Cellulose beads

Scheme 7.34 Generation of pyrazole and oxazole libraries on cellulose beads.

Roy, 1. and Gupta, M.N., Lactose hydrolysis by Lactozym immobilized on cellulose beads in batch and fluidized bed modes., Proc. Biochem., 39 (2003) 325-332. 

For the preparation of the chiral stationary phase (3-methylbenzoyl cellulose) and of the analytical HPLC columns, see ref1421. The preparative column (glass column 5 cm i.d. x 75 cm Btichi AG, Flawil, Switzerland) was slurry-packed with a suspension of 3-methylbenzoyl-cellulose beads (550 g) in hexane/ iPrOH (9 l). The glass column was topped with a column of the same dimension as a reservoir. After decantation of the material in the column, the reservoir was taken away and the stationary phase washed by pumping the eluent through the column equipped with an inlet plunger, at a flow rate of 60 mL-min 1... 

G. T. Tsao, Characteristics of yeast invertase immobilized on porous cellulose beads, Biotechnol. Bioeng. 1977, 19, 365-375. 

Other means of separation, such as ammonium sulphate precipitation and bonding of the antibody to cellulose beads may also be used for heterogeneous fluoroimmunoassays. 

This approach was used for the study of the kinetic properties of invertase immobilized on the cellulose bead surface [27,30,33]. In the following example the kinetic model described for invertase was used [34]... 

Cross-linked cellulose based adsorbent beads have been under development at University Department of Chemical Technology (UDCT), Mumbai, and IIT, Delhi for use in expanded bed chromatography. Properties of the beads are claimed to be equivalent or even superior to the imported products. Purification protocols for expanded bed chromatography using cellulose beads for several enzymes are being developed. 

Cellulose beads medium medium (alkanes, alcohols, acetonitrile) 50 strong medium... 

Roussel and Popescu [54] extended this work by developing a lipophilicity parameter, log k w The authors were able to explain the relationship between chiral retention of the enantiomers and their lipophilic interactions with the CSPs. Quantification of the influence of structural parameters Xi, X2 and X3 was also possible. The relationship between lipophilicity and chiral chromatographic behavior was explained for compounds 23-30 and an extension to other alkyl substituted atropisomers was made. A related study concerning the resolution of 23-30 on various p-methylbenzoyl cellulose beads has also been published [55] but will not be described here because it employs the same methodology as above. 

The real beauty of this system is that the self-cleavage reaction can be performed on an affinity column directly after purification on cellulose beads, so that the protein of interest can be eluted directly without any attached protein affinity tags. Naturally, fusion proteins may be engineered with an intein protein affinity tag fused at either the N- or C-terminus of the protein of interest, as appropriate. 

The first report of the use of cellulose beads as support for microwave-assisted SPOS was published in 2003 and described the generation of a library of pyrazoles and isoxazoles [49]. The synthesis was performed using commercially available amino cellulose (Perloza VT-100) containing aminoaryl ethyl sulfone groups in flexible chains (Scheme 16.27). Initially, the solid support was treated with excess formyl imidazole and the corresponding yS-keto compounds to generate cellulose-bound enaminones in a one-pot Bredereck-type condensation. The reaction was catalyzed by (+)-camphor-10-sulfonic acid (CSA) and performed under microwave-irradiation conditions in an open vessel to enable the methanol formed to be removed from the reaction equilibrium [49]. 

Francotte, E. and Wolf, R.M. (1991) Benzoyl cellulose beads in the pure polymeric form as a new powerflill sorbent for the chromatographic resolution of racemates. Chirality 3, 43-55. 

Reaction with polyphenolic resins Glutaraldehyde cross-linked in cellulose beads... 

Glucoamylase immobilized with a glutaraldehyde-mediator on either phenol-formaldehyde resin or on silanized silica has been applied successfully to the saccharification of liquefied barley starch to obtain glucose syrups of up to DE 96. D-GIucose isomerase entrapped in cellulose beads and then glutaralde-... 

Rashid, H. (2001). Centrifugal granulating process for preparing drug-layered pellets based on microcrystalline cellulose beads. PhD Dissertation, University of Helsinki, Helsinki, Finland. 

Luo XG, Zhang LN (2009) High effective adsorption of organic dyes on magnetic cellulose beads entrapping activated carbon. J Hazard Mater 171 340-347... 

Cellulose beads are spherical particles with diameters in the micrometer to millimeter scale, which are used in chromatography, solid-supported synthesis, protein immobilization, drug release, and so forth. In principle, bead production can be simplified into two procedures dropping and dispersion. Gericke has reported a method of preparing beads by dropping... 

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