Enzymatic synthesis of benzoin in supercritical carbon dioxide

Celebi, Nuray
Yildiz, Nuray
Demir, Ayhan Sıtkı
Calimli, Ayla
Enantioselective enzymatic hydrolysis of benzoyl-benzoin catalyzed by Candida cylindracea (CCL) lipase was carried out in SCCO2. It was found that CCL lipase enantioselectively hydrolyzed the (R)-benzoin. The enantiomeric excess of product (ee(p)) was maximized at 35 degrees C near the critical region 90 bar and obtained 61.3% at a 50% conversion. CCL did not catalyze the reaction in an atmospherical condition.


Optimization of supercritical CO2 extraction of Thymbra spicata oil
Sonsuzer, S; Şahin, Serpil; Yılmaz, Levent (Elsevier BV, 2004-07-01)
The supercritical fluid extraction (SFE) of aroma compounds from Thymbra spicata was studied. Response surface methodology (RSM) was used to optimize the parameters of the supercritical fluid extraction. Independent variables were temperature (40, 50 and 60 degreesC), pressure (80, 100 and 120 bar) and time (30, 60 and 90 min). Dependent variables were yield, monoterpene, sesquiterpene and oxygenated monoterpene contents.
Enhanced solubility of siloxy-modified polyhedral oligomeric silsesquioxanes in supercritical carbon dioxide
Demirtas, Cansu; Dilek Hacıhabiboğlu, Çerağ (Elsevier BV, 2019-01-01)
Alkyl siloxy functionalization increases the solubility of polyhedral oligomeric silsesquioxanes (POSS) in supercritical carbon dioxide over an order of magnitude compared to its counterpart with fluoroalkyl groups. The studied component, octatrimethylsiloxy POSS also exhibits higher solubility than other previously studied POSS types with various alkyl and methacryl groups. The octatrimethylsiloxy POSS-CO2 solid-vapor equilibrium curves have been constructed at temperatures between 308 and 328 K by measuri...
Supercritical CO2 intercalation of layered silicates
Serhatkulu, Gulay; Dilek Hacıhabiboğlu, Çerağ; Gulari, Esin (Elsevier BV, 2006-12-01)
In this study, we use supercritical CO2 as the processing medium for intercalating the structure of natural clay, Cloisite Na+, and depositing CO2-philic sugar acetate, P-D-galactose pentaacetate, between the layers of the clay. Based on our measurements of the phase behavior of the P-D-galactose pentaacetate-CO2 system, we select two processing conditions: a dense gas solution (DGS) at 40 degrees C and 11.7 MPa with 2.4 wt.% sugar acetate in CO2 and a gas-expanded liquid (GEL) at 40 degrees C and 7.9 MPa w...
Complex-radical cyclocopolymerization of allyl a-(N-maleimido)acetate with styrene and maleic anhydride
Rzaev, ZMO; Salamova, UU; Altindal, S (Wiley, 1997-08-01)
Radical copolymerizations of allyl alpha-(N-maleimido)acetate (AMI) with styrene (D, electron-donor) or maleic anhydride (A, electron-acceptor) were carried out in benzene and/or methyl ethyl ketone (MEK) at 50-70 degrees C in the presence of 2,2'-azoisobutyronitrile (AIBN) as initiator. The structure and properties of copolymers synthesized were derived from IR, chemical, DTA and TGA analyses. Side-chain unsaturation of macromolecules was also proved by the crosslinking effect observed. Kinetic parameters ...
Phase Behavior of Carbon Dioxide and Polyhedral Oligomeric Silsesquioxanes with Two Different Functional Groups
Dumanlilar, Beril; Dilek Hacıhabiboğlu, Çerağ (Elsevier BV, 2020-09-01)
Phase behavior of carbon dioxide and polyhedral oligomeric silsesquioxanes (POSS) modified with two different functional groups is studied in the temperature range of 308-323 K, up to 22 MPa. Different than the common types, one of the eight functional groups attached to the Si atoms of these POSS is a CO2-philic functional group, methacryl, while the rest are branched alkyl chains, either isooctyl (MIOPOSS) or isobutyl (MIBPOSS). Methacrylisobutyl POSS-CO2 binary system exhibits pressure-induced melting te...
Citation Formats
N. Celebi, N. Yildiz, A. S. Demir, and A. Calimli, “Enzymatic synthesis of benzoin in supercritical carbon dioxide,” JOURNAL OF SUPERCRITICAL FLUIDS, pp. 386–390, 2007, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/57697.