Hokkaido Research Organization

Hokkaido University researchers have identified new lipids in some herbal teas in detail for the first time, preparing the ground for investigating their contribution to the health benefits of the teas. SAPPORO, Japan, April 3, 2024 /PRNewswire/ -- Herbal teas are enjoyed worldwide, not only for their taste and refreshment but also for a wide range of reputed health benefits. But the potential significance of a category of compounds called lipids in the teas has been relatively unexplored. Researchers at Hokkaido University, led by Associate Professor Siddabasave Gowda and Professor Shu-Ping Hui of the Faculty of Health Sciences, have now identified 341 different molecular species from five categories of lipids in samples of four types of herbal tea. They published their results in the journal Food Chemistry. Continue Reading The four types of herbal tea investigated in this study for their bioactive lipids. (Photo provided by Siddabasave Gowda) Lipids are a diverse collection of natural substances that share the property of being insoluble in water. They include all of the fats and oils that are common constituents of many foods, but they have generally not been examined as significant components of teas. The Hokkaido team selected four teas for their initial analysis: dokudami (Houttuynia cordata, fish mint), kumazasa (Sasa veitchii), sugina (Equisetum arvense, common horsetail) and yomogi (Artemisia princeps, Japanese mugwort). "These herbs are native to Japan and have been widely consumed as tea from ancient times due to their medicinal properties," says Gowda. The medicinal benefits attributed to these and other herbal teas include antioxidant, antiglycation, anti-inflammatory, antibacterial, antiviral, anti-allergic, anticarcinogenic, antithrombotic, vasodilatory, antimutagenic, and anti-aging effects. The lipids in the teas were separated and identified by combining two modern analytical techniques called high-performance liquid chromatography and linear ion trap-Orbitrap mass spectrometry. The analysis revealed significant variations in the lipids in the four types of tea, with each type containing some known bioactive lipids. These included a distinct category of lipids called short-chain fatty acid esters of hydroxy fatty acids (SFAHFAs), some of which had never previously been found in plants. SFAHFAs detected in tea could be a novel source of short-chain fatty acids, which are essential metabolites for maintaining gut health. "The discovery of these novel SFAHFAs opens new avenues for research," says Hui, adding that the lipid concentrations found in the teas are at levels that could be expected to have significant nutritional and medical effects in consumers. The lipids discovered also included α-linolenic acid, already known for its anti-inflammatory properties, and arachidonic acid which has been associated with a variety of health benefits. These two compounds are examples of a range of poly-unsaturated fatty acids found in the teas, a category of lipids that are well-known for their nutritional benefits. "Our initial study paves the way for further exploration of the role of lipids in herbal teas and their broad implications for human health and nutrition," Gowda concludes. "We now want to expand our research to characterize the lipids in more than 40 types of herbal tea in the near future." Contacts: Associate Professor Siddabasave Gowda Faculty of Health Sciences Graduate School of Global Food Resources Hokkaido University Tel: +81-11-706-3687 Email: [email protected] Professor Shu-Ping Hui Faculty of Health Sciences Hokkaido University Tel: +81-11-706-3693 Email: [email protected] Sohail Keegan Pinto (International Public Relations Specialist) Public Relations & Communications Division Office of Public Relations and Social Collaboration Hokkaido University Tel: +81-11-706-2186 Email: [email protected] Paper : Lipsa Rani Nath, et al. Dissecting new lipids and their composition in herbal tea using untargeted LC/MS. Food Chemistry. March 4, 2024 DOI: 10.1016/j.foodchem.2024.138941 Funding: This study was supported by the Japan Society for the Promotion of Science (JSPS; 22K1485002, 21H02376, 21K1481201); and the Japan Science and Technology Agency (JST) SPRING (JPMJSP2119). Press release on Hokkaido University website: Photo: SOURCE Hokkaido University

Cellulose, abundantly available from plant biomass, can be converted into molecules used to make a new class of recyclable polymers, to sustainably replace some plastics. Cellulose, abundantly available from plant biomass, can be converted into molecules used to make a new class of recyclable polymers, to sustainably replace some plastics. Researchers at Hokkaido University have taken a significant step forward in the drive to make recyclable yet stable plastics from plant materials. This is a key requirement to reduce the burden of plastic pollution in the environment. They developed a convenient and versatile method to make a variety of polymers from chemicals derived from plant cellulose; crucially, these polymers can be fully recycled. The method was published in the journal ACS Macro Letters. Cellulose is one of the most abundant components of biomass derived from plants, being a key part of the tough cell walls surrounding all plant cells. It can be readily obtained from plant wastes, such as straw and sawdust, therefore, using it as a feedstock for polymer manufacture should not reduce the availability of agricultural land for food production. Cellulose is a long-chain polysaccharide polymer, meaning that it is composed of multiple sugar groups, specifically glucose, linked together by chemical bonds. To make their new polymers, the Hokkaido team used two commercially available small molecules, levoglucosenone (LGO) and dihydrolevoglucosenone (Cyrene), which are made from cellulose. They developed novel chemical processes to convert LGO and Cyrene into a variety of unnatural polysaccharide polymers. Varying the precise chemical structure of the polymers offers the ability to generate different materials for a range of possible applications. "Our biggest challenges were controlling the polymerization reaction that links the smaller monomer molecules together, and obtaining polysaccharides materials that are sufficiently stable for common applications while still able to be broken up and recycled by specific chemical conditions," says Assistant Professor Feng Li, a corresponding author. Li adds that the biggest surprise during the research was the high transparency of the polymer films they made, which might be crucial for the kind of specialist applications that these polymers seem most suited for. "As the materials are quite rigid it may be difficult to use them as flexible plastic materials, such as plastic bags, so I expect they will be more suited for high performance materials for optical, electronic, and biomedical applications," Professor Toshifumi Satoh, the other corresponding author, adds. Other research groups around the world are also exploring the potential for making plastic-replacing polymers from plants, and some such 'bioplastics' are already commercially available, but Satoh's group have added a significant new opportunity to this fast-developing field. The team now plan to explore further possibilities, but the feasible structural variations are so numerous that they would like to join forces with specialists in computational chemistry, artificial intelligence and automated synthesis to explore the options. "We hope this work will develop a wide variety of useful unnatural polysaccharide polymers to become part of a sustainable closed loop of synthesis from biomass with efficient recycling," Li concludes.

Molecules that are induced by light to rotate bulky groups around central bonds could be developed into photo-activated bioactive systems, molecular switches, and more. Molecules that are induced by light to rotate bulky groups around central bonds could be developed into photo-activated bioactive systems, molecular switches, and more. Researchers at Hokkaido University, led by Assistant Professor Akira Katsuyama and Professor Satoshi Ichikawa at the Faculty of Pharmaceutical Sciences, have extended the toolkit of synthetic chemistry by making a new category of molecules that can be induced to undergo an internal rotation on interaction with light. Similar processes are believed to be important in some natural biological systems. Synthetic versions might be exploited to perform photochemical switching functions in molecular computing and sensing technologies, or in bioactive molecules including drugs. They report their findings in Nature Chemistry. "Achieving a system like ours has been a significant challenge in photochemistry," says Katsuyama. "The work makes an important contribution to an emerging field in molecular manipulation." Insights into the possibilities for light to significantly alter molecular conformations have come from examining some natural proteins. These include the rhodopsin molecules in the retina of the eye, which play a crucial role in converting light into the electrical signals that create our sense of vision in the brain. Details are emerging of how the absorption of light energy can induce a twisting rearrangement of part of the rhodopsin molecule, required for it to perform its biological function. "Mimicking this in synthetic systems might create molecular-level switches with a variety of potential applications," Katsuyama explains. A key innovation by the Hokkaido team was to achieve photo-induced (i.e., light-driven) rotation of molecular groups around a series of chemical bonds that incorporate a nitrogen atom together with other bonded carbon atoms. The rotational properties were enabled by adding molecular components that contained an atom from the 'chalcogen' group of elements in the periodic table, specifically sulfur or selenium, to a simple organic molecule: an amide compound. This brought a new level of control and versatility to synthetic photo-induced rotational systems. Some of the chemical groups that rotate around the central bonds were relatively large, based on rings of six bonded carbon atoms. This facilitated the large-scale molecular changes that might be required for practical use in molecular switching systems. In addition to demonstrating the photo-induced changes, the team also performed theoretical calculations that gave insights into the likely mechanisms by which the rearrangements proceeded. The team also explored the effects of temperature on the transformations. The combination of theoretical and experimental work should help guide future research towards exploring and controlling modifications to the systems already achieved. "Our next research priority is focused on the potential of our methods for making new bioactive molecules activated by light. These could be applied in biological research or possibly developed as drugs," Ichikawa concludes. Using light to activate the conformational changes allows control over where and when the changes occur. This could be vital for precisely targeted applications in biological systems, including eventual therapeutic possibilities.