Sulfur dioxide limit standard and residues in Chinese medicinal materials / 中国中药杂志

The traditional sulfur fumigation processing method has been widely used in the initial processing and storage of traditional Chinese medicinal materials due to its economy, efficiency, convenience, high operability and effect on mold and insect prevention. However, excessive sulfur fumigation of traditional Chinese medicinal materials would lead to the changes in chemical compositions, and even endanger human health. This study showed that traditional Chinese medicinal materials were sulfur fumigated directly after being harvested for quick drying, or fumigated after being weted in the storage process for preventing mold and insects. We found that the sulfur dioxide limits for traditional Chinese medicinal materials were stricter than those for foods. Based on the existing limit standards, we obtained the data of sulfur dioxide residues for 35 types of traditional Chinese medicinal materials in a total of 862 batches. According to the limit standard in the Chinese Pharmacopoeia (150， 400 mg·kg⁻¹), the average over-standard rate of sulfur dioxide was as high as 52.43%, but it was reduced to 29.47% if calculated based on the limit for vegetable additive standard (500 mg·kg⁻¹). Sulfur fumigation issue shall be considered correctly: sulfur dioxide is a type of low toxic substance and less dangerous than aflatoxin and other highly toxic substances, and a small amount of residue would not increase the toxicity of traditional Chinese medicinal materials. However, sulfur fumigation might change the content of chemical substances and affect the quality of traditional Chinese medicinal materials. Furthermore, the exposure hazards of toxic substances are comprehensively correlated with exposure cycle, exposure frequency, and application method. In conclusion, it is suggested to strengthen the studies on the limit standard of traditional Chinese medicinal materials, formulate practical and feasible limit standard for sulfur dioxide residues in traditional Chinese medicinal materials that are consistent with the medication characteristics of traditional Chinese medicinal materials and can guarantee people's demand for safe medication.

Quantitative analysis and stability of -hydroxybenzyl hydrogen sulfite in sulfur-fumigated Gastrodiae Rhizoma / 中国中药杂志

Studies on the characteristic chemical markers of sulfur fumigation have become an effective auxiliary way for quality control of traditional Chinese medicine. This study established a quantitative analysis method for the determination of -hydroxybenzyl hydrogen sulfite (-HS) in Gastrodiae Rhizoma (GR) based on UPLC-MS/MS. Then, 37 batches of GR were screened, and the results showed that 27 batches of them were sulfur-fumigated. Especially, the GR samples in Yunnan producing areas were sulfur-fumigated more seriously. Based on the stability of -HS after different storage time and heat treatment methods, it was found that the content of -HS was stable and reliable in the storage period of 8 months and under normal heat treatment (50, 60, 70, 80 °C) conditions. In conclusion, this study shows a high sensitivity, good selectivity and good stability of -HS, which can provide reference for the quality control and sulfur fumigation screening of GR.

Quality changes in Gastrodia Rhizoma of different origins and forms before and after sulfur fumigation / 中国中药杂志

As Gastrodiae Rhizoma (GR) is one of the herbs more seriously affected by sulfur fumigation, so its quality has been always of a great concern. In this paper, GR samples collected from eight main producing areas and in three forms were fumigated with sulfur and quantitatively and qualitatively analyzed based on UPLC-Q-TOF-MS/MS. The results showed that the contents of gastrodin, parishin, parishin B and parishin C were decreased, while the content of parishin E was increased after sulfur fumigation treatment. Besides, a new sulfur marker named p-hydroxybenzyl hydrogen sulfite was produced in sulfur-fumigated GR samples. As compared with producing origins, forms had a greater impact on the quality of GR, especially in Hongtianma and Wutianma. Besides, the contents of gastrodins and parishins in Hongtianma from Jilin were lowest as compared with those in other producing areas. This might be correlated with planting patterns and environmental factors. In conclusion, sulfur fumigation has a more obvious impact on the quality of GR than origins and forms, which is attributed to the generation of new sulfur fumigated markers.

Changes of chemical compositions and sulfur dioxide residues of Gastrodiae Rhizoma with different storage times / 中国中药杂志

To study the effect of different storage time on the chemical compositions and sulfur dioxide residues of sulfur-fumigated Gastrodiae Rhizoma (GR), and provide scientific basis for solving the quality and safety issues of sulfur-fumigated traditional Chinese medicinal materials. GR, sulfur-fumigated GR and its medicinal slices were stored under the same conditions, and then 8 active ingredients and sulfur dioxide residues were measured respectively. The results showed that the content of gastrodins in sulfur-fumigated GR and its medicinal slices was significantly lower than that in the non-fumigated GR. Moreover, the content of sulfur dioxide residue in sulfur-fumigated GR was significantly higher than that in its medicinal slices. That is to say, sulfur fumigation degree had significantly higher effect on GR quality as compared with its medicinal slices. During the whole storage time (8 months), the content of the eight chemical components in GR was not changed greatly in general. However, after the storage for 4 months, the content of 8 components and sulfur dioxide residues in all of GR samples were significantly changed. In particular, the content of sulfur dioxide residue in GR medicinal materials decreased up to 50% or more.

Geographical origin discriminant of Dendrobium officinale based on stable isotope ratios / 中国中药杂志

The isotopic ratios of strontium isotope (Sr) and light elements (C/H/O/N) in Dendrobium officinale from different producing areas (Shaoguan, Guangdong; Yulin, Guangxi; Shibing, Guizhou; Wenshan, Yunnan and Zhejiang province) were determined with thermal ionization mass spectrometry (TI-MS) and isotope ratio mass spectrometry (IRMS)．The differences of the stable isotope ratios in D. officinale were obtained by the variance analysis and the correlation analysis, and pattern recognition techniques with principal component analysis (PCA) was used to classify the geographical origins of D. officinale from different producing areas．The isotopic ratios of strontium isotope can be used to identified D. officinale in Zhejiang province, and the isotopic ratios of light elements showed the difference followed with the different producing areas. For δD and δ¹⁸ O in samples, maybe influenced by the environment effect. A positive correlation was found between δD and δ ¹⁸O.The principal component analysis was used to discern the samples of D. officinale from different producing areas based on detection technology of stable isotope ratios.These results revealed that it was possible and feasible to classify the geographical origin of D. officinale by the method of determination of isotopes,and provided a new method to identificate origin information of Chinese medicinal materials.

Secondary metabolic responses to treatment of 2-aminoindan-2-phosphonic acid in cell lines from Arnebia euchroma / 中国中药杂志

The accumulation of rosmarinic acid, acetylshikonin, deoxyshikonin, β, β'-dimethylacrylshikonin and isovalerylshikonin was investigated in cell suspension cultures of Arnebia euchroma (Royle) Johnst under the influence of 2-aminoindan-2-phosphonic acid (AIP), an inhibitor of phenylalanine ammonia lyase (PAL), and of the effector methyl jasmonate (MeJA). The results showed that methyl jasmonate promoted the accumulation of rosmarinic acid and shikonin derivatives. Conversely, 2-aminoindan-2-phosphonic acid suppressed the formation of rosmarinic acid, which indicated that AIP, indeed, was able to inhibit the phenylpropanoid pathway in A. euchroma. Meanwhile, the content of total shinkonins and other four kinds of shikonin derivatives, though varied in degrees, was also inhibited. And the inhibition was dose-dependent and time-dependent. Acetylshikonin responsed most rapidly to the treatment of AIP, the content reduced after 24 h of treatment and decreased to only half of those untreated control 48 h after teratment. β, β'-Dimethylacrylshikonin, difffer from acetylshikonin, responded much slowly to the treatment, inhibition could only be observed 96 h later. These suggest that phenylpropanoid pathway plays an important role in the shikoninsbiosynthesis, and this study provides a reference for the further research in metabolic regulation of producing shikonins by cell culture technology and biosynthesis pathways of shikonin derivatives. Still, shikonins biosynthesis pathways is complicated, the exact dose- and time-effect relationship of AIP and interaction between AIP and other effectors like MeJA need further research.

Transcriptome-based gene mining and bioinformatics analysis of p-hydroxybenzoate geranyltransferase genes in Arnebia euchroma / 中国中药杂志

The p-hydroxybenzoate geranyltransferases(PGT) play an important role in the biosynthesis pathways of shikonin derivatives. Six PGTs were obtained from transcriptome datebase of Arnebia euchroma by using bioinformatics methods and the proteins＇physiochemical properties they encoded were predicted. The result of protein domain prediction showed all of the six protein sequences contained the conserved domain of Ubia prenyltransferase family and possessed the motif NDxxDxxxD for prenyldiphosphate binding and a GX(K/Y)STAL sequence for putative aromatic ring binding. The phylogenetic tree showed that PGT and p-hydroxybenzoate polyprenyltransferase(PPT) belonged to two different clades. The results of gene expression analyses showed that the expression levels in the red shikonin-proficient line and the overground part of A. euchroma that could produce shikonin derivatives was much higher than the white shikonin-deficient line and the underground part, which suggested a positive correlation between the expression levels of PGT genes and shikonin production. This study aims to lay a foudation for further understanding of the function and enzymatic properties of PGT and provide a basis for the biosynthesis pathways and metabolic regulation of shikonin derivatives.

Mitogen-activated protein kinase genes of Artemisia annua and their expression analysis under Cadmium stress / 中国中药杂志

In order to study Artemisia annua under cadmium stress, whether there are corresponding MAPK genes involved in transduction of the cadmium signal. 17 AaMAPK genes, named AaMAPK1-AaMAPK17 repectively, were finally obtained by using Trinity method for de novo assembly of transcripts from SRA database and BLAST search against AtMAPK genes and determing conserved domain using a series of bioinformatics tools. There exist 16 MAPK genes contained T[D/E]Y conserved domains among the obtained genes. The expressions of these genes were analyzed by Real-time PCR under cadmium stress. The results showed that the expressions level of AaMAPK3 and AaMAPK10 were down-regulated and MAPK7, MAPK9 and MAPK12 were up-regulated. These indicated that there exist corresponding MAPK genes involved in transduction of the cadmium signal.