Unlocking coffee’s hidden chemistry: new diterpenes show anti-diabetic promise
Three of the compounds demonstrated significant inhibitory effects on α-glucosidase, a key enzyme in carbohydrate digestion. The findings could pave the way for new functional food ingredients targeting type 2 diabetes.
Functional foods are known not only for their nutritional value but also for delivering biologically active compounds with potential health benefits, such as antioxidant, neuroprotective, or glucose-lowering properties. Identifying these compounds from complex food matrices remains a major challenge. Traditional methods are often time-consuming and inefficient. As a result, scientists have been turning to advanced techniques like nuclear magnetic resonance (NMR) and liquid chromatography–mass spectrometry (LC-MS/MS) to speed up the discovery of bioactive molecules, especially in chemically diverse systems like roasted coffee.
A study (DOI: 10.48130/bpr-0024-0035) published in Beverage Plant Research on 18 February 2025 by Minghua Qiu’s team, Kunming Institute of Botany, Chinese Academy of Sciences, shows promising anti-diabetic potential and expands our understanding of coffee’s functional components.
In this study, researchers developed a three-step, activity-oriented strategy to efficiently identify bioactive diterpene esters in roasted Coffea arabica beans. The goal was to discover both abundant and trace-level compounds with α-glucosidase inhibitory activity, while minimizing solvent use and analysis time. The first step involved dividing the crude diterpene extract into 19 fractions via silica gel chromatography, followed by ^1H NMR and α-glucosidase activity screening. A cluster heatmap based on ^1H NMR spectral data grouped the fractions and pinpointed Fr.9–Fr.13 as the most bioactive, characterized by distinct proton signals. Next, ^13C-DEPT NMR of representative fraction Fr.9 revealed an aldehyde group, consistent with the ^1H NMR data. Fr.9 was then purified using semi-preparative HPLC, and three new diterpene esters—named caffaldehydes A, B, and C—were isolated. Structural elucidation through 1D and 2D NMR and high-resolution mass spectrometry (HRESIMS) confirmed their identities. These compounds, differing in their fatty acid chains (palmitic, stearic, and arachidic acids), showed moderate α-glucosidase inhibitory activity with IC₅₀ values of 45.07, 24.40, and 17.50 μM respectively—more potent than the control drug acarbose. To detect trace bioactives beyond the scope of NMR or HPLC, the team performed LC-MS/MS on pooled fraction groups and constructed a molecular network using GNPS and Cytoscape. This revealed three additional unknown diterpene esters (compounds 4–6) closely related to caffaldehydes A–C, sharing common fragment ions but featuring different fatty acids (magaric, octadecenoic, and nonadecanoic acids). Their absence in compound databases confirmed their novelty. Together, these findings demonstrate the effectiveness of this integrative dereplication approach in discovering structurally diverse, biologically relevant compounds in complex food matrices like roasted coffee.
This research opens the door to developing new functional food ingredients or nutraceuticals derived from coffee, targeting glucose regulation and potentially aiding in diabetes management. More broadly, the dereplication strategy introduced here—using minimal solvent and advanced spectral analysis—can be adapted for rapid screening of bioactive metabolites in other complex food matrices. Future work will explore the biological activity of the newly identified trace diterpenes and assess their safety and efficacy in vivo.
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References
DOI
Original Source URL
https://doi.org/10.48130/bpr-0024-0035
Funding information
This study was supported financially by the National Natural Science Foundation of China, China (U1902206) , Key Research and Development Project of Yunnan Province (202003AD15 0006), China Postdoctoral Science Foundation (2023M743591), Postdoctoral Fellowship Program of CPSF (GZC20232766), Special Research Assistant of Chinese Academy of Sciences, Yunnan Caiyun Postdoctoral Program, Coffee Industry Science and Technology Mission in Zhenkang County, Yunnan (202204BI090009), Project of Yunnan International Joint Innovation platform (202203AP140106), Project of Expert workstation of Yunnan Science and Technology Association (2024).
About Beverage Plant Research
Beverage Plant Research (e-ISSN 2769-2108) is the official journal of Tea Research Institute, Chinese Academy of Agricultural Sciences and China Tea Science Society. Beverage Plant Research is an open access, online-only journal published by Maximum Academic Press which publishing original research, methods, reviews, editorials, and perspectives, which advance the biology, chemistry, processing, and health functions of tea and other important beverage plants.
Journal
Beverage Plant Research
Method of Research
Experimental study
Subject of Research
Not applicable
Article Title
Bioactive oriented discovery of diterpenoids in Coffea arabica basing on 1D NMR and LC-MS/MS molecular network
Your morning coffee really does make you happier
Researchers from Bielefeld University and the University of Warwick tracked young adults’ behavior and mood in everyday life for four weeks
People who regularly consume caffeine are usually in a better mood after a cup of coffee or another caffeinated drink—an effect that is much more pronounced in the morning than later in the day. This finding comes from a new study by researchers at Bielefeld University and the University of Warwick, published in the journal Scientific Reports. Participants reported feeling significantly happier and more enthusiastic on those mornings compared with other days at the same hour when they had not yet had coffee.
Links to negative moods such as sadness and feeling upset were also observed, though these effects were less pronounced: after drinking coffee, participants felt slightly less sad or upset than on comparable days without coffee. Unlike the boost in positive emotions, this effect was not dependent on the time of day.
In total, 236 young adults in Germany were studied over a period of up to four weeks. Participants completed short questionnaires on their smartphones seven times a day, indicating their current mood and whether they had consumed a caffeinated drink in the preceding 90 minutes. Accordingly, the study focused on caffeine consumption in everyday life, not just in artificial laboratory settings.
Perceived effect regardless of consumption habits
The researchers also investigated whether coffee has different effects on different individuals. Justin Hachenberger from the Bielefeld University in Germany says, ‘We were somewhat surprised to find no differences between individuals with varying levels of caffeine consumption or differing degrees of depressive symptoms, anxiety, or sleep problems. The links between caffeine intake and positive or negative emotions were fairly consistent across all groups.’
The researchers expected that people with higher levels of anxiety would experience negative mood changes, such as increased nervousness, after consuming caffeine. However, Hachenberger emphasises that people who react to caffeine in a bad way may avoid it and that the study did not include people who completely abstain from caffeine.
Role of caffeine withdrawal symptoms remains unclear
The researchers explain the mood-boosting effect of caffeine on morning mood with its ability to block adenosine receptors, which promotes wakefulness and makes people feel more energetic. ‘Caffeine works by blocking adenosine receptors, which can increase dopamine activity in key brain regions—an effect that studies have linked to improved mood and greater alertness’, says Professor Anu Realo from the University of Warwick.
Yet, it remains unclear whether these effects are related to a reduction in withdrawal symptoms after a night’s sleep. ‘Even people with moderate caffeine consumption can experience mild withdrawal symptoms that disappear with the first cup of coffee or tea in the morning’, says Anu Realo.
Caffeine consumption: a universal habit
‘Around 80 per cent of adults worldwide consume caffeinated beverages, and the use of such stimulating substances dates far back in human history’, says Professor Sakari Lemola from Bielefeld University, the study’s senior author. ‘Even wild animals consume caffeine; bees and bumblebees prefer nectar from plants that contain caffeine.’
Still, the study authors caution that caffeine can lead to dependence. Excessive intake is linked to various health risks, and consuming it later in the day can lead to sleep problems.
Published in a highly cited journal
The journal Scientific Reports, in which the study was published, is the third most cited scientific journal in the world, according to its own information. Data provider Clarivate reports an impact factor of 3.9 (2024).
Journal
Scientific Reports
Method of Research
Observational study
Subject of Research
People
Article Title
The association of caffeine consumption with positive affect but not with negative affect changes across the day
Article Publication Date
15-Aug-2025
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