Cloning and expression of SmDXS2 gene in Swertia mussotii / 中国中药杂志

1-deoxy-D-xylulose-5-phosphate synthase2(DXS2) is the first key enzyme of the MEP pathway,which plays an important role in terpene biosynthesis of plants. According to the data of Swertia mussotii transcriptome, DXS2 gene(Gen Bank number MH535905) was cloned and named as Sm DXS2. The bioinformatics results showed that Sm DXS2 has no intron,with a 2 145 bp open reading frame encoding a polypeptide of 714 amino acids. They are belonging to 20 kinds of amino acids,and the most abundant amino acids include Ala,Gly and Trp. The predicted protein molecular weight was 76. 91 k Da and its theoretical isoelectric point(p I) was6. 5,which belonging to a hydrophilic protein. α-Helix and loop were the major motifs of predicted secondary structure of DXS2. The three function domains are TPP＿superfamily,Transket＿pyr＿ superfamily and Transketolase＿C superfamily,respectively. The Sm DXS2 protein shared high identity with other DXS2 proteins of plants. Phylogenetic analysis showed that Sm DXS2 protein is grouped with the gentian DXS2 protein. The recombinant protein of Sm DXS2 gene in Escherichia coli was approximately 92. 00 k Da(containing sumo-His tag protein 13 k Da),which was consistent with the anticipated size.This work will provide a foundation for further functional research of Sm DXS2 protein and increasing the product of iridoid compound by genetic engineering in S. mussotii.

Cloning and expression of geranyl pyrophosphate synthase gene in Swertia mussotii / 中草药

Objective: To clone the geranyl pyrophosphate synthase gene from Swertia mussotii (SmGPPS), analyze the bioinformation of SmGPPS, and perform the gene expression. Methods: According to the SmGPPS gene sequence of transcriptome of S. mussotii, the specific primers were designed, the cDNA complete sequences was obtained by RT-PCR and the sequence was analyzed using bioinformatics. Prokaryotic expression vector pET-28a-SmGPPS was constructed and transformed into Escherichia coli BL-21 (DE3) for expression under 37℃ and induced by 1 mmol/L IPTG. The relative expression of gene SmGPPS in the leaf, stem, and flower of S. mussotii was also studied. Results: The results showed that SmGPPS cDNA complete sequences had a length of 1 119 bp encoding 372 amino acid residues. And the protein secondary and tertiary structures were analyzed and forecasted. The SmGPPS protein shared high identity with other GPPS proteins of plants. The SDS-PAGE results showed that the expressed proteins were consistent with the anticipated size. Relative RT-PCR analysis indicated that SmGPPS showed the highest transcript abundance in the leaf. Conclusion: This work will provide a foundation for further functional research of SmGPPS protein and increasing the product of iridoid compound by genetic engineering in S. mussotii.

Simultaneous determination of protocatechuic acid, salidroside, and chlorogenic acid in sargentodoxa cuneata by HPLC / 国际中医中药杂志

Objective To establish a method for the determination of protocatechuic acid, salidroside, and chlorogenic acid in Sargentodoxa cuneata. Methods The separation was performed on a Waters XSELECT CSH C18 (150 mm × 4.6 mm, 5 μm) with methanol-acetonitrile-0.2 % phosphoric acid as the mobile phase in a gradient elution at a flow rate of 0.8 ml/min. The detection wavelength was 260 nm and the column temperature was 35 ℃. Results The linear ranges of protocatechuic acid, salidroside, and chlorogenic acid were 0.0020-0.0120, 0.0600-0.3602, 0.0750-4.5006 mg/ml, respectively. The average recoveries were 98.01% (RSD=0.07%), 98.53 % (RSD=0.12%), and 101.10 % (RSD=1.92%), respectively. Conclusions The method is simple, accurate, and highly reproducible, which could provide the scientific evidence for the quality control of Sargentodoxa cuneata.

Electrocardiogram analysis in high risk population of unexplained sudden death in Yunnan province / 中华心血管病杂志

<p><b>OBJECTIVE</b>The purpose of this study was to analyze the electrocardiographic features of the people living in the area with high incidence of unexplained sudden deaths in Yunnan province.</p><p><b>METHOD</b>The electrocardiograms of 338 residents from three villages (Dayao, Ninglang, Heqing) with high incidence of unexplained sudden deaths and one control village (Dali) were analyzed [averaged age was (33.4 +/- 11.7) years, 175 men and 163 women].</p><p><b>RESULTS</b>The incidence of cardiac arrhythmias was similar low in all groups. The left ventricular hypertrophy was observed in 34.6% of residents from Dayao. QTc significantly prolonged in the residents from all 3 high incidence areas compare the control area of Dali [control (386.8 +/- 27.22) ms, Ninglang (428.92 +/- 25.71) ms, Heqing (440.67 +/- 28.03) ms, Dayao (417.7 +/- 24.00) ms, P < 0.05 vs. control]. Incidence of U wave was significantly higher in Heqing village than that in control village (P < 0.05). The QUc of these 3 villages was: (613.67 +/- 37.34) ms, (597.19 +/- 46.47) ms, (608.59 +/- 39.59) ms respectively, and also significantly longer than the control village of Dali (589.33 +/- 41.27) ms (P < 0.05). The typical pattern of U wave presents as enlarged U wave and apparent T-U complex. In the 7 residents who have the family history of unexplained sudden death, 6 residents have U wave, and 4 of them present typical U wave pattern.</p><p><b>CONCLUSION</b>The significant ECG changes in villages with high incidence of unexplained sudden death in Yunnan province were prolonged QTc, enlarged U wave and apparent T-U complex and these ECG features suggested the repolarization abnormalities of the heart in these subjects.</p>

Experimental study on processing of Paeonia lactiflora / 中国中药杂志

<p><b>OBJECTIVE</b>To provide experimental data for the quality control of processed Paeonia lactiflora, a Chinese herbal medicine.</p><p><b>METHOD</b>Traditional processing of P. lactiflora was simulated, content of paeoniflorin and water extracts among different preparations were assayed by HPLC; The quantitative correlations among different processing conditions were analyzed, the effects of processing parameters on the contents of paeoniflorin and water extracts were assayed a nanalysed.</p><p><b>RESULT AND CONCLUSION</b>The controlled processing parameters were correlated with covariables which showed that processing procedures was controllable, and the heating temperature was a factor impacting the content of paeoniflorin.</p>