Milla Leppä

PhD thesis topic

The effects of variable tannin fingerprints on the bioactivity of promising legume crops: mechanistic studies via method developments in chemistry

Main aims

(1) To create two new separation methods for complex proanthocyanidin (PA) structures and thus gain completely novel data about chemical structures of these compounds by high resolution MS and MS/MS.

(2) To better understand the linkage between PA stuctures and their chemical properties and bioactivities and even develop an updated method for measuring their protein precipitation activity.

(3) To investigate the exact PA fingerprints of at least 100 legume crops by our unique UPLC-MS/MS tool.

(4) To study how the PA fingerprint of faba bean (Vicia faba) is affected by agricultural practices.

Motivation

Previous studies have shown that by using tannin-rich forage legumes, it is possible to significantly decrease the methane emissions of ruminants. At the same time by careful selection of tannins, it is possible to combat nematode infections as well and even achieve other benefits such as better meat and milk quality. However, legumes differ dramatically in both their tannin concentration and composition. Thus the optimal tannin profile needed to achieve the best bioactivities is not yet known. By combining the data obtained from high resolution and tandem MS with bioactivity measurements, I have the opportunity to increase the fundamental knowledge of PA structure‒bioactivity relationships. All this is insanely cool 🙂

Results so far

The PA fingerprints of selected plant species have been extracted and separated by a novel chromatography tool, and analysed by high-resolution MS and MS/MS. At the moment the results are being interpreted and written for my 1st manuscript. Method developments for the second purification tool and for the new protein precipitation activity tool are currently under way.