Vinyl Decanoate Research Articles

Block Copolymers of Poly(N-Vinyl Pyrrolidone) and Poly(Vinyl Esters) Bearing n-alkyl Side Groups via Reversible Addition-Fragmentation Chain-Transfer Polymerization: Synthesis, Characterization, and Thermal Properties.

Amphiphilic block copolymers of N-vinyl pyrrolidone (NVP) and various vinyl esters (VEs), PNVP-b-PVEs, namely vinyl butyrate (VBu), vinyl decanoate (VDc), and vinyl stearate (VSt), were synthesized through RAFT polymerization techniques. The sequential addition of the monomers methodology was employed starting from the polymerization of NVP followed by the polymerization of the Ves' monomer. The polymerization of NVP was conducted at 60 °C in benzene solution using AIBN as the initiator and O-ethyl S-(phthalimidylmethyl) xanthate as the CTA. The resulting PNVP macro-CTA was further applied for the polymerization of the vinyl ester in dioxane solution at 80 °C using, again, AIBN as the initiator. The block copolymers were characterized through size-exclusion chromatography (SEC) and NMR spectroscopy. The thermal behavior of the copolymers was studied by Differential Scanning Calorimetry (DSC), whereas their thermal stability via Thermogravimetric Analysis (TGA) and Differential Thermogravimetry (DTG).

Ionic liquid pretreatment of lignocellulose for complete hemicellulose removal to produce high-purity cellulose mixed esters

Strategic valorization of agricultural waste can serve as waste management and promote sustainable biorefineries. Sugarcane bagasse is a readily available lignocellulosic biomass and can be converted into valuable cellulose-based thermoplastics. However, the cellulose purity significantly influences the material properties of the resulting thermoplastics, potentially limiting their applications. Therefore, conventional production necessitates harsh pretreatment of lignocellulose to isolate high-purity cellulose, followed by chemical modification. Here, we demonstrate a facile and green pretreatment method for complete removal of hemicellulose by incubating bagasse in a mixed system of an ionic liquid, 1-ethyl-3-methylimidazolium acetate (EmimOAc), and dimethyl sulfoxide (DMSO) at 140 °C, followed by precipitation in water, achieving >99 % hemicellulose removal. The pretreated bagasse, containing 71 % cellulose and 28 % lignin, underwent homogeneous transesterification with vinyl decanoate and isopropenyl acetate, using EmimOAc as both the solvent and catalyst, assisted by a co-solvent of DMSO. The polysaccharide derivative in the resulting acylated bagasse was separated from the lignin derivative by precipitation in methanol. The obtained polysaccharide derivative with high cellulose purity displayed a high weight-average molar mass of 1.5×106 g mol−1 and a polydispersity of 4. It also exhibited superior thermal stability (thermal degradation temperature, Td−5 %: 359 °C; glass transition temperature, Tg: 144 °C) compared to pulp-derived cellulose acetate decanoate (Td−5 %: 349 °C; Tg: 129 °C).

Lipase-Mediated Mechanoenzymatic Synthesis of Sugar Esters in Dissolved Unconventional and Neat Reaction Systems.

Mechanochemical and biocatalytic approaches in modern research are two major assets to develop greener processes. In the present study, these modular tools of sustainability are pointed toward the production of versatile and daily employed compounds such as surfactants. Toward this aim, glycolipids, a class of nonionic surfactants composed of ubiquitous and primary metabolites such as sugar and fatty acid moieties, represent a promising alternative to petroleum-derived surface-active agents. Therefore, the combination of biocatalysis with mechanochemistry aiming at glycolipid synthesis seemed a logical step that was taken in this study for the first time. The monoacylated model compound glucose-6-O-decanoate was synthesized with the help of a bead mill apparatus using two different unconventional dissolved reaction systems, namely, menthol-based hydrophobic deep eutectic solvents and 2-methyl-2-butanol, thus reaching up to 12% yield in the latter based on the conversion of vinyl decanoate, after only 90 min of reaction. In addition, a neat reaction system using an excess of vinylated fatty ester as an adjuvant allowed a 27 mM/h space-time yield. The overall significant increase in productivities, up to 6 times, compared to standard heating and shaking methods, shows the tremendous potential of mechanoenzymatic synthesis.

Dextran-Based Nanoparticles for Encapsulation of Ciprofloxacin

Key success for regenerative endodontics is an effective removal of bacteria inside the root canal during the treatment. Ciprofloxacin (CIP) is one of the triple antibiotics commonly used as the root canal medicament. However, the rapid clearance of antibiotics causes bacterial reinfection. Nanoparticles (NPs) provide an alternative approach for antibiotics delivery system to improve the drug stability and release control. In the previous study, modified dextran was successfully formed the ester linkage with vinyl decanoate via lipase-catalyzed transesterification. The amphiphilic dextran, dextran-decanoate (Dex-D), has been synthesized with the degree of substitution of 83-88% and were applied for CIP-loaded nanoparticles. The suitable technique for producing antibiotic carriers considering by size, shape, and drug encapsulation efficiency was investigated in this work. The preparation methods were compared between nanoprecipitation and solid-in-oil-in-water (s/o/w) ion pairing technique. We found that the obtained Dex-D nanoparticles had stable monodispersed with spherical shape in both techniques. However, Dex-D nanoparticles formed by s/o/w ion pairing technique provided smaller size with better encapsulation efficiency. The antimicrobial activity of CIP-loaded Dex-D nanoparticles against oral pathogens showed satisfactory outcome with the MIC equal to 0.7 μg/mL. Also, the compatibility of nanoparticles and dental stem cells was observed in this work.

Enzymatic acylation of lutein with a series of saturated fatty acid vinyl esters and the thermal stability and anti-lipid oxidation properties of the acylated derivatives.

Lutein was enzymatically acylated with saturated fatty acid vinyl esters of different lengths of carbon chain (C6 -C14 ) under the action of Candida antarctica lipase B (Novozyme 435). The acylation reaction was optimized by considering substrate molar ratio, reaction solvent, type of enzyme, and reaction time. The highest yield (88%) was obtained using the Novozyme 435 to catalyze the acylation reaction of lutein and vinyl decanoate (lutein/vinyl decanoate molar ratio of 1/10) for 16 h in methyl tert-butyl ether. Ten lutein esters were synthesized, isolated, and purified, which were characterized by Fourier-transform infrared spectroscopy, high-resolution mass spectrometry, and nuclear magnetic resonance spectroscopy. We found that the acylation of lutein improved its antioxidant capacity in lipid system and thermal stability. Our study extended the potential application of lutein in lipophilic food, cosmetic, and pharmaceutical industries. Practical Application: Enzyme acylation of lutein improved its antioxidant capacity in lipid system and thermal stability, extended its potential application in food, cosmetic, and pharmaceutical industries. In addition, our study also provided a new perspective and cognition for the further development and utilization of lutein.

Highly Efficient Regioselective Decanoylation of Hyperoside Using Nanobiocatalyst of Fe3O4@PDA-Thermomyces lanuginosus Lipase: Insights of Kinetics and Stability Evaluation.

The immobilization of Thermomyces lanuginosus lipase on polydopamine-functionalized Fe3O4 magnetic nanoparticles (Fe3O4@PDA-TLL) as a nanobiocatalyst was successfully performed for the first time, and the Fe3O4@PDA-TLL was used for regioselective acylation of natural hyperoside with vinyl decanoate. The effects of several crucial factors, such as the reaction solvent, substrate molar ratio, temperature, and immobilized enzyme dosage, were investigated. Under optimum conditions, the reaction rate, 6″-regioselectivity, and maximum substrate conversion were as high as 12.6 mM/h, 100%, and 100%, respectively. An operational stability study demonstrated that the immobilized enzyme could maintain 90.1% of its initial maximum conversion even after reusing it five times. In addition, further investigations on the kinetic parameters, like Vmax, Km, Vmax/Km, and Ea, also revealed that the biocompatible Fe3O4@PDA could act as an alternative carrier for the immobilization of different enzymes.

Analysis of virgin coconut oil (VCO) components after heating and adding Cymbopogon nardus as the essential oil

Cymbopogon nardus has the potential to be an essential oil, used for kitchen spice, cosmetics (aromatherapy), and cancer medicines which contains citrate, eugenol, citronellol, citronellal, geraniol, citronellyl acetate, geranyl acetate, beta-caryophyllene, limonene, and methyl eugenol. This study aimed to analyze the components of Virgin Coconut Oil (VCO) after heating and adding Cymbopogon nardus compared to commercial products. The method of making coconut oil was enzymatic and heated for about ten minutes. Analysis of VCO components after being heated and added citronella was carried out by using ultimate size difference, microscopic analysis, and Gas Chromatography-Mass Spectrometry compared with the commercial VCO product. The results showed that there was an intensity change in the similarity of ion fragments as well as microscopically and carbon content of more than 70%, hydrogen 10%. Separation of VCO components resulted in good separation among ethyl esters such as ethyl caprylate, ethyl laurate, and ethyl myristate detected for 30 minutes by gas chromatography and fragment ion similarity in mass spectrometry. Chemical components in commercial oils were lauric acid, ethyl laurate, glycerol tricaprylate, and vinyl decanoate.

Chemical composition of essential oils from Bambusa vulgaris Leaf (Fresh and Dried) Schrad. Ex J.C. Wendl. [Poaceae] obtained in Nigeria

Essential oil is a hydrophobic concentrated liquid which contains volatile aroma compounds from plants. Bambusa vulgaris grows widely in the tropical and subtropical regions and has been reported to have different ethnomedicinal values such as antimalaria and antioxidant. It is also known to be an ornamental plant. The essential oil was extracted from both the fresh and dried leaves of Bambusa vulgaris by hydrodistillation method using a Clevenger apparatus. The chemical constituents of the essential oils were characterized using gas chromatography and gas chromatography-mass spectrometry. The essential oils obtained are colourless with an herbal odour giving a yield of 0.64 w/w for the fresh sample and 1.08 w/w for the dried sample. A total of thirty-nine (39) compounds were identified from the essential oils of both samples. The major constituents in the fresh leaves were 3-aminodibenzofuran (19.2%), ?-ocimene (11.1%), undecane (9.6%), tridecane (8.6%), [3,2-b] pyridin-6-octahydropyrano (7.1%), 2-mono laurin (6.9%) and vinyl decanoate (5.9%). Prominent compounds of the essential oil in the dried leaves were chlorophenoxymethylenimino sulfur pentafluoride (74.5%) and 2,2,6,6-tetramethyl-3,5-heptanedione (17.3%). Undecane, tridecane, hexadecane and octadecane were found both in the fresh and dried leaves. The chemical constituents of the essential oils from Nigeria Bambusa vulgaris were reported in this study for the first time to the best our knowledge and this could be useful in aromatherapy.

Assessment of oxidation compounds in oaked Chardonnay wines: A GC–MS and 1H NMR metabolomics approach

The oxidation of oaked Chardonnay wine during long-term storage was studied by headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME-GC/MS) and proton (1H) nuclear magnetic resonance (NMR) spectroscopy. Three distinct groups of wine were defined based on the browning index: control, least oxidized (OX1) and most oxidized (OX2). HS-SPME-GC/MS and 1H NMR spectroscopy enabled the profiling of a total of 155 compounds in all wine samples including aldehydes, ketones, esters, polyphenols, among other classes. Acetaldehyde, 3-methylbutanal, 2-phenylacetaldehyde, methional, 3-penten-2-one, β-damascenone and four unknown carbonyl compounds showed the highest percentage of variation with oxidation. Novel oxidation markers found in this work include pentanal, 3-methyl-2-butanone, 3-penten-2-one, 2-methyltetrahydrofuran-3-one, β-damascenone, ethyl 2-methylbutanoate and vinyl decanoate. In addition, several correlations between polyphenols, aroma compounds and absorbance at 420 nm (A420) were observed, suggesting the occurrence of chemical reactions with a possible impact in wine browning.

The effect of the migrating group structure on enantioselectivity in lipase-catalyzed kinetic resolution of 1-phenylethanol

We have studied the effects of the acyl moiety on the enantioselectivity of three lipases: Candida antarctica B, Pseudomonas cepacia and Candida cylindracea, frequently used in kinetic resolutions by acylation or hydrolysis. The size of the acyl group was examined using various enol esters during the transesterification of 1-phenylethanol and the hydrolysis of the corresponding phenylethylesters. C. antarctica-B lipase showed the highest selectivity in the transesterification of 1-phenylethanol with isopropenyl and vinyl acetate, vinyl decanoate, vinyl laurate, (E > 200). The esters 1-phenyl -ethyl-acetate, decanoate and laurate are also hydrolyzed with high selectivities (E > 150) with CAL-B. The results can be correlated to the three-dimensional form of each lipase. The effect of the migrating group on the reactivity and selectivity of the lipases are discussed for both reactions. Nous avons étudié les effets du fragment acyle sur l'énantiosélectivité de trois lipases: Candida antarctica B, Pseudomonas cepacia et Candida cylindracea, fréquemment utilisées dans les dédoublements cinétiques par acylation ou hydrolyse. La taille du groupe acyle a été examinée en utilisant divers esters d'énols dans l'acylation du 1-phényléthanol et par hydrolyse des phenylethylesters correspondants. La lipase de C. antarctica-B a montré une haute sélectivité (E > 200) lors de la transestérification du 1-phényléthanol avec de l'acétate d'isopropényle, l'acétate de vinyle, le décanoate de vinyle, le laurate de vinyle. Avec cette lipase (CAL-B), les esters 1-phényl éthyl-acétate, décanoate et laurate sont hydrolysés avec des sélectivités élevées (E > 150). Les résultats peuvent être corrélés à la forme tridimensionnelle de chaque lipase. Pour les deux réactions, l'effet de la nature du groupe partant sur la réactivité et la sélectivité des lipases est discuté.

Film formation from Pickering stabilized waterborne polymer dispersions

The mechanisms involved in the formation of films from high solids industrial-like – vinyl acetate – VeoVa10 (vinyl decanoate) waterborne dispersions Pickering stabilized with surface modified colloidal silica were studied using a combination of techniques including TEM, FRET, ESEM and SEM. It was found that Pickering stabilized dispersions yield films with the silica forming a honeycomb structure that partially hinders the interdiffusion of the polymers from different particles. Nevertheless, coherent films were formed only 9 °C above the Tg of the polymer, due to the strong capillarity forces developed in the compact array of particles formed during water evaporation in the film formation. These Pickering dispersions allowed achieving the remarkable effect of increasing at the same time the Young's modulus, the stress at break and the elongation at break by increasing the silica concentration. Water uptake of the films decreased with the silica concentration and with the surface modification of the silica. Films with >5 wt. % of the more hydrophobic silica absorbed less water than films stabilized with PVOH, which is the workhorse for VAc-VeoVa10 latexes.

New vinylester-based monoliths as a new stationary phase for capillary electrochromatography.

Vinyl ester-based monoliths are proposed as a new group of stationary phase for CEC. The capillary monolithic columns were prepared by using two vinyl ester monomers, vinyl pivalate (VPV), and vinyl decanoate (VDC) by using ethylene dimethacrylate (EDMA) as the cross-linking agent, and 2-acrylamido-2-methylpropane sulfonic acid as the charge-bearing monomer. The monoliths with different pore structures and permeabilities were obtained by varying the type and composition of the porogen mixture containing isoamyl alcohol and 1,4-butanediol. The electrochromatographic separation of alkylbenzenes was successfully performed by using an acetonitrile/aqueous buffer system as the mobile phase in a CEC system. Vinyl ester monoliths with short alkyl chain length (i.e. poly(VPV-co-EDMA) exhibited better separation performance compared with the monolith with long alkyl chain length (i.e. poly(VDC-co-EDMA). In the case of VPV-based monoliths, the theoretical plate numbers higher than 250000 plates/m were achieved by using a porogen mixture containing 33% v/v of isoamyl alcohol. For both VDC and VPV-based monoliths, the column efficiency was almost independent of the superficial velocity in the range of 2-12 cm/min.

Synthesis of 6-O-decanoyl-d-altrose and 6-O-decanoyl-d-gulose and evaluation of their biological activity on plant growth

Two new growth inhibitory compounds, 6-O-decanoyl-d-altrose and 6-O-decanoyl-d-gulose, were synthesized from d-altrose (C-2 epimer of d-allose) and d-gulose (C-4 epimer of d-allose), respectively, via lipase-catalyzed transesterification using vinyl decanoate. Furthermore, the inhibitory activity of 6-O-decanoyl-d-altrose and 6-O-decanoyl-d-gulose on different plant growths were examined. These two new rare sugar derivatives exhibited the inhibitory activity on the growth of cress, Italian rye grass, and rice seedlings similar to 6-O-decanoyl-d-allose, but in the case of lettuce, they showed the weaker inhibitory activity than 6-O-decanoyl-d-allose. In addition, we found that the co-addition of gibberellins (GAs) with a test solution of 6-O-decanoyl-d-altrose or 6-O-decanoyl-d-gulose on rice seedlings brought the recovery of inhibition. These results suggest that the d-altrose and d-gulose esters as well as the d-allose ester inhibited the biosynthesis of GAs to exhibit the plant growth inhibitory activity.

Thermomechanical and Rheological Studies of Copolymers of Methyl Methacrylate with a Series of Linear Vinyl Esters

A series of copolymers of methyl methacrylate (MMA) with linear vinyl esters (LVEs), including vinyl acetate (VA), vinyl propionate (VP), vinyl hexanoate (VH), and vinyl decanoate (VD), were synthesized by free radical copolymerizations at 60 °C. The LVE composition was varied from 3 to 41 mol % in the resultant copolymers. The glass transition (Tg) of the copolymers ranged from 60 to 108 °C. The storage moduli (E′) of the copolymers decreased as the LVE composition increased from 4 × 109 to 1.5 × 109 Pa. Copolymers containing VD exhibited a more obvious reduction in storage moduli and a larger shift of the tan δ peak. The rheological property analysis of the copolymers at different temperatures showed that the shear storage and loss moduli of poly(LVE-co-MMA) (G′ and G″) were mostly dominated by MWs. Short side chains did not have an obvious impact on the shear moduli and complex viscosities.

Macromolecular surfactants synthesized by lipase-catalyzed transesterification of dextran with vinyl decanoate

Dextran, a neutral bacterial polysaccharide consisting in glucose units linked in α-1,6 was modified by covalent attachment of linear aliphatic hydrocarbon groups via the formation of ester links. Transesterification reaction between dextran and vinyl dodecanoate was carried out in a polar organic solvent (dimethylsulfoxide) and catalyzed by lipase. Modified dextrans were fractionated using solvents of increasing polarity (ethyl acetate, methanol and water). Except for very low amounts of enzyme, modified polymers covered a range of degrees of substitution (ca. from 10 to 150%, defined as the molar ratio of formed ester bonds to available glucose units) with distribution depending on the initial amounts of reactants and lipase. Soluble fractions recovered at each step exhibited increasing degrees of substitution when decreasing solvent polarity (from water to methanol and ethyl acetate). In comparison, modified dextrans prepared by uncatalyzed transesterification (even over much longer times) exhibited degrees of substitution lower than 15% covering narrower ranges. The adsorption of modified dextrans at oil/water and air/water interface was examined by surface pressure and interfacial tension measurements for degrees of substitution varying from 10 to 150%.

Physicochemical Characterization of α-, β-, and γ-Cyclodextrins Bioesterified with Decanoate Chains Used As Building Blocks of Colloidal Nanoparticles

Nanoparticles of amphiphilic α-, β-, and γ-cyclodextrins were obtained by formulation of cyclodextrins enzymatically transesterified with vinyl decanoate. The product of this synthesis is a mixture of bioesterified cyclodextrins with various degrees of substitution (DS) presenting for a same DS different regio-isomers. In a first step, the efficiency of a MALDI-TOF procedure to characterize the average molecular weight of the derivative bulk mixture was demonstrated by comparing the results with those obtained from complementary NMR and HPLC techniques. In a second step, the ultrastructure of nanoparticles prepared from three different batches of synthesis was investigated and correlated with the average molecular weight and DS of the parent derivative.

Total synthesis of crispine A enantiomers through a Burkholderia cepacia lipase-catalysed kinetic resolution

Both enantiomers of the antitumour-active alkaloid crispine A (ee = 95%) were synthesised through the Burkholderia cepacia lipase-catalysed acylation of the primary hydroxy group of N-Boc-protected 1-(3-hydroxypropyl)-6,7-bis(methyloxy)-1,2,3,4-tetrahydroisoquinoline (±)- 3 and the enantioselective hydrolysis of the corresponding O-decanoate (±)- 4 [R = (CH 2) 8Me] with a remote, four-atom distant stereogenic centre. High enantioselectivities were observed for the ( S)-selective O-acylation with vinyl decanoate in the presence of Et 3N and Na 2SO 4 in t-BuOMe at 45 °C ( E = 68), and for the ( S)-selective hydrolysis with H 2O in t-BuOMe at 45 °C ( E = 52). The enzymatic resolutions, performed in two steps, afforded the key alcohol and ester enantiomers with high enantiomeric excesses (ee ⩾ 94%). Ring-closure reactions of alcohol enantiomers (+)- 3 and (−)- 3 with thionyl chloride afforded the desired crispine A enantiomers (+)- 1 and (−)- 1 (ee ⩾ 95%).

Lipase Nanogel Catalyzed Transesterification in Anhydrous Dimethyl Sulfoxide

The present work showed that Candida rugosa lipase, which is inactive in anhydrous dimethyl sulfoxide (DMSO), has been granted its original catalytic activity and greatly enhanced stability when encapsulated into a polyacrylamide nanogel. The molecular simulation and structural analysis suggested that the polyacrylamide nanogel shielded the extraction of essential water and maintained the native configuration of encapsulated lipase in anhydrous DMSO at an elevated temperature. The electron and fluorescence microscopy showed that the lipase nanogel would be well dispersed in anhydrous DMSO where its native counterpart aggregated. The encapsulated lipase behaved as a stable catalyst for transesterification between dextran and vinyl decanoate in anhydrous DMSO at 60 degrees C for 240 h and yielded a dextran-based polymeric surfactant with regioselectivity toward the C-2 hydroxyl group in the glucopyranosyl unit of dextran. All these indicated a high potential of enzyme nanogel for nonaqueous biocatalysis.

Regioselective acylation of 3-O-angeloylingenol by Candida antarctica Lipase B

Acylation of 3-O-angeloylingenol (1) with vinyl acetate, vinyl decanoate and vinyl cinnamate, catalyzed by Candida antarctica Lipase B, was investigated. In each case, compound 1 was quantitatively and regioselectively acylated to afford a single product, 3-O-angeloyl-20-O-acetylingenol (1a), 3-O-angeloyl-20-O-decanoylingenol (1b) and 3-O-angeloyl-20-O-cinnamoylingenol (1c), respectively. The structures of the novel compounds 1b-1c were determined by MS and NMR, and product 1a by comparison of RP-HPLC and TLC with a standard. Compounds 1b-1c induced a bipolar morphology of MM96L melanoma cells at a similar concentration as compound 1, as well as having activity in inhibiting the growth of MM96L melanoma cells.

Optimization of Lipase-Catalyzed Synthesis of Ginsenoside Rb1 Esters Using Response Surface Methodology

In the lipase (Novozyme 435)-catalyzed synthesis of ginsenoside Rb1 esters, different acyl donors were found to affect not only the degree of conversion but also the regioselectivity. The reaction of acyl donors with short carbon chain was more effective, showing higher conversion than those with long carbon chain. Among the three solvent systems, the reaction in tert-amyl alcohol showed the highest conversion rate, while the reaction in the mixed solvent of t-BuOH and pyridine (1:1) had the lowest conversion rate. To allow the increase of GRb1 lipophilicity, we decided to further study the optimal condition of synthesis of GRb1 with vinyl decanoate with 10 carbon chain fatty acids in tert-amyl alcohol. Response surface methodology (RSM) was employed to optimize the synthesis condition. From the ridge analysis with maximum responses, the maximum GRb1 conversion was predicted to be 61.51% in a combination of factors (40.2 h, 52.95 degrees C, substrate mole ratio 275.57, and enzyme amount 39.81 mg/mL). Further, the adequacy of the predicted model was examined by additional independent experiments at the predicted maximum synthesis conditions. Results showed that the RSM was effective to optimize a combination of factors for lipase-catalyzed synthesis of ginsenoside Rb1 with vinyl decanoate.