When it comes to polar organic compound purification, many chemists turn to normal-phase flash chromatography often utilizing dichloromethane and methanol as the eluting solvents. While this can work, it often can be challenging to optimize due to methanol’s high polarity and protic chemistry.
Improvements in solid phase peptide synthesis strategies and development of resin linkages susceptible to low acid cleavage conditions has enabled synthesis of long peptides while keeping the protecting groups intact. This strategy is now used for the preparation of chemically synthesized proteins, wherein shorter peptide fragments are ligated together. They are also found in the synthesis of peptide macrocycles that utilize head-to-tail cyclization strategies. Although linear synthesis of protected peptides is generally straightforward, purification of these compounds using traditional reversed phase methods is quite challenging. Herein we describe the use of normal phase chromatography for purification of fully protected peptides.
This brochure presents the extensive range of instrumentation for flash purification from Biotage. To complement these products Biotage also offers a complete range of flash consumables, including columns in a variety of sizes packed with irregular and spherical silica, making Biotage your one-stop partner for your flash purification needs. Keywords: Isolera™ Dalton, Isolera™ Spektra, 10 Isolera™ Spektra One and Four, Isolera™ Spektra LS (Large Scale), Isolera™ Prime, Isolera™ ELSD-1080, Biotage® Flash 75/150, Biotage® Flash 400
As reversed-phase flash chromatography gains traction in medicinal chemistry labs the need to monitor its cost and safety are becoming more important. Commonly used reversed-phase solvents typically include water with an organic solvent such as methanol or acetonitrile – each have advantages and disadvantages.
Reversed-phase chromatography is typically used when you need to separate several milligrams of relatively polar compounds that either are not soluble in normal-phase solvents or are not compatible with bare silica because they react, stick, or both. If you are currently using reversed-phase at preparative scale, such as flash chromatography, you know the mobile phase limitations – water with either methanol, acetonitrile, or THF. As with normal-phase flash chromatography, when it comes time to purify you want your crude sample fully solubilized in the weakest possible solvent at the highest possible concentration. ACS 2016
Although capable of very high resolution, RP-HPLC is often limited by low column loading capacity, therefore demanding a significant time investment for peptide purification. As an alternative strategy, reversed-phase flash chromatography can also be used to purify synthetic peptides. The larger particle size used in flash column chromatography enables much larger loading capacity, thereby significantly reducing the time required for peptide purification.
The Isolera leak detection system is designed with safety in mind. Unlike vapor sensing devices with unreliable solvent vapor sensitivity, the Isolera leak detector’s sensitive, solvent-resistant refractive index (RI) monitor rapidly signals the Isolera flash system to stop pumping if any liquid, volatile or non-volatile, is detected thus protecting the chemist, system, and lab from potential hazards.