Scientists identify most bitter substance ever known
Researchers at the Leibniz Institute for Food Systems Biology in Germany extracted three compounds from Amaropostia stiptica mushroom and studied their effect on human taste receptors.
They found the chemicals to be the most bitter substances known to man, expanding our knowledge of natural bitter compounds and their effects on the tongue.
Thousands of different chemical molecules are known to be bitter, mainly sourced from flowering plants or synthetic sources. But, scientists say, bitter compounds from animal, bacterial or fungal origins remain less studied.
Expanding our understanding of such compounds, they say, may unravel the mystery of how the perception of bitterness evolved in humans.
Bitter taste receptors are thought to have evolved to warn human beings against consuming potentially harmful substances.
Not all bitter compounds are toxic or harmful, though, and not every toxic substance – like the death cap mushroom – tastes bitter.
Previous studies have indicated that sensors for bitter substances are not only found in the mouth but also in the stomach, intestines, heart and lungs.
Since these organs are not involved in helping us "taste", the physiological significance of these sensors remains a mystery.
This is where their comprehensive collection of data on bitter compounds helps, the Leibniz Institute researchers say. 'The more well-founded data we have on the various bitter compound classes, taste receptor types and variants, the better we can develop predictive models to identify new bitter compounds and predict bitter taste receptor-mediated effects,' Maik Behrens, co-author of the study, says. 'Our results contribute to expanding our knowledge of the molecular diversity and mode of action of natural bitter compounds'.
In the latest study, scientists assessed the non-toxic bitter bracket mushroom, which tastes 'extremely bitter'. They extracted and examined three previously unknown compounds from the mushroom and determined their chemical structures.
Using lab-grown cell models, the researchers showed these chemicals were involved in activating at least one of the approximately 25 human bitter taste sensor types in the body.
One compound discovered during the study, oligoporin D, stimulated the bitter taste receptor on the tongue, called TAS2R46, even at the lowest concentrations.
Just a gram of oligoporin D dissolved in as much as '106 bathtubs of water' was found to be bitter.
'Oligoporin D activated TAS2R46 already at a submicromolar concentration and thus belongs to the family of most potent bitter agonists,' researchers note in the study.
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Forbes
08-08-2025
- Forbes
Why Do Treehoppers Have Such Bizarro Body Shapes?
Treehoppers detect electrical fields emitted by their predators and may also distinguish between electrical fields emitted by their predators and friendly insects. Treehoppers are small, gentle insects that are famous for their astonishing morphological diversity – there's about 3,200 species of treehoppers in over 400 genera and they vary tremendously in shape and include bizarre features such as horns, spines, balls and tridents (Figure 1). But what is the function of their extraordinary body shapes? Could it be for camouflage, mimicry, or perhaps for physical defense? These are interesting ideas, but such explanations don't make sense for the entire family of treehoppers. Based on the recent discovery that bumblebees and their flowers communicate using static electricity (ref), the authors of that study followed up by asking whether the distinctive body shapes of treehoppers might help them detect static electricity, too. 'If we can link treehopper shapes to certain aspects of their electrical ecology, like specific predators which approach from certain angles with particular static charges, this would really begin to strongly support our ideas around static electricity as an evolutionary driver,' lead author, ecological physicist Sam England, said. Dr England is currently a postdoctoral fellow at the Museum für Naturkunde–Leibniz Institute for Evolution and Biodiversity Science, but this particular study was part of the requirements for the PhD at the University of Bristol. Dr England and collaborators investigated this phenomenon by using a picoammeter to measure treehopper static electricity (Figure 2A). They found that these insects retreat from electrical fields. Dr England and collaborators then found that predatory wasps emit electrical fields (Figure 2B,C,D,E) that are significantly different in both magnitude and polarity from those emitted by friendly stingless bees that often protect treehoppers from their predators. This difference in electrical charge suggests that treehoppers may use electroreception to distinguish between friends and foes, and thus provides a powerful evolutionary reason for treehoppers to have sensitive electroreception capabilities. Dr England and collaborators then used computational methods to demonstrate that the extreme body shapes of treehoppers enhance the electric field strength around the treehopper, and this likely increases their sensitivity to static electricity, thereby providing a powerful reason for them to evolve and maintain their weird body shapes. Are all insects capable of electroreception? 'We don't know for certain how widespread this electrostatic sense is, but given the diversity of animals already shown to have it, plus the breadth of ecological functions they use it for, we feel quite strongly that this sense may be very widespread, especially amongst insects and other small animals,' Dr England replied in email. If electroreception is so widespread amongst insects, why aren't they all bizarrely shaped? 'The answer is likely manyfold, but one answer is that evolution is a process dictated by chance and tradeoffs,' Dr England explained in email. For example, although many animals would probably benefit from having the acute vision of an eagle, most lineages haven't evolved the sensory adaptations necessary for such good vision because the random mutations required to start building a highly acute eye haven't occurred in their lineages, or the physiological cost of maintaining such an eye in most species is greater than the survival benefit they would gain from having better vision, making it maladaptive to have such acute vision. 'In the same ways, maybe treehoppers just happened to stumble across the original mutations that allowed them to grow these elaborate pronotums that other insects just didn't get so lucky with,' Dr England observed in email, 'or something about the electric ecology of treehoppers, like the subtle differences we observed between the charges of predators and mutalists of the treehoppers, means they especially benefit from a hyper-sensitive electroreceptive system, that justifies the costly construction of these large electroreceptive structures.' By demonstrating that the extreme morphology of treehoppers increases the strength of electric field stimuli around these animals, Dr England and collaborators suggest that the enigmatic function of their spectacular pronota is partly as an electroreceptor, and that natural selection for increased electrical sensitivity may have contributed to their diverse evolution. 'We think our study provides a really exciting launch pad for investigating static electricity as a driver of organismal morphology more generally,' Dr England said. Dr England and collaborators are planning to investigate how different treehopper morphologies could be adaptive for different electrical environments. Further, there's other insects, spiders, animals – and even plants – that also have really extreme shapes, which in many cases are currently without explanation. 'Our study provides the first evidence of the electrostatic sense potentially driving morphological evolution, but we can't prove this just yet.' Source: Sam J. England, Ryan A. Palmer, Liam J. O'Reilly, Isaac V. Chenchiah, and Daniel Robert (2025). Electroreception in treehoppers: How extreme morphologies can increase electrical sensitivity, Proceedings of the National Academy of Sciences 122(30):e2505253122 | doi:10.1073/pnas.2505253122 © Copyright by GrrlScientist | hosted by Forbes | Socials: Bluesky | CounterSocial | LinkedIn | Mastodon Science | Spoutible | SubStack | Threads | Tumblr | Twitter
Scientific American
08-08-2025
- Scientific American
This Mushroom's Incredibly Bitter Taste Is New to Science
Ever bite into something so bitter that you had to spit it out? An ages-old genetic mutation helps you and other animals perceive bitterness and thus avoid toxins associated with it. But while most creatures instinctively spit first and ask questions later, molecular biologists have been trying to get a taste of what bitterness can tell us about sensory evolution and human physiology. A new study, published in the Journal of Agricultural and Food Chemistry, is the first analysis of how taste receptors respond to a mushroom's bitter compounds—which include some of the most potently bitter flavors currently known to science. The bitter bracket mushroom is nontoxic but considered inedible because of its taste. Researchers extracted its bitter compounds, finding two familiar ones—and three that were previously unknown. Instead of tasting these substances themselves, the scientists introduced them to an 'artificial tongue' that they made by inserting human taste receptors into fast-growing embryonic kidney cells. One of the newfound bitter substances activated the taste receptors even at the lowest concentration measured, 63.3 micrograms per liter. That's like sensing three quarters of a cup of sugar in an Olympic-sized swimming pool. Humans have about 25 kinds of bitter taste receptors lining our mouths and throats, but these same receptors also grow throughout the body —in the lungs, digestive tract and even brain. Despite their ubiquity, they have been only partially explored. Four of our bitter receptors have no known natural activator. Finding activating compounds could illuminate the interactions that might have shaped those taste receptors' evolution, says study lead author Maik Behrens, a molecular biologist at the Leibniz Institute for Food Systems Biology. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. Previous research focused on bitter compounds from flowering plants, which evolved well after animals gained bitter taste receptors. Behrens thought that mushrooms, being older, might even activate one of the four mystery receptors. The bitter bracket mushroom didn't, but Behrens plans to keep looking—especially since this first chemical analysis of mushroom bitterness has already yielded previously unknown compounds. Such research can also unlock information about taste receptors' many functions in the human body. 'Taste in your mouth does so much more than just perception,' explains University of Miami physiologist Nirupa Chaudhari, who was not involved in the study. Taste can trigger physiological reflexes such as insulin release and stomach acid production, she says, so knowing what activates bitter taste receptors could improve our understanding of bodily processes and disease. Chaudhari considers the new study a good first step toward expanding bitter taste research. With the first analysis complete, researchers are now setting their sights on other mushrooms' bitter secrets—compounds and activated receptors you can't uncover by 'simply chewing on a mushroom,' Behrens says. It's Time to Stand Up for Science Before you close the page, we need to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and we think right now is the most critical moment in that two-century history. We're not asking for charity. If you become a Digital, Print or Unlimited subscriber to Scientific American, you can help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both future and working scientists at a time when the value of science itself often goes unrecognized.
Yahoo
13-04-2025
- Yahoo
Scientists identify most bitter substance ever known
Food scientists have discovered a mushroom chemical they say is the most bitter substance known thus far, a finding that sheds light on how the tongue helps us perceive taste. Researchers at the Leibniz Institute for Food Systems Biology in Germany extracted three compounds from Amaropostia stiptica mushroom and studied their effect on human taste receptors. They found the chemicals to be the most bitter substances known to man, expanding our knowledge of natural bitter compounds and their effects on the tongue. Thousands of different chemical molecules are known to be bitter, mainly sourced from flowering plants or synthetic sources. But, scientists say, bitter compounds from animal, bacterial or fungal origins remain less studied. Expanding our understanding of such compounds, they say, may unravel the mystery of how the perception of bitterness evolved in humans. Bitter taste receptors are thought to have evolved to warn human beings against consuming potentially harmful substances. Not all bitter compounds are toxic or harmful, though, and not every toxic substance – like the death cap mushroom – tastes bitter. Previous studies have indicated that sensors for bitter substances are not only found in the mouth but also in the stomach, intestines, heart and lungs. Since these organs are not involved in helping us "taste", the physiological significance of these sensors remains a mystery. This is where their comprehensive collection of data on bitter compounds helps, the Leibniz Institute researchers say. 'The more well-founded data we have on the various bitter compound classes, taste receptor types and variants, the better we can develop predictive models to identify new bitter compounds and predict bitter taste receptor-mediated effects,' Maik Behrens, co-author of the study, says. 'Our results contribute to expanding our knowledge of the molecular diversity and mode of action of natural bitter compounds'. In the latest study, scientists assessed the non-toxic bitter bracket mushroom, which tastes 'extremely bitter'. They extracted and examined three previously unknown compounds from the mushroom and determined their chemical structures. Using lab-grown cell models, the researchers showed these chemicals were involved in activating at least one of the approximately 25 human bitter taste sensor types in the body. One compound discovered during the study, oligoporin D, stimulated the bitter taste receptor on the tongue, called TAS2R46, even at the lowest concentrations. Just a gram of oligoporin D dissolved in as much as '106 bathtubs of water' was found to be bitter. 'Oligoporin D activated TAS2R46 already at a submicromolar concentration and thus belongs to the family of most potent bitter agonists,' researchers note in the study.
