Purification of polysaccharide from artificially cultivated Anoectochilus roxburghii (wall.) Lindl. by high-speed counter current chromatography and its antitumor activity.

To establish a systematic method for the extraction, purification, characterization and antitumor activity study of polysaccharide from artificially cultivated Anoectochilus roxburghii (wall.) Lindl. (AC-ARPS). High-speed counter current chromatography with two-phase aqueous systems was successfully applied to purify AC-ARPS after one-step separation. The purity of the AC-ARPS obtained by phenol/sulfuric acid method was 95.01%. The chemical structures of AC-ARPS were identified by a series of analytical methods including high-performance liquid chromatography and liquid chromatography with mass spectrometry. High-performance liquid chromatography and liquid chromatography with mass spectrometry indicated that AC-ARPS was mainly composed of mannose, ribose, glucose, galactose and arabinose with a molar ratio of 1.00:8.47:47.30:1.17:1.19. AC-ARPS is a homogeneous polysaccharide with a molecular weight of 25 681 Da. The antitumor effect of AC-ARPS was evaluated on lung cancer A549, osteosarcoma 143B, rat adrenal pheochromocytoma PC 12, breast cancer MCF-7, acute leukemia HL 60, chronic leukemia K562, colon cancer SW620, esophageal cancer OE 19, liver cancer HepG2, and neuroglioma U251 cells in vitro. AC-ARPS showed the best inhibitory effect on OE 19 cells, and the IC50 value was 5.67 ± 0.831 µmol/L. Fluorescence analysis and flow cytometry results showed that AC-ARPS induced apoptosis and G2/M phase arrest in OE 19 cells.

[Determination of Nucleosides and Nucleobases in Natural, Cultured and Tissue Culture Anoectochilus roxburghii Using LC-MS].

OBJECTIVE: To establish a method for simultaneous determination of nucleosides and nucleobases in natural, cultured and tissue culture Anoectochilus roxburghii by high performance liquid chromatography-electrospray ionization/ion trap mass spectrometry (HPLC-ESI/MS). METHODS: The separation was performed on a Welch Ultimate XB-C18 column (250 mm x 4.6 mm,5 µm). 20 mmol/L ammonium acetate solution and methanol were adopted as the mobile phase with gradient elution. The flow rate was 1.0 mL/min. The injection volume was 20 µL. The column temperature and UV wavelength were set at 30 degrees C and 260 nm, respectively. RESULTS: Cytosine, uracil, cytidine, uridine, hypoxanthine, adenine, inosine, guanosine,fl-thymidine and adenosine were identified in natural, cultured and tissue culture Anoectochilus roxburghii. The total content of nucleosides and nucleotides in Anoectochilus roxburghii were 1.6639, 1.8568 and 2.2013 mg/g,respectively. CONCLUSION: The contents of nucleosides and nucleobases in herb are affected by its growth pattern. The total content of nucleosides and nucleotides was tissue culture herb > cultured herb > natural herb. This investigation would provide the theoretic basis for quality standards and applications of Anoectochilus roxburghii in clinical research.

Simultaneous analysis of paralytic shellfish toxins and tetrodotoxins in human serum by liquid chromatography coupled to Q-Exactive high-resolution mass spectrometry.

Paralytic shellfish toxins (PSTs) and tetrodotoxins (TTXs) are powerful neurotoxins. Previous research reported that PSTs and TTXs are found together in seafoods and may pose a serious hazard to public health. In this study, a new analytical method combining modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) with high-performance liquid chromatography coupled to Q-Exactive Orbitrap high-resolution mass spectrometry was developed and validated for the quantification of 10 PSTs and 2 TTXs in human serum. Chromatographic separation was achieved using the HILIC TSK-Gel Amide-80 column. The mass spectrometer was operated in full scan/dd-MS2(data-dependent MS2) mode, and for quantification analysis. The dd-MS2 resolution was set to 17,500 fullwidthat halfmaximum （FWHM）. Results showed that methanol with 1 % (v/v) acetic acid extraction combined with 50 mg graphitized carbon black (GCB) and 50 mg octadecyl bonded silica gel (C18) was most suitable for purification. The mean recovery for all toxins ranged from 85.3 % to 118.2 % (RSD < 12 %). The limits of detection and quantification for human serum were in the ranges of 0.67-2.61 and 2.23-8.69 ng mL-1, respectively. The method was applied to analyze toxins in serum samples obtained from three poisoned patients in a case of poisoning caused by consumption of toxin-contaminated gastropoda (Bullacta exerata). The study has important application for rapid and accurate diagnosis of PSTs and TTXs toxin poisoning patients in clinic.

Uncovering the protective mechanism of Pien-Tze-Huang in rat with alcoholic liver injury based on cytokines analysis and untargeted metabonomics.

Pien-Tze-Huang (PTH) is a well-known traditional Chinese patent medicine with excellent liver-protection effect. However, the mechanism of hepatoprotective action has not yet been entirely elucidated. The aim of this study was to investigate the mechanism of protective effect of PTH on alcohol-induced liver injury in rats using cytokine analysis and untargeted metabolomics approaches. An alcoholic liver disease (ALD) model with SD rats was established, and PTH was administered according to the prescribed dose. The hepatoprotective effect of PTH was evaluated by pathological observation of liver tissue and changes in biochemical index activity and cytokines in serum. Serum samples were analyzed by ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF/MS), and differentially expressed metabolites were screened by multivariate statistical analysis. KEGG combined with metabolic pathway analysis were used to evaluate the underlying metabolic pathways. Results showed liver histopathology injury was attenuated. The levels of IL-6, TNF-α and NF-κB were significantly decreased in rats intervened with PTH groups, suggesting that it may alleviate inflammation via suppressing the inflammatory cytokines signaling pathway. Eighty differentially expressed metabolites were found and identified. Pathway analysis indicated that the hepatoprotective effects of PTH occurred through the regulation of inflammatory cytokines signaling pathway, primary bile acid biosynthesis, vitamin B6 metabolism pathway, cholesterol metabolism, and tyrosine metabolism. PTH showed favorable hepatoprotective effect through multiple pathways. This study has great importance in fully revealing the mechanism of hepatoprotective action and can help improve the clinical application of PTH.

Variability and profiles of lipophilic marine toxins in shellfish from southeastern China in 2017-2020.

A total of 1338 samples were analyzed by ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to study the toxin profiles of lipophilic marine toxins in bivalve mollusks collected from the southeast coast of China from 2017 to 2020. The most abundant toxin was HomoYTX, followed progressively by YTX and PTX2. Low proportions of OA, DTX-1, and DTX-2 were found. No AZA1, AZA2, and AZA3 were quantified above limit of quantitation (LOQ). The highest concentrations of HomoYTX, YTX, PTX2, OA, DTX-1, and DTX-2 were 429, 98.0, 40.3, 33.0, 22.6, and 26.5 µg/kg, respectively. Mussels (Mytilus galloprovincialis, Perna viridis), scallop (Chlamys farreri) and clam (Atrina pectinate) accumulated higher toxin levels than clams (Sinonovaculla Constricta, Ruditapes philippinarum), oyster (Crassostrea gigas) and scallop (Arca granosa). Homo YTX and PTX2 levels reached the maximum in July and June, respectively, and the OA-group peaked in August. The results provide a reliable basis for monitoring marine toxins and protecting the health of aquatic consumers.

Simultaneous determination of twelve paralytic shellfish poisoning toxins in bivalve molluscs by UPLC-MS/MS and its applications to a food poisoning incident.

In this study, an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was originally developed for simultaneously quantitative analysis of twelve paralytic shellfish poisoning toxins, referring to STX, NEO, dcSTX, GTX1, GTX2, GTX3, GTX4, GTX5, C1, C2, dcGTX2, and dcGTX3 in bivalve molluscs. Chromatographic separations were performed on a TSK-Gel Amide-80 column (5 µm, 2.0 × 150 mm, Tosoh Corporation) by gradient elution with 2 mmol L-1 ammonium formate solution-acetonitrile (containing 0.1% formic acid) as mobile phases. The samples were pretreated by extraction with acetonitrile-water (80:20, v/v; containing 0.1% formic acid), followed by cleaning up using an Oasis HLB extraction cartridge (500 mg/6 mL). The present method showed good linearity (r2 > 0.99) with the limits of detection (LODs) and limits of quantification (LOQs) ranged from 1.03 to 10.65 µg/kg and 3.43-35.46 µg/kg, respectively for these toxins. Owing to its sensitivity and rapid properties, the presented method was applied to the determination of PSP toxins in bivalve molluscs involved in a food poisoning incident occurred in Zhangzhou, China, in June 2017.

Toxin and toxicity identification of mangrove horseshoe crab Carcinoscorpius rotundicauda collected from South China.

The presence of paralytic shellfish poisoning (PSP), diarrhetic Shellfish Poisoning (DSP), tetrodotoxin (TTX) and its analogues (11-oxoTTX, 4.9-anhydro-11-oxoTTX, 4.9-anhydroTTX, 5-deoxyTTX, 5.11-dideoxyTTX, 5.6.11-trideoxyTTX and 4.9-anhydro-5.6.11-trideoxy TTX) were initially investigated in Carcinoscorpius rotundicauda collected from south China with Liquid chromatography-tandem mass spectrometry (LC-MS-MS) and mouse bioassay. The TTX toxicity was 10.8 ±â€¯3.9 MU/g muscle, 6.3 ±â€¯0.6 MU/g viscera and 6.3 ±â€¯0.6 MU/g eggs in mean value. Merely dcGTX2 and dcSTX were detected in ten Specimens, ranging from 0.01 to 0.77 µg/g. Analyses suggested that these Carcinoscorpius rotundicauda contain TTX and its analogues as the major toxin and PSPs as the minor, respectively. Besides, no DSPs were found.