Opposite trends of glycosides and alkaloids in Dendrobium nobile of different age based on UPLC‐Q/TOF‐MS combined with multivariate statistical analyses

Abstract

Introduction Alkaloids and glycosides are the active ingredients of the herb Dendrobium nobile, which is used in traditional Chinese medicine. The pharmacological effects of alkaloids include neuroprotective effects and regulatory effects on glucose and lipid metabolism, while glycosides improve the immune system. The pharmacological activities of the above chemical components are significantly different. In practice, the stems of 3‐year‐old D. nobile are usually used as the main source of Dendrobii Caulis. However, it has not been reported whether this harvesting time is appropriate. Objective The aim of this study was to compare the chemical characteristics of D. nobile in different growth years (1–3 years). Methods In this study, ultra‐high‐performance liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry (UPLC‐Q/TOF‐MS) was employed to analyze the constituents of D. nobile. The relative abundance of each constituent was analyzed with multivariate statistical analyses to screen the characteristic constituents that contributed to the characterization and classification of D. nobile. Dendrobine, a component of D. nobile that is used for quality control according to the Chinese Pharmacopoeia, was assayed by gas chromatography. Results As a result, 34 characteristic constituents (VIP > 2) were identified or tentatively identified as alkaloids and glycosides based on MS/MS data. Moreover, the content of alkaloids decreased over time, whereas the content of glycosides showed the opposite trend. The absolute quantification of dendrobine was consistent with the metabolomics results. Conclusion Our findings provide valuable information to optimize the harvest period and a reference for the clinical application of D. nobile.

Transcriptome-based analysis reveals the key genes of sesquiterpene glycosylation in Dendrobium nobile

“…The results showed that compared with the 1-year-old samples, 35 genes of UDP-glycosyltransferase in 3-year-old D. nobile were up-regulated, 24 genes were down regulated, and 125 genes had no significant change (Figure 1C, D). Based on our previous research (Lu et al, 2022), the content of sesquiterpene glycosides in D. nobile will increase with the growth years. Therefore, we have reason to infer that the increase of sesquiterpene glycosides is caused by the upregulation of UDP-glycosyltransferase genes expression.…”

“…Therefore, sesquiterpene UDP-glycosyltransferases play an important role in the biosynthesis of alkaloids and sesquiterpene glycosides in D. nobile. Our previous study found that the content of alkaloids in D. nobile decreases with the increase of growth years, on the contrary, the content of sesquiterpene glycosides keeps increasing, and this phenomenon also indirectly proved that alkaloids and sesquiterpene glycosides have a certain relationship (Lu et al, 2022). In the present continued study, the key glycosyltransferase genes in sesquiterpene glycosylation in D. nobile were explored, predicted and validated by comparing the DGEs of 1 and 3 years old D. nobile through transcriptome technology.…”

Identification of sesquiterpene glycosides from Dendrobium nobile and their α-glycosidase and α-amylase inhibitory activities

“…Among them, protecting the nervous system, regulating lipid metabolism has been closely related to alkaloids (Huang et al, 2019;Lv et al, 2020). However, for the effect of anti-immune activity, sesquiterpene glycosides were found to stimulate the proliferation of the proliferation of B cells in vitro (Lu et al, 2022). Specifically, picrotoxane sesquiterpene glycosides were considered as key intermediates in the biosynthesis of dendrobine, a major quality marker in D. nobile (Gong et al, 2021).…”

Fatty acid metabolites of Dendrobium nobile were positively correlated with representative endophytic fungi at altitude

“…Dendrobium nobile , a Chinese medicinal material with a long history, is immunomodulator, antitumor agent, antidiabetic ( Teixeira and Ng, 2017 ), antioxidant ( Hsu et al, 2022 ), potential Alzheimer treatment agent ( Li D. D. et al, 2022 ), protection agent of the liver ( Zhou et al, 2020 ), and even the protection agent of retina ( Hsu et al, 2022 ), with its stems as the main medicinal part. A variety of metabolites of D. nobile , including alkaloids, lipids, phenolic acids, flavonoids, polysaccharides, and other bioactive substances ( Lu et al, 2022 ), provide a chemical basis for pharmacological action. The synthesis and accumulation of these chemicals are affected by the biological and abiotic environment of the planting habitats ( Mykhailenko et al, 2020 ).…”