Viacheslav Tverezovskiy | Bangor University (original) (raw)

Papers by Viacheslav Tverezovskiy

Chemistry and Physics of Lipids, Oct 1, 2014

Tetrahedron, Feb 1, 2014

Reaction of the bis-dibromocarbene adduct of cyclonona-1,4,7-triene with methyllithium leads to a... more Reaction of the bis-dibromocarbene adduct of cyclonona-1,4,7-triene with methyllithium leads to a mixture of meso and racemic cycloundeca-1,2,5,6,9-pentaenes; the former rearranges at ambient temperature through a set of pericyclic reactions.

Chemical Communications, 2013

Sodium hydroxide solution (17.0 g, 425 mmol, 50 %) was added slowly to a stirred solution of (1Z,... more Sodium hydroxide solution (17.0 g, 425 mmol, 50 %) was added slowly to a stirred solution of (1Z,4Z,7Z)-cyclonona-1,4,7-triene (2.0 g, 16.6 mmol), bromoform (42.0 g, 14.5 ml, 166.6 mmol) and cetremide (0.5 g, 1.35 mmol) in dichloromethane (20 ml). The mixture was stirred rapidly for 72 hrs at room temperature. The product was extracted with dichloromethane (3 x 100 ml) and the combined organic layers were washed with water and brine (150 ml), dried over MgSO 4 and the solvent was evaporated. The bromoform was removed by distillation under vacuum (.5 mmHg), then the oily residue was treated with dichloromethane to give a white precipitate which was 4

L'ozonolyse est un procede bien connu impliquant la reaction d'ozone avec des composes al... more L'ozonolyse est un procede bien connu impliquant la reaction d'ozone avec des composes alcene, par exemple dans des huiles vegetales insaturees ou des acides gras libres et des esters de ceux-ci pour former des produits d'ozonolyse (par exemple des ozonides). Cette invention concerne l'ozonolyse d'huiles insaturees (par exemple des huiles vegetales insaturees et/ou des huiles animales insaturees) en presence d'un co-reactif participant, afin de former des produits de reaction particulierement appropries pour leur utilisation dans la formation de resines.

Foods, 2021

The function of packaging is crucial in the maintenance of fresh meat product quality. This study... more The function of packaging is crucial in the maintenance of fresh meat product quality. This study aimed to assess the efficiency of six films added with coatings 2379L/220 and 2379L/221 (containing sage extracts) to inhibit Salmonella typhimurium, Staphylococcus aureus, and Escherichia coli, which showed that two of the six films had a significant effect. Additionally, the effects of the films on refrigerated skinless chicken breast meat were evaluated based on microbiological content, colour, weight loss, texture and pH. Four of the six films were examined could extend the storability of refrigerated chicken breast fillets for up to seven days. All six treated films improved the pH, colour stability, weight loss, and texture of the chicken fillets. Therefore, these findings suggested that the coatings containing sage extracts having different viscosities (2379L/220 and 2379L/221) were effective as antimicrobial adhesives in food packaging films and can be commercially applied in pr...

The objective of this study was to develop and assess the efficacy of two experimental methodolog... more The objective of this study was to develop and assess the efficacy of two experimental methodologies for the maleinisation of lampante oil to be used for wood protection. Two maleinisation techniques were used to chemically modify low-value lampante oil in an attempt to limit leaching, increase hydrophobicity, and impart some level of antimicrobial performance when impregnated in wood. Pine and beech wood specimens were treated with the modified oils and underwent leaching, accelerated weathering, and fungi tests. The following analysis assessed the efficacy of the modified oil treatments in improving these characteristics.

Dyfyniad o'r fersiwn a gyhoeddwyd / Citation for published version (APA): Wilfred, O., Tai, H... more Dyfyniad o'r fersiwn a gyhoeddwyd / Citation for published version (APA): Wilfred, O., Tai, H., Marriott, R., Liu, Q., Tverezovskiy, V., Curling, S., Fan, Z., & Wang, W. (2018). Biodegradation of Polyactic Acid and starch composites in compost and soil. International Journal of Nano Research, 1(2), 1-11. https://innovationinfo.org/internationaljournal-of-nano-research/article/Biodegradation-of-Polylactic-Acid-and-Starch-Composites-inCompost-and-Soil

Article Information Osita Wilfred1 Hongyun Tai1* Ray Marriott2 Qiuyun Liu2 Viacheslav Tverezovski... more Article Information Osita Wilfred1 Hongyun Tai1* Ray Marriott2 Qiuyun Liu2 Viacheslav Tverezovskiy2 Simon Curling2 Hongxia Tai3 Zhongyong Fan4 Wenxin Wang5 1School of Chemistry, Bangor University, Bangor, UK 2Biocomposites Centre, Bangor University, Bangor, UK 3Zhongcheng Machinery Manufacturing Co, Ltd. of Bohai Petroleum Equipment, Dagang Oilfield, Tianjin, PR China 4Department of Materials Science, Fudan University, Shanghai, PR China 5Charles Institute of Dermatology, School of Medicine, University College Dublin, Dublin 4, Ireland

Polymer Degradation and Stability

Several ester derivatives of rosmarinic acid (rosmarinates) were synthesised, characterised (1D a... more Several ester derivatives of rosmarinic acid (rosmarinates) were synthesised, characterised (1D and 2D NMR, UV and FTIR spectroscopy) and tested for their potential use as antioxidants derived from a renewable natural resource. The intrinsic free radical scavenging activity of the rosmarinates was assessed, initially using a modified DPPH (2, 2-diphenyl-1-picrylhydrazyl radical) method, and found to be higher than that of commercial synthetic hindered phenol antioxidants Irganox 1076 and Irganox 1010. The thermal stabilising performance of the rosmarinates in polyethylene (PE) and polypropylene (PP) was subsequently examined and compared to that of samples prepared similarly but in the presence of Irganox 1076 (in PE) and Irganox 1010 (in PP) which are typically used for polyolefin stabilisation in industrial practice. The melt stability and the long-term thermo-oxidative stability (LTTS) of processed polymers containing the antioxidants were assessed by measuring the melt flow index (MFI), melt viscosity, oxidation induction time (OIT) and long-term (accelerated) thermal ageing performance. The results show that both the melt and the thermo-oxidative stabilisation afforded by the rosmarinates, and in particular the stearyl derivative, in both PE and PP, are superior to those of Irganox 1076 and Irganox 1010, hence their potential as effective sustainable bio-based antioxidants for polymers. The rosmarinic acid used for the synthesis of the rosmarinates esters in this study was obtained from commercial rosemary extracts (AquaROX80). Furthermore, a large number of different strains of UK-grown rosemary plants (Rosmarinum officinalis) were also extracted and analysed in order to examine their antioxidant content. It was found that the carnosic and the rosmarinic acids, and to a much lesser extent the carnosol, constituted the main antioxidant components of the UK-plants, with the two acids being present at a ratio of 3:1, respectively.

European Journal of Wood and Wood Products

Within the Slovenian region of Istria, the olive growing and oil production industry is strong. T... more Within the Slovenian region of Istria, the olive growing and oil production industry is strong. This industry has a long history and the olives grown here have high levels of biologically active compounds including a variety of phenolic compounds. Using residual materials generated by this industry in potential wood protection systems would not only valorise low-value materials and stimulate rural economies but would also provide an alternative to currently used oil-based protection systems. The objective of this study was to produce an oil treatment for wood protection and assess its efficacy in reducing leaching, weathering effects, and fungal decay. Two maleinisation techniques were used to chemically modify low-value lampante oil in an attempt to limit leaching when impregnated in wood. Pinus sylvestris (Scots pine) and Fagus sylvatica (European beech) were treated with the modified oils and underwent leaching, accelerated weathering, and decay tests. Leaching of the treatment oils was relatively low compared with other experiments and beech wood specimens treated with a direct maleinisation treatment showed improvement in performance compared to control specimens. In addition, it was found that the modified oils were not completely removed from the wood after solvent extraction indicating that they could potentially be used as an immobilisation agent in combination with other treatments thereby reducing the amount of active component of the protective agent.

Biochemical Engineering Journal

Separation and Purification Technology

Spent sulphite liquor produced as side stream from sulphite pulping of Eucalyptus globulus hardwo... more Spent sulphite liquor produced as side stream from sulphite pulping of Eucalyptus globulus hardwood could be used for the separation of lignosulphonates by nanofiltration in the retentate stream and succinic acid production via fermentation of the permeate stream by Actinobacillus succinogenes or Basfia succiniciproducens. The potential integration of this process in conventional pulp mills towards the development of a novel biorefinery is dependent on the efficient downstream separation of succinic acid crystals at high yield and purity. This study focuses on the evaluation of five downstream separation processes, namely calcium precipitation, direct crystallisation using acidification or cation-exchange resins, salting-out and reactive extraction, for the purification of succinic acid from crude fermentation broths. Reactive extraction using trioctylamine in 1-hexanol and direct crystallisation coupled with cation-exchange resins led to succinic acid recovery yields of 73% and 79%, respectively. 1 H-NMR analysis showed that these downstream separation processes led to succinic acid crystal purities of ca 98.5% for reactive extraction and higher than 99% for the direct crystallisation method coupled with cation-exchange resins with no detectable acetic acid content when re-crystallisation was employed. It has been demonstrated that succinic acid produced via fermentation using side streams from pulp and paper mills could be separated at high purity and yield from crude fermentation broths rendering feasible its utilisation for poly(butylene succinate) production.

Tetrahedron Letters, 1998

Reaction of 2-acyloxymethyl or 2-acylaminomethyl-1, l-dibromocyclopropanes with methyllithium at-... more Reaction of 2-acyloxymethyl or 2-acylaminomethyl-1, l-dibromocyclopropanes with methyllithium at-90 " C leads to selective bromine-lithium exchange and intramolecular cyclisation to give a l-bromo-3-oxa-or I-0040-4039/98/$ -see front matter

Chemistry and Physics of Lipids, Oct 1, 2014

Tetrahedron, Feb 1, 2014

Reaction of the bis-dibromocarbene adduct of cyclonona-1,4,7-triene with methyllithium leads to a... more Reaction of the bis-dibromocarbene adduct of cyclonona-1,4,7-triene with methyllithium leads to a mixture of meso and racemic cycloundeca-1,2,5,6,9-pentaenes; the former rearranges at ambient temperature through a set of pericyclic reactions.

Chemical Communications, 2013

Sodium hydroxide solution (17.0 g, 425 mmol, 50 %) was added slowly to a stirred solution of (1Z,... more Sodium hydroxide solution (17.0 g, 425 mmol, 50 %) was added slowly to a stirred solution of (1Z,4Z,7Z)-cyclonona-1,4,7-triene (2.0 g, 16.6 mmol), bromoform (42.0 g, 14.5 ml, 166.6 mmol) and cetremide (0.5 g, 1.35 mmol) in dichloromethane (20 ml). The mixture was stirred rapidly for 72 hrs at room temperature. The product was extracted with dichloromethane (3 x 100 ml) and the combined organic layers were washed with water and brine (150 ml), dried over MgSO 4 and the solvent was evaporated. The bromoform was removed by distillation under vacuum (.5 mmHg), then the oily residue was treated with dichloromethane to give a white precipitate which was 4

L'ozonolyse est un procede bien connu impliquant la reaction d'ozone avec des composes al... more L'ozonolyse est un procede bien connu impliquant la reaction d'ozone avec des composes alcene, par exemple dans des huiles vegetales insaturees ou des acides gras libres et des esters de ceux-ci pour former des produits d'ozonolyse (par exemple des ozonides). Cette invention concerne l'ozonolyse d'huiles insaturees (par exemple des huiles vegetales insaturees et/ou des huiles animales insaturees) en presence d'un co-reactif participant, afin de former des produits de reaction particulierement appropries pour leur utilisation dans la formation de resines.

Foods, 2021

The function of packaging is crucial in the maintenance of fresh meat product quality. This study... more The function of packaging is crucial in the maintenance of fresh meat product quality. This study aimed to assess the efficiency of six films added with coatings 2379L/220 and 2379L/221 (containing sage extracts) to inhibit Salmonella typhimurium, Staphylococcus aureus, and Escherichia coli, which showed that two of the six films had a significant effect. Additionally, the effects of the films on refrigerated skinless chicken breast meat were evaluated based on microbiological content, colour, weight loss, texture and pH. Four of the six films were examined could extend the storability of refrigerated chicken breast fillets for up to seven days. All six treated films improved the pH, colour stability, weight loss, and texture of the chicken fillets. Therefore, these findings suggested that the coatings containing sage extracts having different viscosities (2379L/220 and 2379L/221) were effective as antimicrobial adhesives in food packaging films and can be commercially applied in pr...

The objective of this study was to develop and assess the efficacy of two experimental methodolog... more The objective of this study was to develop and assess the efficacy of two experimental methodologies for the maleinisation of lampante oil to be used for wood protection. Two maleinisation techniques were used to chemically modify low-value lampante oil in an attempt to limit leaching, increase hydrophobicity, and impart some level of antimicrobial performance when impregnated in wood. Pine and beech wood specimens were treated with the modified oils and underwent leaching, accelerated weathering, and fungi tests. The following analysis assessed the efficacy of the modified oil treatments in improving these characteristics.

Dyfyniad o'r fersiwn a gyhoeddwyd / Citation for published version (APA): Wilfred, O., Tai, H... more Dyfyniad o'r fersiwn a gyhoeddwyd / Citation for published version (APA): Wilfred, O., Tai, H., Marriott, R., Liu, Q., Tverezovskiy, V., Curling, S., Fan, Z., & Wang, W. (2018). Biodegradation of Polyactic Acid and starch composites in compost and soil. International Journal of Nano Research, 1(2), 1-11. https://innovationinfo.org/internationaljournal-of-nano-research/article/Biodegradation-of-Polylactic-Acid-and-Starch-Composites-inCompost-and-Soil

Article Information Osita Wilfred1 Hongyun Tai1* Ray Marriott2 Qiuyun Liu2 Viacheslav Tverezovski... more Article Information Osita Wilfred1 Hongyun Tai1* Ray Marriott2 Qiuyun Liu2 Viacheslav Tverezovskiy2 Simon Curling2 Hongxia Tai3 Zhongyong Fan4 Wenxin Wang5 1School of Chemistry, Bangor University, Bangor, UK 2Biocomposites Centre, Bangor University, Bangor, UK 3Zhongcheng Machinery Manufacturing Co, Ltd. of Bohai Petroleum Equipment, Dagang Oilfield, Tianjin, PR China 4Department of Materials Science, Fudan University, Shanghai, PR China 5Charles Institute of Dermatology, School of Medicine, University College Dublin, Dublin 4, Ireland

Polymer Degradation and Stability

Several ester derivatives of rosmarinic acid (rosmarinates) were synthesised, characterised (1D a... more Several ester derivatives of rosmarinic acid (rosmarinates) were synthesised, characterised (1D and 2D NMR, UV and FTIR spectroscopy) and tested for their potential use as antioxidants derived from a renewable natural resource. The intrinsic free radical scavenging activity of the rosmarinates was assessed, initially using a modified DPPH (2, 2-diphenyl-1-picrylhydrazyl radical) method, and found to be higher than that of commercial synthetic hindered phenol antioxidants Irganox 1076 and Irganox 1010. The thermal stabilising performance of the rosmarinates in polyethylene (PE) and polypropylene (PP) was subsequently examined and compared to that of samples prepared similarly but in the presence of Irganox 1076 (in PE) and Irganox 1010 (in PP) which are typically used for polyolefin stabilisation in industrial practice. The melt stability and the long-term thermo-oxidative stability (LTTS) of processed polymers containing the antioxidants were assessed by measuring the melt flow index (MFI), melt viscosity, oxidation induction time (OIT) and long-term (accelerated) thermal ageing performance. The results show that both the melt and the thermo-oxidative stabilisation afforded by the rosmarinates, and in particular the stearyl derivative, in both PE and PP, are superior to those of Irganox 1076 and Irganox 1010, hence their potential as effective sustainable bio-based antioxidants for polymers. The rosmarinic acid used for the synthesis of the rosmarinates esters in this study was obtained from commercial rosemary extracts (AquaROX80). Furthermore, a large number of different strains of UK-grown rosemary plants (Rosmarinum officinalis) were also extracted and analysed in order to examine their antioxidant content. It was found that the carnosic and the rosmarinic acids, and to a much lesser extent the carnosol, constituted the main antioxidant components of the UK-plants, with the two acids being present at a ratio of 3:1, respectively.

European Journal of Wood and Wood Products

Within the Slovenian region of Istria, the olive growing and oil production industry is strong. T... more Within the Slovenian region of Istria, the olive growing and oil production industry is strong. This industry has a long history and the olives grown here have high levels of biologically active compounds including a variety of phenolic compounds. Using residual materials generated by this industry in potential wood protection systems would not only valorise low-value materials and stimulate rural economies but would also provide an alternative to currently used oil-based protection systems. The objective of this study was to produce an oil treatment for wood protection and assess its efficacy in reducing leaching, weathering effects, and fungal decay. Two maleinisation techniques were used to chemically modify low-value lampante oil in an attempt to limit leaching when impregnated in wood. Pinus sylvestris (Scots pine) and Fagus sylvatica (European beech) were treated with the modified oils and underwent leaching, accelerated weathering, and decay tests. Leaching of the treatment oils was relatively low compared with other experiments and beech wood specimens treated with a direct maleinisation treatment showed improvement in performance compared to control specimens. In addition, it was found that the modified oils were not completely removed from the wood after solvent extraction indicating that they could potentially be used as an immobilisation agent in combination with other treatments thereby reducing the amount of active component of the protective agent.

Biochemical Engineering Journal

Separation and Purification Technology

Spent sulphite liquor produced as side stream from sulphite pulping of Eucalyptus globulus hardwo... more Spent sulphite liquor produced as side stream from sulphite pulping of Eucalyptus globulus hardwood could be used for the separation of lignosulphonates by nanofiltration in the retentate stream and succinic acid production via fermentation of the permeate stream by Actinobacillus succinogenes or Basfia succiniciproducens. The potential integration of this process in conventional pulp mills towards the development of a novel biorefinery is dependent on the efficient downstream separation of succinic acid crystals at high yield and purity. This study focuses on the evaluation of five downstream separation processes, namely calcium precipitation, direct crystallisation using acidification or cation-exchange resins, salting-out and reactive extraction, for the purification of succinic acid from crude fermentation broths. Reactive extraction using trioctylamine in 1-hexanol and direct crystallisation coupled with cation-exchange resins led to succinic acid recovery yields of 73% and 79%, respectively. 1 H-NMR analysis showed that these downstream separation processes led to succinic acid crystal purities of ca 98.5% for reactive extraction and higher than 99% for the direct crystallisation method coupled with cation-exchange resins with no detectable acetic acid content when re-crystallisation was employed. It has been demonstrated that succinic acid produced via fermentation using side streams from pulp and paper mills could be separated at high purity and yield from crude fermentation broths rendering feasible its utilisation for poly(butylene succinate) production.

Tetrahedron Letters, 1998

Reaction of 2-acyloxymethyl or 2-acylaminomethyl-1, l-dibromocyclopropanes with methyllithium at-... more Reaction of 2-acyloxymethyl or 2-acylaminomethyl-1, l-dibromocyclopropanes with methyllithium at-90 " C leads to selective bromine-lithium exchange and intramolecular cyclisation to give a l-bromo-3-oxa-or I-0040-4039/98/$ -see front matter