(Press-News.org)
Although present in very small amounts, selenium (Se)-based compounds play important roles in protecting the body from oxidative stress, regulating thyroid hormones, strengthening the immune system, and even detoxifying heavy metals. As we begin to understand more about the biological functions of Se, the need to detect and identify Se-containing compounds has become increasingly important.
Researchers from Chiba University, Japan, have developed a new method that selectively detects Se compounds, addressing a long-standing challenge in the identification of unknown Se-containing compounds. Using a previously unexplored approach, the researchers discovered novel Se-containing molecules in gut bacteria.
The study was led by Assistant Professor Yoshikazu Yamagishi from the Graduate School of Medicine and included Dr. Kazuaki Takahashi from the Graduate School of Horticulture, Dr. Sayaka Nagasawa from the Graduate School of Pharmaceutical Sciences, Professor Hirotaro Iwase from the Graduate School of Medicine, and Professor Yasumitsu Ogra from the Graduate School of Pharmaceutical Sciences, Chiba University, Japan. The study was made available online on September 17, 2025, and will appear in Volume 298, Part A of the journal Talanta and scheduled for publication on February 01, 2026.
The team utilized a technique known as isotope pattern screening (IPS), which involves analyzing the isotopic fingerprint patterns or characteristic cluster of peaks in the mass spectrum of an element. “Many unknown Se-containing compounds exist in nature and may have beneficial functions. Our Se-IPS method can identify these unknown compounds, which could reveal new biological roles of Se,” says Dr. Yamagishi.
The method works by identifying Se-containing compounds through their unique isotopic signature. Se naturally occurs as a mix of six stable isotopes (74Se, 76Se, 77Se, 78Se, 80Se, and 82Se), each present in well-known proportions. When these isotopes combine in a molecule, they create a distinct pattern in mass spectrometry data that acts as a molecular fingerprint, confirming the presence of Se.
Previous automated detection methods relied on only two isotopes at a time, such as 78Se-80Se or 80Se-82Se. However, these limited patterns sometimes led to false positives, since other molecules or background noise could accidentally mimic a two-isotope signal. The new method, Se-IPS, improves on this by examining multiple isotope combinations simultaneously. This greatly reduces the chance of errors and makes the detection of Se compounds much more reliable.
“By using as many combinations of isotopes as possible, a more reliable analysis can be achieved,” explains Dr. Yamagishi.
The researchers carried out their analysis using liquid chromatography quadrupole orbitrap mass spectrometry (LC-Q-Orbitrap-MS). In this technique, liquid chromatography separates the compounds in a sample, while the mass spectrometer detects the isotope signatures of Se with high precision.
Applying this approach, the team successfully detected several known Se compounds, such as seleno-L-methionine and methylselenocysteine, in samples from plants, microbes, and biological fluids. They also identified a previously unknown Se-containing molecule, N-(1-carboxyethyl)-S-(methylselanyl)cysteine (CECys-SeCH3), produced by gut microflora cultured from rat fecal samples.
“CECys-SeCH3 has not been detected in animals to our knowledge. Our analysis shows that this compound is a unique metabolite produced by bacteria and may serve as an important source of sulfur and Se for bacterial metabolism,” says Dr. Yamagishi.
By combining precise IPS analysis with advanced mass spectrometry, this new method offers a powerful and selective way to identify Se compounds. This opens the door to finding many more unknown Se molecules and could even be extended to other elements with characteristic isotope patterns, such as tellurium or zinc.
Se deficiency is known to cause several health problems, including Keshan disease, an illness first recognized in China that can lead to heart failure. By providing a way to identify Se compounds in the body, scientists can gain deeper insights into how this essential element supports human health and helps prevent disease.
To see more news from Chiba University, click here.
***
Reference
Authors: Yoshikazu Yamagishi1, Kazuaki Takahashi2, Sayaka Nagasawa1,3, Hirotaro Iwase1, and Yasumitsu Ogra1,3,4
Affiliations: 1Department of Legal Medicine, Graduate School of Medicine, Chiba University, Japan
2Graduate School of Horticulture, Chiba University, Japan
3Laboratory of Forensic Toxicology, Graduate School of Pharmaceutical Sciences, Chiba University, Japan
4Laboratory of Toxicology and Environmental Health, Graduate School of Pharmaceutical Sciences, Chiba University, Japan
DOI: 10.1016/j.talanta.2025.128869
About Assistant Professor Yoshikazu Yamagishi from Chiba University, Japan
Dr. Yoshikazu Yamagishi is an Assistant Professor at the Graduate School of Medicine, Chiba University, Japan. He earned his Ph.D. from Chiba University in 2021. His research focuses on gut bacteria, selenium and tellurium compounds, hemoglobin, and forensic toxicology, with expertise in mass spectrometry and multivariate analysis. Dr. Yamagishi has received several honors, including the 2022 Japan Society of Toxicology Encouragement Award and the Young Investigator Award from the Japanese Society of Forensic Toxicology for his work on postmortem drug metabolism and toxicological mechanisms.
Funding
This study was supported by JSPS KAKENHI, Japan (Grant Numbers 20K18978, 22K19664, and 25K02898) and a grant from the Asahi Glass Foundation, Japan.
END
A new oral GLP-1 medication can help adults with obesity and Type 2 diabetes lose more weight and improve their blood sugar levels compared to a placebo, according to findings from the ATTAIN-2 trial led by a UTHealth Houston researcher.
Obesity is a chronic health condition that can cause serious complications such as Type 2 diabetes, heart disease, high blood pressure, sleep apnea, certain cancers, and more. Current GLP-1 treatments for obesity consist of daily or weekly injectable medications that come with drawbacks, including the need for cold chain ...
A new paper outlines how scientists came together to put together the first microbial conservation roadmap under the leadership of Applied Microbiology International President, Professor Jack Gilbert.
The article, ‘Safeguarding Microbial Biodiversity: Microbial Conservation Specialist Group (MCSG) within the Species Survival Commission of the International Union for Conservation of Nature (IUCN)' is published in Sustainable Microbiology, an AMI journal.
In July 2025, IUCN formally launched the MCSG within its Species Survival Commission, co-chaired by Professor Gilbert and Raquel Peixoto (KAUST / ISME). This came out of a meeting ...
Our brain’s reward system processes and reinforces pleasurable experiences, motivating us to seek out and engage in rewarding activities ranging from eating to social interactions to recreational drug use. Dopamine plays an important role in this process, mediated by the D2 dopamine receptor (D2R). New research published today in Nature Neuroscience finds that the same mechanism that causes drug addiction (desensitization of D2R) also controls the natural devaluation of repeated behaviors (e.g. seeking out the same thrill of going on a rollercoaster for the first time). This is the first natural use found for this mechanism.
Researchers from ...
Bethesda, MD (Nov. 17, 2025) — The American Gastroenterological Association (AGA) has released a comprehensively updated clinical guideline on the pharmacological management of moderate-to-severe Crohn’s disease. The new guideline uses cutting-edge network meta-analyses to recommend prescribing medications based on patients’ prior treatments for moderate-to-severe Crohn’s disease.
The guideline organizes treatments by efficacy to simplify decision-making for gastroenterologists and over 3 million people worldwide living with Crohn’s disease. This living guideline reflects the rapid pace of innovation in medical ...
Cancer research, drug safety testing and ageing biology may all gain a major boost from a new fluorescent sensor developed at Utrecht University. This new tool allows scientists to watch DNA damage and repair unfold in real time inside living cells. The development, which opens the door to experiments that weren’t feasible before, is published today in the journal Nature Communications.
DNA inside our cells is constantly damaged by sunlight, chemicals, radiation or simply by the many processes that keep us alive. Usually, the cell fixes this damage quickly and efficiently. But when repair fails, the consequences can be serious, contributing ...
With a five-year survival rate of less than 5%, glioblastoma is one of the most aggressive types of brain cancer. Until now, all available treatments, including immunotherapy — which involves strengthening the immune system to fight cancer— have proved disappointing. CAR-T cells are genetically modified immune cells manufactured in the laboratory and designed to identify and destroy cancer cells. By targeting a protein present in the tumour environment, a team from the University of Geneva (UNIGE) and ...
A geomagnetic superstorm is an extreme space weather event that occurs when the Sun releases massive amounts of energy and charged particles toward Earth. These storms are rare, occurring about once every 20-25 years. On May 10-11, 2024, the strongest superstorm in over 20 years, known as the Gannon storm or Mother’s Day storm, struck Earth.
A study led by Dr. Atsuki Shinbori from Nagoya University's Institute for Space-Earth Environmental Research has captured direct measurements of this extreme event and provided the ...
The immune system plays a crucial role in fighting tumours and metastases. Consequently, it is decisive to conduct cancer research in mouse models with an immune system that is as natural as possible – which is easier said than done.
Thanks to CRISPR/Cas9 technology, researchers can quickly create a pool of hundreds of tumour cells, each with a different gene switched off. When transplanted into mice, it becomes apparent which of these silenced genes influences the development and spread of cancer. Assisted by such CRISPR screens, scientists are able to identify valuable approaches for the development of new therapies.
But the method comes with a catch. The components of ...
November 20, 2025 - A novel study empirically linking a standardized measure of community resilience in more than 3,100 U.S. counties to cognitive, mental, and physical health outcomes shows that counties with fewer healthcare resources, limited digital tools, and weaker support systems exhibit poorer overall health among their residents. The article appearing in the American Journal of Preventive Medicine, published by Elsevier, indicates that resilience can be measured, strengthened, and designed into our systems of care using modifiable tools like healthcare access, support networks, and technology.
Resilience ...
Bribery and money laundering are far more common among the public than many assume, with millions of people in the UK approached to take part in these activities in the past year, according to a new report co-authored by a researcher from the University of Surrey on behalf of the International Society of Economic Criminology (ISEC).
The report found that 16% of UK adults had been asked for a bribe in the last 12 months and 11% (5.8 million UK adults per year) had been asked to help move money that ...
