Automated analysis of synthesized oligorutin and oligoesculin by laccase

The polymerization of phenolic species is an interesting way to generate derivatives with new or improved properties. The structural analysis of these compounds is complex and requires specific analytical techniques. The size exclusion chromatography coupled with an UV detector (SEC-UV) and matrix-assisted laser desorption ionization coupled with a time-of-flight detector (MALDI-TOF) analyses are two methods used to investigate the masses of biopolymers. To analyse the oligomers of rutin and esculin synthesized by the laccase from Trametes versicolor, these two techniques were used and coupled with an automated platform. The conditions of detection by MALDI-TOF were optimized. The parallel synthesis, the preparation of sample, the SEC analysis, and the MALDI spotting were realized automatically on a Chemspeed platform. The MALDI-TOF technique enables the detection of oligomers up to pentamer and nonamer, whereas the SEC-UV permits the detection of about 17-mer for rutin and esculin. The molecular mass distribution is underestimated by MALDI-TOF analysis compared with SEC-UV, but comes to the determination of absolute masses. So these two techniques would be combined to explore the masses and the oligomer distributions.