Ling-Xiao Chen

Qualitative and quantitative analysis of specific polysaccharides in Dendrobium huoshanense by using saccharide mapping and chromatographic methods

Qualitative and quantitative analysis of specific polysaccharides from ten batches of Dendrobium huoshanense were performed using high performance size exclusion chromatography coupled with multi-angle laser light scattering and refractive index detector (HPSEC-MALLS-RID), gas chromatography-mass spectrometry (GC-MS), nuclear magnetic resonance (NMR) and saccharide mapping based on polysaccharides analysis by using carbohydrate gel electrophoresis (PACE) and high performance thin layer chromatography (HPTLC). Results showed that molecular weights, the radius of gyrations, and contents of specific polysaccharides in D. huoshanense were ranging from 1.16×10(5) to 2.17×10(5)Da, 38.8 to 52.1nm, and 9.9% to 19.9%, respectively. Furthermore, the main monosaccharide compositions were Man and Glc. Indeed, the main glycosidic linkages were β-1,4-Manp and β-1,4-Glcp, and substituted with acetyl groups at O-2 and O-3 of 1,4-linked Manp. Moreover, results showed that PACE and HPTLC fingerprints of partial acidic and enzymatic hydrolysates of specific polysaccharides were similar, which are helpful to better understand the specific polysaccharides in D. huoshanense and beneficial to improve their quality control. These approaches could also be routinely used for quality control of polysaccharides in other medicinal plants.

Evaluation on quality consistency of Ganoderma lucidum dietary supplements collected in the United States

Ganoderma lucidum is a well-known medicinal mushroom. At present, numerous G. lucidum products have emerged in the form of dietary supplements in the United States due to its various benefits. However, the quality consistency of these products based on their label ingredients has seldom been evaluated due to the lack of a suitable toolkit. In this study, 19 batches of products of G. lucidum (Red Reishi, Reishi), herbal/mushroom supplements purchased in the United States, were evaluated based on their bioactive components including triterpenes and polysaccharides by using chromatographic methods and saccharide mapping. The results showed that the measured ingredients of only 5 tested samples (26.3%) were in accordance with their labels, which suggested the quality consistency of G. lucidum dietary supplements in the U.S. market was poor, which should be carefully investigated.

Nortriterpenoids from the Fruiting Bodies of the Mushroom Ganoderma resinaceum

Ganoderma resinaceum is usually used as ethnomedicine for immune-regulation, hyperglycemia, and liver disease. To date, only a few chemical constituents have been reported from G. resinaceum. In this study, fifteen nortriterpenoids including six new nortriterpenoids (1–6) and nine known analogs (7–15), were separated and purified from the fruiting bodies of G. resinaceum. New compounds were identified as lucidone I (1), lucidone J (2), lucidone K (3), lucidone I (4), ganosineniol B (5), and ganosineniol C (6), based on analysis of extensive spectroscopic data (high resolution mass spectrometry (HRMS), nuclear magnetic resonance (NMR), infrared (IR), and ultraviolet (UV)). The known compounds were assigned as lucidone A (7), lucidone B (8), lucidone H (9), lucidone E (10), lucidone F (11), lucidone D (12), lucidone C (13), ganoderense F (14), and ganosineniol A (15), by comparing their spectroscopic data with those reported in the literature. Compounds 3, 4, and 7–13 were examined for α-glucosidase inhibitory activity and display no significant activity, but the finding may support that the side chain of ganoderma triterpenoids played an important role in α-glucosidase inhibitory activity.

Chemical characterization and immunomodulatory activity of acetylated polysaccharides from Dendrobium devonianum

The chain conformation, chemical characters and immunomodulatory activity of polysaccharide from Dendrobium devonianum (DDP) were investigated. Results showed that molecular weights, polydispersity index, radius of gyrations of DDP were 3.99×105 Da1.27, 74.1nm, respectively. By applying the polymer solution theory, the exponent (v) values of z1/2=kMwv was calculated as 0.38, which revealed that DDP existed as a globular shape in aqueous solution, and further confirmed by AFM analysis. Furthermore, the main monosaccharide compositions were Man and Glc with the ratio of 29.61:1.00. Indeed, the main glycosidic linkages were β-1,4-Manp, and substituted with acetyl groups at O-2 and O-3 position. Notably, DDP could promote the immune functions of macrophages including NO release and phagocytosis. Thus, DDP could be explored as a natural immune-stimulating agent in the health and functional food area as well as pharmaceutical industries.

A new nortriterpenoid and an ergostane-type steroid from the fruiting bodies of the fungus Ganoderma resinaceum

Abstract One new expoxy nortriterpenoid (1) and one new ergostane-type steroid (2), together with seven known steroids (3–9), were obtained from the fruiting bodies of the fungus Ganoderma resinaceum. The new compounds were elucidated on the basis of extensive spectroscopic data (MS, NMR, IR, and UV) and the known compounds were identified by comparing spectroscopic data with those reported in literature.

Isolation, Structural Elucidation, and α-Glucosidase Inhibitory Activities of Triterpenoid Lactones and Their Relevant Biogenetic Constituents from Ganoderma resinaceum

Ganoderma resinaceum has been used as an ethnomedicine for lowering blood sugar. To clarify the bioactive chemical constituents contributing to lower blood sugar, chemical investigation on the fruiting bodies of Ganoderma resinaceum was conducted by chromatographic techniques, and led to the isolation of 14 compounds. Their structures were elucidated as triterpenoid lactones (1–4 and 8) and ganoderma acids (5–7 and 9–14) based on the analysis of extensive spectroscopy (mass spectrometry (MS), nuclear magnetic resonance (NMR), infrared (IR), and ultraviolet (UV)) and comparison with literature data. Compounds 3, 5, 6, and 9–14 were evaluated for α-glucosidase inhibitory activity. Compounds 1–7 are new compounds. Compounds 1–4 and 8 were characteristic of an oxaspirolactone moiety, consisting of a five-membered ether ring, a five-membered lactone ring, and a characteristic C-23 spiro carbon. It is rare for natural products that such an oxaspirolactone moiety occurred in the lanostane-type triterpenoids. Compounds 5–7 and 9–14 may be important intermediates of the biosynthetic pathways of 1–4 and 8. Compounds 1 and 2 showed more potent inhibitory activity against α-glucosidase compared with the positive control drug acarbose with IC50 value of 0.75 ± 0.018 mM and 1.64 ± 0.022 mM, respectively.

Development and application of bio-sample quantification to evaluate stability and pharmacokinetics of inulin-type fructo-oligosaccharides from Morinda Officinalis

Graphical abstract Figure. No caption available. HighlightsIon exchange desalting method has been successfully developed for bio‐sample analysis.Stepwise hydrolysis of FOS‐DP5 was observed in simulated fluid and gut microbiota.With poor stability and oral absorption, further study will be performed to the effect of microbiota on FOS. ABSTRACT Inulin‐type fructooligosaccharides (FOS) purified from Morinda Officinalis, with degrees of polymerization (DP) from 3 to 9, have been approved in China as an oral prescribed drug for mild and moderate depression episode, while the stability and oral absorption of this FOS mixtures are largely unknown. As the main active component and quality control marker for above FOS, DP5 was selected as the representative FOS in this study. Desalting method by ion exchange resin was developed to treat bio‐sample, followed by separation and quantification by high performance liquid chromatography‐charged aerosol detector. Results showed that the DP5 was stepwisely hydrolyzed in simulated gastric fluid and gut microbiota, while maintained stable in intestinal fluid. DP5 has poor permeability across Caco‐2 monolayer with Papp of 5.22 × 10−7 cm/s, and very poor oral absorption with bioavailability of (0.50 ± 0.12)% in rat. In conclusion, FOS in Morinda Officinalis demonstrated poor chemical stability in simulated gastric fluid and human gut microbiota, and low oral absorption in rats.

Front Cover: Preparation and identification of oligosaccharides in lotus seeds and determination of their distribution in different parts of lotus

Three fractions (I–III) were separated from crude oligosaccharides of lotus seeds by fast protein liquid chromatography with final purity of 97.6, 96.3, and 96.8%, respectively. The fractions were identified as sucrose, raffinose, and stachyose by using TLC, HPLC with charged aerosol detector (CAD), LC‐MS, and methylation analysis. Subsequently sucrose and raffinose family oligosaccharides (RFOs) with degree of polymerization (DP) 3–5 (raffinose, stachyose, and verbascose) have been quantified by HPLC‐CAD for the first time. All calibration curves for investigated analytes showed good linear regression (R2 > 0.9952). Their limit of detection and limit of quantity were in the ranges 0.14−0.28 and 0.36−0.48 μg/mL, respectively. The recoveries ranged from 96.6 to 103.4%. The contents of sucrose and RFOs DP3–DP5 were different in lotus seeds and other parts of lotus samples, but similar in their own variety. Additionally, the distribution of RFOs in different parts of lotus were also compared and the results indicated that RFOs might be mainly synthesized in lotus seeds. This work is helpful for understanding the way of biosynthesis of RFOs in lotus as well as quality control of plants containing RFOs.