Isolation and purification of four flavanones from peel of Citrus changshanensis

Characterization of chemical profile and quantification of major representative components of Wendan decoction, a classical traditional Chinese medicine formula

Wendan decoction, a classical traditional Chinese medicine formula consisting of six herbal medicines, has been widely used in clinical treatments for thousands of years due to the expectorant effects. However, the chemical basis of Wendan decoction remains unclear, which hinders the elucidation of the scientific connotation and mechanism of its effective components. In this study, an ultra-high performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry method was first developed for characterization of its chemical profile, and a total of 142 chemical components including flavonoids, triterpenoids, alkaloids, coumarins, pungent phytochemicals, and other types were detected, among which 41 components were definitively identified with authentic standards. Furthermore, 14 major representative components were simultaneously quantified by high-performance liquid chromatography with ultraviolet detector, indicating that the content levels of flavonoids were the most abundant in Wendan decoction. In summary, this study established sensitive and practical methods to systematically characterize chemical profile for the first time and simultaneous quantify representative components of Wendan decoction. These findings above would provide a solid chemical basis for disclosure of potential effective components by further in vivo disposal study, and promote therapeutic mechanism researches of Wendan decoction.

Identification of Novel Bioactive Compound Derived from Rheum officinalis against Campylobacter jejuni NCTC11168

Gastric diseases are increasing with the infection of Campylobacter jejuni. Late stages of infection lead to peptic ulcer and gastric carcinoma. C. jejuni infects people within different stages of their life, especially childhood, causing severe diarrhea; it infects around two-thirds of the world population. Due to bacterial resistance against standard antibiotic, a new strategy is needed to impede Campylobacter infections. Plants provide highly varied structures with antimicrobial use which are unlikely to be synthesized in laboratories. A special feature of higher plants is their ability to produce a great number of organic chemicals of high structural diversity, the so-called secondary metabolites. Twenty plants were screened to detect their antibacterial activities. Screening results showed that Rheum officinalis was the most efficient against C. jejuni. Fractionation pattern was obtained by column chromatography, while the purity test was done by thin-layer chromatography (TLC). The chemical composition of bioactive compound was characterized using GC-MS, nuclear magnetic resonance, and infrared analysis. Minimal inhibitory concentration (MIC) of the purified compound was 31.25 µg/ml. Cytotoxicity assay on Vero cells was evaluated to be 497 µg/ml. Furthermore, the purified bioactive compound activated human lymphocytes in vitro. The data presented here show that Rheum officinalis could potentially be used in modern applications aimed at the treatment or prevention of foodborne diseases.

Isolation and Purification of Two Isoflavones from Hericium erinaceum Mycelium by High-Speed Counter-Current Chromatography

High-speed counter-current chromatography (HSCCC) was used to separate and purify two isoflavones for the first time from Hericium erinaceum (H. erinaceum) mycelium using a two-phase solvent system composed of chloroform-dichloromethane-methanol-water (4:2:3:2, v/v/v/v). These two isoflavones were identified as genistein (4′,5,7-trihydroxyisoflavone, C₁₅H₁₀O₅) and daidzein (4′,7-dihydroxyisoflavone, C₁₅H₁₀O₄), using infrared spectroscopy (IR), electro-spary ionisation mass (ESI-MS), ¹H-nuclear magnetic resonance (NMR) and ¹³C-NMR spectra. About 23 mg genistein with 95.7% purity and 18 mg daidzein with 97.3% purity were isolated from 150 mg ethanolic extract of H. erinaceum mycelium. The results demonstrated that HSCCC was a feasible method to separate and purify genistein and daidzein from H. erinaceum mycelium.