusion. Adipate esters were the most effective plasticizers because they interacted best with the PLA and yielded films with appropriate mechanical properties. PMID:23218260

Shirai, M A; Grossmann, M V E; Mali, S; Yamashita, F; Garcia, P S; Müller, C M O

2013-01-30

287

Characterization of wax esters, free fatty alcohols and free fatty acids of crude wax from sunflower seed oil refineries  

Microsoft Academic Search

The sunflower seed wax (10–12%) from oil refineries was purified through two steps, namely, extraction using solvents and precipitation with chilled acetone. Fatty esters, free fatty alcohols and free fatty acids were separated by thin-layer chromatography (TLC). The fractions of fatty esters and free fatty alcohols were separated and identified by gas chromatography (GC) using a Dexil-300 column and OV-101

T. C. Sindhu Kanya; L. Jaganmohan Rao; M. C. Shamanthaka Sastry

2007-01-01

288

Electronically Rich N-Substituted Tetrahydroisoquinoline 3-Carboxylic Acid Esters: Concise Synthesis and Conformational Studies  

PubMed Central

Recent work in our laboratory has shown that the highly substituted, electronically rich 1,2,3,4–tetrahydroisoquinoline–3–carboxylic acid (THIQ3CA) scaffold is a key building block for a novel class of promising anticoagulants (Al-Horani et al. J. Med. Chem. 2011, 54, 6125–6138). The synthesis of THIQ3CA analogs, especially containing specific, electronically rich substituents, has been a challenge and essentially no efficient methods have been reported in the literature. We describe three complementary, glycine donor-based strategies for high yielding synthesis of highly substituted, electronically rich THIQ3CA esters. Three glycine donors studied herein include hydantoin 1, (±)-Boc-?-phosphonoglycine trimethyl ester 2 and (±)-Z-?-phosphonoglycine trimethyl ester 3. Although the synthesis of THIQ3CA analogs could be achieved using either of the three, an optimal, high yielding approach for the desired THIQ3CA esters was best achieved using 3 in three mild, efficient steps. Using this approach, a focused library of advanced N-arylacyl, N-arylalkyl, and bis-THIQ3CA analogs was synthesized. Variable temperature and solvent-dependent NMR chemical shift studies indicated the presence of two major conformational rotamers in 3:1 proportion for N–arylacyl–THIQ3CA analogs, which were separated by a high kinetic barrier of ~17 kcal/mol. In contrast, N–arylalkyl and bis–THIQ3CA variants displayed no rotamerism, which implicates restricted rotation around the amide bond as the origin for high-barrier conformational interconversion. This phenomenon is of major significance because structure-based drug design typically utilizes only one conformation. Overall, the work presents fundamental studies on the synthesis and conformational properties of highly substituted, electronically rich THIQ3CA analogs. PMID:22665943

Al-Horani, Rami A.; Desai, Umesh R.

2012-01-01

289

Purification of fatty acid methyl esters by high-performance liquid chromatography.  

PubMed

The determination by gas chromatography (GC) of fatty acid methyl esters (FAMEs) prepared from complex biological samples is subject to interference from cholesterol. During sample injection on the GC system of FAMEs prepared from tissues that contain cholesterol, we observed a major contaminant that co-eluted with docosahexaenoic acid (DHA, 22:6n-3). To address this problem, FAMEs were purified on an amino-phase high-performance liquid chromatography (HPLC) column using a hexane-isopropanol gradient. The HPLC retention times for both the FAME fraction and cholesterol were stable and reproducible when the amino column was used for sample purification. The purified extracts were analyzed by GC without artifacts or impurity peaks after 50 analytical runs. The method described here will be useful for measurement of 22:6n-3 and other fatty acids important for studies of nutrition or pathology. PMID:10517372

Nightingale, Z D; Blumberg, J B; Handelman, G J

1999-09-24

290

Influence of fatty acid methyl esters from hydroxylated vegetable oils on diesel fuel lubricity.  

PubMed

Current and future regulations on the sulfur content of diesel fuel have led to a decrease in lubricity of these fuels. This decreased lubricity poses a significant problem as it may lead to wear and damage of diesel engines, primarily fuel injection systems. Vegetable oil based diesel fuel substitutes (biodiesel) have been shown to be clean and effective and may increase overall lubricity when added to diesel fuel at nominally low levels. Previous studies on castor oil suggest that its uniquely high level of the hydroxy fatty acid ricinoleic acid may impart increased lubricity to the oil and its derivatives as compared to other vegetable oils. Likewise, the developing oilseed Lesquerella may also increase diesel lubricity through its unique hydroxy fatty acid composition. This study examines the effect of castor and Lesquerella oil esters on the lubricity of diesel fuel using the High-Frequency Reciprocating Rig (HFRR) test and compares these results to those for the commercial vegetable oil derivatives soybean and rapeseed methyl esters. PMID:15607199

Goodrum, John W; Geller, Daniel P

2005-05-01

291

Molecular Model of trans-3-(9-Anthryl)-2-Propenoic Acid Ethyl Ester  

NSDL National Science Digital Library

The Featured Molecules this month come from the paper by Nguyen and Weisman on solvent-free Wittig reactions and the stereochemical consequences of crowding in the transition state. The molecules include those pictured in the paper as well as the cis-isomer of 3-(9-anthryl)-2-propenoic acid ethyl ester. All structures were optimized at the B3LPY/6-31G* level. In the case of ethyl cinnamate, the cis-isomer is slightly more stable thermodynamically than the trans isomer, lending further support for the argument that the observed product distribution arises from the energetics of the transition state.

292

Synthesis and analgesic activity of hydrochlorides and quaternary ammoniums of epibatidine incorporated with amino acid ester.  

PubMed

Hydrochloride derivatives 5a-c and quaternary ammonium derivatives 6a-c of epibatidine incorporated with amino acid ester were synthesized and evaluated for their in vivo analgesic activity and toxicity. Among all tested compounds, compound 6c has the most potent analgesic activity. The quaternary ammonium salts 6a and 6c showed better analgesic activity than the corresponding hydrochlorides 5a and 5c. Both 5a-c and 6a-c showed significantly lower toxicity than epibatidine itself. PMID:14643319

Dong, Jing-Chao; Wang, Xin; Li, Run-Tao; Zhang, Hong-Mei; Cheng, Tie-Ming; Li, Chang-Ling

2003-12-15

293

21 CFR 582.4101 - Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat...  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false Diacetyl tartaric acid esters of mono- and diglycerides of edible...or oils, or edible fat-forming fatty acids. 582.4101 Section 582.4101 Food...Agents § 582.4101 Diacetyl tartaric acid esters of mono- and diglycerides of...

2012-04-01

294

21 CFR 582.4101 - Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat...  

Code of Federal Regulations, 2014 CFR

...2014-04-01 false Diacetyl tartaric acid esters of mono- and diglycerides of edible...or oils, or edible fat-forming fatty acids. 582.4101 Section 582.4101 Food...Agents § 582.4101 Diacetyl tartaric acid esters of mono- and diglycerides of...

2014-04-01

295

21 CFR 582.4101 - Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat...  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Diacetyl tartaric acid esters of mono- and diglycerides of edible...or oils, or edible fat-forming fatty acids. 582.4101 Section 582.4101 Food...Agents § 582.4101 Diacetyl tartaric acid esters of mono- and diglycerides of...

2013-04-01

296

Synthesis and characterization of tri( o-fluorobenzyl)tin esters of heteroaromatic carboxylic acid and crystal structures of tri( o-fluorobenzyl)tin esters of 4-pyridinecarboxylic acid and 3-pyridinecarboxylic acid  

Microsoft Academic Search

Reaction of tri(o-fluorobenzyl)tin chloride with sodium of heteroaromatic carboxylic acid in 1:1 stoichiometry yielded complexes of the type (2-F-Bz)3SnOOCR (R=2-furanyl, 2-furanvingl, 2-thiophenyl, 2-pyridinyl, 3-pyridinyl, 4-pyridinyl, 3-indolyl, 3-indolmethyl and 3-indolpropyl), respectively. These complexes have been characterized by elemental analyses, IR and 1H NMR spectroscopy. The crystal structures of tri(o-fluorobenzyl)tin esters of 4-pyridinecarboxylic acid (5) and 3-pyridinecarboxylic acid (6) were determined by

Handong D. Yin; Chuanhua Wang; Chunlin Ma; Daqi Wang

2004-01-01

297

Production of Fatty Acid Methyl Esters via the In Situ Transesterification of Soybean Oil in Carbon Dioxide-Expanded Methanol  

Technology Transfer Automated Retrieval System (TEKTRAN)

The production of fatty acid methyl esters (FAME) by direct alkali- and acid-catalyzed in situ transesterification of soybean flakes in CO2-expanded methanol was examined at various temperatures and pressures. Attempts to synthesize FAME from soy flakes via alkaline catalysis, using sodium methoxid...

298

Acid-cleavable ketal containing poly(?-amino ester) for enhanced siRNA delivery.  

PubMed

The safe and effective intracellular delivery of nucleic acids remains the most challenging obstacle to the broad application of gene therapy in clinic. Endosomal escape of nucleic acids is also a major barrier for efficient gene delivery. Ketal linkage is known to readily cleave at the acidic pH of endosomal compartments. Here, we report ketal containing poly(?-amino ester) (KPAE) as an acid-cleavable non-viral siRNA delivery system. KPAE efficiently condensed siRNA into nanocomplexes with a diameter of ? 150 nm, which are stable under neutral conditions but rapidly dissociate to release siRNA at acidic pH. KPAE had a buffering capacity due to the presence of secondary amines in its backbone, confirmed by acid-base titration. Moreover, the studies of confocal fluorescence imaging using calcein and LysoTracker Red revealed that KPAE disrupted endosomes by colloid osmotic mechanism and "proton sponge" effects. Cell culture studies demonstrated that KPAE can deliver tumor necrosis factor-? (TNF-?) siRNA to lipopolysaccharide (LPS)-stimulated macrophages and significantly inhibit the expression of TNF-?. The results demonstrate that acid-cleavable KPAE has great potential as gene delivery systems based on its excellent biocompatibility, pH sensitivity and high gene delivery efficiency. PMID:23796834

Guk, Kyeonghye; Lim, Hyungsuk; Kim, Byungkuk; Hong, Minsung; Khang, Gilson; Lee, Dongwon

2013-09-10

299

Effects of fatty acid glycerol esters on intestinal absorptive and secretory transport of ceftibuten.  

PubMed

The effects of fatty acid glycerol esters and Tweens on the intestinal transport of ceftibuten were studied using a diffusion chamber system. The apparent permeation coefficient (P(app)) was used as an index of the mucosal permeability to ceftibuten. The P(app) markedly increased by the addition of hexaglycerol monostearate (HGMS) or hexaglycerol sesquistearate (HGSS) under an H+-gradient condition, while hexaglycerol tristearate (HGTS) and Tweens showed no effect on the absorptive ceftibuten permeability. These results are in agreement with those obtained in the previous study in the brush-border membrane vesicles. On the other hand, in the absence of an H+-gradient, the S-to-M transport of ceftibuten was proven to be significantly higher than the M-to-S one. In addition, either ATP-depletion of the mucosa or the addition of probenecid proved to enhance significantly the permeability of ceftibuten. These findings suggest the existence of an active secretory transport system for ceftibuten in the jejunal mucosa. To estimate potential effects of glycerol esters on efflux pumps as well as peptide transporters, the mucosal-to-serosal (M-to-S) and serosal-to-mucosal (S-to-M) permeability in the presence of the esters was further examined. HGMS, HGSS and HGTS markedly enhanced the M-to-S but not the S-to-M transport in the ATP-depleted jejunum without an H+-gradient, in which conditions contributions of both peptide transporter and efflux pump should be substantially small. HGMS and HGSS significantly enhanced the M-to-S ceftibuten transport in the ATP-depleted jejunum with an H+-gradient (p<0.01 vs. M-to-S transport without surfactant under the same conditions). Whereas, these glycerol esters were found hardly to affect the P(app) of the S-to-M transport. These results indicate that the enhanced intestinal transport of ceftibuten due to the glycerol esters may be based on their effects on peptide transporters but neither on efflux pumps nor on the passive permeation routes. PMID:10328562

Koga, K; Murakami, M; Kawashima, S

1999-04-01

300

Dimer esters in ?-pinene secondary organic aerosol: effect of hydroxyl radical, ozone, relative humidity and aerosol acidity  

NASA Astrophysics Data System (ADS)

The formation of secondary organic aerosol (SOA) from both ozonolysis and hydroxyl radical (OH)-initiated oxidation of ?-pinene under conditions of high nitric oxide (NO) concentrations with varying relative humidity (RH) and aerosol acidity was investigated in the University of North Carolina dual outdoor smog chamber facility. SOA formation from ozonolysis of ?-pinene was enhanced relative to that from OH-initiated oxidation in the presence of initially high NO conditions. However, no effect of RH on SOA mass was evident. Ozone (O3)-initiated oxidation of ?-pinene in the presence of ammonium sulfate (AS) seed coated with organic aerosol from OH-initiated oxidation of ?-pinene showed reduced nucleation compared to ozonolysis in the presence of pure AS seed aerosol. The chemical composition of ?-pinene SOA was investigated by ultra-performance liquid chromatography/electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (UPLC/ESI-HR-Q-TOFMS), with a focus on the formation of carboxylic acids and high-molecular weight dimer esters. A total of eight carboxylic acids and four dimer esters were identified, constituting between 8 and 12% of the total ?-pinene SOA mass. OH-initiated oxidation of ?-pinene in the presence of nitrogen oxides (NOx) resulted in the formation of highly oxidized carboxylic acids, such as 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA) and diaterpenylic acid acetate (DTAA). The formation of dimer esters was observed only in SOA produced from the ozonolysis of ?-pinene in the absence of NOx, with increased concentrations by a~factor of two at higher RH (50-90%) relative to lower RH (30-50%). The increased formation of dimer esters correlates with an observed increase in new particle formation at higher RH due to nucleation. Increased aerosol acidity was found to have a negligible effect on the formation of the dimer esters. SOA mass yield did not influence the chemical composition of SOA formed from ?-pinene ozonolysis with respect to carboxylic acids and dimer esters. The results support the formation of the high-molecular weight dimer esters through gas-phase reactions of the stabilized Criegee Intermediate (sCI) formed from the ozonolysis of ?-pinene. The high molecular weight and polar nature of dimer esters formed in the gas-phase may explain increased particle number concentration as a~result of homogenous nucleation. Since three of these dimer esters (i.e., pinyl-diaterpenyl ester (MW 358), pinyl-diaterebyl ester (MW 344) and pinonyl-pinyl ester (MW 368)) have been observed in both laboratory-generated and ambient fine organic aerosol samples, we conclude that the dimer esters observed in this study can be used as tracers for the O3-initiated oxidation of ?-pinene, and are therefore indicative of enhanced anthropogenic activities, and that the high molecular weight and low volatility esters result in homogenous nucleation under laboratory conditions, increasing the particle number concentration.

Kristensen, K.; Cui, T.; Zhang, H.; Gold, A.; Glasius, M.; Surratt, J. D.

2013-12-01

301

Perennial peanut (Arachis glabrata Benth.) leaves contain hydroxycinnamoyl-CoA:tartaric acid hydroxycinnamoyl transferase activity and accumulate hydroxycinnamoyl-tartaric acid esters.  

PubMed

Many plants accumulate hydroxycinnamoyl esters to protect against abiotic and biotic stresses. Caffeoyl esters in particular can be substrates for endogenous polyphenol oxidases (PPOs). Recently, we showed that perennial peanut (Arachis glabrata Benth.) leaves contain PPO and identified one PPO substrate, caftaric acid (trans-caffeoyl-tartaric acid). Additional compounds were believed to be cis- and trans-p-coumaroyl tartaric acid and cis- and trans-feruloyl-tartaric acid, but lack of standards prevented definitive identifications. Here we characterize enzymatic activities in peanut leaves to understand how caftaric acid and related hydroxycinnamoyl esters are made in this species. We show that peanut leaves contain a hydroxycinnamoyl-CoA:tartaric acid hydroxycinnamoyl transferase (HTT) activity capable of transferring p-coumaroyl, caffeoyl, and feruloyl moieties from CoA to tartaric acid (specific activities of 11 ± 2.8, 8 ± 1.8, 4 ± 0.8 pkat mg(-1) crude protein, respectively). The HTT activity was used to make cis- and trans-p-coumaroyl- and -feruloyl-tartaric acid in vitro. These products allowed definitive identification of the corresponding cis- and trans-hydroxycinnamoyl esters extracted from leaves. We tentatively identified sinapoyl-tartaric acid as another major phenolic compound in peanut leaves that likely participates in secondary reactions with PPO-generated quinones. These results suggest hydroxycinnamoyl-tartaric acid esters are made by an acyltransferase, possibly a BAHD family member, in perennial peanut. Identification of a gene encoding HTT and further characterization of the enzyme will aid in identifying determinants of donor and acceptor substrate specificity for this important class of biosynthetic enzymes. An HTT gene could also provide a means by genetic engineering for producing caffeoyl- and other hydroxycinnamoyl-tartaric acid esters in forage crops that lack them. PMID:24556732

Sullivan, Michael L

2014-05-01

302

Effects of the addition of dimer acid alkyl esters on the properties of ethyl cellulose.  

PubMed

In this study, we synthesized dimer acid (DA) esters, having short to long alkyl chains, (DA-Cn) by the Diels-Alder reaction and subsequent esterification reaction of fatty acids that were prepared by the hydrolysis of waste vegetable oil. It was found that the DA-Cn were thermally more stable than common petroleum-based plasticizer DOP. When the DOP, DA, or DA-Cn with short alkyl chains were added to ethyl cellulose (EC), the optical clarity and SEM images of the samples showed their good miscibility with those additives in a micro-scale. It was also found that the rubbery modulus of the EC decreased with increasing amount of additives; the type of the additives did not affect the rates of the decrease in the rubbery modulus. The main transition temperatures of the EC containing either DA or DA-C1 or DA-C4 decreased with increasing amounts of those additives and were comparable to that of the DOP-containing EC. The above findings suggested that the DA and its esters with short alkyl chains could act as effective plasticizer and, thus, could be used instead of the DOP. In addition, the results obtained from tensile testing and leaching experiments implied that the DA might be better plasticizer than the DA-C1 and DA-C4, at least in some cases, because of hydrogen-bonding with the EC. PMID:25659700

Lee, Sangjun; Ko, Kwang-Hwan; Shin, Jihoon; Kim, Nam-Kyun; Kim, Young-Wun; Kim, Joon-Seop

2015-05-01

303

Environmental Health Perspectives Toxicology of Phthalic Acid Esters Used in Food-Packaging Material  

E-print Network

Phthalic acid esters may be used as plasticizers in food-packaging materials that have direct contact with food. Under normal conditions of use small amounts of the plasticizers would be expected to migrate into the food. The safe use of the phthalic acid esters under these conditions is based on available toxicity data, as well as regulations which, in general, specify the maximum extractable fraction of plasticizer that may enter food. Before the enactment of the Food Additives Amendment to the Federal Food, Drug and Cosmetic Act in 1958, sanctions were granted for the use of five phthalates in food-packaging material (diethyl phthalate, butylphthalyl butyl glycolate, ethylphthalyl ethyl glycolate, diisooctyl phthalate, and di-2-ethylhexyl phthalate), with the limitations that they be used in accordance with good manufacturing practice for food packaging materials, and that di-2-ethylhexyl phthalate and diisooctyl phthalate be used with foods of high water content. Foods of high water content were defined as those from which no fat would be extractedwhen the food was pressed against filter paper; under the conditions of this test, if a water spot was formed the food was considered aqueous and if a fat spot was formed the food was considered fatty. The restriction was applied to di-2-ethylhexyl phthalate and to diisooctyl phthalate because the available toxicological data would not support un-

H. Blumenthal

304

A monolithic lipase reactor for biodiesel production by transesterification of triacylglycerides into fatty acid methyl esters.  

PubMed

An enzymatic reactor with lipase immobilized on a monolithic polymer support has been prepared and used to catalyze the transesterification of triacylglycerides into the fatty acid methyl esters commonly used for biodiesel. A design of experiments procedure was used to optimize the monolithic reactor with variables including control of the surface polarity of the monolith via variations in the length of the hydrocarbon chain in alkyl methacrylate monomer, time of grafting of 1-vinyl-4,4-dimethylazlactone used to activate the monolith, and time used for the immobilization of porcine lipase. Optimal conditions involved the use of a poly(stearyl methacrylate-co-ethylene dimethacrylate) monolith, grafted first with vinylazlactone, then treated with lipase for 2 h to carry out the immobilization of the enzyme. Best conditions for the transesterification of glyceryl tributyrate included a temperature of 37°C and a 10 min residence time of the substrate in the bioreactor. The reactor did not lose its activity even after pumping through it a solution of substrate equaling 1,000 reactor volumes. This enzymatic reactor was also used for the transesterification of triacylglycerides from soybean oil to fatty acid methyl esters thus demonstrating the ability of the reactor to produce biodiesel. PMID:21915852

Urban, Jiri; Svec, Frantisek; Fréchet, Jean M J

2012-02-01

305

Effects of exercise and caffeic acid phenethyl ester after chronic exercise rat model  

PubMed Central

In order to understand whether exercise and caffeic acid phenethyl ester (CAPE) has an effect on obesity and weight control, we investigated the effects of CAPE, and exercise on lipid parameters (triglyceride, total cholesterol, HDL-C, LDL-C), and adipokine substances such as leptin and resistin in rats. 40 male rat were randomly assigned into 4 groups. It was determined that CAPE does not have any significant effect on these parameters but that lipid parameters and leptin values in exercise groups decreased considerably, while no significant change occurred in resistin levels. In order to understand whether diet has an effect on exercise, body weights of all animal groups in pre and post-exercise were compared. A significant weight gain was observed (p = 0.005) in all groups. This study concluded that exercise has a considerable effect on leptin and lipid parameters; however, exercise alone was not sufficient for weight control and could be effective in weight control only when accompanied by a restricted diet. Key points Caffeic acid phenethyl ester is not effective on weight control, lipid parameters, and adipokine substances such as leptin and resistin. Exercise can be effective in weight control only when accompanied by a restricted diet. PMID:24149554

Alp, Ayse; Buyukbas, Sadik; Alp, Harun; Gergerlioglu, H. Serdar; Oz, Mehmet; Basarali, M. Kemal; Kiyici, Aysel

2011-01-01

306

Impact of the pH-DEPENDENT Speciation of Silicic Acid on the Silicon Isotope Composition of Diatoms  

NASA Astrophysics Data System (ADS)

Variations in the natural abundances of the stable isotopes of silicon (?30Si) are a useful tracer of the silica cycle, tracking relative differences in silicic acid drawdown in surface waters by diatoms at times in the past. Refinement of this tracer for silicic acid utilization requires understanding the impact of environmental variables (e.g. temperature, phytoplankton growth rate, pH) on the ?30Si of diatom silica. Initial investigation into the impacts of temperature and growth rate suggested that they do not significantly affect the ?30Si of marine diatoms but no look has been taken at the influence of pH. At the typical seawater pH range of 7.5 to 8.5 most silicic acid is in the undissociated form, Si(OH)_4. By pH 10.5, however, SiO(OH)_3^- predominates. Silicon isotopic fractionation with speciation has never been investigated but if it were 5% of the magnitude suggested for boron isotope fractionation (as might be expected for a secondary isotope effect) then there should be a 1 ppm difference between Si(OH)_4 and SiO(OH)_3^-. Cultures of the diatom, Thalassiosira weissflogii (which utilizes Si(OH)_4 and not SiO(OH)_3^-), grown at pH 7.8 and pH 9.5 display a ?30Si difference of 0.7 ppm, which is consistent with a silicon isotope fractionation on the order of 1 ppm between the different species of silicic acid. In the oceans this should not contribute significantly to the ?30Si variations recorded in diatom silica, as even in dense phytoplankton blooms pH rarely exceeds 8.5. In environments, such as lakes, estuaries, and sea ice brine, where phytoplankton may grow at higher pHs the speciation of silicic acid may make a contribution to diatom ?30Si that cannot be ignored.

Mataliotaki, I.; de La Rocha, C.; Passow, U.; Wolf-Gladrow, D.

2003-04-01

307

Fatty acid hydroxytyrosyl esters: structure/antioxidant activity relationship by ABTS and in cell-culture DCF assays.  

PubMed

A large series of hydroxytyrosyl esters of C2-C18 fatty acids with increasing lipophilicity was prepared by a new highly efficient method based on acylation of methylorthoformate-protected hydroxytyrosol. All products were tested for relative antioxidant effect using ABTS assays in ethanolic medium and DCF assays in L6 cells. No linear correlation between lipophilicity and antioxidant effect was found. ABTS assays showed a growing antioxidant capacity, with respect to hydroxytyrosol, only for medium-sized ester chains (C4-C10) and a nearly constant capacity for the higher homologues. This has been rationalized by molecular dynamics experiments in terms of partial shielding of the catecholic hydroxyls by long-chain esters. A similar and dose-dependent pattern was observed in DCF assays in L6 cells, but a sharp antioxidant activity drop resulted for long-chain esters, probably due to membrane entrapment. PMID:20397651

Tofani, Daniela; Balducci, Valentina; Gasperi, Tecla; Incerpi, Sandra; Gambacorta, Augusto

2010-05-12

308

Highly Functionalized 1,2–Diamino Compounds through Reductive Amination of Amino Acid-Derived ?–Keto Esters  

PubMed Central

1,2-Diamine derivatives are valuable building blocks to heterocyclic compounds and important precursors of biologically relevant compounds. In this respect, amino acid-derived ?–keto esters are a suitable starting point for the synthesis of ?,?–diamino ester derivatives through a two-step reductive amination procedure with either simple amines or ?–amino esters. AcOH and NaBH3CN are the additive and reducing agents of choice. The stereoselectivity of the reaction is still an issue, due to the slow imine-enamine equilibria through which the reaction occurs, affording mixtures of diastereoisomers that can be chromatographically separated. Transformation of the ?,?–diamino esters into pyrrolidinone derivatives allows the configuration assignment of the linear compounds, and constitutes an example of their potential application in the generation of molecular diversity. PMID:23308167

Pérez-Faginas, Paula; Aranda, M. Teresa; García-López, M. Teresa; Infantes, Lourdes; Fernández-Carvajal, Asia; González-Ros, José Manuel; Ferrer-Montiel, Antonio; González-Muñiz, Rosario

2013-01-01

309

Accuracy, Reproducibility, and Interpretation of Fatty Acid Methyl Ester Profiles of Model Bacterial Communities †  

PubMed Central

We determined the accuracy and reproducibility of whole-community fatty acid methyl ester (FAME) analysis with two model bacterial communities differing in composition by using the Microbial ID, Inc. (MIDI), system. The biomass, taxonomic structure, and expected MIDI-FAME profiles under a variety of environmental conditions were known for these model communities a priori. Not all members of each community could be detected in the composite profile because of lack of fatty acid “signatures” in some isolates or because of variations (approximately fivefold) in fatty acid yield across taxa. MIDI-FAME profiles of replicate subsamples of a given community were similar in terms of fatty acid yield per unit of community dry weight and relative proportions of specific fatty acids. Principal-components analysis (PCA) of MIDI-FAME profiles resulted in a clear separation of the two different communities and a clustering of replicates of each community from two separate experiments on the first PCA axis. The first PCA axis accounted for 57.1% of the variance in the data and was correlated with fatty acids that varied significantly between communities and reflected the underlying community taxonomic structure. On the basis of our data, community fatty acid profiles can be used to assess the relative similarities and differences of microbial communities that differ in taxonomic composition. However, detailed interpretation of community fatty acid profiles in terms of biomass or community taxonomic composition must be viewed with caution until our knowledge of the quantitative and qualitative distribution of fatty acids over a wide variety of taxa and the effects of growth conditions on fatty acid profiles is more extensive. PMID:16349327

Haack, Sheridan Kidd; Garchow, Helen; Odelson, David A.; Forney, Larry J.; Klug, Michael J.

1994-01-01

310

Accuracy, reproducibility, and interpretation of fatty acid methyl ester profiles of model bacterial communities  

USGS Publications Warehouse

We determined the accuracy and reproducibility of whole-community fatty acid methyl ester (FAME) analysis with two model bacterial communities differing in composition by using the Microbial ID, Inc. (MIDI), system. The biomass, taxonomic structure, and expected MIDI-FAME profiles under a variety of environmental conditions were known for these model communities a priori. Not all members of each community could be detected in the composite profile because of lack of fatty acid 'signatures' in some isolates or because of variations (approximately fivefold) in fatty acid yield across taxa. MIDI- FAME profiles of replicate subsamples of a given community were similar in terms of fatty acid yield per unit of community dry weight and relative proportions of specific fatty acids. Principal-components analysis (PCA) of MIDI-FAME profiles resulted in a clear separation of the two different communities and a clustering of replicates of each community from two separate experiments on the first PCA axis. The first PCA axis accounted for 57.1% of the variance in the data and was correlated with fatty acids that varied significantly between communities and reflected the underlying community taxonomic structure. On the basis of our data, community fatty acid profiles can be used to assess the relative similarities and differences of microbial communities that differ in taxonomic composition. However, detailed interpretation of community fatty acid profiles in terms of biomass or community taxonomic composition must be viewed with caution until our knowledge of the quantitative and qualitative distribution of fatty acids over a wide variety of taxa and the effects of growth conditions on fatty acid profiles is more extensive.

Kidd, Haack S.; Garchow, H.; Odelson, D.A.; Forney, L.J.; Klug, M.J.

1994-01-01

311

Sorption of phthalic acid esters in two kinds of landfill leachates by the carbonaceous sorbents.  

PubMed

Sorption of phthalic acid esters (PAEs: diethyl phthalate, DEP: dibutyl phthalate, DBP as model compounds) in landfill leachates by activated carbon (AC), carbon nanotubes (CNTs), and biochars, were examined. The young leachate (YL) and old leachate (OL) were synthesized to imitate acetogenic and methanogenic phases, respectively, and glucose (GLU) and fulvic acid (FA) were selected to represent dissolved organic matter (DOM). GLU in leachates generally facilitated the sorption of PAEs while FA restrained sorption of PAEs, suggesting the type of DOM associated with leachates possibly regulated the removal efficiency of PAEs from leachates. The pores and organic carbon of carbonaceous sorbents should be major factors in influencing the sorption of PAEs in leachates. The data showed PAEs in acetogenic leachates was removed more easily than those in methanogenic leachates and CNTs have the less advantage to remove PAEs from methanogenic leachates compared to AC. PMID:23567694

Gao, Bo; Wang, Peng; Zhou, Huaidong; Zhang, Zheyun; Wu, Fengchang; Jin, Jie; Kang, Mingjie; Sun, Ke

2013-05-01

312

Supported phosphate and carbonate salts for heterogeneous catalysis of triglycerides to fatty acid methyl esters  

NASA Astrophysics Data System (ADS)

Fatty acid methyl esters made from vegetable oil, or biodiesel, have been identified as a substitute for diesel derived from crude oil. Biodiesel is currently made using a homogeneous base catalyst to perform the transesterification of triglycerides with methanol to generate fatty acid methyl esters (FAME). The use of a homogeneous catalyst necessitates additional purification of the product and byproducts before sale, and the catalyst is consumed and discarded. The development of a heterogeneous basic catalyst for the production of FAME is desirable. Tribasic phosphate salts and dibasic carbonate salts are active for the production of FAME but generally operate as homogeneous catalysts. Supporting these phosphate and carbonate salts on mesoporous MCM-41, microporous silica gel, and nonporous a-alumina proved successful to greater or lesser degrees depending on the identity of the support and pretreatment of the support. Although these salts were supported and were active for the production of FAME from canola oil, they proved to be operating as homogeneous catalysts due to leaching of the active species off the surface of the support. Further investigation of the active species present in the tribasic phosphate catalysts identified the active support as orthophosphate, and NMR studies revealed the phosphorus to be present as orthophosphate and diphosphate in varying proportions in each catalyst. Evaluation of the acid-washing support pretreatment process revealed that the exposure of the support to acid plays a large role in the development of activity on the surface of the catalyst, but manipulation of these parameters did not prevent leaching of the active site off the surface of the catalyst. Alternate methods of support pretreatment were no more effective in preventing leaching. Tribasic phosphate supported on silica gel is not effective as a heterogeneous catalyst for FAME production from triglycerides because of the lack of stability of the phosphate on the support. The support is not stable under the reaction conditions, and alternatives should be explored to develop a heterogeneous base catalyst for the production of FAME.

Britton, Stephanie Lynne

313

Melanogenesis-inhibitory saccharide fatty acid esters and other constituents of the fruits of Morinda citrifolia (noni).  

PubMed

Five new saccharide fatty acid esters, named nonioside P (3), nonioside Q (4), nonioside R (8), nonioside S (10), and nonioside T (14), and one new succinic acid ester, butyl 2-hydroxysuccinate (=4-butoxy-3-hydroxy-4-oxobutanoic acid) (31), were isolated, along with 26?known compounds, including eight saccharide fatty acid esters, 1, 2, 5, 6, 7, 9, 12, and 13, three hemiterpene glycosides, 15, 17, and 18, six iridoid glycosides, 21-25, and 27, and nine other compounds, 20, 28, 29, and 32-37, from a MeOH extract of the fruit of Morinda citrifolia (noni). Upon evaluation of these and five other glycosidic compounds, 11, 16, 19, 26, and 30, from M. citrifolia fruit extract for their inhibitory activities against melanogenesis in B16 melanoma cells induced with ?-melanocyte-stimulating hormone (?-MSH), most of the saccharide fatty acid esters, hemiterpene glycosides, and iridoid glycosides showed inhibitory effects with no or almost no toxicity to the cells. These compounds were further evaluated with respect to their cytotoxic activities against two human cancer cell lines (HL-60 and AZ521) and their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced with 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells. PMID:22700235

Akihisa, Toshihiro; Tochizawa, Shun; Takahashi, Nami; Yamamoto, Ayako; Zhang, Jie; Kikuchi, Takashi; Fukatsu, Makoto; Tokuda, Harukuni; Suzuki, Nobutaka

2012-06-01

314

Modification of ceftibuten transport by changes in lipid fluidity caused by fatty acid glycerol esters.  

PubMed

The effects of various fatty acid glycerol esters (FAGE) on the transport of ceftibuten in rat intestinal brush-border membrane vesicles (BBMV) were investigated. The HLB numbers of FAGE used were in the range of 6.5 to 15.7. The ceftibuten uptake by BBMV was examined by a rapid filtration method in the presence or absence of FAGE of a non-solubilizing concentration (0.03%, w/v). Tetraglycerol monostearate, hexaglycerol monostearate, hexaglycerol sesquistearate, hexaglycerol tristearate and decaglycerol tristearate were found significantly to enhance the ceftibuten uptake under an inward H+-gradient condition, while FAGE with oleate or laurate did not affect it. The extent of ceftibuten uptake with FAGE correlated with the HLB of the esters (r= -0.90, p<0.001). To elucidate the mechanism of its enhancing action, the effects of FAGE on the membrane lipid fluidity were examined using the fluorescence probes diphenylhexatriene (DPH) and trimethylammonium diphenylhexatriene (TMA-DPH) which distribute in the hydrophobic inner and outer regions of the lipid layer, respectively. The increase in ceftibuten uptake induced by FAGE proved to correlate with an increase in fluidity of the outer lipid layer (r= -0.83, p<0.003) but not the inner lipid layer of BBMV. Hence, the enhancing effect of FAGE with the lower HLB on the ceftibuten transport in the presence of the H+-gradient should, at least in part, be explained by the interaction with the outer lipid regions of BBMV. PMID:9989674

Koga, K; Murakami, M; Kawashima, S

1999-01-01

315

Co-limitation of diatoms by iron and silicic acid in the equatorial Pacific  

NASA Astrophysics Data System (ADS)

The relative roles of silicon (Si) and iron (Fe) as limiting nutrients in the eastern equatorial Pacific (EEP) were examined in a series of nine microcosm experiments conducted over two years between 110°W and 140°W longitude. Si and Fe additions had consistently different but synergistic effects on macronutrient use, phytoplankton biomass and phytoplankton community structure. Silicon addition increased silicic acid use and biogenic silica production, but had no significant effect on the use of inorganic nitrogen or orthophosphate, chlorophyll accumulation, particulate inorganic (PIC) carbon accumulation, or plankton community composition relative to controls. That result, together with observations that Si addition increased the cellular Si content of the numerically dominant diatom by ˜50%, indicates that the main effect of Si was to regulate diatom silicification. Like the effect of Si, Fe addition increased the rate of silicic acid use and biogenic silica production and had no effect on PIC production. Unlike the effect of Si, Fe addition also enhanced rates of organic matter production, had no effect on cellular Si content of diatoms, and resulted in the growth of initially rare, large (>40 ?m) diatoms relative to controls, indicating that Fe limitation acts mainly through its effects on growth rate and phytoplankton community composition. A pennate diatom of the genus Pseudo-nitzschia dominated the diatom assemblage in situ, grew readily in the controls and did not show a strong growth response to either Fe or Si addition suggesting that its growth was regulated by other factors such as grazing or light. Addition of germanium, an inhibitor of diatom cell division, eliminated the effects of Fe on macronutrient use, biogenic silica production and chlorophyll accumulation and phytoplankton community composition, consistent with a predominantly diatom response to Fe addition. The lack of a response of PIC production to Fe suggests that coccolithophores were not Fe limited. Addition of Fe and Si together resulted in the greatest levels of nutrient drawdown and biomass accumulation through the effect of Fe in promoting the growth of large diatoms. The results suggest a form of co-limitation with Si regulating diatom silicification and the rate of biogenic silica production while Fe regulates the production of organic matter through limitation of phytoplankton growth rates, in particular those of large diatoms. The results argue against Si regulation of new production in the EEP under average upwelling conditions. Iron addition was necessary and sufficient to stimulate complete removal of nitrate within the equatorial upwelling zone suggesting that new production was restricted by low ambient dissolved Fe consistent with results from in situ Fe fertilization experiments conducted to the south of the equator outside of the equatorial upwelling zone.

Brzezinski, Mark A.; Baines, Stephen B.; Balch, William M.; Beucher, Charlotte P.; Chai, Fei; Dugdale, Richard C.; Krause, Jeffrey W.; Landry, Michael R.; Marchi, Albert; Measures, Chris I.; Nelson, David M.; Parker, Alexander E.; Poulton, Alex J.; Selph, Karen E.; Strutton, Peter G.; Taylor, Andrew G.; Twining, Benjamin S.

2011-03-01

316

pH-independent controlled-release microspheres using polyglycerol esters of fatty acids.  

PubMed

The release of a drug having low solubility in a certain pH range from controlled-release microspheres using tetraglycerol pentastearate and tetraglycerol monostearate in combination as the matrix base showed pH dependence. Trepibutone, an acidic drug having lower solubility in an acidic medium, was released pH-independently from the microspheres which incorporated magnesium oxide, a solid base. It might have resulted from the pH inside the matrix being kept in an optimum range for drug release due to the incorporation of a solid base. On the other hand, the addition of water soluble acidic or basic excipients was ineffective to achieve pH-independent release. For papaverine, a basic drug, pH-independent drug-release characteristics could be achieved by adding Eudragit L100-55, an enteric polymer. It is thought that the enteric polymer increased the pores for drug release by dissolving in a higher pH range, where the solubility of papaverine is low, and thereby made the release pH-independent. Further, selecting a polyglycerol ester of a fatty acid with an appropriate hydrophile-lipophile balance as the matrix could yield a drug with the desired release rate at any pH. PMID:7891282

Akiyama, Y; Yoshioka, M; Horibe, H; Hirai, S; Kitamori, N; Toguchi, H

1994-11-01

317

Synthesis of p-aminophenyl aryl H-phosphinic acids and esters via cross-coupling reactions: elaboration to phosphinic acid pseudopeptide analogues of pteroyl glutamic acid and related antifolates.  

PubMed

The synthesis of suitably protected p-aminophenyl H-phosphinic acids and esters from the corresponding para-substituted aryl halides has been accomplished via the Pd-catalyzed cross-coupling reaction of anilinium hypophosphite, either in the absence or presence of a tetraalkyl orthosilicate, to provide the free H-phosphinic acid or the corresponding ester, respectively. Subsequent conjugate addition of either a PIII species or phosphorus anion, generated in situ from either the free H-phosphinic acid or ester, to a 2-methylene glutaric acid ester provided the aryl phosphinic acid analogue of p-aminobenzoyl glutamic acid. Alkylation of these suitably protected p-aminophenyl phosphinic acid esters with a 6-(bromomethyl)pteridine or the corresponding (bromomethyl)pyridopyrmidine, followed by hydrolytic removal of protecting groups, provided the target aryl phosphinic acid analogues of folic acid and related antifolates. Alternatively, for the synthesis of the folate or 5-deazafolate analogues on a slightly larger scale, reductive amination with either N2-acetyl or N2-pivaloyl-6-formylpterin or the corresponding formylpyridopyrmidine and the same suitably protected p-aminophenyl phosphinic acid esters, followed by removal of protecting groups, is preferred. In the course of this research, it was observed that the nucleophilicity of both the aniline nitrogen and various PIII species derived from p-aminophenyl phosphinic acid derivatives is significantly reduced compared to that of the unsubstituted counterpart. PMID:17602593

Yang, Yonghong; Coward, James K

2007-07-20

318

Spherical Oligo-Silicic Acid SOSA Disclosed as Possible Endogenous Digitalis-Like Factor  

PubMed Central

The Na+/K+-ATPase is a membrane ion-transporter protein, specifically inhibited by digitalis glycosides used in cardiac therapy. The existence in mammals of some endogenous digitalis-like factors (EDLFs) as presumed ATPase ligands is generally accepted. But the chemical structure of these factors remained elusive because no weighable amounts of pure EDLFs have been isolated. Recent high-resolution crystal structure data of Na+/K+-ATPase have located the hydrophobic binding pocket of the steroid glycoside ouabain. It remained uncertain if the EDLF are targeting this steroid-receptor or another specific binding site(s). Our recently disclosed spherical oligo-silicic acids (SOSA) fulfill the main criteria to be identified with the presumed EDL factors. SOSA was found as a very potent inhibitor of the Na+/K+-ATPase, Ca2+-ATPase, H+/K+-ATPase, and of K-dp-ATPase, with IC50 values between 0.2 and 0.5??g/mL. These findings are even more astonishing while so far, neither monosilicic acid nor its poly-condensed forms have been remarked biologically active. With the diameter ? between 1 and 3?nm, SOSA still belong to molecular species definitely smaller than silica nano-particles with ??>?5?nm. In SOSA molecules, almost all Si-OH bonds are displayed on the external shell, which facilitates the binding to hydrophilic ATPase domains. SOSA is stable for long term in solution but is sensitive to freeze-drying, which could explain the failure of countless attempts to isolate pure EDLF. There is a strong resemblance between SOSA and vanadates, the previously known general inhibitors of P-type ATPases. SOSA may be generated endogenously by spherical oligomerization of the ubiquitously present monosilicic acid in animal fluids. The structure of SOSA is sensitive to the concentration of Na+, K+, Ca2+, Mg2+, and other ions suggesting a presumably archaic mechanism for the regulation of the ATPase pumps.

Kerek, Franz; Voicu, Victor A.

2015-01-01

319

Caffeic acid phenethyl ester: its protective role against certain major eye diseases.  

PubMed

As an effective compound found mainly in the honeybee product propolis, caffeic acid phenethyl ester (CAPE) has been commonly utilized as a medicine and remedial agent, in a number of countries. Specifically, it might inhibit nuclear factor kappa B at micromolar concentrations and demonstrate antioxidant, antineoplastic, antiproliferative, cytostatic, antiviral, antibacterial, antifungal, and anti-inflammatory features. This review article summarizes the recent progress regarding the favorable effects of CAPE on a number of eye disease models, including cataract and posterior capsule opacification, corneal diseases, retina and optic nerve-related diseases, ischemia/reperfusion injury of retina, inflammation and infection-related diseases. CAPE has been found to exhibit promising efficacy, with minimal adverse effects, in animal and cell culture studies of several eye diseases. PMID:25100535

Akyol, Sumeyya; Ugurcu, Veli; Balci, Mehmet; Gurel, Ayse; Erden, Gonul; Cakmak, Ozlem; Akyol, Omer

2014-11-01

320

[Comparative assessment of Cladophora, Spirogyra and Oedogonium biomass for the production of fatty acid methyl esters].  

PubMed

The use of alternative fuels for the mitigation of ecological impacts by use of diesel has been focus of intensive research. In the present work, algal oils extracted from cultivated biomass of Cladophora sp., Spirogyra sp. and Oedogonium sp. were evaluated for the lipase-mediated synthesis of fatty acid monoalkyl esters (FAME, biodiesel). To optimize the transesterification of these oils, different parameters such as the alkyl group donor, reaction temperature, stirring time and oil to alcohol ratio were investigated. Four different alcohols i.e. methanol, ethanol, n-propanol and n-butanol were tested as alkyl group donor for the biosynthesis FAME and methanol was found to be the best. Similarly, temperature 50 C and stirring time of 6 h were optimized for the transesterification of oils with methanol. The maximum biodiesel conversions from Cladophora (75.0%), Spirogyra (87.5%) and Oedogonium (92.0%) were obtained when oil to alcohol ratio was 1 : 8. PMID:25272756

Haq, I; Muhammad, A; Hameed, U

2014-01-01

321

Theoretical, antioxidant and cytotoxic activities of caffeic acid phenethyl ester and chrysin.  

PubMed

The structure-activity relationship was used to describe the antioxidant pharmacophore of caffeic acid phenethyl ester (CAPE) and chrysin by using quantum chemical calculations and the density functional theory method. The Becke three-parameter hybrid exchange functional in combination with the Lee-Yang-Parr correction functional protocol was employed for structure optimization and other computations. Theoretical calculations were conducted to explain the structure-activity relationship and pharmacokinetic behavior of CAPE and chrysin. The free radical scavenging activities of CAPE and chrysin were evaluated by using the 2,2-diphenyl-1-picrylhydrazyl assay. The cytotoxic effects of CAPE and chrysin on the human leukemia cell line (HL-60) were evaluated by using the 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. PMID:24020631

Sulaiman, Ghassan M; Al-Amiery, Ahmed A; Bagnati, Renzo

2014-02-01

322

Intraparticle diffusion limitations in the hydrogenation of monounsaturated edible oils and their fatty acid methyl esters  

SciTech Connect

Intraparticle diffusion limitation in the hydrogenation and isomerization of fatty acid methyl esters (FAMEs) and edible oils (triacylglycerol, TAG) in porous nickel catalyst was investigated both under reactive and under inert conditions. Under reactive conditions, the diffusion coefficients were determined from the best fits of the model simulations applying the intrinsic reacting kinetics of monounsaturated FAME hydrogenation to experiments under diffusion limited conditions. Due to the absence of reaction (hydrogenation of double bonds), the obtained effective H{sub z} diffusion coefficient (D{sub e}) with the HPLC technique is volume averaged and thereby determined by the larger intercrystalline pores (<30% of the total pore volume) only. Moreover, D{sub e} measured under reaction conditions reflected the influence of the micropores, resulting in a 10-fold lower value.

Jonker, G.H.; Veldsink, J.W.; Beenackers, A.A.C.M. [Univ. of Groningen (Netherlands). Dept. of Chemical Engineering] [Univ. of Groningen (Netherlands). Dept. of Chemical Engineering

1998-12-01

323

Experimental and computational thermochemical study of 2- and 3-thiopheneacetic acid methyl esters.  

PubMed

Thiophene-based compounds have widespread use in modern drug design, biodiagnostics, electronic and optoelectronic devices, and conductive polymers. The present study reports an experimental and computational thermochemical study on the relative stabilities of 2- and 3-thiopheneacetic acid methyl esters. The enthalpies of combustion and vaporization were measured by a rotating-bomb combustion calorimeter, Calvet microcalorimetry, and correlation gas chromatography, and the gas-phase enthalpies of formation at T=298.15 K were determined. Standard ab initio molecular orbital calculations at the G3 level were performed, and a theoretical study of the molecular and electronic structure of the compounds studied was carried out. Calculated enthalpies of formation, using atomization and isodesmic reactions are in very good agreement with the experimental results. PMID:17530748

Roux, María Victoria; Temprado, Manuel; Notario, Rafael; Chickos, James S; Santos, Ana Filipa L O M; da Silva, Manuel A V Ribeiro

2007-06-21

324

PAF antagonistic activity of 2-hydroxy-3-methoxybenzoic acid glucose ester from Gentiana scabra.  

PubMed

In order to find out anti-platelet activating factor (PAF) from natural resources, Korean medicinal plants used for the treatments of peripheral circulation disorders were tested for their possible protective effects on PAF-induced anaphylactic shock. From the above screening, the methanol extract of Gentiana scabra showed a potent antagonistic activity against PAF. Water suspension of the extract was partitioned with CH2Cl2 and EtOAc, successively. The EtOAc fraction which showed the highest activity was chromatographed on silica gel to yield 6 fractions. From the fraction which showed higher PAF-antagonistic activity than the other fractions, compound 1 was isolated by recrystallization. On the basis of spectral data, compound 1 was identified as 2-hydroxy-3-methoxybenzoic acid glucose ester. The compound prevented the mice from the PAF-induced death at a dose of 300 micrograms/mouse. PMID:9875472

Huh, H; Kim, H K; Lee, H K

1998-08-01

325

Structural basis for the inhibition of AKR1B10 by caffeic acid phenethyl ester (CAPE).  

PubMed

Caffeic acid phenethyl ester (CAPE), the major bioactive component of honeybee propolis, is a potent selective inhibitor of aldo-keto reductase family member 1B10 (AKR1B10), and a number of derivatives hold promise as potential anticancer agents. However, sequence homology between AKR1B10 and other members of the superfamily, including critical phase I metabolizing enzymes, has resulted in a concern over the selectivity of any potential therapeutic agent. To elucidate the binding mode of CAPE with AKR1B10 and to provide a tool for future in silico efforts towards identifying selective inhibitors, the crystal structure of AKR1B10 in complex with CAPE was determined. The observed interactions provide an explanation for the selectivity exhibited by CAPE for AKR1B10, and could be used to guide further derivative design. PMID:24436249

Zhang, Liping; Zhang, Hong; Zheng, Xuehua; Zhao, Yining; Chen, Shangke; Chen, Yunyun; Zhang, Renwei; Li, Qing; Hu, Xiaopeng

2014-04-01

326

Enzymatic synthesis of caffeic acid phenethyl ester analogues in ionic liquid.  

PubMed

An efficient procedure for transesterification of methyl caffeate was developed to produce caffeic acid phenethyl ester analogues with Candida antarctica lipase B using an ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, as a solvent. The system provided 48.8mM 2-cyclohexylethyl caffeate and 46.9 mM 3-cyclohexylpropyl caffeate with conversion yields of 97.6% and 93.8%, respectively. Reusability of the system was investigated, and the yield of 4-phenylbutyl caffeate was increased from 30.4 to 45.7 mM when the transesterification was carried out under reduced pressure to remove a by-product, methanol. Additionally, we showed that both 2-cyclohexylethyl caffeate and 3-cyclohexylpropyl caffeate exhibit strong antiproliferative activities, which are comparable to that of 5-fluorouracil by MTT assay. PMID:20553773

Kurata, Atsushi; Kitamura, Yuki; Irie, Shiori; Takemoto, Shintaro; Akai, Yoshiaki; Hirota, Yoshitaka; Fujita, Tokio; Iwai, Kazuya; Furusawa, Mina; Kishimoto, Noriaki

2010-07-20

327

What Are the Sources of Exposure to Eight Frequently Used Phthalic Acid Esters in Europeans&quest  

Microsoft Academic Search

Phthalic acid esters (phthalates) are used as plasticizers in numerous consumer products, commodities, and building materials. Consequently, phthalates are found in human residential and occupational environments in high concentrations, both in air and in dust. Phthalates are also ubiquitous food and environmental contaminants. An increasing number of studies sampling human urine reveal the ubiquitous phthalate exposure of consumers in industrialized

Matthias Wormuth; Martin Scheringer; Meret Vollenweider; Konrad Hungerbühler

2006-01-01

328

Quantitative Fourier transform infrared spectroscopy of binary mixtures of fatty acid esters using partial least squares regression  

Microsoft Academic Search

This work describes a quantitative spectroscopic method for the analysis of binary mixtures of fatty acid esters using multivariate data models based upon Fourier Transform Infra Red (FT-IR) spectroscopy. Multivariate calibration of binary mixtures has been performed using Partial Least Squares regression (PLS), with two approaches being applied for fitting the inner relation namely a standard linear function and a

Emma S. Haines; Anthony D. Walmsley; Stephen J. Haswell

1997-01-01

329

Improved Monitoring of Female Codling Moth (Lepidoptera: Tortricidae) with Pear Ester Plus Acetic Acid in Sex Pheromone-treated Orchards  

Technology Transfer Automated Retrieval System (TEKTRAN)

Catch of codling moth, Cydia pomonella (L.), in clear delta traps baited with ethyl (E,Z)-2,4-decadienoate (pear ester, PE) and acetic acid (AA) in separate lures (PE+AA) was compared with catch in orange delta traps baited with a single lure containing PE and the sex pheromone, (E,E)-8,10-dodecadie...

330

Combined effects of carbonation with heating and fatty acid esters on inactivation and growth inhibition of various bacillus spores.  

PubMed

The effects of carbonation treatment (1 to 5 MPa, 30 min) plus heat treatment (30 to 80°C, 30 min) in the presence of various fatty acid esters (FAEs; 0.05 and 0.1%, wt/vol) on counts of viable Bacillus subtilis spores were investigated. FAEs or carbonation alone had no inactivation or growth inhibition effects on B. subtilis spores. However, carbonation plus heat (CH; 80°C, 5 MPa, 30 min) in the presence of mono- and diglycerol fatty acid esters markedly decreased counts of viable spores, and the spore counts did not change during storage for 30 days. The greatest decrease in viable spore counts occurred in the presence of monoglycerol fatty acid esters. Under CH conditions, inactivation and/or growth inhibition occurred at only 80°C and increased with increasing pressure. The greatest decrease in spore counts (more than 4 log units) occurred with CH (80°C, 5 MPa, 30 min) in the presence of monoglycerol fatty acid esters. However, this treatment was less effective against Bacillus coagulans and Geobacillus stearothermophilus spores. PMID:23992501

Klangpetch, Wannaporn; Nakai, Tomoe; Noma, Seiji; Igura, Noriyuki; Shimoda, Mitsuya

2013-09-01

331

75 FR 20785 - Polyglyceryl Phthalate Ester of Coconut Oil Fatty Acids; Exemption from the Requirement of a...  

Federal Register 2010, 2011, 2012, 2013, 2014

EPA issued a final rule in the Federal Register of July 8, 2009, concerning polyglyceryl phthalate ester of coconut oil fatty acids; exemption from the requirement of a tolerance. This document is being issued to correct the inert ingredient name and CAS...

2010-04-21

332

Design and synthesis of novel nitrogen-containing polyhydroxylated aromatics as HIV-1 integrase inhibitors from caffeic acid phenethyl ester.  

PubMed

A series of nitrogen-containing polyhydroxylated aromatics from caffeic acid phenethyl ester were designed and synthesized as HIV-1 integrase inhibitors. Most of these compounds exhibited potent inhibitory activities at micromolar concentrations against HIV-1 integrase in the 3'-end processing and the strand transfer. Their key structure-activity relationship was also discussed. PMID:19625188

Wang, Peng; Liu, Chuan; Sanches, Tino; Zhong, Yuan; Liu, Bo; Xiong, Junlong; Neamati, Nouri; Zhao, Guisen

2009-08-15

333

Caffeic acid phenethyl ester (CAPE) analogues: potent nitric oxide inhibitors from the Netherlands propolis.  

PubMed

The MeOH and water extracts of the Netherlands propolis were tested for their inhibitory activity toward nitric oxide (NO) production in lipopolysaccharide (LPS)-activated murine macrophage-like J774.1 cells. Both of the extract possessed significant NO inhibitory activity with IC(50) values of 23.8 and 51.5 microg/ml, respectively. Then 13 phenolic compounds obtained from the MeOH extract showing stronger NO inhibition were examined on their NO inhibitory activities. Caffeic acid phenethyl ester (CAPE) analogues, i.e., benzyl caffeate, CAPE and cinnamyl caffeate, possessed most potent NO inhibitory activities with IC(50) values of 13.8, 7.64 and 9.53 microM, respectively, which were two- to four-fold stronger than the positive control N(G)-monomethyl-L-arginine (L-NMMA; IC(50), 32.9 microM). Further study on the synthetic analogues of CAPE revealed that both of 3-phenylpropyl caffeate (18; IC(50), 7.34 microM) and 4-phenylbutyl caffeate (19; IC(50), 6.77 microM) possessed stronger NO inhibitory activity than CAPE (10) and that elongation of alkyl side chain of alcoholic parts of caffeic acid esters enhance the NO inhibitory activity. In addition, it was found that CAPE analogues having longer carbon chain (>C(5)) in alcoholic part showed toxic effects toward J774.1 cells. This NO inhibitory effect may directly correlate with antiinflammatory properties of the Netherlands propolis. PMID:12673030

Nagaoka, Takema; Banskota, Arjun H; Tezuka, Yasuhiro; Midorikawa, Kiyoshi; Matsushige, Katsumichi; Kadota, Shigetoshi

2003-04-01

334

A Phosphetane Catalyzes Deoxygenative Condensation of ?-Keto Esters and Carboxylic Acids via P(III)/P(V)?O Redox Cycling.  

PubMed

A small-ring phosphacycle is found to catalyze the deoxygenative condensation of ?-keto esters and carboxylic acids. The reaction provides a chemoselective catalytic synthesis of ?-acyloxy ester products with good functional group compatibility. Based on both stoichiometric and catalytic mechanistic experiments, the reaction is proposed to proceed via catalytic P(III)/P(V)?O cycling. The importance of ring strain in the phosphacyclic catalyst is substantiated by an observed temperature-dependent product selectivity effect. The results point to an inherent distinction in design criteria for organophosphorus-based catalysts operating via P(III)/P(V)?O redox cycling as opposed to Lewis base (nucleophilic) catalysis. PMID:25564133

Zhao, Wei; Yan, Patrick K; Radosevich, Alexander T

2015-01-21

335

Eicosapentaenoic acid ethyl ester supplementation in cachectic cancer patients and healthy subjects: effects on lipolysis and lipid oxidation  

Microsoft Academic Search

Background & aims: Recent reports suggest that weight loss in cachectic cancer patients may be inhibited by supplementation of the n-3 fatty acid eicosapentaenoic acid (20:5n-3; EPA), presumably due to inhibition of lipolysis. The aim of the present double-blind, randomized trial was to assess whether short-term oral EPA ethyl ester (EE) supplementation inhibits lipolysis and lipid oxidation in weight-losing cancer

S. D. ZUIJDGEEST-VAN lEEUWEN; P. C. DAGNELIE; J. L. D. WATTIMENA; J. W. O. VAN DEN BERG; A. VAN DER GAAST; G. R. SWART; J. H. PAUL WILSON

2000-01-01

336

Enzymatic synthesis of theanine from glutamic acid ?-methyl ester and ethylamine by immobilized Escherichia coli cells with ?-glutamyltranspeptidase activity  

Microsoft Academic Search

Theanine (?-glutamylethylamide) is the main amino acid component in green tea. The demand for theanine in the food and pharmaceutical\\u000a industries continues to increase because of its special flavour and multiple physiological effects. In this research, an improved\\u000a method for enzymatic theanine synthesis is reported. An economical substrate, glutamic acid ?-methyl ester, was used in the\\u000a synthesis catalyzed by immobilized

Fei Zhang; Qing-Zhong Zheng; Qing-Cai Jiao; Jun-Zhong Liu; Gen-Hai Zhao

2010-01-01

337

COMPARISON OF SERUM FATTY ACID ETHYL ESTERS AND URINARY 5-HYDROXYTRYPTOPHOL AS BIOCHEMICAL MARKERS OF RECENT ETHANOL CONSUMPTION  

Microsoft Academic Search

Aims: To examine the effects of an acute dose of ethanol on serum fatty acid ethyl esters (FAEEs) concentration and urinary 5-hydroxytryptophol (5-HTOL)\\/5-hydroxyindole-3-acetic acid (5-HIAA) ratio. Methods: Sixteen (14 male, 2 female) heavy alcohol drinkers were tested in a single, 2-day long session. Six participants received 1.5 g\\/l of ethanol\\/l of body water (~0.75 g\\/kg of body weight, low dose

ADAM BISAGA; MICHAEL LAPOSATA; SHAN XIE; SUZETTE M. EVANS

2005-01-01

338

Metal Extraction by Silyl?Substituted Diphosphonic Acids. III. Ester Group Substituent Effects on Phosphoryl Oxygen Basicity  

Microsoft Academic Search

Partial esters of alkylenediphosphonic acids are powerful metal ion extractants for actinides in all oxidation states. A study of americium extraction by silyl?substituted alkylenediphosphonic acids revealed higher extraction efficiency for these ligands compared to their 2?ethylhexyl analogs. The increased efficiency of silyl extractants could arise from differences in phosphoryl oxygen basicity and\\/or metal complex aqueous phase solubility. Substituent effects for

P. R. Zalupski; D. R. McAlister; D. C. Stepinski; A. W. Herlinger

2003-01-01

339

Omega-3 polyunsaturated fatty acids and cardiovascular disease: an emphasis on omega-3-acid ethyl esters 90 for the treatment of hypertriglyceridemia.  

PubMed

A number of epidemiological/observational studies, as well as large-scale randomized intervention studies, have been conducted to provide evidence for the efficacy of ?-3 fatty acids against atherosclerotic diseases. Currently, ?-3 fatty acids are commercially available in many parts of the world containing the same active ingredients as Lotriga(®) (?-3-acid ethyl esters 90 [O3AE highly concentrated ?-3 fatty acid ethyl esters, consisting of eicosapentaenoic acid-ethyl ester and docosahexaenoic acid-ethyl ester [EPA-E/DHA-E]). A recent head-to-head comparative study of O3AEE90 versus EPA-E demonstrated that O3AEE90 4g/day led to a significantly greater reduction in triglycerides (TG) than EPA-E 1.8g/day and that O3AEE90 2g/day produced comparable effects on TG to those with EPA-E 1.8g/day. While both agents were shown to be useful in lowering TG, the hallmark feature of O3AEE90, that is, the presence of the DHA-E component versus its absence in EPA-E, needs to be further examined for its clinical implications. PMID:25319059

Tatsuno, Ichiro

2014-11-01

340

Fatty acids of Thespesia populnea: Mass spectrometry of picolinyl esters of cyclopropene fatty acids  

Technology Transfer Automated Retrieval System (TEKTRAN)

Thespesia populnea belongs to the plant family of Malvaceae which contain cyclopropane and cyclopropene fatty acids. However, previous literature reports vary regarding the content of these compounds in Thespesia populnea seed oil. In this work, the content of malvalic acid (8,9-methylene-9-heptade...

341

Iron and silicic acid concentrations regulate Si uptake north and south of the Polar Frontal Zone in the Pacific Sector of the Southern Ocean  

Microsoft Academic Search

We investigated the relative roles of Fe and silicic acid availabilities in regulating Si uptake rates across the Polar Frontal Zone in the Pacific Sector of the Southern Ocean (59–68°S, 170°W) during the US JGOFS Antarctic Environment Southern Ocean Process Study (AESOPS). Meridional gradients in silicic acid concentration ([Si(OH)4]) of about 0.25–0.56?Mkm?1 were observed in this area during austral spring

Valerie M. Franck; Mark A Brzezinski; Kenneth H Coale; David M Nelson

2000-01-01

342

Condensation of anhydrides or dicarboxylic acids with compounds containing active methylene groups. Part 19: Condensation of phthalic and substituted phthalic anhydrides with benzoylacetic ester  

NASA Technical Reports Server (NTRS)

Phthalylbenzoylacetic ester and its nitro and halogen derivatives were prepared through condensation of phthalic anhydride, nitrophthalic anhydride, and phthalic halide anhydride with benzoylacetic ester in a solution of acetic anhydride and triethylamine. The condensation of hemipinic acid anhydride proceeds similarly, but under more drastic conditions. Derivatives of indan-1,3-dione are also formed, with a small yield, in the reaction of nitrophthalic anhydrides with benzoylacetic ester in the presence of increased quantities of triethylamine.

Rotberg, Y. T.; Oshkaya, V. P.

1985-01-01

343

Concurrent release of admixed antimicrobials and salicylic acid from salicylate-based poly(anhydride-esters)  

PubMed Central

A polymer blend consisting of antimicrobials (chlorhexidine, clindamycin, and minocycline) physically admixed at 10% by weight into a salicylic acid-based poly (anhydride-ester) (SA-based PAE) was developed as an adjunct treatment for periodontal disease. The SA-based PAE/antimicrobial blends were characterized by multiple methods, including contact angle measurements and differential scanning calorimetry. Static contact angle measurements showed no significant differences in hydrophobicity between the polymer and antimicrobial matrix surfaces. Notable decreases in the polymer glass transition temperature (Tg) and the antimicrobials' melting points (Tm) were observed indicating that the antimicrobials act as plasticizers within the polymer matrix. In vitro drug release of salicylic acid from the polymer matrix and for each physically admixed antimicrobial was concurrently monitored by high pressure liquid chromatography during the course of polymer degradation and erosion. Although the polymer/antimicrobial blends were immiscible, the initial 24 h of drug release correlated to the erosion profiles. The SA-based PAE/antimicrobial blends are being investigated as an improvement on current localized drug therapies used to treat periodontal disease. PMID:19180627

Johnson, Michelle L.; Uhrich, Kathryn E.

2008-01-01

344

Locally Delivered Salicylic Acid from a Poly(anhydride-ester): Impact on Diabetic Bone Regeneration  

PubMed Central

Diabetes mellitus (DM) involves metabolic changes that can impair bone repair, including a prolonged inflammatory response. A salicylic acid-based poly(anhydride-ester) (SA-PAE) provides controlled and sustained release of salicylic acid (SA) that locally resolves inflammation. This study investigates the effect of polymer-controlled SA release on bone regeneration in diabetic rats where enhanced inflammation is expected. Fifty-six Sprague-Dawley rats were randomly assigned to two groups: diabetic group induced by streptozotocin (STZ) injection or normoglycemic controls injected with citrate buffer alone. Three weeks after hyperglycemia development or vehicle injection, 5 mm critical sized defects were created at the rat mandibular angle and treated with SA-PAE/bone graft mixture or bone graft alone. Rats were euthanized 4 and 12 weeks after surgery, then bone fill percentage in the defect region was assessed by micro-computed tomography (CT) and histomorphometry. It was observed that bone fill increased significantly at 4 and 12 weeks in SA-PAE/bone graft-treated diabetic rats compared to diabetic rats receiving bone graft alone. Accelerated bone formation in normoglycemic rats caused by SA-PAE/bone graft treatment was observed at 4 weeks but not at 12 weeks. This study shows that treatment with SA-PAE enhances bone regeneration in diabetic rats and accelerates bone regeneration in normoglycemic animals. PMID:23827476

Wada, Keisuke; Yu, Weiling; Elazizi, Mohamad; Barakat, Sandrine; Ouimet, Michelle A.; Rosario-Meléndez, Roselin; Fiorellini, Joseph P.; Graves, Dana T.; Uhrich, Kathryn E.

2013-01-01

345

Effect of ionic liquids on enzymatic synthesis of caffeic acid phenethyl ester.  

PubMed

Although caffeic acid phenethyl ester (CAPE), an active flavonoid, plays an important role in the antioxidant activity of honeybee propolis, the isolation of CAPE from honeybee propolis is time-consuming due to wide variety of impurities present. Therefore, biochemical method to synthesize CAPE was investigated in this study. Since ionic liquids (ILs) possess some unique characteristics as appreciated alternatives to conventional solvents for certain biotransformation, the effect of ILs as reaction media for enzymatic synthesis of CAPE was assessed. Several factors including substrate molar ratio, and reaction temperature affecting the conversion yield of lipase-catalyzed CAPE synthesis were also investigated. Reaction yields were significantly higher in hydrophobic ILs than in hydrophilic ILs (almost zero). Among nine hydrophobic ILs tested, the highest conversion of synthetic reaction was obtained in 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([Emim][Tf(2)N]). A reaction temperature of 70 °C was found to give high conversion. In addition, optimal substrate molar ratio between phenethyl alcohol and caffeic acid (CA) was decreased significantly from 92:1 to 30:1 when ILs were used instead of isooctane. PMID:21909673

Ha, Sung Ho; Anh, Tran Van; Lee, Sang Hyun; Koo, Yoon-Mo

2012-01-01

346

Optimization of ultrasound-accelerated synthesis of enzymatic caffeic acid phenethyl ester by response surface methodology.  

PubMed

The ultrasound-accelerated enzymatic synthesis of caffeic acid phenethyl ester (CAPE) from caffeic acid and phenethyl alcohol was investigated in this study. A commercial immobilized lipase from Candida antarctica, called Novozym® 435, was used as the catalyst. A 5-level-4-factor central-composite rotatable design (CCRD) and response surface methodology (RSM) were employed to evaluate the effects of reaction time, substrate molar ratio, enzyme amount, and ultrasonic power on percent molar conversion of CAPE. The results indicated that reaction time, substrate molar ratio, and ultrasonic power significantly affected percent molar conversion, whereas enzyme amount did not. A model for synthesis of CAPE was established. Based on ridge max analysis, the optimum condition for CAPE synthesis was predicted to be reaction time 9.6 h, substrate molar ratio 1:71, enzyme amount 2938 PLU, and ultrasonic power 2 W/cm(2) with the molar conversion value of 96.03 ± 5.18%. An experiment was performed under this optimal condition and molar conversion of 93.08 ± 0.42% was obtained. PMID:20797894

Chen, Hsiao-Ching; Chen, Jiann-Hwa; Chang, Cheng; Shieh, Chwen-Jen

2011-01-01

347

Olfactory Perception of Oviposition-Deterring Fatty Acids and Their Methyl Esters by the Asian Corn Borer, Ostrinia furnacalis  

PubMed Central

Olfactory perception of myristic, palmitic, stearic and oleic acids and their corresponding methyl esters by Asian corn borer moths, Ostrinia furnacalis (Guenée) (Lepidoptera: Crambidae) was investigated. It was found that mated females with both antennae amputated, in contrast to intact females and females with one antenna removed, could not discriminate between simultaneously provided control filter papers and filters treated with a blend of oviposition-deterring fatty acids. Oviposition by mated females exhibited a very marked periodicity, with all egg masses deposited during the scotophase and most egg masses laid before midnight. According to the peak and trough period of oviposition, electroantennogram (EAG) responses from both mated females and males to the four fatty acids and four methyl esters were tested within two two-hour periods from 3 to 5 hours after the start of darkness and from 1 to 3 hours after light onset, respectively. Significant EAG responses above solvent and background were elicited by all test chemicals from females, and by most of the test compounds from males. EAG values of all test chemicals from mated females were not statistically different between the two test periods except for methyl myristate. Conversely, EAG responses from mated males to myristic acid, stearic acid and their methyl esters significantly differed between the two test periods. PMID:20053122

Guo, Lei; Qing Li, Guo

2009-01-01

348

Selective depressions of surface silicic acid within cyclonic mesoscale eddies in the oligotrophic western North Pacific  

NASA Astrophysics Data System (ADS)

To reveal spatial dynamics of silicic acid [Si(OH)4] in the poorly sampled oligotrophic western North Pacific, we investigated the surface distribution of Si(OH)4 and associated biogeochemical parameters by using an underway survey system with a highly sensitive nutrient analyzer along the 138°E transect (between 30 and 34°N) and the 155°E transect (between 10 and 35°N) during the summers of 2007 and 2008. Surface Si(OH)4 concentrations ranged from the detection limit (11 nmol L-1) to 2462 nmol L-1. High Si(OH)4 concentrations (>1000 nmol L-1) and dynamic fluctuations were generally observed north of 23°N, while consistently stable low concentrations of 415-751 nmol L-1 were observed south of 23°N. Surface nitrate+nitrite (N+N) and phosphate (PO43-) were typically depleted to <20 nmol L-1, except for PO43- in the area south of 16°N. The majority of the study area was characterized by high-Si(OH)4 and low-N+N and PO43-. However, submesoscale/mesoscale depressions of Si(OH)4 were locally observed in the cyclonic eddy fields north of 23°N. Among a total of six Si(OH)4 depressions within the eddies, a complete Si(OH)4 depletion (<11 nmol L-1) was observed on the cyclonic side near the Kuroshio axis (33.1°N, 138°E). This depletion was closely coupled with a diatom bloom, suggesting that Si(OH)4 was exhausted by diatoms. All of the Si(OH)4 depressions were selective and not accompanied by local depressions of N+N and PO43-. This unique phenomenon might be driven by biogeochemical processes such as selective Si export (Si pump), anomalous Si uptake associated with diatom physiology, and/or Si uptake supported by N2 fixation.

Hashihama, Fuminori; Kanda, Jota; Maeda, Yousaku; Ogawa, Hiroshi; Furuya, Ken

2014-08-01

349

Abiotic degradation of four phthalic acid esters in aqueous phase under natural sunlight irradiation.  

PubMed

Abiotic degradability of four phthalic acid esters (PAEs) in the aquatic phase was evaluated over a wide pH range 5-9. The PAE solutions in glass test tubes were placed either in the dark and under the natural sunlight irradiation for evaluating the degradation rate via hydrolysis or photolysis plus hydrolysis, respectively, at ambient temperature for 140 d from autumn to winter in Osaka, Japan. The efficiency of abiotic degradation of the PAEs with relatively short alkyl chains, such as butylbenzyl phthalate (BBP) and di-n-butyl phthalate (DBP), at neutral pH was significantly lower than that in the acidic or alkaline condition. Photolysis was considered to contribute mainly to the total abiotic degradation at all pH. Neither hydrolysis nor photolysis of di-ethylhexyl phthalate (DEHP) proceeded significantly at any pH, especially hydrolysis at neutral pH was negligible. On the other hand, the degradation rate of di-isononyl phthalate (DINP) catalyzed mainly by photolysis was much higher than those of the other PAEs, and was almost completely removed during the experimental period at pH 5 and 9. As a whole, according to the half-life (t1/2) obtained in the experiments, the abiotic degradability of the PAEs was in the sequence: DINP (32-140 d) > DBP (50-360 d), BBP (58-480 d) > DEHP (390-1600 d) under sunlight irradiation (via photolysis plus hydrolysis). Although the abiotic degradation rates for BBP, DBP, and DEHP are much lower than the biodegradation rates reported, the photolysis rate for DINP is comparable to its biodegradation rate in the acidic or alkaline condition. PMID:19634437

Lertsirisopon, Ruttapol; Soda, Satoshi; Sei, Kazunari; Ike, Michihiko

2009-01-01

350

Synthesis, Chemical and Enzymatic Hydrolysis, and Aqueous Solubility of Amino Acid Ester Prodrugs of 3-Carboranyl Thymidine Analogues for Boron Neutron Capture Therapy of Brain Tumors  

PubMed Central

Various water-soluble L-valine-, L-glutamate-, and glycine ester prodrugs of two 3-Carboranyl Thymidine Analogues (3-CTAs), designated N5 and N5-2OH, were synthesized for Boron Neutron Capture Therapy (BNCT) of brain tumors since the water solubilities of the parental compounds proved to be insufficient in preclinical studies. The amino acid ester prodrugs were prepared and stored as hydrochloride salts. The water solubilities of these amino acid ester prodrugs, evaluated in phosphate buffered saline (PBS) at pH 5, pH 6 and pH 7.4, improved 48 to 6600 times compared with parental N5 and N5-2OH. The stability of the amino acid ester prodrugs was evaluated in PBS at pH 7.4, Bovine serum, and Bovine cerebrospinal fluid (CSF). The rate of the hydrolysis in all three incubation media depended primarily on the amino acid promoiety and, to a lesser extend, on the site of esterification at the deoxyribose portion of the 3-CTAs. In general, 3'-amino acid ester prodrugs were less sensitive to chemical and enzymatic hydrolysis than 5'-amino acid ester prodrugs and the stabilities of the latter decreased in the following order: 5'-valine > 5'-glutamate > 5'-glycine. The rate of the hydrolysis of the 5'-amino acid ester prodrugs in Bovine CSF was overall higher than in PBS and somewhat lower than in Bovine serum. Overall, 5'-glutamate ester prodrug of N5 and the 5'-glycine ester prodrugs of N5 and N5-2OH appeared to be the most promising candidates for preclinical BNCT studies. PMID:22889558

Hasabelnaby, Sherifa; Goudah, Ayman; Agarwal, Hitesh K.; Abd alla, Mosaad S. M.; Tjarks, Werner

2012-01-01

351

Investigation of 60Co ?-irradiated L-(-) malic acid, N-methyl- DL-valine and L-glutamic acid ?-ethyl ester by electron paramagnetic resonance technique  

NASA Astrophysics Data System (ADS)

The electron paramagnetic resonance spectra of ?-irradiated L-(-) malic acid, N-methyl- DL-valine and L-glutamic acid ?-ethyl ester powders have been investigation at room temperature. Radiation damage centres are attributed to HOOCCH 2?HCOOH, (CH 3) 2?CH(NHCH 3)COOH and C 2H 5OCOCH 2CH 2?(NH 2)COOH radicals, respectively. The spectra have been computer simulated. The EPR parameters of the observed radicals have been determined and discussed.

Ba?kan, M. Halim; Ayd?n, Murat; Osmano?lu, ?emsettin

352

Synthesis of a series of caffeic acid phenethyl amide (CAPA) fluorinated derivatives: comparison of cytoprotective effects to caffeic acid phenethyl ester (CAPE).  

PubMed

A series of catechol ring-fluorinated derivatives of caffeic acid phenethyl amide (CAPA) were synthesized and screened for cytoprotective activity against H2O2 induced oxidative stress in human umbilical vein endothelial cells (HUVEC). CAPA and three fluorinated analogs were found to be significantly cytoprotective when compared to control, with no significant difference in cytoprotection between caffeic acid phenethyl ester (CAPE) and CAPA. PMID:20598894

Yang, John; Marriner, Gwendolyn A; Wang, Xinyu; Bowman, Phillip D; Kerwin, Sean M; Stavchansky, Salomon

2010-07-15

353

Synthesis and Antioxidant Evaluation of Enantiomerically Pure Bis-(1,2,3-triazolylmethyl)amino Esters from Modified ?-Amino Acids  

PubMed Central

The efforts for synthesis of enantiomerically pure bis-(1,2,3-triazolylmethyl)amino esters 6 are reported in good yields from an in situ generated ?-azidomethyl ketone. Optimum experimental conditions were established for preparation of ?-halomethyl ketones 10 and ?-N,N-dipropargylamino esters 11, all derived from ?-amino acids. The starting materials reacted under conventional click chemistry conditions, revealing a specific reactivity of bromomethyl ketones over chloromethyl ketones. The antioxidant activity of compounds 6 was assayed by DPPH method. The compound 6c with an IC50 of 75.57 ± 1.74??g?mL?1 was the most active. Technically, this methodology allows the preparation of a combinatorial library of analogues with different structural characteristics depending on the nature of the modified ?-amino acids employed in the synthesis. PMID:25386592

Sarmiento-Sánchez, Juan I.; Ochoa-Terán, Adrián; Rivero, Ignacio A.

2014-01-01

354

Synthesis and anti-TMV activity of novel ?-amino acid ester derivatives containing quinazoline and benzothiazole moieties.  

PubMed

Here, a series of ?-amino acid ester derivatives containing quinazoline and benzothiazoles was synthesized and evaluated for anti-tobacco mosaic virus (TMV) activity. The compounds 3n, 3o, 3p and 3q showed good antiviral activity against TMV at a concentration of 500 ?g/mL, with curative rates of 55.55%, 52.32%, 52.77% and 50.91%, respectively, and protection rates of 52.33%, 55.96%, 54.21% and 50.98%, respectively. These values were close to those of the commercially available antiviral agent ningnanmycin (which has curative and protection rates of 55.27% and 52.16%, respectively). To our knowledge, this is the first report of the anti-TMV activity of ?-amino acid ester derivatives containing quinazoline and benzothiazoles moieties; the results indicate that these novel compounds can potentially be used as protective agents against TMV diseases. PMID:24934508

Xiao, Han; Li, Pei; Hu, Deyu; Song, Bao-An

2014-08-01

355

Preparation of C18-functionalized Fe3O4@SiO2 core-shell magnetic nanoparticles for extraction and determination of phthalic acid esters in Chinese herb preparations.  

PubMed

The extraction and determination of phthalic acid esters (PAEs) residue in Chinese herbal preparations (CHP) by C18-functionalized magnetic nanoparticles (C18-FS-MNP) has been firstly performed. It was synthesized through coating Fe3O4 nanoparticles with sodium silicate, followed by freeze-drying technique and then modified with C18 groups. C18-FS-MNPs prepared via freeze-drying technique were superior to those particles prepared via common vacuum drying method in terms of dispersion and extraction recovery. C18-FS-MNPs demonstrated obvious enrichment effect for four model PAEs and 478-627-fold enrichment factors were obtained. The limit of detection was <1.89ng/mL and relative standard deviation was ranging from 3.7 to 5.8%. It was successfully applied for determination of trace PAEs residue in CHP with good recoveries. PMID:25213260

Guo, Bize; Ji, Shunli; Zhang, Feifang; Yang, Bingcheng; Gu, Jiangping; Liang, Xinmiao

2014-11-01

356

Caffeic acid phenethyl ester protects against the dopaminergic neuronal loss induced by 6-hydroxydopamine in rats.  

PubMed

Caffeic acid phenethyl ester (CAPE) is a botanical compound abundant in honeybees' propolis. It has anti-inflammatory, antiviral, antioxidant, immunomodulatory and antitumor properties. Its beneficial effects against neurodegenerative diseases, including Parkinson's disease, have also been suggested and some mechanisms have been proposed. Mitochondrial damage and oxidative stress are critical events in neurodegeneration. Release of cytochrome c from mitochondria to cytosol and the downstream activation of caspase-3 have been suggested as targets of the protective mechanism of CAPE. Most of the studies addressing the protective effect of CAPE have been performed in cell culture. This is the first study to demonstrate the protective effect of CAPE against the dopaminergic neuronal loss induced by 6-hydroxydopamine (6-OHDA) in rats. It also demonstrates, for the first time, the inhibitory effect of CAPE on mitochondrial permeability transition (MPT), a mediator of neuronal death that triggers cytochrome c release and caspase-3 activation. Scavenging of reactive oxygen species (ROS) and metal chelation was demonstrated in the brain-affected areas of the rats treated with 6-OHDA and CAPE. Additionally, we demonstrated that CAPE does not affect brain mitochondrial function. Based on these findings and on its ability to cross the blood-brain barrier, CAPE is a promising compound to treat Parkinson's and other neurodegenerative diseases. PMID:23291456

Barros Silva, R; Santos, N A G; Martins, N M; Ferreira, D A S; Barbosa, F; Oliveira Souza, V C; Kinoshita, A; Baffa, O; Del-Bel, E; Santos, A C

2013-03-13

357

Caffeic Acid Phenethyl Ester as a Potential Treatment for Advanced Prostate Cancer Targeting Akt Signaling  

PubMed Central

Prostate cancer is the fifth most common cancer overall in the world. Androgen ablation therapy is the primary treatment for metastatic prostate cancer. However, most prostate cancer patients receiving the androgen ablation therapy ultimately develop recurrent castration-resistant tumors within 1–3 years after treatment. The median overall survival time is 1–2 years after tumor relapse. Chemotherapy shows little effect on prolonging survival for patients with metastatic hormone-refractory prostate cancer. More than 80% of prostate tumors acquire mutation or deletion of tumor suppressor phosphatase and tensin homolog (PTEN), a negative regulator of PI3K/Akt signaling, indicating that inhibition of PI3K/Akt might be a potential therapy for advanced prostate tumors. Caffeic acid phenethyl ester (CAPE) is a strong antioxidant extracted from honeybee hive propolis. CAPE is a well-known NF-?B inhibitor. CAPE has been used in folk medicine as a potent anti-inflammatory agent. Recent studies indicate that CAPE treatment suppresses tumor growth and Akt signaling in human prostate cancer cells. We discuss the potential of using CAPE as a treatment for patients with advanced prostate cancer targeting Akt signaling pathway in this review article. PMID:23466879

Lin, Hui-Ping; Lin, Ching-Yu; Liu, Chun-Chieh; Su, Liang-Cheng; Huo, Chieh; Kuo, Ying-Yu; Tseng, Jen-Chih; Hsu, Jong-Ming; Chen, Chi-Kuan; Chuu, Chih-Pin

2013-01-01

358

Production of fatty acid butyl esters using the low cost naturally immobilized Carica papaya lipase.  

PubMed

In this work, the low cost naturally immobilized Carica papaya lipase (CPL) was investigated for production of fatty acid butyl esters (FABE) to fulfill the aim of reducing the lipase cost in the enzymatic butyl-biodiesel process. The CPL showed specificities to different alcohol acyl acceptors. Alcohols with more than three carbon atoms did not have negative effects on the CPL activity. The CPL catalyzed butanolysis for FABE production was systematically investigated. The reaction solvent, alcohol/oil molar ratio, enzyme amount, reaction temperature, and water activity all affected the butanolysis process. Under the optimized conditions, the highest conversion of 96% could be attained in 24 h. These optimal conditions were further applied to CPL catalyzed butanolysis of other vegetable oils. All of them showed very high conversion. The CPL packed-bed reactor was further developed, and could be operated continuously for more than 150 h. All of these results showed that the low cost Carica papaya lipase can be used as a promising lipase for biodiesel production. PMID:24954104

Su, Erzheng; Wei, Dongzhi

2014-07-01

359

Kinetics of enzymatic synthesis of liquid wax ester from oleic acid and oleyl alcohol.  

PubMed

The kinetics of wax ester synthesis from oleic acid and oleyl alcohol using immobilized lipase from Candida antartica as catalyst was studied with different types of impeller (Rushton turbine and AL-hydrofoil) to create different mixing conditions in 2l stirred tank reactor. The effects of catalyst concentration, reaction temperature, and impeller tip speed on the synthesis were also evaluated. Rushton turbine impeller exhibited highest conversion rate at lower impeller tip speed as compared to AL-hydrofoil impeller. A second-order reversible kinetic model from single progress curve for the prediction of fractional conversion at given reaction time was proposed and the corresponding kinetic parameter values were calculated by non-linear regression method. The results from the simulation using the proposed model showed satisfactory agreement with the experimental data. Activation energy shows a value of 21.77 Kcal/mol. The thermodynamic parameters of the process, enthalpy and entropy, were 21.15 Kcal/mol and 52.07 cal/mol.K, respectively. PMID:20124754

Radzi, Salina Mat; Mohamad, Rosfarizan; Basri, Mahiran; Salleh, Abu Bakar; Ariff, Arbakariya; Rahman, Mohammad Basyaruddin Abdul; Rahman, Raja Noor Zaliha Raja Abdul

2010-01-01

360

Gallic acid esters from the stem bark of Mimusops elengi L.  

PubMed

Phytochemical investigation of the ethanolic extract of the stem bark of Mimusops elengi L. (Sapotaceae) led to the isolation of new gallic acid esters, characterised as phenyl propanoxyl gallate (1), beta-D-glucopyranosyl (6'-->1'')-beta-D-glucopyranosyl-4''-(4''-ethylphenyl) gallate (2), 2'-(1'''-geranyloxy)-beta-D-glucopyranosyl (6'-->1'')-beta-D-glucopyranosyl-4''-phenoxy gallate (3), beta-D-glucopyranosyl (6'-->1'')-beta-D-glucopyranosyl 3,4,5-trihydroxy benzoate (4), beta-D-glucopyranosyl-(6'-->1'')-beta-D-glucopyranosyl-4''-(4'''-n-butylphenyl) 3,4,5-trihydroxy benzoate (5), beta-D-glucopyranosyl(6'-->1'')-beta-D-rhamnosyl 3,4,5-trihydroxy benzoate (6) and beta-D-(2'-phenyl glucopyranosyl)-(6'-->1'')-(2'', 4''-diphenylrhamnopyranosyl)-3,4,5-trihydroxylbenzoate (7), along with the known compounds: farnon-3-one, stigmasta-5-en-3-beta-ol, olean-18-en-2-one-3-ol, lup-20(29)-en-3beta-ol and stigmasta-5-en-3beta-D-glucopyranoside. Their structures were elucidated on the basis of spectroscopic analyses and chemical reactions. PMID:20496236

Akhtar, Nida; Ali, Mohd; Alam, Mohd Sarwar

2010-06-01

361

Caffeic acid phenethyl ester (CAPE), an active component of propolis, inhibits Helicobacter pylori peptide deformylase activity.  

PubMed

Helicobacter pylori (H. pylori) is a major causative factor for gastrointestinal illnesses, H. pylori peptide deformylase (HpPDF) catalyzes the removal of formyl group from the N-terminus of nascent polypeptide chains, which is essential for H. pylori survival and is considered as a promising drug target for anti-H. pylori therapy. Propolis, a natural antibiotic from honeybees, is reported to have an inhibitory effect on the growth of H. pylori in vitro. In addition, previous studies suggest that the main active constituents in the propolis are phenolic compounds. Therefore, we evaluated a collection of phenolic compounds derived from propolis for enzyme inhibition against HpPDF. Our study results show that Caffeic acid phenethyl ester (CAPE), one of the main medicinal components of propolis, is a competitive inhibitor against HpPDF, with an IC50 value of 4.02 ?M. Furthermore, absorption spectra and crystal structural characterization revealed that different from most well known PDF inhibitors, CAPE block the substrate entrance, preventing substrate from approaching the active site, but CAPE does not have chelate interaction with HpPDF and does not disrupt the metal-dependent catalysis. Our study provides valuable information for understanding the potential anti-H. pylori mechanism of propolis, and CAPE could be served as a lead compound for further anti-H. pylori drug discovery. PMID:23611786

Cui, Kunqiang; Lu, Weiqiang; Zhu, Lili; Shen, Xu; Huang, Jin

2013-05-31

362

Negative polarity of phenyl-C61 butyric acid methyl ester adjacent to donor macromolecule domains  

NASA Astrophysics Data System (ADS)

Interfacial fields within organic photovoltaics influence the movement of free charge carriers, including exciton dissociation and recombination. Open circuit voltage (Voc) can also be dependent on the interfacial fields, in the event that they modulate the energy gap between donor HOMO and acceptor LUMO. A rise in the vacuum level of the acceptor will increase the gap and the Voc, which can be beneficial for device efficiency. Here, we measure the interfacial potential differences at donor-acceptor junctions using Scanning Kelvin Probe Microscopy, and quantify how much of the potential difference originates from physical contact between the donor and acceptor. We see a statistically significant and pervasive negative polarity on the phenyl-C61 butyric acid methyl ester (PCBM) side of PCBM/donor junctions, which should also be present at the complex interfaces in bulk heterojunctions. This potential difference may originate from molecular dipoles, interfacial interactions with donor materials, and/or equilibrium charge transfer due to the higher work function and electron affinity of PCBM. We show that the contact between PCBM and poly(3-hexylthiophene) doubles the interfacial potential difference, a statistically significant difference. Control experiments determined that this potential difference was not due to charges trapped in the underlying substrate. The direction of the observed potential difference would lead to increased Voc, but would also pose a barrier to electrons being injected into the PCBM and make recombination more favorable. Our method may allow unique information to be obtained in new donor-acceptor junctions.

Alley, Olivia J.; Wu, Meng-Yin; Johns, Gary L.; Dawidczyk, Thomas J.; Hardigree, Josué F. Martínez; Markovic, Nina; Arnold, Michael S.; Katz, Howard E.

2015-01-01

363

Effects of caffeic acid phenethyl ester on lipopolysaccharide-induced lung injury in rats.  

PubMed

Extracts of propolis, a natural beehive product, have been known for centuries to have a variety of beneficial medical properties, among which their anti-inflammatory effect is a major one. Caffeic acid phenethyl ester (CAPE), an active propolis component, has antimicrobial, anti-inflammatory, antioxidant, carcinostatic and immunomodulatory properties. In this study, we aimed to investigate the efficacy of CAPE in endotoxin-induced lung injury in rats. Lung injury was induced by a footpad injection of lipopolysaccharide (LPS). In the treatment group, 10 micromol kg(-1) CAPE was injected intraperitoneally immediately after LPS injection. At 24 h after LPS and/or CAPE injection, blood and lung tissue specimens were collected. MDA levels and MPO activity in serum and lung tissue, serum total antioxidant levels, lung tissue Na(+)/K(+) ATP-ase activity and histopathological evaluation were determined to assess the efficacy of CAPE treatment. CAPE was found to be efficient in reducing inflammation and lung tissue damage induced by LPS in rats. PMID:15953745

Koksel, Oguz; Ozdulger, Ali; Tamer, Lulufer; Cinel, Leyla; Ercil, Menderes; Degirmenci, Ulas; Unlu, Serdar; Kanik, Arzu

2006-01-01

364

The protective effect of caffeic acid phenethyl ester against cyclosporine A-induced cardiotoxicity in rats.  

PubMed

Cyclosporine A (CsA) is the immunosuppressor, which is most frequently used in transplant surgery and in the treatment of autoimmune diseases. Oxidative stress has been considered as one of the possible mechanisms of CsA-induced cardiotoxicity. The present investigation examines the ability of caffeic acid phenethyl ester (CAPE), which is an active component of propolis extracts, as a natural antioxidant to protect against CsA-induced oxidative stress and cardiotoxicity. CsA cardiotoxicity was induced by subcutaneous injection of CsA at a dose of 15 mg/kg/body weight daily for 21 days in rats. Cardiotoxicity was evaluated by morphological and biochemical studies. CsA treated rats showed degenerative changes with cardiac fibrosis localized around the fibers. These latters were disorganised and the network was disappeared. The ROS production was increased whereas cytochrome-c-oxidase decreased. The expression and levels of matrix metalloproteinase 2 (MMP2) were increased whereas those of its inhibitor were downregulated. CAPE subcutaneous administration (15 micromol/kg/day) improved cardiac cytoarchitecture, decreased the levels and the expression of MMP2, and increased those of TIMP2 proteins. Moreover, it increased cytochrome-c-oxidase activity and decreased ROS production. These results suggest that CAPE could have protective effect against CsA-induced cardiotoxicity. PMID:15967562

Rezzani, R; Giugno, L; Buffoli, B; Bonomini, F; Bianchi, R

2005-09-01

365

Sono-alkalization pretreatment of sewage sludge containing phthalate acid esters.  

PubMed

This work experimentally elucidates the efficiencies of sono-alkalization treatment on municipal sewage sludge. The total solids (TS) concentration of the sewage sludge was pre-adjusted at 29.7 g/L. Two parameters such as sodium hydroxide (NaOH) dosage and sonication time were considered by the central composite design (CCD) program to investigate the effect on the degradation of phthalate acid esters (PAEs) and solubilization of soluble chemical oxygen demand (SCOD). The mean concentrations of dibutyl phthalate (DBP), di-(2-ethylhexyl) phthalate (DEHP) and butyl benzyl phthalate (BBP) in the sewage sludge were 718, 41 and 8 mg/kg dry weight sludge, respectively. Sono-alkalization process was effective on the degradation of DBP but worthless for DEHP and BBP. Overall degradation of DBP in sewage sludge was estimated to be 100% at the NaOH dosage of 68 m Mand sonication time of 2.2 min. Sono-alkalization was responsible for 6,000 mg/L increase of SCOD based on the decrease of volatile solids in sewage sludge. PMID:21847788

Ma, Ying-Shih; Lin, Jih-Gaw

2011-01-01

366

Antimicrobial effect of para-alkoxyphenylcarbamic acid esters containing substituted N-phenylpiperazine moiety  

PubMed Central

In current research, nine basic esters of para-alkoxyphenylcarbamic acid with incorporated 4-(4-fluoro-/3-trifluoromethylphenyl)piperazin-1-yl fragment, 6i–6m and 8f–8i, were screened for their in vitro antimicrobial activity against Candida albicans, Staphylococcus aureus and Escherichia coli, respectively. Taking into account the minimum inhibitory concentration assay (MIC), as the most active against given yeast was evaluated 8i (MIC = 0.20 mg/mL), the most lipophilic structure containing para-butoxy and trifluoromethyl substituents. Investigating the efficiency of the compounds bearing only a single atom of fluorine and appropriate para-alkoxy side chain against Candida albicans, the cut-off effect was observed. From evaluated homological series, the maximum of the effectiveness was noticed for the stucture 6 k (MIC = 0.39 mg/mL), containing para-propoxy group attached to phenylcarbamoyloxy fragment, beyond which the compounds ceased to be active. On the contrary, all the tested molecules were against Staphylococcus aureus and Escherichia coli (MICs > 1.00 mg/mL) practically inactive. PMID:24294237

Malík, Ivan; Bukovský, Marián; Andriamainty, Fils; Gališinová, Jana

2013-01-01

367

Electron Affinity of Phenyl-C61-Butyric Acid Methyl Ester (PCBM)  

SciTech Connect

The gas-phase electron affinity (EA) of phenyl-C61-butyric acid methyl ester (PCBM), one of the best-performing electron acceptors in organic photovoltaic devices, is measured by lowtemperature photoelectron spectroscopy for the first time. The obtained value of 2.63(1) eV is only ca. 0.05 eV lower than that of C60 (2.68(1) eV), compared to a 0.09 V difference in their E1/2 values measured in this work by cyclic voltammetry. Literature E(LUMO) values for PCBM that are typically estimated from cyclic voltammetry, and commonly used as a quantitative measure of acceptor properties, are dispersed over a wide range between -4.3 and -3.62 eV; the reasons for such a huge discrepancy are analyzed here, and the protocol for reliable and consistent estimations of relative fullerene-based acceptor strength in solution is proposed.

Larson, Bryon W.; Whitaker, James B.; Wang, Xue B.; Popov, Alexey A.; Rumbles, Garry; Kopidakis, Nikos; Strauss, Steven H.; Boltalina, Olga V.

2013-07-25

368

Preparation of caffeic Acid phenethyl ester-incorporated nanoparticles and their biological activity.  

PubMed

The aim of this study is to fabricate caffeic acid phenethyl ester (CAPE)-incorporated nanoparticles using methoxy poly(ethylene glycol)-b-poly(?-caprolactone) (CE) copolymer and to study their antitumor activity against pulmonary metastasis model of CT26 colon carcinoma cells. CAPE-incorporated nanoparticles showed spherical shapes having small diameters less than 300 nm and CAPE was continuously released from CE nanoparticles over 4 days. CAPE-incorporated polymeric micelles properly inhibited proliferation and induced apoptosis of CT26 cells as well as CAPE itself. Furthermore, they showed similar anti-invasive and antimigrative effect against CT26 cells at in vitro compared with CAPE itself, indicating that CAPE-incorporated nanoparticles have at least equivalent anticarcinogenic activity against CT26 cells compared with CAPE itself. At pulmonary metastasis model of CT26 cells using nude mouse, CAPE-incorporated nanoparticles have superior antimetastatic efficacy against, that is, control treatment with pulmonary metastasis model showed significant increase of lung weight because of the metastasis of tumor cells, whereas CAPE or CAPE-incorporated nanoparticles properly inhibited metastasis of tumor cells. We suggest CAPE-incorporated nanoparticles as a promising candidate for antimetastatic chemotherapeutic agent. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:144-154, 2015. PMID:25417897

Lee, Hyo-Young; Jeong, Young-Il; Kim, Eun Jin; Lee, Kyung Dong; Choi, Seon-Hee; Kim, Yun Jin; Kim, Da Hye; Choi, Ki-Choon

2015-01-01

369

[Determination of phthalic acid esters in imitation jewellery and investigation of their migration risk].  

PubMed

A reliable gas chromatography-mass spectrometry (GC-MS) method was developed for the determination of 14 phthalic acid esters (PAEs) in imitation jewellery. The influences of sample pretreatment methods including microwave extraction, ultrasonic extraction, accelerated solvent extraction (ASE) and Soxhlet extraction on the determination of PAEs were investigated. The migration risk of dibutyl phthalate (DBP), bis(2-ethyl hexyl) phthalate (DEHP) and dioctyl phthalate (DOP) in plastic imitation jewellery was investigated under the simulated body temperature and sweat environment within 0 h to 168 h. The results showed that the target compounds can be effectively extracted with hexane-acetone (1:1, v/v) under microwave extraction for 35 min. The limit of quantification (LOQ) of the method was 5 mg/kg for 12 PAEs (25 mg/kg for diisononyl phthalate (DINP) and diisodecyl phthalate (DIDP)). The calibration curves were linear within 0.1-50 mg/L (0.5-250 mg/L for DINP and DIDP) with the correlation coefficients above 0.99. The recoveries ranged from 90.95% to 98.67% at three spiked levels. The migration risk of DEHP was higher than DBP and DOP with 0.75% dissolved after soaking for 72 h under the simulated conditions. The sensitivity, recovery and selectivity of the method can meet the requirements of the practical work. PMID:23189657

Lai, Ying; Huang, Zongping; Ge, Xiuxiu; Lin, Rui; Chen, Hexiu

2012-07-01

370

The effect of caffeic acid phenethyl ester analogues in a modified resistant hepatocyte model.  

PubMed

We present a study of the chemoprotective effects of two caffeic acid phenethyl ester (CAPE)-related structures: LQM717 and LQM706. The modified resistant hepatocyte model in rats was used to study the chemoprevention of these CAPE analogues, which are inexpensive and easily obtained. In the liver cancer model used, we detected extensive necrosis and lipid peroxidation after 24 h, many altered hepatic foci, putatively preneoplastic lesions with ?-glutamyl transpeptidase staining after 30 days, and liver tumors at 12 months. We tested the effect of the CAPE analogues on necrosis, lipid peroxidation, proliferation, p65 activation, altered hepatic foci, and tumors. Both compounds exerted protective effects on lipid peroxidation, necrosis, cell proliferation, p65 activation, and preneoplastic lesions. Rats under a carcinogenic protocol showed a 52, 71.74, and 51.6% decrease in the number of preneoplastic nodules when pretreated with CAPE, LQM706, and LQM717, respectively. At 12 months after carcinogenic treatment, eight of eight rats developed liver cancer, whereas in the group of rats that received pretreatment with CAPE, LQM706, or LQM717, 62.5, 83.3, or 42.85%, respectively, had tumors. In conclusion, LQM717 has the potential to enhance chemoprotection activity much better than CAPE by markedly reducing the formation of liver cancers in this model, and this is a compound that is easy to obtain. PMID:23388162

Macías-Pérez, José R; Beltrán-Ramírez, Olga; Vásquez-Garzón, Verónica R; Salcido-Neyoy, Martha E; Martínez-Soriano, Pablo A; Ruiz-Sánchez, Mónica B; Angeles, Enrique; Villa-Treviño, Saúl

2013-04-01

371

Identification of native catechin fatty acid esters in green tea (Camellia sinensis).  

PubMed

Catechins are potent antioxidants and make up the primary class of polyphenols present in tea (Camellia sinensis). They are especially abundant in the less-fermented green teas that have been employed in various foods to enhance shelf life stability (Senanayake, N. J. Funct. Foods 2013, in press. Gramza, A.; Korczak, J. Trends Food Sci. 2005, 16, 351-358). The antioxidative activity of native (polar) catechins has proven to be useful in foods of relatively high polarity, while mixed results have been achieved in high-fat foods. However, the polarity of catechins can be attenuated by esterification with fatty acids, producing adducts that effectively partition into lipids and protect against rancidity even in high-fat foods (Cutler, S.; Fuller, E.; Rotberg, I.; Wray, C.; Troung, M.; Poss, M. International Patent WO 2013/036934 A1, March 14, 2013. Zhong, Y.; Shahidi, F. J. Agric. Food Chem. 2011, 59, 6526-6533). In this work, a search for the presence of naturally occurring lipid-conjugated catechins was undertaken in various green tea varieties. Rather than the traditional aqueous infusion, dried tea leaves were extracted with organic solvents followed by analysis for catechin adducts with both lower polarities and increased molecular weights as monitored by liquid chromatography and tandem mass spectrometry. Native catechin palmitates were identified and indirectly confirmed by synthesis and nuclear magnetic resonance as natural components of several Chinese green teas. Evidence of other fatty catechin esters was also observed. PMID:24251649

Myers, Richard A; Fuller, Ewa; Yang, Weichun

2013-11-27

372

Stimulation of H+ Efflux and Inhibition of Photosynthesis by Esters of Carboxylic Acids 1  

PubMed Central

Suspensions of mechanically isolated Asparagus sprengeri Regel mesophyll cells were used to investigate the influence of various carboxyester compounds on rates of net H+ efflux in the dark or light and photosynthetic O2 production. Addition of 0.15 to 1.5 millimolar malathion, ?-naphthyl acetate, phenyl acetate, or p-nitrophenyl acetate stimulated H+ efflux and inhibited photosynthesis within 1 minute. In contrast, the more polar esters methyl acetoacetate or ethyl p-aminobenzoate had little or no effect on either of these two processes. A 0.15 millimolar concentration of ?-naphthylacetate stimulated the normal rate of H+ efflux, 0.77 nanomoles H+ per 106 cells per minute by 750% and inhibited photosynthesis by 100%. The four active carboxyester compounds also stimulated H+ efflux after the normal rate of H+ efflux was eliminated with 0.01 milligrams per milliliter oligomycin or 100% N2. Oligomycin reduced the ATP level by 70%. Incubation of cells with malathion, ?-naphthyl acetate, or p-nitrophenyl acetate resulted in the generation of the respective hydrolysis products ethanol, ?-naphthol, and p-nitrophenol. It is proposed that inhibition of photosynthesis and stimulation of H+ efflux result when nonpolar carboxyester compounds enter the cell and generate acidic carboxyl groups when hydrolyzed by esterase enzymes. PMID:16663308

Duhaime, Donna E.; Bown, Alan W.

1983-01-01

373

Therapeutic effect of caffeic acid phenethyl ester on cerulein-induced acute pancreatitis  

PubMed Central

AIM: To evaluate the therapeutic role of caffeic acid phenethyl ester (CAPE) in a rat model of cerulean-induced acute pancreatitis (AP). METHODS: Seventy male Wistar albino rats were divided into seven groups. Acute edematous pancreatitis was induced by subcutaneous cerulein injection (20 ?g/kg) four times at 1-h intervals. CAPE (30 mg/kg) was given by subcutaneous injection at the beginning (CAPE 1 group) and 12 h after the last cerulein injection (CAPE 2 group). Serum amylase, lipase, white blood cell count, and tumor necrosis factor (TNF)-? levels were measured, and pancreatic histopathology was assessed. RESULTS: In the AP group, amylase and lipase levels were found to be elevated and the histopathological evaluation showed massive edema and inflammation of the pancreas, with less fatty necrosis when compared with sham and control groups. Amylase and lipase levels and edema formation decreased significantly in the CAPE therapy groups (P < 0001); especially in the CAPE 2 group, edema was improved nearly completely (P = 0001). Inflammation and fatty necrosis were partially recovered by CAPE treatment. The pathological results and amylase level in the placebo groups were similar to those in the AP group. White blood cell count and TNF-? concentration was nearly the same in the CAPE and placebo groups. CONCLUSION: CAPE may be useful agent in treatment of AP but more experimental and clinical studies are needed to support our observation of beneficial effects of CAPE before clinical usage of this agent. PMID:19891017

Buyukberber, Mehmet; Sava?, M Cemil; Bagci, Cahit; Koruk, Mehmet; Gulsen, Murat T; Tutar, Ediz; Bilgic, Tugba; Ceylan, Nurdan Ö

2009-01-01

374

Caffeic Acid Phenethyl Ester Inhibits Epithelial-Mesenchymal Transition of Human Pancreatic Cancer Cells  

PubMed Central

Background. This study aimed to investigate the effect of propolis component caffeic acid phenethyl ester (CAPE) on epithelial-mesenchymal transition (EMT) of human pancreatic cancer cells and the molecular mechanisms underlying these effects. Methods. The transforming growth factor ? (TGF-?-) induced EMT in human pancreatic PANC-1 cancer cells was characterized by observation of morphology and the expression of E-cadherin and vimentin by western blotting. The migration potential was estimated with wound closure assay. The expression of transcriptional factors was measured by quantitative RT-PCR and immunocytochemistry staining. The orthotopic pancreatic cancer xenograft model was used for in vivo assessment. Results. The overexpression of vimentin was attenuated by CAPE, and the alteration in morphology from polygonal to spindle shape was partially reversed by CAPE. Furthermore, CAPE delayed the TGF-?-stimulated migration potential. CAPE treatment did not reduce the expression levels of Smad 2/3, Snail 1, and Zeb 1 but inhibited the expression of transcriptional factor Twist 2. By using an orthotopic pancreatic cancer model, CAPE suppressed the expression of Twist 2 and growth of PANC-1 xenografts without significant toxicity. Conclusion. CAPE could inhibit the orthotopic growth and EMT of pancreatic cancer PANC-1 cells accompanied by downregulation of vimentin and Twist 2 expression. PMID:23662124

Chen, Ming-Jen; Shih, Shou-Chuan; Wang, Horng-Yuan; Lin, Ching-Chung; Liu, Chia-Yuan; Wang, Tsang-En; Chu, Cheng-Hsin; Chen, Yu-Jen

2013-01-01

375

Beneficial effects of caffeic acid phenethyl ester in a rat model of vascular injury  

PubMed Central

The aim of this study was to evaluate whether caffeic acid phenethyl ester (CAPE), an active component of propolis, was able to reduce neointimal formation in a model of endothelial injury of rat carotid artery (balloon angioplasty). Furthermore, we investigated the relationship between neointima formation and nuclear factor-?B (NF-?B) activation and we correlated NF-?B activation to the expression of inducible isoform of cyclo-oxygenase (COX-2) in injured carotids.In control group a significant proliferation of neointima was observed 14 days after balloon angioplasty, which was correlated to an increase of NF-?B/DNA binding activity as well as p50/p65 nuclear levels compared to those observed in the carotids from sham-operated rats. Furthermore, NF-?B activation was correlated to increased COX-2, but not ?-actin, protein expression.Treatment of rats for 14 days with CAPE (3, 10, 30?mg?kg?1) caused a significant inhibition of all the parameters assayed, except ?-actin protein expression.These results indicate that treatment with CAPE may lead to a reduction of neointima formation by inhibiting NF-?B activation and suggest that this agent may have therapeutic relevance for the prevention of human restenosis. PMID:12023937

Maffia, Pasquale; Ianaro, Angela; Pisano, Barbara; Borrelli, Francesca; Capasso, Francesco; Pinto, Aldo; Ialenti, Armando

2002-01-01

376

Separation of fatty acid esters from cholesterol in esterified natural and synthetic mixtures by supercritical carbon dioxide  

Microsoft Academic Search

The solubility of cholesterol in supercritical carbon dioxide was determined by a continuous flow method. The solubility of\\u000a cholesterol increased with increasing pressure and exhibited retrograde behavior. The Chrastil equation was used to describe\\u000a the relationship between solubility and the density of carbon dioxide. A model mixture was made by adding cholesterol and\\u000a fatty acid esters together. Squid visceral oil

An-I Yeh; J. H. Liang; L. S. Hwang

1991-01-01

377

Optimization of the curing conditions of PVC plastisols based on the use of an epoxidized fatty acid ester plasticizer  

Microsoft Academic Search

The use of an epoxidized fatty acid ester (EFAE) as a natural-based plasticizer for plasticized PVC (P-PVC) has been evaluated in this work. The effect of the curing conditions has been studied by following several test techniques such as mechanical properties, thermal behavior, color changes, solvent migration and microstructure. Different curing processes at isothermal conditions (ranging from 160°C to 220°C)

O. Fenollar; D. García; L. Sánchez; J. López; R. Balart

2009-01-01

378

A differential scanning calorimetry study on the oxidation of C 12 -C 18 saturated fatty acids and their esters  

Microsoft Academic Search

The autoxidation of lauric, myristic, palmitic, and stearic acids, their ethyl esters, and palmitic and stearic triglycerides\\u000a was investigated by means of the isothermal and nonisothermal differential scanning calorimetry methods under oxygen flow.\\u000a The activation energies of oxidation of all investigated compounds were similar (106.0–134.3 kJ\\/mol) and did not depend on\\u000a length of the carbon chain. Kinetic parameters of start

G. Litwinienko; A. Daniluk; T. Kasprzycka-Guttman

1999-01-01

379

Rigid urethane foams from hydroxymethylated castor oil, safflower oil, oleic safflower oil, and polyol esters of castor acids  

Microsoft Academic Search

Castor, safflower, and oleic safflower oil derivatives with enhanced reactivity and hydroxyl group content were prepared by\\u000a hydroformylation with a rhodium-triphenylphosphine catalyst, followed by hydrogenation. Rigid urethane foams prepared from\\u000a these hydroxymethylated derivatives had excellent compressive strengths, closed cell contents, and dimensional stability.\\u000a Best properties were obtained from hydroxymethylated polyol esters of castor acids.

C. K. Lyon; V. H. Garrett; E. N. Frankel

1974-01-01

380

Bioactivation of Cyclopenta- and Cyclohexa-Fused Polycyclic Aromatic Hydrocarbons via the Formation of Benzylic Sulfuric Acid Esters  

Microsoft Academic Search

There has been accumulated evidence that sulfo-conjugation plays an important role in the formation of electrophilic, mutagenic, and tumorigenic sulfuric acid ester metabolites from some hydroxymethyl aromatic hydrocarbons. In the present study, we have investigated whether sulfotransferases can also activate cyclopenta- and cyclohexa-fused polycyclic aromatic hydrocarbons containing secondary benzylic hydroxyl group(s). Thus, 3,4-dihydroxy-3,4-dihydrocyclopenta[cd]pyrene, as well as its monohydroxy analogs, covalently

Young-Joon Surh; Steven R. Tannenbaum

1994-01-01

381

The General Applicability of in Situ Transesterification for the Production of Fatty Acid Esters from a Variety of Feedstocks  

Microsoft Academic Search

We previously described a method for fatty acid methyl ester (FAME) production wherein acylglycerol transesterification was\\u000a achieved by reacting flaked full fat soybeans with alkaline methanol to create a product that met ASTM specifications for\\u000a biodiesel. In the present work we explore the general applicability of this approach, termed in situ transesterification,\\u000a to feedstocks other than soybeans. Materials investigated were

Michael J. Haas; Karen M. Scott; Thomas A. Foglia; William N. Marmer

2007-01-01

382

Physicochemical and Structural Properties of Glycerin Gel Prepared using Glycyrrhizic Acid Diethyl Ester.  

PubMed

Glycyrrhizic acid diethyl ester (GZ-DE) was developed as a prodrug of glycyrrhizic acid (GZ), a hepatitis therapeutic drug. We fortuitously found that GZ-DE gels with glycerin selectively while searching for a safe solvent with which to dissolve GZ-DE. Based on this gelation, the aim of this study was to investigate the preparation of the gel and study the rheology, physicochemical and structural properties of the glycerin gel by differential scanning calorimeter (DSC), capillary electrophoresis (CEP), nuclear magnetic resonance (NMR), and small angle X-ray scattering (SAXS). The glycerin gel was prepared by the addition of at least 2.0% w/w GZ-DE. This gel did not flow at room temperature. After mixing glycerin and GZ-DE, a gel was formed after 2 days at 25°C or 3 h at 60°C. Glycerin gel containing 2.4% w/w GZ-DE provided the following results: 1) The glycerin gel exhibited creep at a constant stress of less than 10 Pa, but it is a fragile gel, showing Newtonian flow at 10 Pa stress. 2) Dynamic viscoelastic measurements showed that the elastic modulus (G') exceeds the viscous modulus (G''), indicating that glycerin gel has solid-like properties. 3) DSC showed a significant difference between the glass transition temperature of glycerin and glycerin gel. 4) CEP did not reveal a new compound in the glycerin gel. 5) NMR confirmed that glycerin gel is a physical gel. 6) SAXS measurements revealed that the glycerin gel has an oval-shaped basic frame (119 nm long and 65 nm wide). PMID:25452268

Koga, Kenjiro; Kimura, Toshiyuki; Sakai, Kenichi; Kushida, Hiroshi; Yoshikawa, Nobuji

2014-01-01

383

Therapeutic effects of docosahexaenoic acid ethyl ester in patients with generalized peroxisomal disorders.  

PubMed

Generalized peroxisomal disorders are severe congenital diseases that involve the central nervous system, leading to severe psychomotor retardation, retinopathy, liver disease, and early death. In these disorders, peroxisomes are not normally formed and their enzymes are deficient. Characteristically, plasmalogen synthesis and beta-oxidation of very-long-chain fatty acids (VLCFAs) are affected. We found that patients with generalized peroxisomal disorders have a profound brain deficiency of docosahexaenoic acid (DHA; 22:6n-3) and low DHA concentrations in all tissues and the blood. Given the fundamental role of DHA in neuronal and retinal membranes, a DHA deficiency of this magnitude might be pathogenic. Thus, we studied the possible therapeutic effect of normalizing DHA concentrations in patients with peroxisomal disorders. We chose the DHA ethyl ester (DHA-EE) because of its high degree of purity at daily oral doses of 100-500 mg. This article summarizes the results of treatment of 13 patients with DHA-EE, with some follow-up evidence of clinical improvement. Supplementation with DHA-EE normalized blood DHA values within a few weeks. Plasmalogen concentrations increased in erythrocytes in most patients and after DHA concentrations were normalized, amounts of VLCFAs decreased in plasma. Liver enzymes returned almost to normal in most cases. From a clinical viewpoint, most patients showed improvement in vision, liver function, muscle tone, and social contact. In 3 patients, normalization of brain myelin was detected by magnetic resonance imaging. In 3 others, myelination improved. In a seventh patient, myelination is progressing at a normal rate. These results suggest a fundamental role of DHA in the pathogenesis of Zellweger syndrome. DHA therapy is thus strongly recommended, not only to alleviate symptoms in patients with life-threatening diseases, but also to clarify remaining questions regarding the role of DHA in health and disease. PMID:10618001

Martínez, M; Vázquez, E; García-Silva, M T; Manzanares, J; Bertran, J M; Castelló, F; Mougan, I

2000-01-01

384

Partitioning of Homologous Nicotinic Acid Ester Prodrugs (Nicotinates) into Dipalmitoylphosphatidylcholine (DPPC) Membrane Bilayers  

PubMed Central

The partitioning behavior of a series of perhydrocarbon nicotinic acid esters (nicotinates) between aqueous solution and dipalmitoylphosphatidylcholine (DPPC) membrane bilayers is investigated as a function of increasing alkyl chain length. The hydrocarbon nicotinates represent putative prodrugs, derivatives of the polar drug nicotinic acid, whose functionalization provides the hydrophobic character necessary for pulmonary delivery in a hydrophobic, fluorocarbon solvent, such as perfluorooctyl bromide. Independent techniques of differential scanning calorimetry and 1,6-diphenyl-1,3,5 hexatriene (DPH) fluorescence anisotropy measurements are used to analyze the thermotropic phase behavior and lipid bilayer fluidity as a function of nicotinate concentration. At increasing concentrations of nicotinates over the DPPC mole fraction range examined (XDPPC = 0.6 – 1.0), all the nicotinates (ethyl (C2H5); butyl (C4H9); hexyl (C6H13); and octyl (C8H17)) partition into the lipid bilayer at sufficient levels to eliminate the pretransition, and decrease and broaden the gel to fluid phase transition temperature. The concentration at which these effects occur is chain length-dependent; the shortest chain nicotinate, C2H5, elicits the least dramatic response. Similarly, the DPH anisotropy results demonstrate an alteration of the bilayer organization in the liposomes as a consequence of the chain length-dependent partitioning of the nicotinates into DPPC bilayers. The membrane partition coefficients (logarithm values), determined from the depressed bilayer phase transition temperatures, increase from 2.18 for C2H5 to 5.25 for C8H17. The DPPC membrane/water partitioning of the perhydrocarbon nicotinate series correlates with trends in the octanol/water partitioning of these solutes, suggesting that their incorporation into the bilayer is driven by increasing hydrophobicity. PMID:20227859

Ojogun, Vivian; Vyas, Sandhya M.; Lehmler, Hans-Joachim; Knutson, Barbara L

2010-01-01

385

Accumulation of short n-chain ethyl esters by esterases of lactic acid bacteria under conditions simulating ripening Parmesan cheese.  

PubMed

EstA from Lactobacillus helveticus CNRZ32 (Lbh-EstA), EstB, and EstC from Lactobacillus casei LILA, and EstA from Lactococcus lactis MG1363 (Lcl-EstA) were evaluated for their ability to accumulate esters in a model system simulating Parmesan cheese ripening conditions (10 degrees C, 2 to 3% NaCl, pH 5.4 to 5.5, aw = 0.850 to 0.925) using Capalase K from kid goat as a positive control. All of the LAB esterases and Capalase K mediated the accumulation of esters in the model system in an enzyme specific manner, which was influenced by a, and selectivity for fatty acid chain-length. In general, enzyme mediated accumulation of ethyl esters was higher at aw values of 0.850 and 0.900 than at aw of 0.925, demonstrating that aw is a critical parameter influencing ester accumulation. The substrate selectivity of esterases, aw, and enzyme type may be important factors in the development of fruity flavors, as evidenced by results in this model system simulating Parmesan cheese ripening conditions. PMID:14507018

Fenster, K M; Rankin, S A; Steele, J L

2003-09-01

386

Contribution to the analysis of the essential oil of Helichrysum italicum (Roth) G. Don. Determination of ester bonded acids and phenols.  

PubMed

The essential oil of Helichrysum italicum (Roth) G. Don (everlasting or Immortelle essential oil) was isolated by hydrodistillation and analysed by GC and GCMS. Forty four compounds were identified. The main components were alpha-pinene(12.8%), 2-methyl-cyclohexyl pentanoate (11.1 %), neryl acetate (10.4%), 1,7-di-epi-alpha-cedrene (6.8%) and other compounds. The oil was fractionated and ester-containing fraction was hydrolysed with KOH/H(2)SO(4). The liberated volatiles were analysed by GC and GC-MS: three phenols and twenty seven volatile carboxylic acids were identified[70% low fatty acids (C(2)-C(5)), 15% C(10)-C(12) acids and 15% other acids]. The main acids were acetic acid (24.3%) propanoic acid (17.2%), 2-methylpropanoic acid (11.4%),dodecanoic acid (8.7%), 2-methylbutanoic acid (8.3%), (Z)-2-methylbutenoic acid(5.1%) and decanoic acid (4.6%). With respect to the identified bonded carboxylic acids,the minimal number of esters in the oil was twenty seven, but their overall quantity was probably larger due to different possible combinations of alcohols with acids to form esters. On the other hand, only six main esters were identified in the oil before fractionation and hydrolysis. PMID:18463581

Masteli?, Josip; Politeo, Olivera; Jerkovi?, Igor

2008-01-01

387

Silicon isotope constraints on sources and utilization of silicic acid in the northern South China Sea  

NASA Astrophysics Data System (ADS)

The stable silicon isotopic composition (?30Si) of waters and diatoms has increasingly been used to investigate the biogeochemical cycling of Si in the major ocean basins. Here we present the first Si isotope data set from the northern South China Sea (NSCS), a large marginal sea system in the western North Pacific to examine sources and utilization of silicic acid (Si(OH)4). During two cruises in July-August 2009 (summer) and January 2010 (winter), samples for isotope measurements of dissolved Si(OH)4 (?30SiSi(OH)4) and of biogenic silica (?30SiBSi) in suspended particles were collected along a transect perpendicular to the coast from the inner shelf to the deep-water slope, as well as at the South East Asian Time-series Study (SEATS) station located in the NSCS basin. Surface ?30SiSi(OH)4 generally increased from values ?+2.3‰ on the inner shelf to ?+2.8‰ above the deep basin, suggesting an increasing utilization of dissolved Si(OH)4 reflecting the transition from eutrophic to oligotrophic conditions. The ?30SiBSi values were systematically lower than the corresponding ?30SiSi(OH)4 in the euphotic zone (above 100 m) on the shelf and slope. In contrast at station SEATS in the NSCS basin, ?30SiBSi signatures in both seasons were within error equal to ?30SiSi(OH)4 in the surface mixed layer (above 50 m) and ?30SiBSi in waters below were significantly higher than the corresponding ?30SiSi(OH)4. By comparing the field data with the Si isotope fractionation revealed by the Rayleigh or the steady state models, we demonstrate the existence of variable Si(OH)4 origins in different areas of the NSCS. Surface waters on the inner shelf were largely fed by nutrients from the Pearl River input. While the primary source of Si(OH)4 for the euphotic zone on the outer shelf and slope was upwelling or vertical mixing from underlying waters, the Si(OH)4 in the surface mixed layer of the NSCS basin might have originated from horizontal mixing with other highly fractionated surface waters. As a consequence, the Si isotope dynamics in the NSCS are largely controlled by variable biological fractionation of Si in waters from different sources with different initial Si isotopic compositions rather than any single source water.

Cao, Zhimian; Frank, Martin; Dai, Minhan; Grasse, Patricia; Ehlert, Claudia

2012-11-01

388

Acidic 1,3-propanediaminetetraacetato lanthanides with luminescent and catalytic ester hydrolysis properties  

NASA Astrophysics Data System (ADS)

In acidic solution, a serials of water-soluble coordination polymers (CPs) were isolated as zonal 1D-CPs 1,3-propanediaminetetraacetato lanthanides [Ln(1,3-H3pdta)(H2O)5]n·2Cln·3nH2O [Ln=La, 1; Ce, 2; Pr, 3; Nd, 4; Sm, 5] (1,3-H4pdta=1,3-propanediaminetetraacetic acid, C11H18N2O8) in high yields. When 1 eq. mol potassium hydroxide was added to the solutions of 1D-CPs, respectively, two 1D-CPs [Ln(1,3-H2pdta)(H2O)3]n·Cln·2nH2O [Ln=Sm, 6; Gd, 7] were isolated at room temperature and seven 2D-CPs [Ln(1,3-H2pdta)(H2O)2]n·Cln·2nH2O [Ln=La, 8; Ce, 9; Pr, 10; Nd, 11; Sm, 12; Eu, 13; Gd, 14] were isolated at 70 °C. When the crystals of 1-4 were hydrothermally heated at 180 °C with 1-2 eq. mol potassium hydroxide, four 3D-CPs [Ln(1,3-Hpdta)]n·nH2O [Ln=La, 15; Ce, 16; Pr, 17; Nd, 18] were obtained. The two 2D-CPs [Ln(1,3-Hpdta)(H2O)]n·4nH2O (Sm, 19; Eu, 20) were isolated in similar reaction conditions. With the increments of pH value in the solution and reaction temperature, the structure becomes more complicated. 1-5 are soluble in water and 1 was traced by solution 13C{1H} NMR technique, the water-soluble lanthanides 1 and 5 show catalytic activity to ester hydrolysis reaction respectively, which indicate their important roles in the hydrolytic reaction. The europium complexes 13 and 20 show visible fluorescence at an excitation of 394 nm. The structure diversity is mainly caused by the variation of coordinated ligand in different pH values and lanthanide contraction effect. Acidic conditions are favorable for the isolations of lanthanide complexes in different structures and this may helpful to separate different lanthanides. The thermal stability investigations reveal that acidic condition is favorable to obtain the oxides at a lower temperature.

Chen, Mao-Long; Shi, Yan-Ru; Yang, Yu-Chen; Zhou, Zhao-Hui

2014-11-01

389

Oviposition response ofLobesia botrana females to long-chain free fatty acids and esters from its eggs.  

PubMed

Avoidance of occupied ovisposition sites supposes that females perceive information related to their own progency. Fatty acids identified from egg extracts have been reevaluated using a different extraction method, and we have investigated the dose-dependent oviposition response of European grape vine moths (Lobesia botrana) to myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, methyl palmitate, methyl oleate, and ethyl palmitate; all except ethyl palmitate have been identified from eggs ofL. botrana. A methylene dichloride extract of eggs fromL. botrana revealed the presence of saturated free fatty acids (myristic, palmitic, and stearic) and unsaturated acids (palmitoleic, oleic, linoleic, and linolenic) in amounts ranging from 3.9 ng/egg equivalent for myristic acid to 30 ng/egg equivalent for palmitic and oleic acids. The extract also contained traces of methyl palmitate and methyl stearate. The greatest avoidance indexes were observed in response to palmitic, palmitoleic, and oleic acids. All the other compounds tested caused weaker responses. A reduction in the number of eggs laid was observed when moths were exposed to each of the esters applied at 0.3 µg per application spot. Reduction in eggs laid was also observed at a 10-fold higher dose of oleic acid. The present results confirm that general and simple molecules can be involved in the regulation of oviposition site selection and that they may participate in chemical marking of the eggs. PMID:24226990

Gabel, B; Thiéry, D

1996-01-01

390

Effects of ricinoleic acid esters from castor oil of Ricinus communis on the vitellogenesis of Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) ticks.  

PubMed

This study examines the effects of ricinoleic acid esters from Ricinus communis castor oil on the vitellogenesis of Rhipicephalus sanguineus ticks attached to hosts that were fed with commercial rabbit food containing these esters. The oocytes of ticks from the treatment group (TG) showed cytoplasmic changes that inhibited the development of oocytes I and II to the advanced stages (IV and V) in addition to preventing the maturation of oocytes V, resulting in small ones. In addition, sperm was not observed in ampoules. Our findings confirm the acaricide potential of ricinoleic acid esters. PMID:21070770

Arnosti, André; Brienza, Paula Desjardins; Furquim, Karim Christina Scopinho; Chierice, Gilberto Orivaldo; Bechara, Gervásio Henrique; Calligaris, Izabela Braggião; Camargo-Mathias, Maria Izabel

2011-02-01

391

Deep-Sea Research II 48 (2001) 40814100 Phytoplankton pigment distribution in relation to silicic acid,  

E-print Network

Deep-Sea Research II 48 (2001) 4081­4100 Phytoplankton pigment distribution in relation to silicic Polar Frontal Region (PFR), surface pigment samples were collected during austral summer (January) were regions of enhanced accumulation of phytoplankton pigments. The mesoscale survey across the PF

Kurapov, Alexander

392

Very-long-chain 3-hydroxy fatty acids, 3-hydroxy fatty acid methyl esters and 2-alkanols from cuticular waxes of Aloe arborescens leaves.  

PubMed

The present work aimed at a comprehensive chemical characterization of the cuticular wax mixtures covering leaves of the monocot species Aloe arborescens. The wax mixtures were found to contain typical aliphatic compound classes in characteristic chain length distributions, including alkanes (predominantly C31), primary alcohols (predominantly C28), aldehydes (predominantly C32), fatty acid methyl esters (predominantly C28) and fatty acids (bimodal distribution around C32 and C28). Alkyl esters ranging from C42 to C52 were identified, and found to mainly contain C28 alcohol linked to C16-C20 acids. Three other homologous series were identified as 3-hydroxy fatty acids (predominantly C28), their methyl esters (predominantly C28), and 2-alkanols (predominantly C31). Based on structural similarities and homolog distributions, the biosynthetic pathways leading to these novel wax constituents can be hypothesized. Further detailed analyses showed that the A. arborescens leaf was covered with 15?g/cm(2) wax on its adaxial side and 36?g/cm(2) on the abaxial side, with 3:2 and 1:1 ratios between epicuticular and intracuticular wax layers on each side, respectively. Terpenoids were found mainly in the intracuticular waxes, whereas very-long-chain alkanes and fatty acids accumulated to relatively high concentrations in the epicuticular wax, hence near the true surface of the leaf. PMID:25200334

Racovita, Radu C; Peng, Chen; Awakawa, Takayoshi; Abe, Ikuro; Jetter, Reinhard

2014-09-01

393

Palladium-catalyzed alkoxycarbonylation of conjugated dienes under acid-free conditions: atom-economic synthesis of ?,?-unsaturated esters.  

PubMed

Carbonylation reactions constitute important methodologies for the synthesis of all kinds of carboxylic acid derivatives. The development of novel and better catalysts for these transformations is of interest for both academic and industrial research. Here, a benign palladium-based catalyst system for the alkoxycarbonylation of conjugated dienes under acid-free conditions has been developed. This atom-efficient transformation provides straightforward access to a variety of ?,?-unsaturated esters in good to excellent yields and often with high selectivities. As an industrially relevant example the (formal) synthesis of dimethyl adipate and ?-caprolactam from 1,3-butadiene is demonstrated. PMID:24984942

Fang, Xianjie; Li, Haoquan; Jackstell, Ralf; Beller, Matthias

2014-08-18

394

Intestinal absorption and biliary elimination of glycyrrhizic acid diethyl ester in rats  

PubMed Central

Background The purpose of this study was to evaluate absorption and elimination from the gastrointestinal tract of glycyrrhizic acid diethyl ester (GZ-DE) which was prepared as a prodrug of glycyrrhizic acid (a poorly absorbed compound) in rats. Methods After the GZ-DE solution was administered via the intravenous, intraduodenal, intraileal, and stomach routes, GZ-DE and GZ concentrations in bile were determined by high-performance liquid chromatography. The stability of GZ-DE was estimated from residual GZ-DE and GZ produced in GZ-DE solutions prepared with distilled water, a pH 1.2 solution, 0.9% NaCl solution, and phosphate-buffered solution (pH 7.4) at 37°C. Results GZ-DE was eliminated into bile by the pharmacokinetic parameters of apparent distribution rate constant (4.56 ± 0.36 per hour) and apparent elimination rate constant (0.245 ± 0.042 per hour). After intravenous and intraduodenal administration of GZ-DE, the concentration ratio of GZ-DE to GZ in bile was approximately 4:1, and the bioavailability of GZ containing GZ-DE was three-fold higher compared with the bioavailability of GZ after intraduodenal administration. GZ-DE was immediately precipitated in pH 1.2 solution and was converted to GZ by hydrolysis in pH 7.4 solution. Conclusion Improvement of intestinal absorption of GZ was made possible by administration of GZ-DE into the intestine where absorption of GZ is lower than in the strong acidic environment of the stomach. However, because the elimination rate in bile simulated from kinetic parameters of GZ-DE was higher than the conversion rate from GZ-DE to GZ by hydrolysis, it is thought that the availability of GZ as a revolutionary prodrug was not high from the viewpoint of bioavailability of GZ in the liver by intestinal administration of GZ-DE. PMID:24174868

Koga, Kenjiro; Kawamura, Mayuri; Iwase, Hiroshi; Yoshikawa, Nobuji

2013-01-01

395

Biochemical mechanism of Caffeic Acid Phenylethyl Ester (CAPE) selective toxicity towards melanoma cell lines  

PubMed Central

In the current work, we investigated the in-vitro biochemical mechanism of caffeic acid phenylethyl ester (CAPE) toxicity and eight hydroxycinnamic/caffeic acid derivatives in-vitro, using tyrosinase enzyme as a molecular target in human SK-MEL-28 melanoma cells. Enzymatic reaction models using tyrosinase/O2 and HRP/H2O2 were used to delineate the role of one- and two-electron oxidation. Ascorbic acid (AA), NADH and GSH depletion were used as markers of quinone formation and oxidative stress in CAPE induced toxicity in melanoma cells. Ethylenediamine, an o-quinone trap, prevented the formation of o-quinone and oxidations of AA and NADH mediated by tyrosinase bioactivation of CAPE. The IC50 of CAPE towards SK-MEL-28 melanoma cells was 15?M. Dicoumarol, a diaphorase inhibitor, and 1-bromoheptane, a GSH depleting agent, increased CAPE’s toxicity towards SK-MEL-28 cells indicating quinone formation played an important role in CAPE induced cell toxicity. Cyclosporin-A and trifluoperazine, inhibitors of the mitochondrial membrane permeability transition pore (PTP), prevented CAPE toxicity towards melanoma cells. We further investigated the role of tyrosinase in CAPE toxicity in the presence of a shRNA plasmid, targeting tyrosinase mRNA. Results from tyrosinase shRNA experiments showed that CAPE led to negligible anti-proliferative effect, apoptotic cell death and ROS formation in shRNA plasmid treated cells. Furthermore, it was also found that CAPE selectively caused escalation in the ROS formation and intracellular GSH (ICG) depletion in melanocytic human SK-MEL-28 cells which express functional tyrosinase. In contrast, CAPE did not lead to ROS formation and ICG depletion in amelanotic C32 melanoma cells, which do not express functional tyrosinase. These findings suggest that tyrosinase plays a major role in CAPE’s selective toxicity towards melanocytic melanoma cell lines. Our findings suggest that the mechanisms of CAPE toxicity in SK-MEL-28 melanoma cells mediated by tyrosinase bioactivation of CAPE included quinone formation, ROS formation, intracellular GSH depletion and induced mitochondrial toxicity. PMID:20685355

Kudugunti, Shashi K.; Vad, Nikhil M.; Whiteside, Amanda J.; Naik, Bhakti U.; Yusuf, Mohd. A.; Srivenugopal, Kalkunte S.; Moridani, Majid Y.

2010-01-01

396

Detection of okadaic acid esters in the hexane extracts of spanish mussels  

Microsoft Academic Search

Two types of low polar derivatives of OA and dinophysitoxins have been reported in shellfish or in phytoplankton: 7-O-acyl esters containing a fatty acyl group attached through the 7-OH group and diol esters in which the carboxylic group of the toxins has been esterified. These compounds cannot be directly detected by liquid chromatography and fluorimetric detection as 9-anthryldiazomethane derivatives, owing

M. L. Fernández; A. Míguez E. Cacho; A. Martínez

1996-01-01

397

40 CFR 721.5375 - Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter, bis-[[[[(sub-sti-tut-ed)] amino]-alkyl-phenyl...  

Code of Federal Regulations, 2011 CFR

...Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter...sub-sti-tut-ed)] amino]-alkyl-phenyl...Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter...sub-sti-tut-ed)] amino]-alkyl-phenyl...ni-tro-thio-phene-car-boxy-lic acid, ethyl ester,...

2011-07-01

398

40 CFR 721.5375 - Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter, bis-[[[[(sub-sti-tut-ed)] amino]-alkyl-phenyl...  

Code of Federal Regulations, 2010 CFR

...Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter...sub-sti-tut-ed)] amino]-alkyl-phenyl...Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter...sub-sti-tut-ed)] amino]-alkyl-phenyl...ni-tro-thio-phene-car-boxy-lic acid, ethyl ester,...

2010-07-01

399

40 CFR 721.5375 - Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter, bis-[[[[(sub-sti-tut-ed)] amino]-alkyl-phenyl...  

Code of Federal Regulations, 2012 CFR

...Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter...sub-sti-tut-ed)] amino]-alkyl-phenyl...Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter...sub-sti-tut-ed)] amino]-alkyl-phenyl...ni-tro-thio-phene-car-boxy-lic acid, ethyl ester,...

2012-07-01

400

40 CFR 721.5375 - Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter, bis-[[[[(sub-sti-tut-ed)] amino]-alkyl-phenyl...  

Code of Federal Regulations, 2013 CFR

...Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter...sub-sti-tut-ed)] amino]-alkyl-phenyl...Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter...sub-sti-tut-ed)] amino]-alkyl-phenyl...ni-tro-thio-phene-car-boxy-lic acid, ethyl ester,...

2013-07-01

401

40 CFR 721.5375 - Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter, bis-[[[[(sub-sti-tut-ed)] amino]-alkyl-phenyl...  

Code of Federal Regulations, 2014 CFR

...Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter...sub-sti-tut-ed)] amino]-alkyl-phenyl...Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter...sub-sti-tut-ed)] amino]-alkyl-phenyl...ni-tro-thio-phene-car-boxy-lic acid, ethyl ester,...

2014-07-01

402

Phthalic Acid Esters in Soils from Vegetable Greenhouses in Shandong Peninsula, East China  

PubMed Central

Soils at depths of 0 cm to 10 cm, 10 cm to 20 cm, and 20 cm to 40 cm from 37 vegetable greenhouses in Shandong Peninsula, East China, were collected, and 16 phthalic acid esters (PAEs) were detected using gas chromatography-mass spectrometry (GC-MS). All 16 PAEs could be detected in soils from vegetable greenhouses. The total of 16 PAEs (?16PAEs) ranged from 1.939 mg/kg to 35.442 mg/kg, with an average of 6.748 mg/kg. Among four areas, including Qingdao, Weihai, Weifang, and Yantai, the average and maximum concentrations of ?16PAEs in soils at depths of 0 cm to 10 cm appeared in Weifang, which has a long history of vegetable production and is famous for extensive greenhouse cultivation. Despite the different concentrations of ?16PAEs, the PAE compositions were comparable. Among the 16 PAEs, di(2-ethylhexyl) phthalate (DEHP), di-n-octyl phthalate (DnOP), di-n-butyl phthalate (DnBP), and diisobutyl phthalate (DiBP) were the most abundant. Compared with the results on agricultural soils in China, soils that are being used or were used for vegetable greenhouses had higher PAE concentrations. Among PAEs, dimethyl phthalate (DMP), diethyl phthalate (DEP) and DnBP exceeded soil allowable concentrations (in US) in more than 90% of the samples, and DnOP in more than 20%. Shandong Peninsula has the highest PAE contents, which suggests that this area is severely contaminated by PAEs. PMID:24747982

Chai, Chao; Cheng, Hongzhen; Ge, Wei; Ma, Dong; Shi, Yanxi

2014-01-01

403

Caffeic acid phenethyl ester (CAPE) prevents inflammatory stress in organotypic hippocampal slice cultures.  

PubMed

Caffeic acid phenethyl ester (CAPE) is an antioxidant component of propolis, a natural product secreted by honeybee. Recent literature shows that CAPE inhibits nuclear factor kappa B (NFkappaB) activation in cell lines. Since NFkappaB was shown to be a crucial factor in neuroinflammation and to be associated with some neuropathologies, CAPE might reduce these disorders in brain too and have therapeutic applications. To test this hypothesis we used a model of endotoxic insult (interferon-gamma, followed by lipopolysaccharide) on rat organotypic hippocampal cultures. Cerebral inflammatory responses were strongly inhibited by CAPE (100 microM): reductions of NFkappaB nuclear activity, tumor necrosis factor alpha and nitric oxide productions were observed. At the dose of maximal effects (100 microM), an increase of cAMP-responsive element binding protein (CREB) activity, which anti-inflammatory role is well known, was seen. We compared CAPE effects with those of other drugs: anti-inflammatory as acetyl-salicylate and dexamethasone (glucocorticoid), antioxidant as pyrrolidine dithiocarbamate, or selective permeant inhibitor of NFkappaB as SN 50 peptide. These studies lead us to conclude that CAPE presents an interesting and original neuropharmacological profile compared to these drugs and might be helpful in the prevention of neurotoxic events due to excessive inflammatory reaction in brain. CAPE interferes with several effectors of neuroinflammation that might have complementary and synergic effects and allows a rather durable control since an acute treatment at the time of endotoxin exposure allows to control inflammatory factors for over 48 h. PMID:12877982

Montpied, Pascale; de Bock, Frédéric; Rondouin, Gérard; Niel, Gilles; Briant, Laurence; Courseau, Anne-Sophie; Lerner-Natoli, Mireille; Bockaert, Joël

2003-07-23

404

Behavior of stable carbon isotope of phthalate acid esters during photolysis under ultraviolet irradiation.  

PubMed

The photolysis of three phthalic acid esters (PAEs) (dimethyl (DMP), di-n-butyl (DBP), and di-n-octyl (DOP) phthalates) under ultraviolet (UV) irradiation at 254nm in laboratory experiments was investigated by gas chromatography coupled with isotope ratio mass spectrometry through a combustion interface (GC-C-IRMS). The degradation processes of DMP, DBP and DOP were well described by a first-order kinetic, with rate constants of 0.02636, 0.1005 and 0.958h(-1) for DMP, DBP and DOP, respectively, indicating that the photolysis rate of PAEs is related to the number of carbon atoms in molecule. The results of TOC analysis indicated that PAEs could not be completely mineralized under UV irradiation. Stable carbon isotope fractionation of the three PAEs produced during photolysis was evaluated with compound-specific isotope analysis (CSIA). Pronounced (13)C-enrichment, with maximum ?(13)C shifts of ??(13)CDMP=10.04±0.13‰ (f=0.09), ??(13)CDBP=7.4±0.19‰ (f=0.06) and ??(13)CDOP=2.9±0.17‰ (f=0.25) in the residual DMP, DBP and DOP, respectively, were clearly a direct evidence for photolysis of three PAEs. The order of stable carbon isotope fractionation of the three PAEs during photolysis, DMP>DBP>DOP, is an inverse function of the number of carbon atoms in molecule. The kinetic isotope effects (KIE) values, from 1.0018 to 1.0045 for the three PAEs, were consistent with the KIE values (1.00-1.03) of the C-O bond cleavage reported in literature. PMID:23694733

Peng, Xuewei; Li, Xianguo; Feng, Lijuan

2013-09-01

405

Identification of differential proteins in colorectal cancer cells treated with caffeic acid phenethyl ester  

PubMed Central

AIM: To investigate the molecular mechanisms of the anti-cancer activity of caffeic acid phenethyl ester (CAPE). METHODS: Protein profiles of human colorectal cancer SW480 cells treated with or without CAPE were analysed using a two-dimensional (2D) electrophoresis gel-based proteomics approach. After electrophoresis, the gels were stained with Coomassie brilliant blue R-250. Digital images were taken with a GS-800 Calibrated Densitometer, and image analysis was performed using PDQuest 2-D Analysis software. The altered proteins following CAPE treatment were further identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry following a database search. The identified proteins were validated by Western blot and immunofluorescence assay. RESULTS: CAPE induced human colorectal cancer cell apoptosis. Four up-regulated proteins and seven down-regulated proteins in colorectal cancer cells treated with CAPE were found. The identified down-regulated proteins in CAPE-treated colorectal cancer cells were Triosephosphate Isomerase (Tim), Proteasome subunit alpha 4 (PSMA4) protein, Guanine nucleotide binding protein beta, Phosphoserine aminotransferase 1 (PSAT1), PSMA1, Myosin XVIIIB and Tryptophanyl-tRNA synthetase. Notably, CAPE treatment led to the down-regulation of PSAT1 and PSMA1, two proteins that have been implicated in tumorigenesis. The identified up-regulated proteins were Annexin A4, glyceraldehyde-3-phosphate dehydrogenase, Glucosamine-6-phosphate deaminase 1 (GNPDA1), and Glutathione peroxidase (GPX-1). Based on high match scores and potential role in cell growth control, PSMA1, PSAT1, GNPDA1 and GPX-1 were further validated by Western blotting and immunofluorescence assay. PSMA1 and PSAT1 were down-regulated, while GNPDA1 and GPX-1 were up-regulated in CAPE-treated colorectal cancer cells. CONCLUSION: These differentiated proteins in colorectal cancer cells following CAPE treatment, may be potential molecular targets of CAPE and involved in the anti-cancer effect of CAPE. PMID:25206290

He, Yu-Jun; Li, Wan-Ling; Liu, Bao-Hua; Dong, Hui; Mou, Zhi-Rong; Wu, Yu-Zhang

2014-01-01

406

Effects of caffeic acid phenethyl ester on palatal mucosal defects and tooth extraction sockets  

PubMed Central

Aim The purpose of this study was to evaluate the effects of caffeic acid phenethyl ester (CAPE) on palatal mucosal defects and tooth extraction sockets in an experimental model. Materials and methods Forty-two male Sprague-Dawley rats with a mean age of 7 weeks and weighing 280–490 g were used in this study. The rats were randomly divided into two groups: group A (the control group, n=21) and group B (the experimental group, n=21). Under anesthesia with ketamine (8 mg/100 g, intraperitoneally), palatal mucosal defects were created and tooth extraction was performed in the rats in groups A and B. Group A received no treatment, whereas group B received CAPE. CAPE was injected daily (10 ?mol/kg, intraperitoneally). The rats were killed on days 7, 14, and 30 after the procedures. Palatal mucosa healing and changes in bone tissue and fibrous tissue were evaluated histopathologically. Result Pairwise comparisons showed no statistically significant difference between days 7 and 14 in either group (P>0.05). At day 30, bone healing was significantly better in group B (CAPE) than in group A (control) (P<0.05). Fibrinogen levels at day 30 were significantly higher in group A (control) than in group B (CAPE) (P<0.05). Pairwise comparisons showed no statistically significant difference in palatal mucosa healing levels between days 7 and 14 in both groups (P>0.05). Conclusion In conclusion, the findings of this study suggest that CAPE can significantly improve tooth socket healing. PMID:25364232

Günay, Ahmet; Arpa?, Osman Fatih; Atilgan, Serhat; Yaman, Ferhan; Atalay, Yusuf; Acikan, ?zzet

2014-01-01

407

Labdanolic acid methyl ester (LAME) exerts anti-inflammatory effects through inhibition of TAK-1 activation  

SciTech Connect

Labdane derivatives obtained from the diterpenoid labdanediol suppressed NO and PGE{sub 2} production in LPS-stimulated RAW 264.7 macrophages. However, mechanisms involved in these inhibitory effects are not elucidated. In this study, we investigated the signaling pathways involved in the anti-inflammatory effects of labdanolic acid methyl ester (LAME) in peritoneal macrophages and examined its therapeutic effect in a mouse endotoxic shock model. LAME reduced the production of NO and PGE{sub 2} in LPS-activated macrophages. This effect involved the inhibition of NOS-2 and COX-2 gene expression, acting at the transcription level. Examination of the effects of the diterpene on NF-?B signaling showed that LAME inhibits the phosphorylation of I?B? and I?B?, preventing their degradation and the nuclear translocation of the NF-?B p65 subunit. Moreover, inhibition of MAPK signaling was also observed. A further experiment revealed that LAME inhibited the phosphorylation of transforming growth factor-? (TGF-?)-activated kinase 1 (TAK1), an upstream signaling molecule required for IKK and mitogen-activated protein kinases (MAPKs) activation. Inflammatory cytokines such as IL-6, TNF-? and IP-10 were downregulated in the presence of this compound after stimulation with LPS. Additionally, LAME also improved survival in a mouse model of endotoxemia and reduced the circulatory levels of cytokines (IL-6, TNF-?). In conclusion, these results indicate that labdane diterpene LAME significantly attenuates the pro-inflammatory response induced by LPS both in vivo and in vitro. Highlights: ? LAME reduced the production of NO and PGE{sub 2} in LPS-activated macrophages. ? IL-6, TNF-? and IP-10 were also inhibited by LAME. ? Inhibition of TAK-1 activation is the mechanism involved in this process. ? LAME improved survival in a mouse model of endotoxemia. ? LAME reduced the circulatory levels of cytokines (IL-6, TNF-?).

Cuadrado, Irene [Departamento de Farmacología, Facultad de Farmacia, Universidad Complutense, Plaza Ramón y Cajal s/n, 28040 Madrid (Spain)] [Departamento de Farmacología, Facultad de Farmacia, Universidad Complutense, Plaza Ramón y Cajal s/n, 28040 Madrid (Spain); Cidre, Florencia; Herranz, Sandra [Unidad de Inflamación y Cáncer. Área de Biología Celular y Desarrollo. Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid (Spain)] [Unidad de Inflamación y Cáncer. Área de Biología Celular y Desarrollo. Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid (Spain); Estevez-Braun, Ana [Instituto Universitario de Bio-Orgánica “Antonio González”. Universidad de La Laguna. Avda. Astrofísico Fco. Sánchez 2. 38206. La Laguna, Tenerife (Spain) [Instituto Universitario de Bio-Orgánica “Antonio González”. Universidad de La Laguna. Avda. Astrofísico Fco. Sánchez 2. 38206. La Laguna, Tenerife (Spain); Instituto Canario de Investigaciones del Cáncer (ICIC) (Spain); Heras, Beatriz de las, E-mail: lasheras@farm.ucm.es [Departamento de Farmacología, Facultad de Farmacia, Universidad Complutense, Plaza Ramón y Cajal s/n, 28040 Madrid (Spain); Hortelano, Sonsoles, E-mail: shortelano@isciii.es [Unidad de Inflamación y Cáncer. Área de Biología Celular y Desarrollo. Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid (Spain)] [Unidad de Inflamación y Cáncer. Área de Biología Celular y Desarrollo. Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid (Spain)

2012-01-01

408

Caffeic Acid Phenethyl Ester Protects against Amphotericin B Induced Nephrotoxicity in Rat Model  

PubMed Central

The present study was conducted to investigate whether caffeic acid phenethyl ester (CAPE), an active component of propolis extract, has a protective effect on amphotericin B induced nephrotoxicity in rat models. Male Wistar-Albino rats were randomly divided into four groups: (I) control group (n = 10), (II) CAPE group (n = 9) which received 10??mol/kg CAPE intraperitoneally (i.p.), (III) amphotericin B group (n = 7) which received one dose of 50?mg/kg amphotericin B, and (IV) amphotericin B plus CAPE group (n = 7) which received 10??mol/kg CAPE i.p. and one dose of 50?mg/kg amphotericin B. The left kidney was evaluated histopathologically for nephrotoxicity. Levels of malondialdehyde (MDA), nitric oxide (NO), enzyme activities including catalase (CAT), and superoxide dismutase (SOD) were measured in the right kidney. Histopathological damage was prominent in the amphotericin B group compared to controls, and the severity of damage was lowered by CAPE administration. The activity of SOD, MDA, and NO levels increased and catalase activity decreased in the amphotericin B group compared to the control group (P = 0.0001, P = 0.003, P = 0.0001, and P = 0.0001, resp.). Amphotericin B plus CAPE treatment caused a significant decrease in MDA, NO levels, and SOD activity (P = 0.04, P = 0.02, and P = 0.0001, resp.) and caused an increase in CAT activity compared with amphotericin B treatment alone (P = 0.005). CAPE treatment seems to be an effective adjuvant agent for the prevention of amphotericin B nephrotoxicity in rat models. PMID:25032223

Altunta?, Atila; Y?lmaz, H. Ramazan; Altunta?, Ay?egül; Uz, Efkan; Demir, Murat; Gökçimen, Alparslan; Aksu, O?uzhan; Bayram, Dilek ?enol; Sezer, Mehmet Tu?rul

2014-01-01

409

Caffeic acid phenethyl ester decreases acute pneumonitis after irradiation in vitro and in vivo  

PubMed Central

Background Lung cancer is relatively resistant to radiation treatment and radiation pneumonitis is a major obstacle to increasing the radiation dose. We previously showed that Caffeic acid phenethyl ester (CAPE) induces apoptosis and increases radiosensitivity in lung cancer. To determine whether CAPE, an antioxidant and an inhibitor of NF-kappa B, could be a useful adjuvant agent for lung cancer treatment, we examine the effects of CAPE on irradiated normal lung tissue in this study. Methods We compared the effects of CAPE on cytotoxicity and intracellular oxidative stress in normal lung fibroblast and a lung cancer cell line. For in vivo analysis, whole thorax radiation (single dose 10 Gy and 20 Gy) was delivered to BALB/c male mice with or without CAPE pretreatment. NF- kappaB activation and the expression levels of acute inflammatory cytokines were evaluated in mice after irradiation. Results The in vitro studies showed that CAPE cause no significant cytotoxicity in normal lung as compared to lung cancer cells. This is probably due to the differential effect on the expression of NF-kappa B between normal and malignant lung cells. The results from in vivo study showed that CAPE treatment decreased the expression of inflammatory cytokines including IL-1 alpha and beta, IL-6, TNF-alpha and TGF- beta, after irradiation. Moreover, histological and immunochemical data revealed that CAPE decreased radiation- induced interstitial pneumonitis and TGF-beta expression. Conclusion This study suggests that CAPE decreases the cascade of inflammatory responses induced by thoracic irradiation without causing toxicity in normal lung tissue. This provides a rationale for combining CAPE and thoracic radiotherapy for lung cancer treatment in further clinical studies. PMID:16336675

Chen, Miao-Fen; Keng, Peter C; Lin, Paul-Yang; Yang, Cheng-Ta; Liao, Shuen-Kuei; Chen, Wen-Cheng

2005-01-01

410

Protective Effect of Caffeic Acid Phenethyl Ester (CAPE) on Amiodarone-Induced Pulmonary Fibrosisin Rat  

PubMed Central

Treatment with amiodarone, a commonly prescribed antidysrhythmic agent, is associated with pulmonary fibrosis (PF) which is a commonly progressive and untreatable disease. Caffeic acid phenethyl ester (CAPE) is a phenolic antioxidant and an active anti-inflammatory , anticancer, antimicrobial and antioxidant component of propolis (bee glue; a resinous hive product collected by honey bees). In the current study, the effects of CAPE on amiodarone-induced pulmonary fibrosis in rat were investigated. Male rats were divided in to 4 groups. The first group only received amiodarone (6.25 mg/Kg) on first and third day. The second group received only vehicle (distilled water) with the same volume and in the same time as the first group. The third and fourth groups received amiodarone and were treated with CAPE , 5 and 10 µmol /day respectively, from 2 days before the first dose of amiodarone and until 21 days after the second dose of amiodarone. At the end of treatment course, lung tissue was removed for histopathology and biochemical evaluations. Malondialdehyde (MDA) concentration, myeloperoxidase MPO) and super oxide dismutase (SOD) activities were determined in lung tissue. Histopathological evaluation was performed using light microscopy. MDA level and the activity of myeloperoxidase and superoxide dismutase enzymes significantly decreased in the group which was treated with CAPE (5 µmol/Kg). However, 10 µmol/Kg CAPE had not such an effect. Both doses of CAPE could histopathologically reduce the fibrogenic effects of amiodarone . CAPE was shown to be effective in reducing amiodarone-induced pulmonary fibrosis with the dose of 5 µmol/Kg. PMID:24250361

Zaeemzadeh, Narjes; Hemmati, Aliasghar; Arzi, Ardeshir; Jalali, Mohammadtaha; Rashidi, Iran

2011-01-01

411

Caffeic acid phenethyl ester (CAPE): scavenger of peroxynitrite in vitro and in sepsis models.  

PubMed

Excessive free radical production by immune cells has been linked to cell death and tissue injury during sepsis. Peroxynitrite is a short-lived oxidant and a potent inducer of cell death that has been identified in several pathological conditions. Caffeic acid phenethyl ester (CAPE) is an active component of honeybee products and exhibits antioxidant, anti-inflammatory, and immunomodulatory activities. The present study examined the ability of CAPE to scavenge peroxynitrite in RAW 264.7 murine macrophages stimulated with lipopolysaccharide/interferon-? that was used as an in vitro model. Conversion of 123-dihydrorhodamine to its oxidation product 123-rhodamine was used to measure peroxynitrite production. Two mouse models of sepsis (endotoxemia and cecal ligation and puncture) were used as in vivo models. The level of serum 3-nitrotyrosine was used as an in vivo marker of peroxynitrite. The results demonstrated that CAPE significantly improved the viability of lipopolysaccharide/interferon-?-treated RAW 264.7 cells and significantly inhibited nitric oxide production, with effects similar to those observed with an inhibitor of inducible nitric oxide synthase (1400W). In addition, CAPE exclusively inhibited the synthesis of peroxynitrite from the artificial substrate SIN-1 and directly prevented the peroxynitrite-mediated conversion of dihydrorhodamine-123 to its fluorescent oxidation product rhodamine-123. In both sepsis models, CAPE inhibited cellular peroxynitrite synthesis, as evidenced by the absence of serum 3-nitrotyrosine, an in vivo marker of peroxynitrite. Thus, CAPE attenuates the inflammatory responses that lead to cell damage and, potentially, cell death through suppression of the production of cytotoxic molecules such as nitric oxide and peroxynitrite. These observations provide evidence of the therapeutic potential of CAPE treatment for a wide range of inflammatory disorders. PMID:24667629

Kassim, Mustafa; Mansor, Marzida; Kamalden, Tengku Ain; Shariffuddin, Ina Ismiarti; Hasan, Mohd Shahnaz; Ong, Gracie; Sekaran, Shamala Devi; Suhaimi, Anwar; Al-Abd, Nazeh; Yusoff, Kamaruddin Mohd

2014-08-01

412

Induction of apoptosis by a potent caffeic acid derivative, caffeic acid undecyl ester, is mediated by mitochondrial damage in NALM-6 human B cell leukemia cells  

PubMed Central

Caffeic acid esters have various biological activities, and we previously reported that undecyl caffeate (caffeic acid undecyl ester, CAUE), a new caffeic acid derivative, has strong pharmacological activity. The present study investigated the cytotoxicity of both CAUE and its parent compound, caffeic acid phenethyl ester (CAPE), and characterized the mechanisms by which they induce apoptosis in the human B cell leukemia cell line NALM-6. Treatment with CAUE reduced cell survival in NALM-6 cells but had no significant effect on the survival of normal lymphocytes. When assessing the 50% inhibitory concentration (IC50) for cytotoxicity, CAUE had 10-fold higher activity than CAPE in NALM-6 cells. CAUE treatment resulted in induction of apoptotic features in NALM-6 cells, including cleaved poly (ADP-ribose) polymerase and activated caspase-3. A caspase inhibitor completely blocked CAUE-induced apoptosis. CAUE treatment resulted in a concentration- and time-dependent decrease in both mitochondrial membrane potential and downregulation of Bcl-2 expression. Moreover, CAUE-induced apoptosis was enhanced in the Bcl-2 knockdown condition induced by small interfering RNA. These data suggest that CAUE-induced apoptosis was mediated via an apoptotic intrinsic pathway including mitochondrial damage and was caspase-dependent. These data also suggest that CAUE is a powerful anti-leukemic agent that acts via induction of apoptosis by mitochondrial damage and selective action in leukemia cells. PMID:23229564

TOMIZAWA, AYAKO; KANNO, SYU-ICHI; OSANAI, YUU; GOTO, AKANE; SATO, CHIZURU; YOMOGIDA, SHIN; ISHIKAWA, MASAAKI

2013-01-01

413

Caffeic Acid Phenethyl Ester as a Protective Agent against Nephrotoxicity and/or Oxidative Kidney Damage: A Detailed Systematic Review  

PubMed Central

Caffeic acid phenethyl ester (CAPE), an active component of propolis, has been attracting the attention of different medical and pharmaceutical disciplines in recent years because of its antioxidant, anti-inflammatory, antiproliferative, cytotoxic, antiviral, antifungal, and antineoplastic properties. One of the most studied organs for the effects of CAPE is the kidney, particularly in the capacity of this ester to decrease the nephrotoxicity induced by several drugs and the oxidative injury after ischemia/reperfusion (I/R). In this review, we summarized and critically evaluated the current knowledge regarding the protective effect of CAPE in nephrotoxicity induced by several special medicines such as cisplatin, doxorubicin, cyclosporine, gentamycin, methotrexate, and other causes leading to oxidative renal injury, namely, I/R models and senility. PMID:25003138

Akyol, Sumeyya; Ugurcu, Veli; Altuntas, Aynur; Hasgul, Rukiye; Cakmak, Ozlem

2014-01-01

414

Enzymatic production of L-alanyl-L-glutamine by recombinant E. coli expressing ?-amino acid ester acyltransferase from Sphingobacterium siyangensis.  

PubMed

An enzymatic production method for synthesizing L-alanyl-L-glutamine (Ala-Gln) from L-alanine methyl ester hydrochloride (AlaOMe) and L-glutamine (Gln) was developed in this study. The cultivation conditions for an Escherichia coli strain overexpressing ?-amino acid ester acyltransferase from Sphingobacterium siyangensis AJ 2458 (SAET) and reaction conditions for Ala-Gln production were optimized. A high cell density culture broth prepared by fed-batch cultivation showed 440 units/mL of Ala-Gln-producing activity. In addition, an Ala-Gln-producing reaction using intact E. coli cells overexpressing SAET under optimum conditions was conducted. A total Ala-Gln yield of 69.7 g/L was produced in 40 min. The molar yield was 67% against both AlaOMe and Gln. PMID:23470770

Hirao, Yoshinori; Mihara, Yasuhiro; Kira, Ikuo; Abe, Isao; Yokozeki, Kenzo

2013-01-01

415

Angiotensin converting enzyme inhibitory activity of amino acid esters of carbohydrates.  

PubMed

L-alanyl-D-glucose, L-valyl-D-glucose, L-phenylalanyl-D-glucose and L-phenylalanyl-lactose esters were synthesized enzymatically using two lipases viz., Rhizomucor miehei lipase (RML) and porcine pancreas lipase (PPL) and tested for their potential as inhibitors of angiotensin converting enzyme (ACE) in vitro. The esters exhibited concentration related ACE inhibitory activity. The potency of the various esters measured in terms of IC50 values were as follows: L-phenylalanyl-D-glucose, IC50-0.121 mM (mixture of five diastereomeric esters: 6-O-24.1%; 3-O-23.3%; 2-O-19.2%; 2,6-di-O-16.6% and 3,6-di-O-16.8% from the total yield of 92.4%); L-phenylalanyl-lactose, IC50-0.229 mM (mixture of three diastereomeric esters: 6-O-42.1%; 6'-O-30.9%; and 6,6'-di-O-27.0% from the total yield of 50.58%); alanyl-D-glucose, IC50-0.23 mM (mixture of five diastereomeric esters: 6-O-46.7%; 3-O-11.5%; 2-O-19.9%; 2,6-di-O-6.6% and 3,6-di-O-15.3% from the total yield of 26.5%) and L-valyl-D-glucose, IC50-0.396 mM (mixture of five diastereomeric esters: 6-O-32.4%; 3-O-26.5%; 2-O-26.4%; 2,6-di-O-8.8% and 3,6-di-O-5.9% from the total yield of 68.2%). These in vitro data suggest a potential therapeutic role for the aminoesters of carbohydrates as inhibibitors of ACE. PMID:16529809

Kamath, Vasudeva; Rajini, P S; Lohith, K; Somashekar, B R; Divakar, S

2006-03-30

416

Acidity of nickel silicate and its bearing on the catalytic activity for ethylene dimerization and butene isomerization  

SciTech Connect

Experimental results obtained with nickel silicate catalysts precipitated at pH 6-10 (Group 1) or containing 4-90% nickel oxide (Group 2) provided evidence that 1-butene was the primary product of ethylene dimerization; that 2-butene was a secondary isomerization product; that the selectivity for 2-butene isomerization ran parallel to the previously measured dimerization activity, i.e., had maxima at 100/sup 0/ and 600/sup 0/C pretreatment temperatures; that the montmorillonite sites which were activated at 100/sup 0/C consisted of protonic acid sites; that the protonic sites for dimerization and isomerization differed and that the number of isomerization sites was about one order of magnitude greater than that of dimerization sites; and that the antigorite sites activated at 600/sup 0/C were nonprotonic acid sites. The experiments included n-butylamine titration with dicinnamalacetone indicator, ammonia chemisorption, selective poisoning studies with water and sodium, deuterium tracer studies, and IR spectroscopy.

Sohn, J.R.; Ozaki, A.

1980-01-01

417

Modeling studies investigating the causes of preferential depletion of silicic acid relative to nitrate during SERIES, a mesoscale iron enrichment in the NE subarctic Pacific  

NASA Astrophysics Data System (ADS)

Numerical modeling experiments were conducted to examine the reasons for observed changes in the silicic acid ([Si(OH) 4]) to nitrate ([NO3-]) drawdown ratio after the onset of algal iron stress during SERIES. During phytoplankton blooms and immediately after them, cells encounter a range of iron stress (between iron-replete and iron-deplete) and therefore show a range of growth rates. For these reasons, the potential influence of phytoplankton growth rate, under conditions of algal iron stress, on silicic acid and nitrate depletion were investigated in numerical experiments by altering the timing of a shift in the [Si(OH) 4]: [NO3-] uptake ratio. These simulations suggested that the continued growth of iron-stressed phytoplankton at sub-maximum rates, with an elevated [Si(OH) 4]: [NO3-] uptake ratio, induced depletion of silicic acid in the surface water and resulted in simultaneous limitation of growth by both iron and silicic-acid supply. Therefore, bottom-up control played an important role in terminating the phytoplankton bloom in SERIES. In the model simulations, the enhancement of diatom silicification due to increased rates of biomass-normalized silicic-acid uptake, led to increases in the export flux of opal after the onset of algal iron-stress and, consequently, it stimulated the silica pump. The regulation of both the [Si(OH) 4]: [NO3-] uptake ratio and the growth rate of phytoplankton by iron supply are important factors that determine the relative consumption of silicic acid and nitrate upon iron stress, although the potential influence of a floristic shift in the diatom assemblage cannot be ruled out. These findings offer insights into the impact of iron fertilization, both artificial and natural, on the biogeochemical cycling of nutrients in high-nitrate, low-chlorophyll waters.

Takeda, S.; Yoshie, N.; Boyd, P. W.; Yamanaka, Y.

2006-10-01

418

Friedel-crafts alkylation of benzene by normal omega-chloroalkanoic acids and their methyl esters and nitriles  

SciTech Connect

In the Friedel-Crafts alkylation of benzene by normal 1-haloalkanes with three or more carbon atoms a mixture of phenylalkanes forms, due to isomerization of the alkyl chain and migration of a hydrogen atoms. Under analogous conditions the alkylation of benzene by omega-chloroalkanoic acids, Cl(CH/sub 2/)/sub n/COOH, and omega-bromoalkanonitriles proceeds with isomerization of the alkyl chain, but beginning only with 6-chlorohexanoic acid and 6-bromohexanonitrile. Such a difference in the behavior of these halogen derivatives has not received a convincing explanation, although the mechanism of Friedel-Crafts alkylation of benzene should be the same in the two cases. For a better understanding of this difference, this work presents a systematic study of benzene alkylation by 4-chlorobutyric, 5-chlorovaleric, 6-chlorohexanoic, and 7-chloroheptanoic acids and their methyl esters and nitriles, and by ..gamma..-butyro- and delta-valerolactones. The catalyst was crystalline AlCl/sub 3/ twice sublimed from Mg. For comparison, alkylation with the respective 1-chloroalkanes was carried out. In the alkylation of benzene by omega-chloroalkanoic acids Cl(CH/sub 2/)/sub n/COOH (where n = 3-6) and their methyl esters and nitriles, in the presence of AlCl/sub 3/, the degree of isomerization of the alkyl chain is less than with the corresponding 1-chloroalkanes, depending on the increase in electron acceptor activity in the sequence HOOC- > CH/sub 3/OCO- > CN-.

Zakharkin, L.I.; Anikina, E.V.

1987-08-20

419

EXTRACTION OF RARE EARTH METALS WITH 2-ETHYLHEXYL PHOSPHONIC ACID MONO2-ETHYLHEXYL ESTER IN THE PRESENCE OF DIETHYLENETRIAMINEPENTAACETIC ACID IN AQUEOUS PHASE  

Microsoft Academic Search

The extraction equilibria of rare earth metals with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (commercial name, PC-88A, henceforth abbreviated as HR) dissolved in n-heptane were measured at 303 K. It was found that rare earth metals are extracted with the dimer of the extractant, (HR)2, as follows.The extraction equilibrium constants of metals were obtained and compared with the extraction equilibrium constants

Fukiko Kubota; Masahiro Goto; Fumiyuki Nakashio

1993-01-01

420

Lipase catalyzed synthesis of L-alanyl, L-leucyl and L-phenylalanyl esters of D-glucose using unprotected amino acids.  

PubMed

Enzymatic synthesis of l-alanyl, l-leucyl and l-phenylalanyl esters of D-glucose was carried out in a non-polar solvent using lipases from Rhizomucor miehei and porcine pancreas. The unprotected amino acids at millimolar concentrations were used in presence of 10 to 50% (w/w) glucose of the lipases to give ester yields up to >99%. The reaction mixture on analysis by 2-D NMR showed that the product is a mixture of 6-O-, 3-O- and 2-O-monoesters and 2,6-di-O- and 3,6- di-O-esters. PMID:15604758

Vijayakumar, Giriyapura R; Lohith, Kenchaiah; Somashekar, Bhandya R; Divakar, Soundar

2004-09-01

421

Solid dispersions of the penta-ethyl ester prodrug of diethylenetriaminepentaacetic acid (DTPA): formulation design and optimization studies.  

PubMed

The penta-ethyl ester prodrug of diethylenetriaminepentaacetic acid (DTPA), which exists as an oily liquid, was incorporated into a solid dispersion for oral administration by the solvent evaporation method using blends of polyvinylpyrrolidone (PVP), Eudragit® RL PO and ?-tocopherol. D-optimal mixture design was used to optimize the formulation. Formulations that had a high concentration of both Eudragit® RL PO and ?-tocopherol exhibited low water absorption and enhanced stability of the DTPA prodrug. Physicochemical properties of the optimal formulation were evaluated using Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). In vitro release of the prodrug was evaluated using the USP Type II apparatus dissolution method. DSC studies indicated that the matrix had an amorphous structure, while FTIR spectrometry showed that DTPA penta-ethyl ester and excipients did not react with each other during formation of the solid dispersion. Dissolution testing showed that the optimized solid dispersion exhibited a prolonged release profile, which could potentially result in a sustained delivery of DTPA penta-ethyl to enhance bioavailability. In conclusion, DTPA penta-ethyl ester was successfully incorporated into a solid matrix with high drug loading and improved stability compared to prodrug alone. PMID:24047113

Yang, Yu-Tsai; Di Pasqua, Anthony J; Zhang, Yong; Sueda, Katsuhiko; Jay, Michael

2014-11-01

422

Comparative study of (Z)-4-oxo-4-ureido-but-2-enoic acid and p-toluenesulfonic acid 3-nitrophenyl ester by crystal engineering and DFT calculation  

NASA Astrophysics Data System (ADS)

In this work, we reported on the synthesis and characterization of (Z)-4-oxo-4-ureido-but-2-enoic acid and p-toluenesulfonic acid 3-nitrophenyl ester and their detailed crystal structure information were studied. The crystallization of (Z)-4-oxo-4-ureido-but-2-enoic acid results in reduced ?-conjugation in the molecule and weaker intra-molecular hydrogen bonding. The main driving force for the molecular self-assembly of (Z)-4-oxo-4-ureido-but-2-enoic acid was found to be the strong intermolecular hydrogen bonds. Compared with (Z)-4-oxo-4-ureido-but-2-enoic acid with six type of strong H-bonds, p-toluenesulfonic acid 3-nitrophenyl ester possesses much lower melting point (110-111°C), average packing energy (-3.7 kcal mol-1), molecular deformation energy (-0.6 kcal mol-1) and highest torsional angle change (9.3°). This can be ascribed to the week intermolecular interaction between center molecule and adjacent molecules.

Zhang, Y. F.; Huang, L.; Sun, Y. B.; Han, B.; Cheng, H. S.

2013-07-01

423

Redox intermediates of flavonoids and caffeic acid esters from propolis: an EPR spectroscopy and cyclic voltammetry study.  

PubMed

The redox properties of flavonoids: chrysin (1), tectochrysin (2), galangin (3), isalpinin (4), pinostrobin (5), pinobanksin (6), pinobanksin-3-acetate (7), and of caffeic acid ester (8) and diacetylcaffeic acid ester (9), all isolated from propolis, were investigated by cyclic voltammetry in acetonitrile. The choice of aprotic solvent lowered the reactivity of the radical intermediates and made possible to identify redox steps and intermediates not detected so far. The oxidation potentials (vs. saturated calomel electrode) of the investigated compounds were in the region of 1.5 V for 3 and 4; 1.9 V for 1, 2, and 5; 2.0 V for 6 and 7; 1.29 V for 8; and 2.3 V for 9. These oxidation potentials were mainly influenced by the presence of a double bond in 2,3-position and substituent R1 in position 3. Comparison with our earlier data revealed that flavonoids, 1-4, and caffeic acid ester 8 with lower oxidation potentials showed the maximal lipid antioxidant activity, whereas those with higher potentials (5, 6, 7, and 9) are less active. On reduction of 1-9 several one-electron-steps were typically observed in the potential regions: -1.5 V, -1.8 V, and -2 V. where in simultaneous EPR experiments anion radicals of 1 and 3 were observed with the center of unpaired spin density on ring A. Upon oxidation of flavonoids 1-4 carbonyl carbon-centered radicals, .C(O)R, were identified as consecutive products using the EPR spin trapping technique. PMID:7797098

Rapta, P; Misík, V; Stasko, A; Vrábel, I

1995-05-01

424

Use of caffeic acid phenethyl ester and cortisone may prevent proliferative vitreoretinopathy.  

PubMed Central

PURPOSE: To investigate whether caffeic acid phenethyl ester (CAPE) and cortisone prevent proliferative vitreoretinopathy (PVR). METHODS: Twenty pigmented rabbits were used in this study. All rabbits except controls received an intravitreal injection of 0.15 ml (75,000 U) of platelet-rich plasma into their left eye. The animals were divided into four groups: group I was treated with intraperitoneal injection of 0.5 ml (15 micromol/kg) of CAPE for 3 days, group II received 0.15 ml (4 mg/kg) of intravitreal cortisone, group III received nothing (blank group), and group IV (control group) received only 1 ml of 1% ethanol intraperitoneally daily for 3 days. Proliferative changes were graded in a masked fashion by indirect ophthalmoscopy for a 15-day follow-up period. The malondialdehyde (MDA), reduced glutathione (GSH) and total nitrite (NO) levels were measured in the vitreous humor. RESULTS: The grades of PVR were B-C in group I, and C-D in group II. The PVR grade in the control group was C-D. The mean MDA level in group I (4.0+/-0.8 micromol/l) was significantly lower than in the blank group (6.0 micromol/l) (p < 0.05). The mean GSH level in group I (71.0+/-11.2 micromol/l) was significantly different than in the blank group (p < 0.05). The MDA and GSH levels in group II were 4.7+/-0.6 micromol/l and 53.8+/-7.8 micromol/l, respectively. Both these levels were not significantly different from the blank group (p > 0.05). The NO levels in both treatment groups were significantly lower than in the blank group (p < 0.001). CONCLUSION: These findings suggest an inhibitory effect of CAPE on PVR. The inhibitory effect was supported by lower MDA and NO with higher GSH levels in treatment groups than in the blank group. There was no detected significant effect of cortisone for preventing PVR experimentally. PMID:15203555

Turkoz, Yusuf; Er, Hamdi; Borazan, Mehmet; Yilmaz, Harun; Mizrak, Bülent; Parlakpinar, Hakan; Cigremis, Yilmaz

2004-01-01

425

Highly conductive PEDOT\\/silicate hybrid anode for ITO-free polymer solar cells  

Microsoft Academic Search

In this work, we prepared ITO-free photovoltaic devices (PVDs) using a transparent poly(3,4-ethylenedioxythiophene):silicate (PEDOT:SiOx) composite anode equipped with low surface resistance and high transparency. A mixture of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C60 butyric acid methyl ester (PCBM) was used as a photoactive layer. PEDOT:SiOx film was fabricated with an inorganic silicate network via the oxidative polymerization of EDOT and in-situ

Youn Soo Kim; Seok Bin Oh; Jong Hyeok Park; Mi Suk Cho; Youngkwan Lee

2010-01-01

426

Dimethylamino Acid Esters as Biodegradable and Reversible Transdermal Permeation Enhancers: Effects of Linking Chain Length, Chirality and Polyfluorination  

Microsoft Academic Search

Purpose  Series of N,N-dimethylamino acid esters was synthesized to study their transdermal permeation-enhancing potency, biodegradability and reversibility\\u000a of action. Effects of chirality, linking chain length and polyfluorination were investigated.\\u000a \\u000a \\u000a \\u000a Materials and Methods  \\u000a In vitro activities were evaluated using porcine skin and four model drugs—theophylline, hydrocortisone, adefovir and indomethacin.\\u000a Biodegradability was determined using porcine esterase, reversibility was measured using electrical resistance.\\u000a \\u000a \\u000a \\u000a Results  No

Jakub Novotný; Petra Kova?íková; Michal Novotný; Barbora Jan?šová; Alexandr Hrabálek; Kate?ina Vávrová

2009-01-01

427

FTIR measurements of mid-IR absorption spectra of gaseous fatty acid methyl esters at T=25-500 °C  

NASA Astrophysics Data System (ADS)

Gas-phase mid-infrared (IR) absorption spectra (2500-3400 cm-1) for eleven fatty acid methyl esters (FAMEs) have been quantitatively measured at temperatures between 25 and 500 °C using an FTIR spectrometer with a resolution of 1 cm-1. Using these spectra, the absorption cross section at 3.39 ?m, corresponding to the monochromatic output of a helium-neon laser, is reported for each of these fuels as a function of temperature. The data indicate that the 3.39 ?m cross section values of saturated FAMEs vary linearly with the logarithm of the number of Csbnd H bonds in the molecule.

Campbell, M. F.; Freeman, K. G.; Davidson, D. F.; Hanson, R. K.

2014-09-01

428

Synthesis of 3-(4-heteroaryl-phenyl)-8-oxabicyclo[3.2.1]octane-2-carboxylic acid methyl esters  

Microsoft Academic Search

Cross coupling protocols were applied for the synthesis of 3-(4-heteroaryl-phenyl)-8-oxabicyclo[3.2.1]oct-2-ene-2-carboxylic acid methyl esters. Stille conditions produced the corresponding products in reasonable yields. Samarium iodide reduction of the resulting coupling products produced the 2?-carbomethoxy-3?-aryl-8-oxabicyclo[3.2.1]octane diastereoisomers as the major, and the 2?-carbomethoxy-3?-aryl-8-oxabicyclo[3.2.1]octane diastereoisomer as the minor products. Both diastereomers manifested inhibition of the dopamine (DAT) and serotonin (SERT) transporters, with some selectivity

Lokman Torun; Shanghao Liu; Bertha K. Madras; Peter C. Meltzer

2006-01-01

429

The first guaian-12-oic acid glucopyranosyl ester and other constituents from Picris rhagadioloides (L.) Desf. (Asteraceae).  

PubMed

The first guaian-12-oic acid glucopyranosyl ester was isolated from the roots of Picris rhagadioloides (L.) Desf. (Asteraceae), in addition to five costuslactone-type guaianolides, four germacranolides and three phenolic compounds. This is the first time that the known phenolics syringaldehyde and syringaresinol, as well as the known sesquiterpene lactones glucozaluzanin C, cichorioside C and hypochoeroside A have been described from a Picris species. The compounds were characterized on the basis of physicochemical, 1D- and 2D-NMR spectroscopic, and mass spectrometric data. PMID:18305430

Michalska, Klaudia; Kisiel, Wanda

2008-01-01

430

Compositional effects on Si-OH bond length in hydrous silicates with implications for trends in the SiOH acidity  

NASA Astrophysics Data System (ADS)

Theoretical calculations of the structure and Brønsted acidity of SiOH groups in silica clusters have never addressed the question if these vary with the degree of SiOH deprotonation. In this connection, a statistical analysis is presented of Si-OH bond lengths in crystalline hydrogen silicates with well-determined structures with a special emphasis placed on effects of the silicate composition. It is found that among hydrogen silicates of large cations with low charges the Si-OH bonds are always longer than terminal Si-O bonds in the same anion and correlate in length with the anionic charge per tetrahedron. The findings are explained by steric limitations on charge balancing at oxygen atoms by hydrogen bonds and/or cations. It is suggested that similar limitations and imbalances may underlie the well-known trends in the Brønsted acidity of silicic acids and silicas in aqueous media: decreased acidity with increased SiOH deprotonation and increased acidity with increased tetrahedra connectivity.

Zarubin, Dmitri P.

2014-04-01

431

N(G)-nitro-L-arginine and its methyl ester inhibit brain synthesis of kynurenic acid possibly via nitric oxide-independent mechanism.  

PubMed

The effect of nitric oxide synthase (NOS) inhibitors on the brain production of endogenous glutamate receptor antagonist, kynurenic acid, was estimated in vitro. Under standard incubation conditions N(G)-nitro-L-arginine, but not N(G)-nitro-L-arginine methyl ester, up to 5 mM, or 7-nitroindazole, up to 100 microM, inhibited de novo synthesis of kynurenic acid in cortical slices. However, during prolonged incubation, N(G)-nitro-L-arginine methyl ester also reduced the production of kynurenic acid. The substrate for NOS, L-arginine (up to 5 mM), did not influence kynurenic acid synthesis and did not reverse the N(G)-nitro-L-arginine-evoked changes, suggesting that the observed effects are not related to disturbed generation of NO. Enzymatic studies revealed that N(G)-nitro-L-arginine and its methyl ester blocked the activity of brain kynurenine aminotransferase (KAT) I. The activity of KAT II was diminished only by N(G)-nitro-L-arginine. Kinetic analyses have shown that N(G)-nitro-L-arginine and its methyl ester reduce Vmax and increase Km of KAT I, whereas N(G)-nitro-L-arginine diminishes Vmax of KAT II. In conclusion, we report that N(G)-nitro-L-arginine and its methyl ester impair brain synthesis of kynurenic acid, probably via NO-independent mechanism, what could contribute, at least partially, to the enhancement of neurotoxicity or seizures observed in some experimental designs based on their use. PMID:11985333

Luchowski, P; Kocki, T; Urba?ska, E M

2001-01-01

432

EFFECT OF QUARTZ/MULLITE BLEND CERAMIC ADDITIVE ON IMPROVING RESISTANCE TO ACID OF SODIUM SILICATE-ACTIVATED SLAG CEMENT. CELCIUS BRINE.  

SciTech Connect

We evaluated the usefulness of manufactured quartz/mullite blend (MQMB) ceramic powder in increasing the resistance to acid of sodium silicate-activated slag (SSAS) cementitious material for geothermal wells. A 15-day exposure to 90{sup o} CO{sub 2}-laden H{sub 2}SO{sub 4} revealed that the MQMB had high potential as an acid-resistant additive for SSAS cement. Two factors, the appropriate ratio of slag/MQMB and the autoclave temperature, contributed to better performance of MQMB-modified SSAS cement in abating its acid erosion. The most effective slag/MQMB ratio in minimizing the loss in weight by acid erosion was 70/30 by weight. For autoclave temperature, the loss in weight of 100 C autoclaved cement was a less than 2%, but at 300 C it was even lower. Before exposure to acid, the cement autoclaved at 100 C was essentially amorphous; increasing the temperature to 200 C led to the formation of crystalline analcime in the zeolitic mineral family during reactions between the mullite in MQMB and the Na from sodium silicate. In addition, at 300 C, crystal of calcium silicate hydrate (1) (CSH) was generated in reactions between the quartz in MQMB and the activated slag. These two crystalline phases (CSH and analcime) were responsible for densifying the autoclaved cement, conveying improved compressive strength and minimizing water permeability. The CSH was susceptible to reactions with H{sub 2}SO{sub 4}, forming two corrosion products, bassanite and ionized monosilicic acid. However, the uptake of ionized monosilicic acid by Mg dissociated from the activated slag resulted in the formation of lizardite as magnesium silicate hydrate. On the other hand, the analcime was barely susceptible to acid if at all. Thus, the excellent acid resistance of MQMB-modified SSAS cement was due to the combined phases of lizardite and analcime.

SUGAMA, T.; BROTHERS, L.E.; VAN DE PUTTE, T.R.

2006-06-01

433

Heat-shrink tubing as a solid-phase microextraction coating for the enrichment and determination of phthalic acid esters.  

PubMed

Heat-shrink tubing, which shrinks in one plane only (its diameter) when heated, commonly used for sealing protection in electrical engineering, was found to be able to function as a solid-phase microextraction coating. Its utility was demonstrated for the determination of phthalic acid esters in an aqueous solution combined with high-performance liquid chromatography equipped with a UV absorbance detector. The preparation procedure was rather simple and only ?10 min was needed. The fiber cost is extremely low (?10 cent each). The parameters affecting the extraction were optimized. Heat-shrink tubing fiber exhibited a significant enrichment effect for the three examined phthalic acid esters and up to 931-fold enrichment factor was obtained. The limit of detection was <10 ?g/L for all analytes. The operation repeatability and fiber-to-fiber reproducibility were 1.2-8.3 and 5.4-9.1%, respectively. It was successfully applied for the analysis of bottled drinking water with recoveries ranging from 90.1-100.5%. PMID:25296949

Luo, Xi; He, Chengxia; Zhang, Feifang; Wang, Hailong; Yang, Bingcheng; Liang, Xinmiao

2014-12-01

434

Extended use of a selective inhibitor of acid lipase for the diagnosis of Wolman disease and cholesteryl ester storage disease.  

PubMed

Lysosomal acid lipase (LAL) deficiency produces two well defined inborn disorders, Wolman disease (WD) and cholesteryl ester storage disease (CESD). WD is a severe, early-onset condition involving massive storage of triglycerides and cholesteryl esters in the liver, with death usually occurring before one year of life. CESD is a more attenuated, later-onset disease that leads to a progressive and variable liver dysfunction. Diagnosis of LAL deficiency is mainly based on the enzyme assay of LAL activity in fibroblasts. Recently, a selective acid lipase inhibitor was used for the determination of enzyme activity in dried-blood filter paper (DBFP) samples. To extend and to validate these studies, we tested LAL activity with selective inhibition on DBFP samples, leukocytes and fibroblasts. Our results showed a clear discrimination between patients with LAL deficiency and healthy controls when using DBFP, leukocytes or fibroblasts (p<0.001). Deficiency of LAL was also demonstrated in individuals referred to our laboratory with suspected clinical diagnosis of WD, CESD, and Niemann-Pick type B. We conclude that the assay of LAL using selective inhibitor is a reliable and useful method for the identification of LAL deficiency, not only in DBFP samples but also in leukocytes and fibroblasts. This is important as enzyme replacement therapy for LAL deficiency is currently being developed, making the correct diagnosis a critical issue. PMID:24508470

Civallero, G; De Mari, J; Bittar, C; Burin, M; Giugliani, R

2014-04-10

435

A study of the autoxidation of some unsaturated fatty acid methyl esters using Fourier transform Raman spectroscopy  

NASA Astrophysics Data System (ADS)

Near-infrared Fourier transform Raman and Fourier transform infrared spectroscopy have been used to investigate the chemical changes taking place during the curing reaction of several fatty acid methyl esters, which are used for modelling processes in the autoxidation of alkyd resin coatings. We have studied methyl oleate, methyl linoleate, and methyl linolenate in an attempt to monitor the degree of unsaturation within the fatty acid methyl esters (FAMES) during the complex autoxidation/polymerisation reaction that takes place once the paint system is coated onto a substrate and exposed to the atmosphere. The peaks around 1655 cm -1 have been assigned as follows: to the trans isomer at 1670 cm -1, the cis isomer at 1655 cm -1 and the conjugated structure at 1640 cm -1 [B. Schrader, Raman/Infrared Atlas of Organic Compounds (2nd Edn), VCH, Weinheim (1989); J. K. Abenyega, M. Claybourn and G. Ellis, in preparations]. Raman spectra for the cure of methyl linoleate after 24 h show several interesting features, suggesting the formation of a highly conjugated cyclic structure. Current theories about the mechanism for the autoxidation of methyl linoleate make no mention of this aromatic product.

Agbenyega, J. K.; Claybourn, M.; Ellis, G.

436

Ethanesulfohydroxamic acid ester prodrugs of nonsteroidal anti-inflammatory drugs (NSAIDs): synthesis, nitric oxide and nitroxyl release, cyclooxygenase inhibition, anti-inflammatory, and ulcerogenicity index studies.  

PubMed

The carboxylic acid group of the anti-inflammatory (AI) drugs indo-methacin, (S)-naproxen and ibuprofen was covalently linked via a two-carbon ethyl spacer to a sulfohydroxamic acid moiety (CH(2)CH(2)SO(2)NHOH) to furnish a group of hybrid ester prodrugs that release nitric oxide (NO) and nitroxyl (HNO). Biological data acquired for this hitherto unknown class of ethanesulfohydroxamic acid ester prodrugs showed (i) all compounds exhibited superior NO, but similar HNO, release properties relative to arylsulfohydroxamic acids, (ii) the (S)-naproxen and ibuprofen prodrug esters are more potent AI agents than their parent NSAID, (iii) the indomethacin prodrug ester, in contrast to indomethacin which is highly ulcerogenic, showed no visible stomach lesions [ulcer index (UI) = 0 for a 80 ?mol/kg oral dose] while retaining potent AI activity, and iv) that the indomethacin prodrug ester, unlike indomethacin which is an ulcerogenic selective COX-1 inhibitor, is a selective COX-2 inhibitor (COX-2 selectivity index = 184) devoid of ulcerogenicity that is attributed to its high COX-2 SI and/or ability to release cytoprotective NO. PMID:21280601

Huang, Zhangjian; Velázquez, Carlos A; Abdellatif, Khaled R A; Chowdhury, Morshed A; Reisz, Julie A; DuMond, Jenna F; King, S Bruce; Knaus, Edward E

2011-03-10

437

Guiding optimal biofuels : a comparative analysis of the biochemical production of ethanol and fatty acid ethyl esters from switchgrass.  

SciTech Connect

In the current study, processes to produce either ethanol or a representative fatty acid ethyl ester (FAEE) via the fermentation of sugars liberated from lignocellulosic materials pretreated in acid or alkaline environments are analyzed in terms of economic and environmental metrics. Simplified process models are introduced and employed to estimate process performance, and Monte Carlo analyses were carried out to identify key sources of uncertainty and variability. We find that the near-term performance of processes to produce FAEE is significantly worse than that of ethanol production processes for all metrics considered, primarily due to poor fermentation yields and higher electricity demands for aerobic fermentation. In the longer term, the reduced cost and energy requirements of FAEE separation processes will be at least partially offset by inherent limitations in the relevant metabolic pathways that constrain the maximum yield potential of FAEE from biomass-derived sugars.

Paap, Scott M.; West, Todd H.; Manley, Dawn Kataoka; Dibble, Dean C.; Simmons, Blake Alexander; Steen, Eric J. [Joint BioEnergy Institute, Emeryville, CA; Beller, Harry R. [Lawrence Berkeley National Laboratory, Berkeley, CA; Keasling, Jay D. [Lawrence Berkeley National Laboratory, Berkeley, CA; Chang, Shiyan [Tsinghua University, Beijing, PR China

2013-01-01

438

Non-aqueous gel polymer electrolyte with phosphoric acid ester and its application for quasi solid-state supercapacitors  

NASA Astrophysics Data System (ADS)

A mechanically-stable non-aqueous proton-conducting gel polymer electrolyte that is based on methacrylate monomers, is considered here for application in solid-state type supercapacitors. An electrochemical cell using activated carbon as active materials and the new gel polymer electrolyte has been characterized at room temperature using cyclic voltammetry, galvanostatic charge-discharge cycle tests as well as impedance spectroscopy. The use of phosphoric acid ester (instead of phosphoric acid) as a proton donor has led to an increase of both the operation voltage window (up to 1.3 V) and the electrolyte ionic conductivity (on the level of an order of magnitude). The resulting double layer capacitance of the microporous activated carbon was found to be as high as 120 F g-1; even more important, the supercapacitor utilizing non-aqueous proton-conducting gel polymer electrolyte is well-behaved in the wide temperature range (namely, from -40 to 80 °C).

?atoszy?ska, Anna A.; ?ukowska, Gra?yna Zofia; Rutkowska, Iwona A.; Taberna, Pierre-Louis; Simon, Patrice; Kulesza, Pawel J.; Wieczorek, W?adys?aw

2015-01-01

439

Adhesion Properties of Catechol-Based Biodegradable Amino Acid-Based Poly(ester urea) Copolymers Inspired from Mussel Proteins.  

PubMed

Amino acid-based poly(ester urea) (PEU) copolymers functionalized with pendant catechol groups that address the need for strongly adhesive yet degradable biomaterials have been developed. Lap-shear tests with aluminum adherends demonstrated that these polymers have lap-shear adhesion strengths near 1 MPa. An increase in lap-shear adhesive strength to 2.4 MPa was achieved upon the addition of an oxidative cross-linker. The adhesive strength on porcine skin adherends was comparable with commercial fibrin glue. Interfacial energies of the polymeric materials were investigated via contact angle measurements and Johnson-Kendall-Roberts (JKR) technique. The JKR work of adhesion was consistent with contact angle measurements. The chemical and physical properties of PEUs can be controlled using different diols and amino acids, making the polymers candidates for the development of biological glues for use in clinical applications. PMID:25427310

Zhou, Jinjun; Defante, Adrian P; Lin, Fei; Xu, Ying; Yu, Jiayi; Gao, Yaohua; Childers, Erin; Dhinojwala, Ali; Becker, Matthew L

2015-01-12

440

Inhibitory activities of propolis and its promising component, caffeic acid phenethyl ester, against amyloidogenesis of human transthyretin.  

PubMed

Transthyretin (TTR) is a homotetrameric serum protein associated with amyloidoses such as familial amyloid polyneuropathy and senile systemic amyloidosis. The amyloid fibril formation of TTR can be inhibited through stabilization of the TTR tetramer by the binding of small molecules. In this study, we examined the inhibitory potency of caffeic acid phenethyl ester (CAPE) and its derivatives. Thioflavin T assay showed that CAPE suppressed the amyloid fibril formation of TTR. Comparative analysis of the inhibitory potencies revealed that phenethyl ferulate was the most potent among the CAPE derivatives. The binding of phenethyl ferulate and the selected compounds to TTR were confirmed by the 8-anilino-1-naphthalenesulfonic acid displacement and X-ray crystallography. It was also demonstrated that Bio 30, which is a CAPE-rich commercially available New Zealand propolis, inhibited TTR amyloidogenesis and stabilized the TTR tetramer. These results suggested that a propolis may be efficient for preventing TTR amyloidosis. PMID:25314129

Yokoyama, Takeshi; Kosaka, Yuto; Mizuguchi, Mineyuki

2014-11-13

441

EFFECT OF QUARTZ\\/MULLITE BLEND CERAMIC ADDITIVE ON IMPROVING RESISTANCE TO ACID OF SODIUM SILICATE-ACTIVATED SLAG CEMENT. CELCIUS BRINE  

Microsoft Academic Search

We evaluated the usefulness of manufactured quartz\\/mullite blend (MQMB) ceramic powder in increasing the resistance to acid of sodium silicate-activated slag (SSAS) cementitious material for geothermal wells. A 15-day exposure to 90{sup o} COâ-laden HâSOâ revealed that the MQMB had high potential as an acid-resistant additive for SSAS cement. Two factors, the appropriate ratio of slag\\/MQMB and the autoclave temperature,

T. SUGAMA; L. E. BROTHERS; T. R. VAN DE PUTTE

2006-01-01

442

Chemical reactivity and spectroscopy of the thiol ester-linked p-coumaric acid chromophore in the photoactive yellow protein from Ectothiorhodospira halophila.  

PubMed

We have recently identified p-coumaric acid as the chromophore of the photoactive yellow protein (PYP) from the purple sulfur bacterium Ectothiorhodospira halophila, a blue-light photoreceptor with rhodopsin-like photochemistry [Hoff, W. D., Düx, P., Hård, K., Nugteren-Roodzant, I. M., Crielaard, W., Boelens, R., Kaptein, R., Van Beeumen, J., & Hellingwerf, K. J. (1994) Biochemistry 33, 13959-13962]. Here we report on the chemistry of the linkage of this new photoactive cofactor to apoPYP: (i) Analysis of chromophore-peptide conjugates of PYP by high-resolution mass spectrometry unambiguously shows that the p-coumaric acid molecule is bound to Cys 69 via a thiol ester bond. The PYP chromophore is the first cofactor known to be stably thiol ester-linked to its apoprotein. (ii) The chemical reactivity of this thiol ester bond with respect to dithiothreitol, performic acid, and high pH is similar to that of disulfide bridges. These treatments result in the cleavage of the thiol ester bond, concomitant with strong shifts in the UV/vis absorbance band of the chromophore. (iii) The spectral properties of the PYP chromophore under different conditions are related to the structural integrity of the protein, the presence of the thiol ester bond, and the ionization state of the phenolic proton of the chromophore. These results are important for the general problem of spectral tuning in photoreceptor proteins. PMID:8573584

Hoff, W D; Devreese, B; Fokkens, R; Nugteren-Roodzant, I M; Van Beeumen, J; Nibbering, N; Hellingwerf, K J

1996-01-30

443

Selective uptake of cholesteryl esters from apolipoprotein-E-free high-density lipoproteins by rat parenchymal cells in vivo is efficiently coupled to bile acid synthesis.  

PubMed Central

[3H]Cholesteryl ester-labelled human high-density lipoprotein (HDL) was injected into rats and its decay, intrahepatic cellular distribution and the kinetics of biliary secretion were determined. At 10 min after injection the hepatic uptake of cholesteryl esters from HDL was 3-fold higher as compared with the apolipoprotein. Selective uptake was exerted only by parenchymal cells (5.6-fold more cholesteryl esters than apolipoprotein) and not by liver endothelial or Kupffer cells. The kinetics of biliary secretion of processed cholesteryl esters initially associated with HDL or low-density lipoprotein (LDL) were compared in unrestrained rats, equipped with permanent catheters in bile duct, duodenum and heart. At 72 h after injection of [3H]cholesteryl oleate-labelled HDL, 51.0 +/- 2.5% of the injected dose was recovered as bile acids, which is about twice as high as the secretion of biliary radioactivity after injection of [3H]cholesteryl oleate-labelled LDL. Oestradiol treatment stimulated only liver uptake of LDL cholesteryl esters, and resulted in a 2-fold higher liver uptake than with HDL. However, the rate of radioactive bile acid formation from [3H]cholesteryl oleate-labelled HDL was still more rapid than for LDL. It is concluded that the selective uptake pathway for cholesteryl esters from HDL in parenchymal cells is more efficiently coupled to the formation of bile acids than is the cholesteryl ester uptake from LDL. This efficient coupling may facilitate the role of HDL in reverse cholesterol transport. PMID:1747108

Pieters, M N; Schouten, D; Bakkeren, H F; Esbach, B; Brouwer, A; Knook, D L; van Berkel, T J

1991-01-01

444

21 CFR 172.852 - Glyceryl-lacto esters of fatty acids.  

Code of Federal Regulations, 2010 CFR

...diglycerides) may be safely used in food in accordance with the following prescribed conditions: (a) They are manufactured from glycerin, lactic acid, and fatty acids conforming with § 172.860 and/or oleic acid derived from tall oil fatty acids...

2010-04-01

445

Substituted thiobenzoic acid S-benzyl esters as potential inhibitors of a snake venom phospholipase A2: Synthesis, spectroscopic and computational studies  

NASA Astrophysics Data System (ADS)

4-Chlorothiobenzoic acid S-benzyl ester (I), 3-nitrothiobenzoic acid S-benzyl ester (II), 4-nitrothiobenzoic acid S-benzyl ester (III) and 4-methylthiobenzoic acid S-benzyl ester (IV) were prepared and characterized by 1H and 13C NMR, Mass spectrometry and IR spectroscopy. Quantum chemical calculations were performed with Gaussian 09 to calculate the geometric parameters and vibrational spectra. Phospholipase A2 (PLA2) was purified from Crotalus durissus cumanensis venom by molecular exclusion chromatography, followed by reverse phase-high performance liquid chromatography. Two studies of the inhibition of phospholipase A2 activity were performed using phosphatidilcholine and 4-nitro-3-octanoyloxybenzoic acid as substrates, in both cases compound II showed the best inhibitory ability, with 74.89% and 69.91% of inhibition, respectively. Average percentage of inhibition was 52.49%. Molecular docking was carried out with Autodock Vina using as ligands the minimized structures of compounds (I-IV) and as protein PLA2 (PDB code 2QOG). The results suggest that compounds I-IV could interact with His48 at the active site of PLA2. In addition, all compounds showed Van der Waals interactions with residues from hydrophobic channel of the enzyme. This interaction would impede normal catalysis cycle of the PLA2.

Henao Castañeda, I. C.; Pereañez, J. A.; Jios, J. L.

2012-11-01

446

Inhibitory effect of gallic acid and its esters on 2,2'-azobis(2-amidinopropane)hydrochloride (AAPH)-induced hemolysis and depletion of intracellular glutathione in erythrocytes.  

PubMed

The protective effect of gallic acid and its esters, methyl, propyl, and lauryl gallate, against 2,2'-azobis(2-amidinopropane)hydrochloride (AAPH)-induced hemolysis and depletion of intracellular glutathione (GSH) in erythrocytes was studied. The inhibition of hemolysis was dose-dependent, and the esters were significantly more effective than gallic acid. Gallic acid and its esters were compared with regard to their reactivity to free radicals, using the DPPH and AAPH/pyranine free-cell assays, and no significant difference was obtained. Gallic acid and its esters not only failed to inhibit the depletion of intracellular GSH in erythrocytes induced by AAPH but exacerbated it. Similarly, the oxidation of GSH by AAPH or horseradish peroxidase/H(2)O(2) in cell-free systems was exacerbated by gallic acid or gallates. This property could be involved in the recent findings on pro-apoptotic and pro-oxidant activities of gallates in tumor cells. We provide evidence that lipophilicity and not only radical scavenger potency is an important factor regarding the efficiency of antihemolytic substances. PMID:20397726

Ximenes, Valdecir F; Lopes, Mariana G; Petrônio, Maicon Segalla; Regasini, Luis Octavio; Silva, Dulce H Siqueira; da Fonseca, Luiz M

2010-05-12

447

Wolman disease/cholesteryl ester storage disease: efficacy of plant-produced human lysosomal acid lipase in mice*  

PubMed Central

Lysosomal acid lipase (LAL) is an essential enzyme that hydrolyzes triglycerides (TGs) and cholesteryl esters (CEs) in lysosomes. Genetic LAL mutations lead to Wolman disease (WD) and cholesteryl ester storage disease (CESD). An LAL-null (lal?/?) mouse model resembles human WD/CESD with storage of CEs and TGs in multiple organs. Human LAL (hLAL) was expressed in Nicotiana benthamiana using the GENEWARE® expression system (G-hLAL). Purified G-hLAL showed mannose receptor-dependent uptake into macrophage cell lines (J774E). Intraperitoneal injection of G-hLAL produced peak activities in plasma at 60 min and in the liver and spleen at 240 min. The t1/2 values were: ?90 min (plasma), ?14 h (liver), and ?32 h (spleen), with return to baseline by ?150 h in liver and ?200 h in spleen. Ten injections of G-hLAL (every 3 days) into lal?/? mice produced normalization of hepatic color, decreases in hepatic cholesterol and TG contents, and diminished foamy macrophages in liver, spleen, and intestinal villi. All injected lal?/? mice developed anti-hLAL protein antibodies, but suffered no adverse events. These studies demonstrate the feasibility of using plant-expressed, recombinant hLAL for the enzyme therapy of human WD/CESD with general implications for other lysosomal storage diseases. PMID:18413899

Du, Hong; Cameron, Terri L.; Garger, Stephen J.; Pogue, Gregory P.; Hamm, Lee A.; White, Earl; Hanley, Kathleen M.; Grabowski, Gregory A.

2008-01-01

448

Wolman disease/cholesteryl ester storage disease: efficacy of plant-produced human lysosomal acid lipase in mice.  

PubMed

Lysosomal acid lipase (LAL) is an essential enzyme that hydrolyzes triglycerides (TGs) and cholesteryl esters (CEs) in lysosomes. Genetic LAL mutations lead to Wolman disease (WD) and cholesteryl ester storage disease (CESD). An LAL-null (lal(-/-)) mouse model resembles human WD/CESD with storage of CEs and TGs in multiple organs. Human LAL (hLAL) was expressed in Nicotiana benthamiana using the GENEWARE expression system (G-hLAL). Purified G-hLAL showed mannose receptor-dependent uptake into macrophage cell lines (J774E). Intraperitoneal injection of G-hLAL produced peak activities in plasma at 60 min and in the liver and spleen at 240 min. The t(1/2) values were: approximately 90 min (plasma), approximately 14 h (liver), and approximately 32 h (spleen), with return to baseline by approximately 150 h in liver and approximately 200 h in spleen. Ten injections of G-hLAL (every 3 days) into lal(-/-) mice produced normalization of hepatic color, decreases in hepatic cholesterol and TG contents, and diminished foamy macrophages in liver, spleen, and intestinal villi. All injected lal(-/-) mice developed anti-hLAL protein antibodies, but suffered no adverse events. These studies demonstrate the feasibility of using plant-expressed, recombinant hLAL for the enzyme therapy of human WD/CESD with general implications for other lysosomal storage diseases. PMID:18413899

Du, Hong; Cameron, Terri L; Garger, Stephen J; Pogue, Gregory P; Hamm, Lee A; White, Earl; Hanley, Kathleen M; Grabowski, Gregory A

2008-08-01

449

Biocatalytic potential of lipase from Staphylococcus sp. MS1 for transesterification of jatropha oil into fatty acid methyl esters.  

PubMed

An extracellular lipase producing isolate Staphylococcus sp. MS1 was optimized for lipase production and its biocatalytic potential was assessed. Medium with tributyrin (0.25 %) and without any exogenous inorganic nitrogen source was found to be optimum for lipase production from Staphylococcus sp. MS1. The optimum pH and temperature for lipase production were found to be pH 7 and 37 °C respectively, showing lipase activity of 37.91 U. It showed good lipase production at pH 6-8. The lipase was found to be stable in organic solvents like hexane and petroleum ether, showing 98 and 88 % residual activity respectively. The biotransformation using the concentrated enzyme in petroleum ether resulted in the synthesis of fatty acid methyl esters like methyl oleate, methyl palmitate and methyl stearate. Thus, the lipase under study has got the potential to bring about transesterification of oils into methyl esters which can be exploited for various biotechnological applications. PMID:25115850

Sharma, Monika; Singh, Shelley Sardul; Maan, Pratibha; Sharma, Rohit

2014-11-01

450

Gas-liquid chromatographic detection an determination of diacetyl tartaric acid ester of diglyceride in dairy and nondairy coffee cream powders.  

PubMed

Diacetyl tartaric acid ester of diglyceride was directly extracted from dairy or nondairy coffee cream powder under acidic conditions with ethyl acetate; then the extract was saponified with methanolic potash. After acidification with HCl, free fatty acid was removed with ether and the reaction mixture was absorbed on an anion exchange column. Tartaric acid was eluted with 2N HCl-acetone (1+1). An aliquot of the trimethylsilyl (TMS) derivative of the eluate was injected into a gas chromatograph with flame ionization detection, and a 1.5% SE-30 column. Recoveries of diacetyl tartaric acid ester of diglyceride at 50, 200, and 2000 ppm were 85.6-99.5%. PMID:7228822

Inoue, T; Iwaida, M; Ito, Y; Tonogai, Y

1981-03-01

451

Caffeic Acid Phenethyl Ester: Consequences of Its Hydrophobicity in the Oxidative Functions and Cytokine Release by Leukocytes  

PubMed Central

Numerous anti-inflammatory properties have been attributed to caffeic acid phenethyl ester (CAPE), an active component of propolis. NADPH oxidases are multienzymatic complexes involved in many inflammatory diseases. Here, we studied the importance of the CAPE hydrophobicity on cell-free antioxidant capacity, inhibition of the NADPH oxidase and hypochlorous acid production, and release of TNF-? and IL-10 by activated leukocytes. The comparison was made with the related, but less hydrophobic, caffeic and chlorogenic acids. Cell-free studies such as superoxide anion scavenging assay, triene degradation, and anodic peak potential (Epa) measurements showed that the alterations in the hydrophobicity did not provoke significant changes in the oxidation potential and antiradical potency of the tested compounds. However, only CAPE was able to inhibit the production of superoxide anion by activated leukocytes. The inhibition of the NADPH oxidase resulted in the blockage of production of hypochlorous acid. Similarly, CAPE was the more effective inhibitor of the release of TNF-? and IL-10 by Staphylococcus aureus stimulated cells. In conclusion, the presence of the catechol moiety and the higher hydrophobicity were essential for the biological effects. Considering the involvement of NADPH oxidases in the genesis and progression of inflammatory diseases, CAPE should be considered as a promising anti-inflammatory drug. PMID:25254058

Paracatu, Luana Chiquetto; Faria, Carolina Maria Quinello Gomes; Rennó, Camila; Palmeira, Patricia; da Fonseca, Luiz Marcos; Ximenes, Valdecir Farias

2014-01-01

452

Amino acid ester prodrugs conjugated to the ?-carboxylic acid group do not display affinity for the L-type amino acid transporter 1 (LAT1).  

PubMed

L-type amino acid transporter (LAT1) is an intriguing target for carrier-mediated transport of drugs as it is highly expressed in the blood-brain barrier and also in various types of cancer. Several studies have proposed that in order for compounds to act as LAT1 substrates they should possess both negatively charged ?-carboxyl and positively charged ?-amino groups. However, in some reports, such as in two recent publications describing an isoleucine-quinidine ester prodrug (1), compounds having no free ?-carboxyl group have been reported to exhibit high affinity for LAT1 in vitro. In the present study, 1 was synthesized and its affinity for LAT1 was evaluated both with an in situ rat brain perfusion technique and in the human breast cancer cell line MCF-7 in vitro. 1 showed no affinity for LAT1 in either model nor did it show any affinity for LAT2 in an in vitro study. Our results confirm the earlier reported requirements for LAT1 substrates. Thus drugs or prodrugs with substituted ?-carboxyl group cannot bind to LAT with high affinity. PMID:25305508

Rautio, Jarkko; Kärkkäinen, Jussi; Huttunen, Kristiina; Gynther, Mikko

2014-10-01

453

40 CFR 721.3130 - Sulfuric acid, mono-C9-11-alkyl esters, sodium salts.  

Code of Federal Regulations, 2013 CFR

...mono-C9-11-alkyl esters, sodium salts. 721.3130 Section 721.3130 ...mono-C9-11 -alkyl esters, sodium salts. (a) Chemical substance and significant...mono-C9-11 -alkyl esters, sodium salts (PMN P-01-149; CAS No....

2013-07-01

454

40 CFR 721.3130 - Sulfuric acid, mono-C9-11-alkyl esters, sodium salts.  

Code of Federal Regulations, 2010 CFR

...mono-C9-11-alkyl esters, sodium salts. 721.3130 Section 721.3130 ...mono-C9- 11-alkyl esters, sodium salts. (a) Chemical substance and significant...mono-C9-11 -alkyl esters, sodium salts (PMN P-01-149; CAS No....

2010-07-01

455

Antiangiogenic properties of an unusual benzo[k,l]xanthene lignan derived from CAPE (caffeic acid phenethyl ester).  

PubMed

Angiogenesis is normally a highly regulated process that occurs during development, reproduction, and wound repair. However, angiogenesis can also become a fundamental pathogenic process in cancer and several other diseases. To date, the synthesis of angiogenesis inhibitors has been researched in several ways also starting from bioactive plant compounds. In the present study, we tested both in an angiogenesis bioassay and in ovarian cell culture, the potential antiangiogenic effect of a natural-derived benzo[k,l]xanthene lignan (5). This unusual compound was synthesized through the biomimetic dimerization of CAPE (caffeic acid phenethyl ester), a bioactive component of honeybee propolis. The lignan showed a significant, dose-related inhibitory effect on new vessel growth in the angiogenesis bioassay and it inhibited Vascular Endothelial Growth Factor secretion in ovarian cell culture. Therefore, we indicate the natural-derived benzo[k,l]xanthene lignan 5 as a potential new angiogenesis inhibitor. PMID:20924642

Basini, Giuseppina; Baioni, Laura; Bussolati, Simona; Grasselli, Francesca; Daquino, Carmelo; Spatafora, Carmela; Tringali, Corrado

2012-02-01

456

Synthesis of caffeic acid phenethyl ester derivatives, and their cytoprotective and neuritogenic activities in PC12 cells.  

PubMed

Twenty-one caffeic acid phenethyl ester (CAPE) derivatives were synthesized, and characterized by IR, HR-MS, (1)H and (13)C NMR analyses. All compounds were evaluated for their cytoprotective effects against H2O2-induced cytotoxicity and neuritogenic activities in the neurite outgrowth in PC12 cells. Compounds 1 and 20 exhibited stronger cytoprotective activities than their parent compound CAPE at 4 nM. Compounds 1, 4, 12 and 13 showed potential neuritogenic activities at 0.5 nM, while compounds 19 and 20 induced neurite outgrowth at 10 nM. The results from this study suggested that CAPE and its derivatives may be potential functional food ingredients for the prevention of neurodegenerative diseases. PMID:24840770

Shi, Haiming; Xie, Dongsheng; Yang, Ruoling; Cheng, Yaqian

2014-06-01

457

Catalyst-free fatty acid methyl ester production from wet activated sludge under subcritical water and methanol condition.  

PubMed

Wet activated sludge was converted directly into biodiesel using water as hydrolysis reagent to enhance the extraction of lipid in activated sludge, and as catalyst for the conversion of neutral lipids into biodiesel under subcritical conditions. At 175°C, 3.5MPa, a methanol to sludge ratio of 30 (mL/g) and a sludge water content of 84wt.%, about 90% conversion to fatty acid methyl esters was achieved within 24h without the need for conventional catalysts such as KOH and H(2)SO(4). Since water is employed as a catalyst, its removal is not required; therefore, the processing costs for producing biodiesel from activated sludge are reduced. The method has the potential for applications to other feedstock with high water contents such as micro-algae. PMID:22940307

Huynh, Lien Huong; Tran Nguyen, Phuong Lan; Ho, Quoc Phong; Ju, Yi-Hsu

2012-11-01

458

Study by Infrared Spectroscopy of Ultrathin Films of Behenic Acid Methyl Ester on Solid Substrates and at the Air\\/Water Interface  

Microsoft Academic Search

Ultrathin films of behenic acid methyl ester (BAME) deposited by spin coating on solid substrates or spread at the air\\/water interface were studied by infrared spectroscopy and Brewster angle microscopy. Anisotropic optical constants of BAME were determined from a transmittance spectrum at normal incidence and a parallel- polarized reflectance spectrum at grazing incidence. A transmittance spectrum recorded at oblique incidence

Isabelle Pelletier; Hélène Bourque; Thierry Buffeteau; Daniel Blaudez; Bernard Desbat; Michel Pezolet

2002-01-01

459

Analysis of Fatty Acid Methyl Ester (FAME) Content and Distribution in Biodiesel Blends Using Heart-Cutting 2D Gas Chromatography Application  

Microsoft Academic Search

The analysis of the fatty acid methyl ester (FAME) content in blended biodiesel samples is described using a heart- cutting two-dimensional (2D) gas chromatographic (GC) system. A Capillary Flow Technology Deans switch is used to interface a primary nonpolar capillary column to a secondary polar capillary column. The primary column separates most of the petroleum hydrocarbons from the FAMEs. The

James D. McCurry; Chunxiao Wang

460

40 CFR 721.8350 - 2-Propenoic acid, 7-oxa-bi-cy-clo[4.1.0]hept-3-ylmethyl ester.  

Code of Federal Regulations, 2010 CFR

(1) The chemical substance 2-propenoic acid, 7-oxabicyclo[4.1.0]hept-3-ylmethyl ester (PMN P-89-31) is subject to reporting under this section for the significant new uses described in paragraph (a)(2) of this section. (2) The significant new uses are: (i) Protection in the...

2010-07-01