- Immobilization of lipase on biocompatible co-polymer of polyvinyl alcohol and chitosan for synthesis of laurate compounds in supercritical carbon dioxide using response surface methodology
-
Biocompatible co-polymer matrix has great importance for enzyme immobilization and subsequent biocatalytic applications to synthesize important organic moieties. Citronellyl laurate is a fatty-acid-ester having pleasant fruity aroma and widely used as/in emulsifier, lubricant in textile, paint or ink-additives, surfactants, perfumery and food-flavouring ingredient. In present study, Burkholderia cepacia lipase (BCL) was immobilized on biodegradable co-polymer of chitosan (CHI) and polyvinyl alcohol (PVA). The synthesized bio-catalyst {PVA:CHI:BCL (6:4:2.5)} was characterized by SEM, TGA, lipase assay and protein-content analysis. This biocatalyst was applied to synthesize citronellyl laurate in supercritical carbon-dioxide (SC-CO2) using response surface methodology with five-factor-three-level Box-Behnken-design to optimize reaction parameters (citronellol: 8.5 mmol; vinyl laurate: 19.87 mmol; biocatalyst: 175.6 mg; temperature: 46.02 °C; pressure: 8.81 MPa) which provided 94 ± 1.52% yield. The protocol is extended to synthesize various important 12 laurate compounds with excellent yield (90-98%) and noteworthy recyclability (upto studied 5 recycles). Interestingly, immobilized PVA/CHI/lipase biocatalyst showed 4-fold higher bio-catalytic activity than free lipase in SC-CO2. Moreover, the biocatalyst activity assessment study showed remarkable activity-stability of immobilized biocatalyst in SC-CO2 media as compared to free enzyme. Thus, present protocol demonstrated potential biocatalytic applications for synthesis of important laurate compounds with excellent recyclability in SC-CO2 as greener biocatalyst and reaction medium.
- Badgujar, Kirtikumar C.,Bhanage, Bhalchandra M.
-
p. 1224 - 1236
(2015/07/08)
-
- A novel poly(p-styrenesulfonic acid) grafted carbon nanotube/graphene oxide architecture with enhanced catalytic performance for the synthesis of benzoate esters and fatty acid alkyl esters
-
Considering the issue of low yield in the synthesis of benzoate esters and fatty acid alkyl esters, designing a high catalytic activity composite catalyst is very significant and attractive. In this study, the rational design strategy was used to develop a novel poly(p-styrenesulfonate acid, namely PSSF) grafted multi-walled carbon nanotube composite with graphene oxide nanomaterial (PSSF-mCNTs-GO) using a simple two-step method. FT-IR and Raman spectroscopy, XRD, SEM, TEM, and NH3-TPD were used to characterize the inorganic-organic hybrid material. In particular, the addition of GO remarkably enhanced its catalytic performance in the production of fatty acid alkyl esters (92.16%) and benzoate esters (90.27%), in which the conversion was more than doubled as a result of its strong π-π interaction with the substrate. In addition, PSSF-mCNTs-GO can be separated from the substrate conveniently and still maintained a relatively high catalytic activity even after 6 times recycling, which indicates its rather good reusability. This novel catalyst is promising in the synthesis of biodiesel and benzoate esters.
- Bian, Gang,Jiang, Pingping,Zhang, Weijie,Jiang, Kelei,Hu, Ling,Jian, Zhang,Shen, Yirui,Zhang, Pingbo
-
p. 90757 - 90765
(2015/11/16)
-
- A simple route to synthesize mesoporous ZSM-5 templated by ammonium-modified chitosan
-
Uniform mesoporous zeolite ZSM-5 crystals have been successfully fabricated through a simple hydrothermal synthetic method by utilizing ammonium-modified chitosan and tetrapropylammonium hydroxide (TPAOH) as the meso- and microscale template, respectively. It was revealed that mesopores with diameters of 5-20nm coexisted with microporous network within mesoporous ZSM-5 crystals. Ammonium-modified chitosan was demonstrated to serve as a mesoporogen, self-assembling with the zeolite precursor through strong static interactions. As expected, the prepared mesoporous ZSM-5 exhibited greatly enhanced catalytic activities compared with conventional ZSM-5 and Al-MCM-41 in reactions involving bulky molecules, such as the Claisen-Schmidt condensation of 2-hydroxyacetophenone with benzaldehyde and the esterification reaction of dodecanoic acid and 2-ethylhexanol. Mesoporous zeolite: Ammonium-modified chitosan served as a mesoporogen in the hydrothermal synthesis of mesoporous zeolite Socony Mobil (ZSM)-5, self-assembling with the zeolite precursor through strong static interactions (see figure; TPA=tetrapropylammonium, HTCC=N-(2-hydroxy)propyl-3-trimethylammonium chitosan chloride).
- Jin, Junjiang,Zhang, Xingdi,Li, Yongsheng,Li, Hua,Wu, Wei,Cui, Yunlong,Chen, Qian,Li, Liang,Gu, Jinlou,Zhao, Wenru,Shi, Jianlin
-
p. 16549 - 16555
(2013/02/22)
-
- Solid acid catalysts for biodiesel production - Towards sustainable energy
-
The advantages of biodiesel as an alternative fuel and the problems involved in its manufacturing are outlined. The pros and cons of making biodiesel via fatty acid esterification using solid acid catalysts are examined. The main problem is finding a suitable catalyst that is active, selective, and stable under the process conditions. Various solid acids (zeolites, ion-exchange resins, and mixed metal oxides) are screened as catalysts in the esterification of dodecanoic acid with 2-ethylhexanol, 1-propanol, and methanol at 130-180°C. The most promising candidate is found to be sulphated zirconia. The catalyst's stability towards thermal decomposition and leaching is tested and the effects of the surface composition and structure on the catalytic activity are discussed.
- Kiss, Anton A.,Dimian, Alexandre C.,Rothenberg, Gadi
-
-
- WAX COMPOSITION OF SARGASSUM FULVELLUM
-
Sixty-seven compounds were characterized in the wax of Sargassum fulvellum.Characteristic components were the 5-methylhexyl esters of octanoic, decanoic, lauric, myristic, palmitic, palmitoleic, stearic, oleic, linoleic and linolenic, and the 2-ethylhexyl esters of the same acids.The wax of S. fulvellum contains hydrocarbons (1.6percent), esters (21.8percent), free acids (74.9percent) and free alcohols (0.3percent).The principal free alcohols range in chain length only from C6 to C7. - Key Word Index: Sargassum fulvellum; Sargassaceae; Phaeophyta; wax; 5-methylhexyl esters; 2-ethylhexyl esters; 5-methylhexanol; 2-ethylhexanol.
- Miyazawa, Mitsuo,Uematsu, Tosihisa,Kameoka, Hiromu
-
p. 1788 - 1791
(2007/10/02)
-
