FWD 2 Botanical Adulterants Monitor: BAM20 - HPTLC Method to Authenticate Rieshi Dietary Supplements
ABC Logo
 


Botanical Adulterants Monitor: Issue 20, September 2020

HPTLC Method to Authenticate Reishi Dietary Supplements

Reviewed: Frommenwiler DA, Trefzer D, Schmid M, Cañigueral S, Reich E. Comprehensive HPTLC fingerprinting: A novel economic approach to evaluating the quality of Ganoderma lucidum fruiting body. J Liq Chromatogr Rel Techn. 2020;43(11-12);414-423.

Keywords: Adulteration, fruiting body, Ganoderma lucidum, Ganoderma spp., HPTLC

Dietary supplements made from various fungal parts (fruiting body, mycelium) have seen a rapid increase in sales in the United States over the past few years. For many of the popular mushrooms, quality parameters are not well-established, and proper authentication remains challenging. For reishi (Ganoderma lucidum, Ganodermataceae) mushrooms, the situation is complicated since the taxonomy is a matter of debate; some authors believe that the lumping of all Ganoderma species which are morphologically similar into G. lucidum is appropriate, while others propose that the scientific name Ganoderma lingzhi should be used for reishi originating from Eastern Asia and G. lucidum should be restricted to reishi from Europe.1-3 This taxonomic debate is not yet settled. Furthermore, two additional species, G. japonicum and G. tsugae, are listed with the common name “reishi” in the American Herbal Products Association’s Herbs of Commerce, 2nd edition.4 This means that these two species can also be sold as reishi in the United States. In Asia, reishi fruiting bodies are mostly differentiated with G. lucidum assigned to red forms of reishi and other species (e.g., G. japonicum) assigned to black forms.5

The authors of this investigation developed a high-performance thin-layer chromatography (HPTLC) method for the authentication of ingredients claiming to be made from G. lucidum fruiting body. The method evaluates the fingerprint of triterpenoic acids (ganoderic acids A, B, C2, D, and G) and ergosterol. In addition, the amount of total triterpenoic acids was determined by quantitative HPTLC, and samples evaluated using acceptance criteria (not less than 0.3% by weight of triterpenoic acids) established in the USP monograph.6 Plates were assessed under white light, UV at 254 nm and 366 nm, or after derivatization with 10% sulfuric acid in methanol.

A total of 50 commercial reishi samples were obtained from or provided by different companies and institutions from USA, France, Switzerland, and Canada. Commercial samples originated from Canada (n = 5), China (n = 9), France (n = 1), Germany (n = 3), Korea (n = 1), the United States (n = 21), or were of unknown origin (n = 10). The label description indicated G. lucidum fruiting body (n = 43), Ganoderma spp. (n = 4), or reishi mushroom (n = 3). A reference sample provided by USP, and authenticated samples of 13 other fungal species, including G. applanatum and G. sinensis, were also included in the analysis.

According to the authors’ assessment, 22 samples complied with USP specifications, five were of questionable quality, and the remaining 23 samples had some deficiencies, mainly the lack of characteristic bands for one or several of the ganoderic acids. Ganoderic acid contents ranged between 0.05-0.64%; 21 samples were below the 0.3% specification for ganoderic acid listed in the USP monograph. However, it is not clear if any of these samples actually claimed to comply with USP specifications.

Comment: Authentication of reishi based on chemical fingerprints is challenging, since the triterpenoic acid pattern is reportedly variable depending on the origin of the sample.1,7,8 However, the published data consistently report the presence of ganoderic and other acids in reishi fruiting bodies and even in mycelium obtained from submerged cultures of the fungus.9 It is unclear if any of the commercial products analyzed by Frommenwiler et al. was adulterated, although some supplements lacked zones for triterpenoic acids. Nevertheless, the paper represents the largest investigation of commercial reishi fruiting body to date and provides a valuable insight into the variability of marketed products. For industry members who manufacture or sell reishi products, the proposed HPTLC method is a helpful tool to evaluate the quality of their material, and to determine compliance with specifications set forth by the USP.

References

  1. Hennicke F, Cheikh-Ali Z, Liebisch T, Maciá-Vicente JG, Bode HB, Piepenbring M. Distinguishing commercially grown Ganoderma lucidum from Ganoderma lingzhi from Europe and East Asia on the basis of morphology, molecular phylogeny, and triterpenic acid profiles. Phytochemistry. 2016;127:29-37.
  2. Moncalvo JM, Wang HF, Hseu RS. Gene phylogeny of the Ganoderma lucidum complex based on ribosomal DNA sequences: comparison with traditional taxonomic characters. Mycol Res. 1995;99:1489–1499.
  3. Lloyd AL, Richter BS, Jusino MA, Truong C, Smith ME, Robert A. Blanchett RA, Smith JA. Identifying the “mushroom of immortality”: Assessing the Ganoderma species composition in commercial reishi products. Front Microbiol. 2018; 9: 1557
  4. McGuffin M, Kartesz JT, Leung AY, Tucker AO. American Herbal Products Association’s Herbs of Commerce. 2nd ed. Silver Spring, MD: American Herbal Products Association; 2000.
  5. Upton R. American Herbal Pharmacopoeia and Therapeutic Compendium: Reishi Mushroom: (Ganoderma lucidum). Standards of Analysis, Quality Control, and Therapeutics. Santa Cruz, CA: American Herbal Pharmacopoeia. Monograph; 2000.
  6. United States Pharmacopeial Convention. Ganoderma lucidum fruiting body powder. In: United States Pharmacopoeia 43 and National Formulary 38. Rockville, MD, USA: United States Pharmacopeial Convention, 2020;5008.
  7. Xin H, Fang L, Xie J, Qi W, Niu Y, Yang F, Cai D, Zhang Y, Wen Z. Identification and quantification of triterpenoids in lingzhi or reishi medicinal mushroom, Ganoderma lucidum (Agaricomycetes), with HPLC-MS/MS methods. Int J Med Mushrooms. 2018;20(10):919-934.
  8. Min BS, Nakamura N, Miyashiro H, Bae KW, Hattori M. Triterpenes from the spores of Ganoderma lucidum and their inhibitory activity against HIV-1 protease. Chem Pharm Bull. 1999;46:1607-1612.
  9. Xu P, Ding ZY, Qian Z, Zhao CX, Zhang KC. Improved production of mycelial biomass and ganoderic acid by submerged culture of Ganoderma lucidum SB97 using complex media. Enzyme Microb Technol. 2008;42(4):325-331.