Key Points
- Certain components within chaga mushrooms are believed to be medically beneficial; however, quality control of these fungi is an underutilized process.
- Using supercritical fluid-based techniques, researchers created a new protocol for extracting, identifying, and quantifying six chaga components.
- The procedures achieved notable results regarding linearity and extract yields, making the approach effective as an alternative to traditional chromatographic analysis.
University of Helsinki (Finland) and University of Vienna (Austria) researchers used supercritical fluid-based techniques to identify and quantify notable components within commercial chaga (Inonotus obliquus) samples. Their research was published in the Journal of Chromatography A (1).
Top view healing chaga mushroom on old birch trunk close up. Red parasite mushroom growth on tree. Bokeh background. | Image Credit: © exebiche – stock.adobe.com
The chaga mushroom (Inonotus obliquus) is a tree-destroying fungus that parasitizes the trunks of living trees. This mushroom has gained popularity in the West for its potential health benefits, with it being believed to be good for boosting the immune system, fighting cancer, and lowering cholesterol (2). Chaga is typically consumed through infusions, inhalations, or aqueous macerates. Nowadays, the chaga mushroom is commonly used as a functional food ingredient. The sclerotia of the fungi, which are resting structures made up of compact mycelium masses that contain nutritional reserves and allow for fungal persistence, have been shown to have a broad range of traditional and medicinal uses (3).
There is an increasing market for chaga supplements, which are promoted for having antioxidant, anti-inflammatory, and antidiabetic properties; as such, there is a need for standardized identity and quality control methodologies. Currently, the quality control of I. obliquus is only regulated by the State Pharmacopoeia of the Union of Soviet Socialist Republics, with a quality criterion of a threshold of 10% chromogen complex. The chromogen complex is a complex mixture of polyphenols, melanins, organic acids with bound elements such as potassium and iron, and other secondary metabolites. Using this complex can yield ambiguous results, making it an unsuitable marker for quality in pharmaceutical analyses.
In this study, the researchers created a supercritical fluid-based protocol for extracting, isolating, identifying, and quantifying six characteristic chaga components: lanosterol, ergosterol, inotodiol, trametenolic acid B, betulin, and inonotsutriol A. Semi-preparative SFC was utilized to obtain lanosterol, inotodiol, and inonotsutriol A. When properly utilized, ultra-high performance SFC (UHPSFC) allowed for standard compounds to be separated within 10 min. Notable results regarding linearity (R2 ≥ 0.99) were obtained for photodiode array detection, with the lowest detection limit being 0.424 μg/mL.
A 20-minute exhaustive supercritical fluid extraction (SFE) method was applied to 14 commercial chaga samples, yielding extracts ranging from 0.17% to 0.58%. The qualitative composition of the extracts was consistent, with the most abundant constituents being inotodiol, trametenolic acid B, and lanosterol. Further, the scientists said this system allowed inonotsutriol A to be quantified in commercial chaga samples for the first time.
Overall, SFC allowed for fast, selective, and environmentally friendly extraction, isolation, and analysis of compounds. By optimizing various operational factors of SFE, a selective and exhaustive supercritical CO2-based extraction method was achieved. The protocol successfully generated standard-compound-containing extracts when applied to the commercial samples, verifying the method’s reliability. With this research, scientists can enhance their understanding of triterpenoids in I. obliquus, all while establishing a robust quality and identity control method for this fungal material and its preparations.
This study highlights the importance of using environmentally friendly supercritical fluid technologies. When these techniques are properly utilized, this paves the way for improved standardization in authenticity and quality control testing methodologies.
References
(1) Kapp, K.; Gafriller, J.; Kirchweger, B.; Rollinger, J. M.; Grienke, U. Supercritical Fluid-Based Protocol for the Identification and Quantitation of Triterpenoids in Commercial Inonotus obliquus (Chaga) Samples. J. Chromatogr. A 2025, 1758, 466197. DOI: 10.1016/j.chroma.2025.466197
(2) Brown, M. J. What Are Chaga Mushrooms and Are They Healthy? Healthline 2023. https://www.healthline.com/nutrition/chaga-mushroom (accessed 2025-7-24)
(3) Sclerotium. ScienceDirect 2025. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/sclerotium (accessed 2025-7-24)