Screening of housekeeping genes in Gelsemium elegans and expression patterns of genes involved in its alkaloid biosynthesis / 生物工程学报

Gelsemium elegans is a traditional Chinese herb of medicinal importance, with indole terpene alkaloids as its main active components. To study the expression of the most suitable housekeeping reference genes in G. elegans, the root bark, stem segments, leaves and inflorescences of four different parts of G. elegans were used as materials in this study. The expression stability of 10 candidate housekeeping reference genes (18S, GAPDH, Actin, TUA, TUB, SAND, EF-1α, UBC, UBQ, and cdc25) was assessed through real-time fluorescence quantitative PCR, GeNorm, NormFinder, BestKeeper, ΔCT, and RefFinder. The results showed that EF-1α was stably expressed in all four parts of G. elegans and was the most suitable housekeeping gene. Based on the coexpression pattern of genome, full-length transcriptome and metabolome, the key candidate targets of 18 related genes (AS, AnPRT, PRAI, IGPS, TSA, TSB, TDC, GES, G8H, 8-HGO, IS, 7-DLS, 7-DLGT, 7-DLH, LAMT, SLS, STR, and SGD) involved in the Gelsemium alkaloid biosynthesis were obtained. The expression of 18 related enzyme genes were analyzed by qRT-PCR using the housekeeping gene EF-1α as a reference. The results showed that these genes' expression and gelsenicine content trends were correlated and were likely to be involved in the biosynthesis of the Gelsemium alkaloid, gelsenicine.

Material Basis Analysis of Toxicity Attenuation and Efficacy Reservation of Processing of Gelsemium elegans Rhizomes / 中国实验方剂学杂志

Objective::On the basis of previous research, to detect the changes of six main alkaloids in Gelsemium elegans rhizomes before and after being processed, so as to reveal its internal mechanism of processing. Method::The contents of gelsemine, humantenidine, koumine, gelsenicine, gelsevirine and humantenine in G. elegans rhizomes was determined simultaneously by HPLC, the content changes of these components before and after processing and its reasons were analyzed by cluster analysis and principal component analysis. The mobile phase was methanol (A)-0.1%formic acid aqueous solution (B) for gradient elution (0-10 min, 22%A; 10-20 min, 22%-30%A; 20-30 min, 30%-40%A). The flow rate was 1.0 mL·min-1. The detection wavelength was set at 254 nm, the injection volume was 10 μL, and the column temperature was 30 ℃. Result::Before processing, contents of the above six components in raw products were 1.444, 1.129, 3.590, 1.603, 2.376, 1.631 mg·g-1, after processing, the contents of these six components were 2.258, 0.343, 1.176, 0.115, 0.459, 0.281 mg·g-1, respectively. Gelsenicine, the most toxic ingredient of G. elegans rhizomes, decreased most significantly with a decreasing rate of 92.83%, while the less toxic ingredient, gelsemine, increased by 56.37%after processing. The contents of other four components in G. elegans rhizomes decreased to varying degrees after processing. The results of cluster analysis indicated that G. elegans rhizomes were clearly divided into two categories before and after processing. Principal component analysis showed that the first principal component before and after processing was changed from koumine to gelsemine. Conclusion::The degradation of toxic components and content changes of other components may be one of the intrinsic mechanism of toxicity attenuation and efficacy reservation of G. elegans rhizomes being processed.

Simultaneous Quantitative Analysis of Koumine, Gelsemine and Gelsenicine in Biological Samples by LC-MS/MS / 法医学杂志

OBJECTIVES@#To establish a LC-MS/MS method which is accurate and sensitive for determination of koumine, gelsemine, and gelsenicine in biological samples and to verify the method.@*METHODS@#Strychnine was used as internal standard. Analytes in blood, urine and liver with 1% sodium hydroxide solution were extracted by ethyl acetate. Chromatographic separation was achieved on a ZORBAX SB-C₁₈ column （150 mm×2.1 mm, 5 μm）, and gradient elution was performed with the buffer solution of methanol-20 mmol/L ammonium acetate （including 0.1% formic acid and 5% acetonitrile） as mobile phase. Qualitative and quantitative analysis was performed in the multiple reaction monitoring mode coupled with an electrospray ionization source under positive ion mode（ESI⁺）.@*RESULTS@#The linearity of koumine, gelsemine and gelsenicine in blood, urine and liver was good within corresponding linear limitation and the correlation coefficients （r）>0.995 0. The limits of detection were 0.1 ng/mL （0.1 ng/g）, 0.1 ng/mL （0.1 ng/g） and 0.01 ng/mL （0.01 ng/g）, respectively. The extraction recovery and accuracy of the alkaloids ranged from 61.9% to 114.6% and 92.4% to 114.3%, respectively. The relative standard deviations of the intra-day and inter-day precisions were not more than 11.0%.@*CONCLUSIONS@#The method is selective, sensitive and suitable for simultaneous determination of koumine, gelsemine and gelsenicine in body fluids and tissues, which offering technical support for clinical diagnosis and treatment and forensic toxicological analysis of Gelsemium elegans poisoning.