TY - CONF

T1 - Semi-automated microwave assisted solid-phase peptide synthesis

AU - Pedersen, Søren Ljungberg

PY - 2008

Y1 - 2008

N2 - Despite the development of new coupling reagents and solid supports, SPPS is still often faced with difficulties in the assembly of long or ‘difficult' sequences, e.g. due to aggregation and steric hindrance giving rise to incomplete reactions. The use of convenient and precise heating with microwaves for SPPS has gained in popularity as it for many syntheses has provided significant improvement in terms of speed, purity, and yields, maybe especially in the synthesis of long and "difficult" peptides. Thus, precise microwave heating has emerged as one new parameter for SPPS, in addition to coupling reagents, resins, solvents etc. We have previously reported on microwave heating to promote a range of solid-phase reactions in SPPS.Here we present a new, flexible semi-automated instrument for the application of precise microwave heating in solid-phase synthesis. It combines a slightly modified Biotage Initiator microwave instrument, which is available in many laboratories, with a modified semi-automated peptide synthesizer from MultiSynTech. A custom-made reaction vessel is placed permanently in the microwave oven, thus the reactor does not have to be moved between steps. Mixing is achieved by nitrogen bubling. Washing steps are automated, however the activated amino acid derivatives have to be added manually.First, we developed optimized protocols for short cycle times in semi-automated SPPS with general Fmoc chemistry. We utilized a microwave-compatible temperature probe for exact temperature measurements during microwave heating. Then we developed protocols for on-resin reductive amination for anchoring of the first amino acids to a BAL handle. Finally, we used the new instrument and the optimized protocols to assist in the synthesis of a range of difficult and long sequences. We believe that these successful syntheses demonstrate that this semi-automated instrument and the methods developed for it, can be an efficient starting point for SPPS with microwave heating.

AB - Despite the development of new coupling reagents and solid supports, SPPS is still often faced with difficulties in the assembly of long or ‘difficult' sequences, e.g. due to aggregation and steric hindrance giving rise to incomplete reactions. The use of convenient and precise heating with microwaves for SPPS has gained in popularity as it for many syntheses has provided significant improvement in terms of speed, purity, and yields, maybe especially in the synthesis of long and "difficult" peptides. Thus, precise microwave heating has emerged as one new parameter for SPPS, in addition to coupling reagents, resins, solvents etc. We have previously reported on microwave heating to promote a range of solid-phase reactions in SPPS.Here we present a new, flexible semi-automated instrument for the application of precise microwave heating in solid-phase synthesis. It combines a slightly modified Biotage Initiator microwave instrument, which is available in many laboratories, with a modified semi-automated peptide synthesizer from MultiSynTech. A custom-made reaction vessel is placed permanently in the microwave oven, thus the reactor does not have to be moved between steps. Mixing is achieved by nitrogen bubling. Washing steps are automated, however the activated amino acid derivatives have to be added manually.First, we developed optimized protocols for short cycle times in semi-automated SPPS with general Fmoc chemistry. We utilized a microwave-compatible temperature probe for exact temperature measurements during microwave heating. Then we developed protocols for on-resin reductive amination for anchoring of the first amino acids to a BAL handle. Finally, we used the new instrument and the optimized protocols to assist in the synthesis of a range of difficult and long sequences. We believe that these successful syntheses demonstrate that this semi-automated instrument and the methods developed for it, can be an efficient starting point for SPPS with microwave heating.

KW - Former LIFE faculty

KW - Peptidsyntese

KW - Mikrobølge

KW - Peptide synthesis

KW - Microwave

M3 - Poster

Y2 - 31 August 2008 through 5 September 2008

ER -