Rapid characterization of non-volatile phenolic compounds reveals the reliable chemical markers for authentication of traditional Chinese medicine Xiang-ru among confusing Elsholtzia species

Abstract

The aerial parts of Mosla chinensis Maxim. and Mosla chinensis cv. 'Jiangxiangru' (MCJ) are widely utilized in traditional Chinese medicine (TCM), known collectively as Xiang-ru. However, due to clinical effectiveness concerns and frequent misidentification, the original plants have increasingly been substituted by various species within the genera Elsholtzia and Mosla. The challenge in distinguishing between these genera arises from their similar morphological and metabolic profiles. To address this issue, our study introduced a rapid method for metabolic characterization, employing high-resolution mass spectrometry-based metabolomics. Through detailed biosynthetic and chemometric analyses, we pinpointed five phenolic compounds—salviaflaside, cynaroside, scutellarein-7-O-D-glucoside, rutin, and vicenin-2—among 203 identified compounds, as reliable chemical markers for distinguishing Xiang-ru from closely related Elsholtzia species. This methodology holds promise for broad application in the analysis of plant aerial parts, especially in verifying the authenticity of aromatic traditional medicinal plants. Our findings underscore the importance of non-volatile compounds as dependable chemical markers in the authentication process of aromatic traditional medicinal plants.

Keywords

Genus Elsholtzia / Genus Mosla / Traditional Chinese medicine / Xiang-ru / Non-volatile phenolic compounds / Liquid chromatography-mass spectrometry

References

[1] Pharmacopoeia of the Peoples Republic of China[S]. Beijing: People’s Medical Publishing House, 2015, 1: 271.

[2] Cao L, Si HY, Liu Y, et al. Essential oil composition, antimicrobial and antioxidant properties of Mosla chinensis maxim[J]. Food Chem, 2008, 115(3): 801-805.

[3] Chen SQ, Chen JX, Xu YF, et al. Elsholtzia: a genus with antibacterial, antiviral, and anti-inflammatory advantages[J]. J Ethnopharmacol, 2022, 297: 115549.

[4] Xie ZW. Traditional Chinese Medicine Theory and Application[M]. Beijing: People’s Medical Publishing House, 2008: 916-918.

[5] Pharmacopoeia of the Peoples Republic of China[S]. Beijing: People’s Medical Publishing House, 1997, 1: 420.

[6] Pharmacopoeia of the Peoples Republic of China[S]. Beijing: People’s Medical Publishing House, 1985, 1: 223.

[7] Pharmacopoeia of the Peoples Republic of China[S]. Beijing: People’s Medical Publishing House, 1990, 1: 230.

[8] Seo YH, Trinh TA, Ryu SM, et al. Chemical constituents from the aerial parts of Elsholtzia ciliata and their protective activities on glutamate-induced HT22 cell death[J]. J Nat Prod, 2020, 83(10): 3149-3155.

[9] Zhao MP, Liu XC, Lai DW, et al. Analysis of the essential oil of Elsholtzia ciliate aerial parts and its insecticidal activities against liposcelis bostrychophila[J]. Helv Chim Acta, 2016, 99(1): 90-94.

[10] Peng L, Xiong Y, Wang M, et al. Chemical composition of essential oil in Mosla chinensis Maxim cv. jiangxiangru and its inhibitory effect on Staphylococcus Aureus biofilm formation[J]. Open Life Sci, 2018, 13: 1-10.

[11] Pasdaran A, Sheikhi D. Volatile oils: potential agents for the treatment of respiratory infections[J]. Microbiol Respir System Infect, 2016, 16: 237-261.

[12] Shu RG, Hu HW, Zhang PZ, et al. Triterpenes and flavonoids from Mosla chinensis[J]. Chem Nat Compd, 2012, 48(4): 706-707.

[13] Nguyen D, Tran H, Schwaiger S, et al. Effect of non-volatile constituents of Elsholtzia ciliata (Thunb. ) Hyl. from southern Vietnam on reactive oxygen species and nitric oxide release in macrophages[J]. Chem Biodivers, 2021, 18(1): e2000577.

[14] Kalua CM, Allen MS, Bedgood Jr DR, et al. Olive oil volatile compounds, flavour development and quality: a critical review[J]. Food Chem, 2007, 100(1): 273-286.

[15] Shimizu T, Watanabe M, Fernie AR, et al. Targeted LC-MS analysis for plant secondary metabolites[J]. Methods Mol Biol, 2018, 1778: 171-181.

[16] Want EJ. LC-MS untargeted analysis[J]. Methods Mol Biol, 2018, 1738: 99-116.

[17] Emwas AH. The strengths and weaknesses of NMR spectroscopy and mass spectrometry with particular focus on metabolomics research[J]. Methods Mol Biol, 2015, 1277: 161-193.

[18] Li SL, Han QB, Qiao CF, et al. Chemical markers for the quality control of herbal medicines: an overview[J]. Chin Med, 2008, 3: 7.

[19] Xiong QQ, Sun CH, Li A, et al. Metabolomics and biochemical analyses revealed metabolites imp ortant for the antioxidant properties of purple glutinous rice[J]. Food Chem, 2022, 389: 133080.

[20] Tsugawa H, Cajka T, Kind T, al. MS-DIAL: data-independent MS/MS deconvolution for comprehensive metabolome analysis[J]. Nat Methods, 2015, 12(6): 523-526.

[21] Fraisier-Vannier O, Chervin J, Cabanac G, et al. MS-CleanR: a feature-filtering workflow for untargeted LC-MS based metabolomics[J]. Anal Chem, 2020, 92(14): 9971-9981.

Funding

National Key R&D Program of China(2022YFC3501700)

Young Elite Scientists Sponsorship Program by Cast(2021-QNRC1-02)

Ability Establishment of Sustainable Use for Valuable Chinese Medicine Resources(2060302)

Research Project of Science and Technology Commission of Shanghai Municipalit(21DZ2202300)