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Synthesis and curing of alkyd enamels based on ricinoleic acid  [PDF]
Jovi?i? Mirjana C.,Radi?evi? Radmila ?.,Simendi? Vesna B.
Hemijska Industrija , 2010, DOI: 10.2298/hemind100824056j
Abstract: A combination of an alkyd resin with a melamine-formaldehyde resin gives a cured enamel film with the flexibility of the alkyd constituent and the high chemical resistance and hardness of the melamine resin at the same time. The melamine resin is a minor constituent and plays the role of a crosslinking agent. In this paper, alkyd resins of high hydroxyl numbers based on trimethylolpropane, ricinoleic acid and phthalic anhydride were synthesized. Two alkyds having 30 and 40 wt% of ricinoleic acid were formulated by calculation on alkyd constant. Alkyds were characterized by FTIR and by the determination of acid and hydroxyl numbers. Then synthesized alkyds were made into baking enamels by mixing with melamine-formaldehyde resins (weight ratio of 70:30 based on dried mass). Two types of commercial melamine resins were used: threeisobutoxymethyl melamine-formaldehyde resin (TIMMF) and hexamethoxymethyl melamine resin (HMMMF). Prepared alkyd/melamine resin mixtures were cured in a differential scanning calorimeter (DSC) under non-isothermal mode. Apparent degree of curing as a function of temperature was calculated from the curing enthalpies. Kinetic parameters of curing were calculated using Freeman-Carroll method. TIMMF resin is more reactive with synthesized alkyds than HMMMF resin what was expected. Alkyd resin with 30 wt% of ricinoleic acid is slightly more reactive than alkyd with 40 wt% of ricinoleic acid, probably because it has the high contents of free hydroxyl and acid groups. The gel content, Tg, thermal stability, hardness, elasticity and impact resistance of coated films cured at 150°C for 60 min were measured. Cured films show good thermal stability since the onset of films thermal degradation determined by thermogravimetric analysis (TGA) is observed at the temperatures from 281 to 329°C. Films based on alkyd 30 are more thermal stable than those from alkyd 40, with the same melamine resin. The type of alkyd resin has no significant effect on the gel content and the hardness of film. Hardness of cured film increases with increasing of Tg. The values of the films elasticity are satisfied for all prepared samples and are independent on the type of alkyd or melamine resin. The impact resistances of coated films are very high.
Synthetic Biolubricant Basestocks from Epoxidized Ricinoleic Acid: Improved Low Temperature Properties  [PDF]
Salimon, J.,Salih, N.,Yousif, E.
Kemija u Industriji , 2011,
Abstract: This paper presents a series of structural modifications of epoxidized ricinoleic acid for biolubricant to improve the cold flow behavior and oxidation stability of vegetable oils through measurement of pour point (PP) and oxidation onset temperature (OT) and signal maximum temperature (SMT) of each synthetic compound. The results showed that butyl 10,12-dihydroxy-9-behenoxystearate with bulky ester behenyl mid-chain exhibited the most favorable low-temperature performance PP=– 47 °C). On the other hand, butyl 10,12-dihydroxy-9-octyloxystearate exhibited higher oxidation stability ( OT = 221 °C) than the other synthetic esters. It was discovered that increasing chain length of the mid-chain ester had a positive influence on the low temperature properties of synthesized compounds. Improved oxidation stability is achieved when the chain length of the mid-chain ester decreases. The synthesized ester structures were confirmed by NMR and FTIR analysis.
Modification of oligo-Ricinoleic Acid and Its Derivatives with 10-Undecenoic Acid via Lipase-Catalyzed Esterification  [PDF]
Douglas G. Hayes,Vinay K. Mannam,Ran Ye,Haizhen Zhao,Salvadora Ortega,M. Claudia Montiel
Polymers , 2012, DOI: 10.3390/polym4021037
Abstract: Lipases were employed under solvent-free conditions to conjugate oligo-ricinoleic acid derivatives with 10-undecenoic acid, to incorporate a reactive terminal double bond into the resultant product. First, undecenoic acid was covalently attached to oligo-ricinoleic acid using immobilized Candida antarctica lipase (CAL) at a 30% yield. Thirty percent conversion also occurred for CAL-catalyzed esterification between undecenoic acid and biocatalytically-prepared polyglycerol polyricinoleate (PGPR), with attachment of undecenoic acid occurring primarily at free hydroxyls of the polyglycerol moiety. The synthesis of oligo-ricinoleyl-, undecenoyl- structured triacylglycerols comprised two steps. The first step, the 1,3-selective lipase-catalyzed interesterification of castor oil with undecenoic acid, occurred successfully. The second step, the CAL-catalyzed reaction between ricinoleyl-, undecenoyl structured TAG and ricinoleic acid, yielded approximately 10% of the desired structured triacylglycerols (TAG); however, a significant portion of the ricinoleic acid underwent self-polymerization as a side-reaction. The employment of gel permeation chromatography, normal phase HPLC, NMR, and acid value measurements was effective for characterizing the reaction pathways and products that?formed.
Effect of ricinoleic acid in acute and subchronic experimental models of inflammation  [PDF]
Celme Vieira,Stefano Evangelista,Rocco Cirillo,Annalisa Lippi,Carlo Alberto Maggi,Stefano Manzini
Mediators of Inflammation , 2000, DOI: 10.1080/09629350020025737
Abstract: Observational studies indicate that topical application of ricinoleic acid (RA), the main component of castor oil, exerts remarkable analgesic and anti-inflammatory effects. Pharmacological characterization has shown similarities between the effects of RA and those of capsaicin, suggesting a potential interaction of this drug on sensory neuropeptide-mediated neurogenic inflammation. The aim of this study was to assess RA anti-inflammatory activities in comparison with capsaicin in several models of acute and subchronic inflammation. The acute inflammation was induced by intradermal injection of carrageenan in the mouse or by histamine in the guinea-pig eyelid. In either experiment, the extent of the oedema thickness was measured. Subchronic oedema was induced by complete Freund's adjuvant injection in the ventral right paw of mice. Tissue substance P (SP) was measured in the carrageenan experiments by radioimmunoassay (RIA). It was found that the acute topical application of RA (0.9 mg/mouse) or capsaicin (0.09 mg/mouse) significantly increased the mouse paw oedema induced by carrageenan, while an 8-day repeated topical treatment with the same doses of both compounds resulted in a marked inhibition of carrageenaninduced paw oedema matched by a reduction in SP tissue levels. Similar effects were found against histamine-induced eyelid oedema in guinea-pigs after acute or repeated application of RA or capsaicin. RA and capsaicin given for 1–3 weeks reduced the established oedema induced by Freund's adjuvant, a subchronic model of inflammation, particularly if given by the intradermal route. Either in mouse paw or in guineapig eyelid, capsaicin but not RA by itself produced a slight hyperemia and activation of a behavioural response (e.g. scratching of the eyelids). On the basis of the present results, RA may be seen as a new capsaicin-like, non-pungent anti-inflammatory agent suitable for peripheral application.
Growth Temperatures and Various Concentrations of Ricinoleic Acid Affect Fatty Acid Composition in Two Strains of Hansenula polymorpha  [PDF]
Wanida Rakpuang
Pakistan Journal of Biological Sciences , 2009,
Abstract: The fatty acid composition of two strains (wild-type and M2 mutant cells of Hansenula polymorpha strain CBS 1976) were studied at different growth temperatures and various concentrations of ricinoleic acid. Two strains of yeast cultured on YEPD medium containing 1, 2, 3 and 8 mM of ricinoleic acid at 25, 30, 37 and 45°C. Lipids were extracted from the yeast culture and the fatty acids esterified with BF3-MeOH. Gas chromatography analysis of total lipids showed that C16:1 (Δ7), which has been synthesized in low concentration by WT strain, was found to increase in the M2 mutant. The biotransformation of C16:1 (Δ7) found in M2 indicated the presence of dehydroxylation and β-oxidation systems. An increase in the growth temperature from 25 to 45°C resulted in a decrease in the total unsaturated fatty acids of C16:1, C18:1, C18:2 and C18:3 from 44.0 to 22.1% and 65.0 to 49.3% of the total fatty acids in M2 and wild-type strains, respectively. The differential production of unsaturated fatty acids, especially C16:1, indicated that regulation of unsaturated fatty acid levels, is an important control point in membrane composition in the adaptation of H. polymorpha M2 to diet and temperature.
Application of lipase technology for transesterification of fatty acid ester  [PDF]
Biodiversitas , 2005,
Abstract: We have reported the potency of microbial extracellular enzyme for synthesis of fatty acid ester. Further investigation was aimed to study capacity of the enzyme on bioprocess of crude palm oil by transesterification of saturated fatty acid to fatty acid ester. We have studied some lipases from culture filtrate of Candida rugosa FM-9301, Bacillus subtilis FM-9101 and Pseudomonas aerogenes FM-9201, which were preincubated in a medium containing olive oil as inducers, using a shaker under conditions that allowed for lipase production at pH 4.5-6.5 and room temperature for 5 days. Those strains shown different activities during the hydrolysis of substrates, which resulted in decreasing or increasing free fatty acids those, were liberated from media containing crude palm oil and organic solvents. The optimal transesterification condition was at temperature of 45-50 C and at pH 4.5 for C. rugosa and pH 6.0 to 7.0 for P. aerogenes and B. subtilis. Under the enzyme concentration of 50% (v/v), the transesterification was rapidly occurred, while at the concentration of 20% (v/v) the enzymatically biosynthesis required longer incubation period. The substrates incubated with C. rugosa lipase exhibited higher linoleic and linolenic acid (7.16 and 2.15%, respectively), than that of B. subtilis lipase (4.85% and 1.43%, respectively), while P. aerogenes lipase (3.73% and 1.11%, respectively).
V Rahimi-Movaghar,A Yazdi,S Saadat
Acta Medica Iranica , 2008,
Abstract: "nThe dysesthesia and paresthesia that occurs in laboratory rats after spinal cord injury (SCI) results in autophagia. This self-destructive behavior interferes with functional assessments in designed studies and jeopardizes the health of the injured rat. In this study, we evaluated role of saturated picric acid in the prevention of autophagia and self-mutilation. All rats were anesthetized with an intraperitoneal injection of a mixture of ketamine (100 mg/kg) and xylazine (10 mg/kg) for the SCI procedures. In the first 39 rats, no solution applied to the hind limbs, but in the next 26 cases, we smeared the saturated picric acid on the tail, lower extremities, pelvic, and abdomen of the rats immediately after SCI. In the rats without picric acid, 23 rats died following autophagia, but in the 26 rats with picric acid, there was no autophagia (P < 0.001). Picric acid side effects in skin and gastrointestinal signs such as irritation, redness and diarrhea were not seen in any rat. Saturated picric acid is a topical solution that if used appropriately and carefully, might be safe and effectively prevents autophagia and self-mutilation. When the solution is applied to the lower abdomen and limbs, we presume that its bitterness effectively prevents the rat from licking and biting the limb.
Use of caffeic acid phenethyl ester and cortisone may prevent proliferative vitreoretinopathy  [PDF]
Yusuf Turkoz,Hamdi Er,Mehmet Borazan,Harun Y lmaz,Bülent M zrak,Hakan Parlakp nar,Y lmaz igremis
Mediators of Inflammation , 2004, DOI: 10.1080/09629350410001688512
Abstract: PURPOSE: To investigate whether caffeic acid phenethyl ester (CAPE) and cortisone prevent proliferative vitreoretinopathy (PVR).


物理学报 , 1994,
Abstract: This report presents the results on the investigation of the effect of ricionoleic acid on the structures of the liquid crystal state of mixed phospholipid-cholesterol liposomes by means of the Small Angle X-ray Scattering (SAXS) and 31P Nuclear Magnetism Resomance(31P-NMR). The study shows that the ricinoleic acid helps to stabilize the structure of the mixed phospholipid-cholesterol liposomes and that the polyphase liposome with ricinoleic acid prepared from phosphoric buffer solution containing polyvinylpyrrolidone (PVP) is in the cubic-hexagonal phase.
Synthesis and Antiradical/Antioxidant Activities of Caffeic Acid Phenethyl Ester and Its Related Propionic, Acetic, and Benzoic Acid Analoguesc  [PDF]
Luc M. LeBlanc,Aurélie F. Paré,Jacques Jean-Fran?ois,Martin J. G. Hébert,Marc E. Surette,Mohamed Touaibia
Molecules , 2012, DOI: 10.3390/molecules171214637
Abstract: 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.
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