Metabolomics analysis of peony root using NMR spectroscopy and impact of the preprocessing method for NMR data in multivariate analysis

Comprehensive study on genetic and chemical diversity of Asian medicinal plants, aimed at sustainable use and standardization of traditional crude drugs

Our representative studies to achieve sustainable use of crude drugs and ensure their stable quality are introduced: comprehensive studies on genetic, chemical, and sometimes pharmacological diversity of Asian medicinal plants including Paeonia lactiflora, Glycyrrhiza uralensis, Ephedra spp., Saposhnikovia divaricata, and Curcuma spp., as well as their related crude drugs. (1) For peony root, after genetic and chemical diversity analysis of crude drug samples including white and red peony root in China, the value-added resources with quality similar to red peony root were explored among 61 horticultural P. lactiflora varieties, and two varieties were identified. In addition, an optimized post-harvest processing method, which resulted in high contents of the main active components in the produced root, was developed to promote cultivation and production of brand peony root. (2) Alternative resources of glycyrrhiza, ephedra herb and saposhnikovia root and rhizome of Japanese Pharmacopoeia grade were discovered in eastern Mongolia after field investigation and quality assessment comparing Mongolian plants with Chinese crude drugs. Simultaneously, suitable specimens and prospective regions for cultivation were proposed. (3) Because of the wide distribution and morphological similarities of Curcuma species, classification of some species is debated, which leads to confusion in the use of Curcuma crude drugs. Molecular analyses of the intron length polymorphism (ILP) markers in genes encoding diketide-CoA synthase (DCS) and curcumin synthase (CURS) and trnK sequences, combined with essential oils analysis, were demonstrated as useful for standardization of Curcuma crude drugs. The above studies, representing various facets, can be applied to other crude drugs.

Metabolite profiling of Drynariae Rhizoma using 1H NMR and HPLC coupled with multivariate statistical analysis

Drynariae Rhizoma has been used to treat bone diseases and kidney deficiency in traditional medicine. Recently its aqueous extract was reported to enhance memory function. Although the Japanese standards for non-Pharmacopoeial crude drugs 2022 prescribed Drynaria roosii as the botanical origin, some counterfeits and both raw and stir-fired crude drugs are available in markets. To distinguish Drynariae Rhizoma derived from D. roosii appropriately from others and verify the validity of uses of stir-fried ones, 1H NMR-based metabolite profiling coupled with HPLC were performed. Raw samples derived from D. roosii contained naringin (1), neoeriocitrin (2), 5,7-dihydroxychromone-7-O-neohesperidoside (3), caffeic acid 4-O-β-D-glucoside (4), protocatechuic acid (5), trans-p-coumaric acid 4-O-β-D-glucoside (6), and kaempferol 3-O-α-L-rhamnoside 7-O-β-D-glucoside (8). Stir-fried samples were characterized by presence of 5-hydroxymethyl-2-furaldehyde (13), and were divided into two types; one possessing similar composition to raw samples (Type I) and another without above components except 5 (Type II). Quantitative analyses using qHNMR and HPLC, followed by principal component analysis demonstrated that the raw samples had higher contents of 1 (0.93-9.86 mg/g), 2 (0.74-7.59 mg/g), 3 (0.05-2.48 mg/g), 4 (0.27-2.51 mg/g), 6 (0.14-1.26 mg/g), and 8 (0.04-0.52 mg/g), and Type II had a higher content of 5 (0.84-1.32 mg/g). The counterfeit samples derived from Araiostegia divaricata var. formosana were characterized by higher content of ( -)-epicatechin 3-O-β-D-allopyranoside (10) (1.44-11.49 mg/g) without 1 and 2. These results suggested that Drynariae Rhizoma samples derived from other botanical origins and Type II stir-fried samples cannot substitute for D. roosii rhizome.