Prostratin, a tigliane phorbol ester with promise for the treatment of HIV, was identified and quantified in Euphorbia fischeriana root extracts obtained from several different sites in China. The greatest yield was recovered from root samples collected from Yakeshi, Inner Mongolia (63.54μg/g dry weight, or 0.00635% by mass). Prostratin was not detected in extracts of Euphorbia sp., E. esula, E. lucorum or Stellera chamaejasme. The presence of prostratin was verified by 1H and 13C NMR. Major fragmentation products were identified from ESI MSn spectra after HPLC separation, providing a reproducible fingerprint for unambiguously recognizing the compound in plant extracts.

狼毒大戟为大戟科多年生草本植物.本研究以狼毒大戟(Euphorbia fischoriana)为试验材料,构建狼毒大戟cDNA文库及EST测序.研究结果表明,我们成功地构建了狼毒大戟的cDNA文库,并获得了2099个EST的序列.进一步对这些ESTs数据进行了Unigene的拼接、ORF预测和相应的功能注释及分类,发现了一些可能参与Prostratin生物合成的候选结构基因Transketolase,NADPH-cytochrome P450 reductase,Cytochrome P450,S-adenosylmethionine synthetase,acetyltransferas,l-deoxy-D-xylulose-5-phosphate synthase (DXP)和候选调节基因AP2类ERF转录因子(APE-like ethylene-responsive transcription factor,AP2-like ERF),此研究为今后开展抗HIV次生代谢物Prostratin的代谢工程奠定了基础.

Taxoid 14β-hydroxylase directs a side-route of taxol pathway that leading to a large number of 14β-hydroxy taxoid side products. A RNAi vector was used to suppress the expression of taxoid 14β-hydroxylase (14OH) gene in Taxus×media suspension cells. The dsRNA expression unit was introduced into Taxus×media cells via Agrobacterium tumefaciens-mediated transformation approach. PCR-Southern blot analysis of transgenic cells showed that the dsRNA unit was integrated into the genome of Taxus×media. The levels of transcripts for 14OH gene in transformed and the control cell lines were determined by using RT-PCR method. In addition,the yield of taxoids were analyzed by HPLC. The transcription of 14OH gene was suppressed and the total amount of three C-14 oxygenated taxoids (yunnanxane,sinenxan A,sinenxan C) in Taxus×media transgenic cell lines reduced significantly as compared to those in the non-transgenic control. Inhibition of the 14OH gene via RNAi might provide a new way to enhance the production of Taxol in Taxus cells.