Study of the Unique Characteristics of Multi-Elements of the Wild Astragali Radix from Shanxi Province by Inductively Coupled Plasma Mass Spectrometry.

BACKGROUND: Astragali Radix (AR) is widely used because of its dual use in medicine and food. Wild Astragali Radix from Hunyuan county of Shanxi province in China is accepted as a geo-authentic medicine with high quality and good medicinal effects. Multi-elements of Astragali Radix partially reflect its efficacy and safety. However, there has been no systemic research about the elemental analysis of geo-authentic Astragali Radix until now. OBJECTIVE: In this paper, multi-elemental profiling of Astragali Radix from Gansu, Jilin, Inner Mongolia, Shaanxi and Shanxi provinces in China was carried out. METHODS: A microwave digestion coupled with inductively coupled plasma-MS (ICP-MS), principal component analysis (PCA), and partial-least square-discriminate analysis (PLS-DA) were used for analysis of the unique elemental accumulation ability of Shanxi wild AR. RESULTS: Compared to the samples from Gansu, Jilin, Inner Mongolia, Shaanxi provinces, and the cultivated samples from Shanxi, for 53 stably detected elements, the concentrations of most elements (Ba, Cs, Ga, La, Pr, and so on) were significantly higher while a few (Cd, Cu, P, W and Zn) were significantly lower in wild Astragali Radix from Shanxi. After binary logistic regression, combinational variable Ba-P was found to be a good marker to distinguish wild Astragali Radix of Shanxi province from the samples with other origins, and the total positive prediction probability of the test samples, both bought from the market and gathered from their original field, could reach 93.8% through external validation using the model. CONCLUSION: Multi-elemental analysis coupled with PCA, PLS-DA, nonparametric analysis and binary logistic regression can be a good tool for the identification of wild Astragali Radix from Shanxi province. HIGHLIGHTS: An ICP-MS method was developed and validated for multi-elements. Fifty-three elements in Astragali Radix from samples with different origins were compared. The wild Astragali Radix from Shanxi had unique elemental characteristics. Combinational variable Ba-P is a good marker to identify wild AR from Shanxi.

Study of enrichment difference of 64 elements among white tea subtypes and tea leaves of different maturity using inductively coupled plasma mass spectrometry.

A microwave digestion-inductively coupled plasma mass spectrometry (ICP-MS)-based analytical method for 64 elements in white tea was developed. The determination coefficient R2 were ranged from 0.9970 to 1.0000 in 3 orders of magnitude for the 64 detected elements, and the limits of detection (LODs) of the method were from 0.0004 to 35.906 ng/mL. The stability of the method was monitored by quality control samples (QCs) and the accuracy was validated by certified reference material. Application of this method in 3 white tea subtypes showed that most of 54 elements that above LODs (Al, Pb, Cd, Hg, As, rare earth elements, and etc.) displaying gradually increasing trend in subtypes of Baihaoyinzhen, Baimudan, and Shoumei which are manufactured from tea leaves of increasing maturity, while few elements (Zn, P and Ni) decreased. Then, a further application of this method in fresh samples of the bud and the 1st, 2nd, 3rd, 4th, and 5th leaf confirmed that more mature tea leaf has higher enrichment efficiency for most elements. In conclusion, a comprehensive microwave digestion-ICP-MS-based analytical method was established and applied in the content measurements of 64 elements in 3 white tea subtypes and fresh tea leaves of different maturity, and it demonstrated that more mature tea leaf has higher enrichment efficiency for most elements.

Selenium biofortification and its effect on multi-element change in Auricularia auricular.

Auricularia auricular could be useful as a candidate for human selenium supplementation. This study examined the effects of exogenous Se on the growth, yield, nutritive value, and mineral accumulation of A. auricular. Selenate or selenite (0.5-40.0 µg g-1) had no effect on mycelium morphology or the yield of fruiting bodies. In some cases, they affected the accumulation of inter-elements and significantly decreased the concentrations of copper, iron, and chromium in the Se-enriched fruiting bodies compared to that with control treatments. The polysaccharide (116.5-131.6 µg g-1) and protein (105.2-113.4 µg g-1) content in Se-enriched fruiting bodies were not significantly different from those observed in the controls (polysaccharide, 114.1 µg g-1; protein, 105.6 µg g-1). Thus, A. auricular can absorb inorganic Se from the substrate and convert it to organic Se compounds (selenocystine (≥4.1%), selenomethionine (≥91.9%), and Se-methylselenocysteine (≥2.3%)).

Cloning of nitrite reductase gene from Haematococcus pluvialis and transcription and enzymatic activity analysis at different nitrate and phosphorus concentration.

Haematococcus pluvialis is an economic microalga to produce astaxathin. To study the nitrogen metabolic process of H. pluvialis, the transcription level and enzyme content of nitrite reductase at different nitrate and phosphorus concentrations were studied. In this research, nitrite reductase gene (nir) was first cloned from H. pluvialis, which consists of 5592 nucleotides and includes 12 introns. The cDNA ORF is 1776 bp, encoding a 592 amino acid protein with two conserved domains. Phylogenetic analysis showed that the nir gene in H. pluvialis had the highest affinity with other freshwater green algae. Nitrogen and phosphorus play an important role in the growth of H. pluvialis. The single factor experiments of nitrogen on growth conditions showed that the group with 0.2 g/L NaNO3 had a relative high biomass. The single factor experiments of phosphorus on growth conditions showed that the group with 0.06 g/L K2HPO4 had a relative high biomass. The transcription level and enzymatic activity of nitrite reductase were detected at different nitrate and phosphorus concentrations. In the absence of nitrogen and phosphorus in the medium, nitrite reductase activity is the highest. This research provides theoretical guidance for optimization of culture medium for H. pluvialis and also provides an experimental basis for understanding of nitrogen metabolism pathway in H. pluvialis.