FluoroFlash Silica Gel for Fluorous Separations
June 2010 Fluorous Technical Newsletter
CEOverture
There are two important elements to fluorous separations: the fluorous tagged molecules and the fluorous media used to separate those molecules from non-fluorous molecules. Initially the fluorous media was a fluorous liquid phase, typically a perfluorocarbon solvent. In the late 90′s, fluorous modified silica gel was developed within the labs of Prof. Dennis Curran at the University of Pittsburgh and found to be a highly effective solid phase medium for fluorous separations. Over the last decade, fluorous silica gel has been used in several forms and formats in both preparative and analytical applications. Fluorous Technologies Inc. is uniquely equipped to provide both fluorous tags and fluorous separation media as well as the intellectual property rights required to use them in a fluorous separation. This issue of the Fluorous Technical Newsletter highlights the various forms of our FluoroFlash® brand of fluorous silica gel and their application to provide fast and simple purification of complex mixtures.
Cheers,
Philip E. Yeske
President & CEO
Fluorous Technologies Inc.
FluoroFlash® Silica Gel Grades and Standard Formats
Our FluoroFlash® silica gel is available in three forms:
- 5 micron spherical form used primarily for HPLC and analytical applications
- 40 micron aspherical form used for fluorous solid phase extraction (FSPE) applications
- 125 micron aspherical form used for multi-well plate FSPE applications
Each grade of FluoroFlash® silica gel has been developed for superior performance.
Our standard FluoroFlash® sorbent formats include FSPE cartridges, multi-well FSPE plates, F-HPLC columns, NuTip pipette tips, TLC plates, and loose bulk silica gel. We can also provide custom packing into other formats to fit your needs.
Analytical Applications Using FluoroFlash® Silica Gel
Fluorous Enrichment
There are two principle ways that fluorous silica gel is used in analytical applications. The first is in the enrichment of targeted molecular classes from complex biological samples. The enriched samples can then be analyzed by standard techniques such as MS. Cysteinyl peptides in a tryptic digest, for example, can be fluorous tagged and the sample enriched for those tagged peptides. Fluorous enrichment can be conducted either off-line or on-line. For off-line enrichment, we offer pipette tip formatted fluorous silica gel and FSPE cartridges. And for on-line enrichment, try using our micro-LC trap cartridges. Each of these formats is available in several sizes to match your sample size. An excellent example of sample enrichment was recently published by Prof. Steven Levery of the University of Copenhagen who used FluoroFlash® tags and FSPE cartridges for analysis of glycosphingolipids enriched from a crude ganglioside mixture extracted from bovine brain tissue.
Fluorous Reaction Monitoring and Method Development
The second main analytical application is to monitor reactions or assist in FSPE method development for preparative fluorous separations. While most applications require little or no method development, there are times when using shorter fluorous tags or larger biomolecules that some development may be necessary. The primary methods to do this are F-HPLC and F-TLC. Using either approach allows fast monitoring of reactions or evaluation of various fluorophobic and fluorophilic wash conditions to achieve the desired separation. We provide analytical HPLC columns in standard 4.6mm diameter in 50 and 150 mm lengths. Alternatively, you can use F-TLC plates to develop preparative methods. Spot, elute, and visualize just like normal silica TLC plates. Prof. Kenichi Hatanaka used FluoroFlash® F-TLC plates to separate two fluorous tagged compounds that were not separable using standard TLC.
Preparative Applications using FluoroFlash® Silica Gel
Fluorous Solid Phase Extraction (FPSE)
Fluorous silica gel has been used in the preparation of small molecules, peptides, and carbohydrates from milligrams to hundreds of grams in quantity. Most commonly this has been in the form of FSPE cartridges used to easily and quickly separate fluorous tagged molecules from non-tagged by-products. FSPE is highly reproducible and easily scalable. Our FluoroFlash® FSPE cartridges are pre-packed with 40 micron fluorous silica gel and are available in sizes ranging from 2 to 20 grams. FSPE’s using these cartridges are usually performed using standard SPE apparatus.
For compound library applications which require higher throughput we also offer 48 and 96 well plate formats which are available with either the 40 micron or the 125 micron fluorous silica gel. The larger particle size makes gravity FSPE practical while the smaller particle size is usually used with either positive or negative pressure being applied.
Preparative Fluorous HPLC
We also offer preparative scale F-HPLC columns up to 20 x 250 mm size. Preparative F-HPLC is used for fluorous mixture synthesis (FMS) where reactions are simultaneously run on molecules tagged with differing fluorous chain lengths. The final compounds are then demixed based on chain length by F-HPLC. The Winssinger group has recently used FMS in the preparation of a library of natural product analogs of radicicol A. As shown below by utilizing a mixture synthesis approach the researchers prepared 27 individual compounds in 72 reactions. Using traditional approaches it would have taken 202 reactions! In addition, the researchers used a fluorous Mitsunobu reaction for the subsequent macrolactonization of each of these compounds (not shown). The macrocycles were purified using FSPE. All of this using FluoroFlash® products.
Use FluoroFlash® Silica Gel in your Fluorous Separations
FluoroFlash® silica gel has proven to be a powerful and versatile fluorous separation medium applicable to a wide range of molecules, scales, and formats. As the world’s only company solely dedicated to fluorous chemistry, Fluorous Technologies provides FluoroFlash® silica gel in an array of forms and formats. In addition, we can provide you with the guidance and expertise needed to effectively apply these materials. Please contact us and you too can enjoy the advantages of using FluoroFlash® silica gel for fluorous separations.
The Fine Print
Fluorous Technologies is a chemical technology company devoted to the development and commercialization of fluorous products for the life science market. The company uses its patented technology to solve synthesis and separation problems spanning the entire drug discovery and development process. Fluorous chemistry enhances a wide range of applications, including medicinal chemistry, combinatorial chemistry, catalysis, biomolecule production, and proteomics. For more information, please visit: http://fluorous.com
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Fluorous Technologies Inc. is located at 970 William Pitt Way, Pittsburgh, PA 15238 USA.
FluoroFlash® is a registered trademark of Fluorous Technologies Inc.