Some specific molecules contained in the roasted Arabica coffee blend may have antidiabetic effects. This is what a group of Chinese researchers from the University of Chinese Academy of Sciences in Beijing found, publishing their work in Beverage Plant Research. This potential, along with other characteristics, would qualify coffee as a possible functional food.
New Compounds
They have been named cafaldehydes A, B, and C: these are three new diterpenoid esters of coffee detected in the roasted beans of the Arabica blend, associated with a hypoglycemic action, i.e., a significant inhibitory activity on alpha-glucosidase, with IC50 values higher than the positive control, acarbose.
This discovery was made possible by the use of advanced technologies, such as Nuclear Magnetic Resonance (NMR), High-Performance Liquid Chromatography–Solid-Phase Extraction–NMR Spectroscopy (HPLC-SPE-NMR), Liquid Chromatography–Mass Spectrometry with multiple stages (LC-MSn) and High-Performance Liquid Chromatography coupled to multistage Mass Spectrometry (MSn).
These techniques allow the detection of biological activity or metabolomic analysis in a relatively faster way than analyzing the various compounds present in a food. Regarding coffee, diterpenoids are key characteristic components, present in varying amounts depending on the blends and quality, mostly in the form of diterpenoid esters. Although these latter are built from 24-carbon chains, the diterpenoid esters of linoleic acid and palmitic acid are present in greater amounts. To date, more than 70 types of coffee diterpenes have been documented.
Coffee, a Functional Food?
Hypothetically, yes. Functional foods, meaning whole foods, enriched or fortified, in addition to basic nutrition and essential nutrients, offer additional health benefits linked to bioactive ingredients with specific properties, such as antioxidants, neuroprotective, hypoglycemic, and hypolipidemic effects. These bioactive substances can occur naturally, intrinsic to the food—for instance, in berries or in coffee’s kahweol and cafestol oils, diterpenes that influence the body and bitterness of the beverage, to which antitumor and hypoglycemic effects have been attributed—or in modified ingredients such as probiotics.
Because roasted coffee beans form an extremely complex mixture, research is actively pursuing the identification of additional active coffee diterpenes, using techniques or approaches based on LC-MS/MS molecular networking, for example pairing NMR with LC-MS/MS, which can be useful both for detecting bioactive compounds and for evaluating their activity.
The structure of the new bioactive diterpenes in the current study was characterized using spectroscopic analysis with the aim of minimizing chromatographic separation where possible, and consequently reducing solvents and consumables to make the process more eco-friendly and efficient. In particular, the use of silica gel column chromatography enabled the roasted coffee diterpenoid extract to be divided into 19 fractions, and subsequent analyses detected α-glucosidase-inhibitory activity in certain samples, with higher or lower levels depending on the presence of other elements, such as aldehyde groups, saturated fats, carbon atoms, oxidation-related methyl groups, and so on. Cross-referencing the data obtained from this initial analysis of subfractions with other techniques made it possible to identify three additional new trace coffee diterpenoid esters: magaric acid, octadecenoic acid, and nonadecanoic acid, with potential inhibitory activity on α-glucosidase.
Conclusion
Technology has enabled the discovery in the crude extract of the Arabica blend of three new diterpenoid ester compounds, cafaldehydes A, B, and C, with IC50 values higher than acarbose. Additionally, three more new coffee diterpenoid esters with similar activity were identified using an LC-MS/MS-based molecular network. The method proposed in this study could be applied to separate targeted active metabolites from other foods in future research, while reducing solvent use and research time.
Source
Hu G, Quan C, Al-Romaima A et al. Bioactive oriented discovery of diterpenoids in Coffea arabica based on 1D NMR and LC-MS/MS molecular networking. Beverage Plant Research, 2025, 5: e004. Doi:https://www.maxapress.com/article/doi/10.48130/bpr-0024-0035
Abbonati a Karla Miller
