Abstract:The Traditional Chinese Medicine herbs Pollen Typhae and Pollen Typhae Carbonisatus have been used as a hemostatic medicine promoting blood clotting for thousands of years. In this study, a reliable, highly sensitive method based on LC-MS/MS has been developed for differentiation of the heating products of total flavonoids in Pollen Typhae (FPT-N). Twenty three peaks were detected and 18 peaks have been structurally identified by comparing retention times, high resolution mass spectrometry data, and fragment ions with those of the reference substances and/or literature data. Additionally, 15 compounds have been quantified by multiple reaction monitoring in the negative ionization mode. It was found that the contents of the characterized compounds differed greatly from each other in FPT-N samples. Among them, the content of huaicarbon B OPEN ACCESSMolecules 2015, 20 18353 significantly increased at first, while it decreased after heating for 25 min, which could be considered as the characteristic component for distinguishing FPT-N. The present study provided an approach to rapidly distinguish the differences of FPT-N samples. In addition, the actively summarized characteristic fragmentation might help deducing the structure of unknown flavonols compounds. Furthermore, transformation rules of flavonoids during the heating process in carbonisatus development could contribute to hemostatic therapeutic component exploration.

BackgroundTaxol is an efficient anticancer drug; however, the accumulation of taxoids can vary hugely among Taxus species. The mechanism underlying differential accumulation of taxoids is largely unknown. Thus, comparative analysis of the transcriptomes in three Taxus species, including T. media, T. mairei and T. cuspidata, was performed.ResultsKEGG enrichment analysis revealed that the diterpenoid biosynthesis and cytochrome P450 pathways were significantly enriched in different comparisons. Differential expressions of these taxol biosynthesis related genes might be a potential explanation for the interspecific differential accumulation of taxol and its derivatives. Besides, the sequences of several MEP pathway-associated genes, such as DXS, DXR, MCT, CMK, MDS, HDS, HDR, IPPI, and GGPPS, were re-assembled based on independent transcriptomes from the three Taxus species. Phylogenetic analysis of these MEP pathway-associated enzymes also showed a high sequence similarity between T. media and T. cuspidata. Moreover, 48 JA-related transcription factor (TF) genes, including 10 MYBs, 5 ERFs, 4 RAPs, 3 VTCs, and 26 other TFs, were analyzed. Differential expression of these JA-related TF genes suggested distinct responses to exogenous JA applications in the three Taxus species.ConclusionsOur results provide insights into the expression pattern and sequence similarity of several taxol biosynthesis-related genes in three Taxus species. The data give us an opportunity to reveal the mechanism underlying the variations in the taxoid contents and to select the highest-yielding Taxus species.Electronic supplementary materialThe online version of this article (10.1186/s12870-019-1645-x) contains supplementary material, which is available to authorized users.

SummaryTaxus stem barks can be used for extraction of paclitaxel. However, the composition of taxoids across the whole stem and the stem tissue‐specificity of paclitaxel biosynthesis‐related enzymes remain largely unknown. We used cultivated Taxus media trees for analyses of the chemical composition and protein of major stem tissues by an integrated metabolomic and proteomic approach, and the role of TmMYB3 in paclitaxel biosynthesis was investigated. The metabolomic landscape analysis showed differences in stem tissue‐specific accumulation of metabolites. Phytochemical analysis revealed that there is high accumulation of paclitaxel in the phloem. Ten key enzymes involved in paclitaxel biosynthesis were identified, most of which are predominantly produced in the phloem. The full‐length sequence of TmMYB3 and partial promoter sequences of five paclitaxel biosynthesis‐related genes were isolated. Several MYB recognition elements were found in the promoters of TBT, DBTNBT and TS. Further in vitro and in vivo investigations indicated that TmMYB3 is involved in paclitaxel biosynthesis by activating the expression of TBT and TS. Differences in the taxoid composition of different stem tissues suggest that the whole stem of T. media has potential for biotechnological applications. Phloem‐specific TmMYB3 plays a role in the transcriptional regulation of paclitaxel biosynthesis, and may explain the phloem‐specific accumulation of paclitaxel.

LNF can be an effective means for treating RSs in patients with GERD.

Taxus trees are major natural sources for the extraction of taxol, a worldwide used anti-cancer agent. Taxus media is a dioecious woody tree with high taxol yield. However, the sexually dimorphic accumulation of taxoids in T. media is largely unknown. Our study revealed high accumulation of taxoids in the female T. media trees using a UPLC-MS/MS method. Thereafter, many differential metabolites and genes between female and male T. media trees were identified using metabolomic and transcriptomic analyses, respectively. Most of the taxol-related genes predominantly expressed in the female trees. A female-specific R2R3-MYB transcription factor, TmMYB39, was identified. Furthermore, BiFC and Y2H assays suggested the potential interaction between TmMYB39 and TmbHLH13. Several taxol biosynthesis-related promoter sequences were isolated and used for the screening of MYB recognition elements. EMSA analysis indicated that TmMYB39 could bind to the promoters of the GGPPS, T10OH, T13OH, and TBT genes. Interaction between TmMYB39 and TmbHLH13 trans-activated the expression of the GGPPS and T10OH genes. TmMYB39 might function in the transcriptional regulation of taxol biosynthesis through a “MYB-bHLH” module. Our results gave a potential explanation for the sexually dimorphic biosynthesis of taxol in T. media.

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BackgroundTrees of the genus Taxus are highly valuable medicinal plants with multiple pharmacological effects on various cancer treatments. Paclitaxel from Taxus trees is an efficient and widely used anticancer drug, however, the accumulation of taxoids and other active ingredients can vary greatly among Taxus species. In our study, the metabolomes of three Taxus species have been investigated.ResultsA total of 2246 metabolites assigned to various primary and secondary metabolic pathways were identified using an untargeted approach. Analysis of differentially accumulated metabolites identified 358 T. media-, 220 T. cuspidata-, and 169 T. mairei-specific accumulated metabolites, respectively. By searching the metabolite pool, 7 MEP pathway precursors, 11 intermediates, side chain products and derivatives of paclitaxel, and paclitaxel itself were detected. Most precursors, initiated intermediates were highly accumulated in T. mairei, and most intermediate products approaching the end point of taxol biosynthesis pathway were primarily accumulated in T. cuspidata and T. media. Our data suggested that there were higher-efficiency pathways to paclitaxel in T. cuspidata and T. media compared with in T. mairei. As an important class of active ingredients in Taxus trees, a majority of flavonoids were predominantly accumulated in T. mairei rather than T. media and T. cuspidata. The variations in several selected taxoids and flavonoids were confirmed using a targeted approach.ConclusionsSystematic correlativity analysis identifies a number of metabolites associated with paclitaxel biosynthesis, suggesting a potential negative correlation between flavonoid metabolism and taxoid accumulation. Investigation of the variations in taxoids and other active ingredients will provide us with a deeper understanding of the interspecific differential accumulation of taxoids and an opportunity to accelerate the highest-yielding species breeding and resource utilization.

Background Taxol is an efficient anticancer drug accumulated in Taxus species. Pseudotaxus chienii is an important member of Taxaceae, however, the level of six taxoids in P. chienii is largely unknown. Results High accumulation of 10-DAB, taxol, and 7-E-PTX suggested that P. chienii is a good taxol-yielding species for large-scale cultivation. By the omics approaches, a total of 3,387 metabolites and 61,146 unigenes were detected and annotated. Compared with a representative Taxus tree (Taxus yunnanensis), most of the differentially accumulated metabolites and differential expressed genes were assigned into 10 primary and secondary metabolism pathways. Comparative analyses revealed the variations in the precursors and intermediate products of taxol biosynthesis between P. chienii and T. yunnanensis. Taxusin-like metabolites highly accumulated in P. chienii, suggesting a wider value of P. chienii in pharmaceutical industry. Conclusions In our study, the occurrence of taxoids in P. chienii was determined. The differential expression of key genes involved in the taxol biosynthesis pathway is the major cause of the differential accumulation of taxoids. Moreover, identification of a number of differentially expressed transcription factors provided more candidate regulators of taxol biosynthesis. Our study may help to reveal the differences between Pseudotaxus and Taxus trees, and promote resource utilization of the endangered and rarely studied P. chienii.