- Replacing bisphenol-A with bisguaiacol-F to synthesize polybenzoxazines for a pollution-free environment
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In recent years, bisguaiacol F (BGF) is considered as a green alternative to bisphenol A (BPA). The present work deals with the synthesis of BGF and BGF-based benzoxazines, viz., bis[(3-(furan-2-yl) methyl)-3,4-dihydro-2H benzoxazin-6-yl]methane and bis[(3-octadecyl)-3,4-dihydro-2H benzoxazin-6-yl]methane, as an alternative to BPA and polybenzoxazines derived from BPA. A solventless method was adopted for the synthesis of BGF and the benzoxazine monomers. The structure and purity of BGF is confirmed by FT-IR, NMR (1H and 13C), MS and GC. The monomers were polymerized via ring opening polymerization by heating as shown by FT-IR (disappearance of the peak due to the oxazine ring at 933 cm-1). Differential scanning calorimetric (DSC) analysis of the monomers shows a wide range of processability between 77 and 122 °C. Thermal properties of the furfurylamine based polybenzoxazine (BGF-FPbz) and stearylamine based polybenzoxazine (BGF-SPbz) were investigated by thermogravimetric analysis (TGA). The results indicate that BGF-FPbz shows the maximum thermal stability when compared with BGF-SPbz. Both the polymers exhibit good flame retardant properties as shown by their LOI values (more than 26).
- Periyasamy, Thirukumaran,Asrafali, Shakila Parveen,Muthusamy, Sarojadevi,Kim, Seong-Cheol
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- Regioselective synthesis, isomerisation, in vitro oestrogenic activity, and copolymerisation of bisguaiacol F (BGF) isomers
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Bisguaiacol F (BGF), a potentially safer and renewable bisphenol A (BPA) replacement made from lignin-derivable vanillyl alcohol (p-VA), is a promising building block for future aromatic biopolymers. Unfortunately, like BPA synthesis, this electrophilic condensation reaction is also prone to regioselectivity issues, giving rise to m,p′- and o,p′-BGF byproducts. In this work, the hitherto unconsidered influence of m,p′-BGF, viz. the main isomeric byproduct of p,p′-BGF synthesis, on the physicochemical properties of poly(BGF carbonate) (BGF-PC) was systematically investigated by random copolymerisation with different fractions of pure m,p′-BGF (25, 50 and 75 wt%). To do so, the elusive m,p′-isomer was made in unparalleled regioselectivity (72%) by alkylation condensation of isovanillyl alcohol (m-VA) with guaiacol. Surprisingly, no isomeric scrambling due to acid-catalysed isomerisation was encountered for pure BGF isomers, which strongly facilitates their synthesis in contrast to petrochemical bisphenol F (BPF). Furthermore, to ensure safer chemical design, an in vitro human oestrogen receptor α (hERα) transactivation assay was performed. Both pure m,p′- and p,p′-BGF displayed a significantly reduced oestrogenic potency (~426-457 times lower affinity than BPA) and oestrogenic efficacy (~39-50% of BPA's maximum induction). Interestingly, mutual comparison between p,p′-BPF and p,p′-BGF reveals and proves for the first time the direct link between ortho-methoxy substitution and reduced in vitro oestrogenic activity (for transactivation of hERα). In contrast to o,p′-BPA, viz. the main byproduct of p,p′-BPA synthesis, m,p′-BGF was proven suitable for utilization in thermoplastics, thereby avoiding time-consuming and labour-intensive (re)crystallizations to obtain regioisomerically pure p,p′-BGF.
- Koelewijn, Steven-Friso,Ruijten, Dieter,Trullemans, Laura,Renders, Tom,Van Puyvelde, Peter,Witters, Hilda,Sels, Bert F.
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p. 6622 - 6633
(2019/12/26)
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- BISPHENOL ALTERNATIVE DERIVED FROM RENEWABLE SUBSTITUTED PHENOLICS AND THEIR INDUSTRIAL APPLICATION
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A compound is provided according to structure 4, (4) wherein n has a value from 0 to 48 and Z is hydroxyl or a benzene ring bearing substituents R11-R15, wherein R1-R15 are each individually selected from the gr
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Paragraph 0044; 0061
(2017/08/22)
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- Identification and Organoleptic Contribution of Vanillylthiol in Wines
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Vanillylthiol, a chemical compound reminiscent of clove and smoke, has been identified for the first time in young red and dry white wines. The chemical structure of this new aroma was confirmed by original chemical synthesis. Vanillylthiol was prepared by a two-step procedure from vanillin. The conversion of vanillin to divanillyl disulfide was easily achieved by treatment with an inorganic sulfur-donor reagent. Reduction of the disulfide gave the target thiol in good yield. The quantification of vanillylthiol in wine was performed by nonspecific liquid/liquid extraction (CH2Cl2), separation of the volatile compounds using gas chromatography, and specific detection using tandem mass spectrometry (triple quadrupole). Vanillylthiol was found particularly in young wines aged in new oak barrels. These wines contained between a few 50 ng/L to more than 8300 ng/L. The highest levels were found in red wines aged 12 months in new oak barrels. Given its perception threshold in a wine model solution (3.8 μg/L), vanillylthiol may contribute to the spicy, clove-like flavor of red wines aged in oak barrels.
- Floch, Morgan,Shinkaruk, Svitlana,Darriet, Philippe,Pons, Alexandre
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p. 1318 - 1325
(2016/02/27)
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- Anti-inflammatory properties of quebecol and its derivatives
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Herein we report our results on the anti-inflammatory activity of quebecol, a polyphenolic compound discovered in maple syrup. Bioassays demonstrated that quebecol has an anti-inflammatory effect on LPS-induced NF-κB activation and inhibits the secretion of two pro-inflammatory cytokines, IL-6 and TNF-α. We also prepared and tested precursors of quebecol and its derivatives corresponding to its substructures of interest, with the aim to study the structure-activity relationships. Comparing the results obtained for all tested compounds allowed the identification of the main moiety responsible for the anti-inflammatory activity of quebecol.
- Cardinal, Sébastien,Azelmat, Jabrane,Grenier, Daniel,Voyer, Normand
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p. 440 - 444
(2016/01/09)
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- PHENOLIC COMPOUNDS WITH ANTIOXIDANT AND ANTI-CANCER PROPERTIES, ANALOGS AND SYNTHESIS THEREOF
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The present document describes a phytochemical isolated from maple syrup and composition comprising the same. More specifically, the document describes an antioxidant phytochemical compound, derivates thereof, and composition comprising the same. The document also describes a process of synthesizing the antioxidant phytochemical compound.
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Page/Page column 54
(2013/02/27)
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- The Self-Condensation Reactions of the Lignin Model Compounds, Vanillyl and Veratryl Alcohol
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Self-condensation of the lignin model compounds vanillyl and veratryl alcohol leads to the formation of benzyl ether and diphenylmethane structures.It is suggested that these structures may be formed within lignin at it ages in the plant cell wall.
- Hemmingson, Jacqueline A.,Leary, Gordon
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p. 917 - 925
(2007/10/02)
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