Forskning

April 27, 2017

Identification of a phosphodiesterase inhibiting fraction from roasted coffee (Coffea arabica) through activity-guided fractionation

T Rohrig et al (includes Elke Richling), 2017, Identification of a phosphodiesterase inhibiting fraction from roasted coffee (Coffea arabica) through activity-guided fractionation, Journal of Agricultural and Food Chemistry, published online

ABSTRACT:

Recent reports that coffee can significantly inhibit cAMP phosphodiesterases (PDE) in vitro, as well as in vivo, have added another beneficial effect of coffee consumption. However, the PDE-inhibiting substances remain mostly unknown. We chose activity-guided fractionation and an in vitro test system to identify the coffee components responsible for PDE inhibition. This approach indicated that a fraction of melanoidins reveals strong PDE inhibiting potential (IC50 = 130 ± 42 µg/mL). These melanoidins were characterized as water soluble, low molecular weight melanoidins (< 3kDa) with a nitrogen content of 4.2% and a lower carbohydrate content in contrast to other melanoidins. Fractions containing known PDE inhibitors such as chlorogenic acids, alkylpyrazines, or trigonelline as well as N-caffeoyl-tryptophan and N-p-coumaroyl-tryptophan did not exert PDE inhibiting activity. We also observed that the known PDE inhibitor caffeine does not contribute to the PDE-inhibiting effects of coffee.