One new coumarin from seeds of Herpetospermum pedunculosum / 中国中药杂志

This paper aims to investigate the chemical constituents of the seeds of Herpetospermum pedunculosum. One new coumarin and two known lignans were isolated from the ethanolic extract of the seeds of H. pedunculosum with thin layer chromatography(TLC), silica gel column chromatography, Sephedax LH-20 chromatography, Semi-preparative high performance liquid chromatography and recrystallization, etc. Their structures were elucidated as herpetolide H(1), phyllanglaucin B(2), and buddlenol E(3) by analysis of their physicochemical properties and spectral data. Among them, compound 1 was a new compound, and compounds 2 and 3 were isolated from this genus for the first time. In vitro anti-inflammatory activity test showed that herpetolide H had certain NO inhibitory activity for LPS-induced RAW 264.7 cells, with its IC_(50) value of(46.57±3.28) μmol·L~(-1).

Cloning and expression analysis of calmodulin gene from Pinellia ternate / 中国中药杂志

According to the data of Pinellia ternate transcriptome,two calmodulin genes were cloned and named as Pt Ca M1 and PtCa M2 respectively. The results of bioinformatics analysis showed that Pt Ca Ms genes contained a 450 bp open reading frame,encoding149 amino acids.The identity of the coding sequences was 80%,and the identity of amino acids sequence was 91%. Pt Ca Ms genes contained EF-hand structure domain,belonging to the Ca M families. The Real-time PCR analysed the expression patterns of Pt Ca Ms in different tissues and different treatments. RESULTS:: showed that Pt Ca M1 and Pt Ca M2 gene were the highest expression level in tuber. Under Ca Cl2 treatment,the expressions of Pt Ca Ms were significantly higher than the control. Under EGTA,La Cl3 and TFP treatments,the expression level of Pt Ca Ms decreased gradually. In this study,the Pt Ca Ms gene were successfully cloned from P. ternate,which laid a foundation for the functional characteristic of Pt Ca Ms gene and the synthesis of alkaloids from P. ternata for further study.

Effects of nitrogen form on accumulation of alkaloids and expression of relative genes in Atropa belladonna / 中国中药杂志

Hyoscyamine and scopolamine are two main alkaloids in Atropa belladonna with great medicinal value. In this paper, the contents of hyoscyamine and scopolamine, the upstream products in alkaloid synthesis, and the expression levels of key enzyme genes PMT, TRⅠ and H6H in secondary metabolism of A. belladonna seedlings were measured to clarify the mechanism of nitrogen forms regulating alkaloids synthesis.The results showed that the 50/50 (NH⁺₄/NO⁻₃) treatment was more favorable for the accumulation of alkaloids and the conversion of hyoscyamine to scopolamine. The content of putrescine was almost consistent with the change of key enzymes activities in the synthesis of putrescine, they both increased with the rise of ammonium ratio, reaching the highest at 75/25 (NH⁺₄/NO⁻₃). The detection of signaling molecule nitric oxide (NO) showed that the NO concentration decreased with the decrease of nitrate proportion. Further detection of gene expression levels of PMT, TRⅠ and H6H in TAs synthesis pathway showed that a certain amount of ammonium promoted the expression of PMT and H6H in roots. When the ratio of ammonium to nitrate was 50/50, PMT, TRⅠ and H6H in leaves and roots had higher expression levels. It can be speculated that the regulation of the formation of hyoscyamine to scopolamine by nitrogen forms mainly through affecting the expression of key enzyme genes. 50/50 (NH⁺₄/NO⁻₃) treatment increased the gene expression of TRⅠ in both leaves and roots as well as PMT and H6H in roots, promoting the synthesis of putrescine to hyoscyamine and the conversion of hyoscyamine to scopolamine.

Cloning and functional analysis of JAZ genes in Artemisia annua / 药学学报

Jasmonic acid (JA) can promote the biosynthesis of artemisinin.To have an insight into the JA signaling in Artemisia annua,two new genes belonging to JAZ family,namely AaJAZ5 and AaJAZ6,were cloned from Artemisia annua,which might be the negative regulators involved in the JA signaling pathway.Bioinformatic analysis showed that AaJAZ5 and AaJAZ6 contained the conserved domains of ZIM and Jas specific to JAZ family.According to tissue profile analysis,AaJAZ5 had the highest expression level in leaf and AaJAZ6 had the highest expression level in root.The expression levels of both AaJAZ5 and AaJAZ6 were markedly elevated by methyl jasmonate and mechanical wounding.The BiFC results indicated that AaJAZ5,as well as AaJAZ6,physically interacted with AaMYC2.Importantly,only AaJAZ5 could interact with AaCOI1.The interaction assays given by BiFC suggested that AaJAZ5 might play a crucial role in JA signaling.This study facilitated the further analysis of the functional divergence of JAZ-family members and the understanding of molecular mechanism on JA signaling to regulate the artemisinin biosynthesis.

Molecular cloning and characterization of CMK from Artemisia annua / 中国中药杂志

Artemisinin is a preferred medicine in the treatment of malaria. In this study, AaCMK, a key gene involved in the upstream pathway of artemisinin biosynthesis, was cloned and characterized from Artemisia annua for the first time. The full-length cDNA of AaCMK was 1 462 bp and contained an ORF of 1 197 bp that encoded a 399-anomo-acid polypeptide. Tissue expression pattern analysis showed that AaCMK was expressed in leaves, flowers, roots and stems, but with higher expression level in glandular secretory trichomes. In addition, the expression of AaCMK was markedly increased after MeJA treatment. Subcellular localization showed that the protein encoded by AaCMK was localized in chloroplast. Overexpression of AaCMK in Arabidopsis increased the contents of chlorophyll a, chlorophyll b and carotenoids. These results suggest that AaCMK plays an important role in the biosynthesis of terpenoids in A. annua and this research provids a candidate gene that could be used for engineering the artemisinin biosynthesis.

A new napthalenone from roots of Rumex nepalensis / 中国中药杂志

A new napthalenone, rumexone A (1), was isolated from the roots of Rumex nepalensis. The structure of 1 was elucidated by extensive spectroscopic analyses, including 1D and 2D NMR spectra and MS data. Its cytotoxic effect was evaluated using four clinically relevant human cancer cell lines, gastric carcinoma SGC7901, breast carcinoma MDA-MB-231, lung carcinoma A549, and hepatocellular carcinoma HepG2.

Cloning and characterization of an aromatic amino acid aminotransferase (ArAT) gene involved in tropane alkaloid biosynthesis from Hyoscyamus niger / 药学学报

Tropane alkaloids are anticholinergic drugs widely used clinically. Biosynthesis of tropane alkaloids in planta involves a step of transamination of phenylalanine. Based on the sequenced transcriptomes of lateral roots and leaves of Hyoscyamus niger, we found three annotated aromatic amino acid aminotransferases, which were respectively named HnArAT1, HnArAT2 and HnArAT3. Sequence analysis showed that HnArAT3 had highest similarity with the reported Atropa belladonna AbArAT4, which was involved in tropane alkaloid (TA) to provide the precursor of the phenyllactic acid moiety. Tissue expression pattern analysis indicated that HnArAT3 was specifically expressed in lateral roots, where is the organ synthesizing tropane alkaloids. Then, method of virus induced gene silencing (VIGS) was used to characterize the function of HnArAT3 in H. niger. Gene expression analysis given by real-time quantitative PCR showed that all the transgenic lines had lower expression levels of HnArAT3 than the non-transgenic control, and HPLC analysis of alkaloids demonstrated significant decrease in the contents of hyoscyamine, anisodamine and scopolamine in planta. These results suggested that HnArAT3 was involved in the phenyllactic acid branch of TA biosynthetic pathway. Molecular cloning and functional identification of HnArAT3 laid the foundation for further understanding of TA biosynthesis and metabolic regulation, and also provided a new candidate gene for engineering biosynthetic pathway of tropane alkaloids.

Molecular cloning and functional characterization of the gene encoding hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate reductase gene from Artemisia annua L / 药学学报

Artemisinin is the first choice for malaria treatment. The plastidial MEP pathway provides 5-carbon precursors (IPP and its isomer DMAPP) for the biosynthesis of isoprenoid (including artemisinin). Hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate reductase (HDR) is the last enzyme involved in the MEP pathway, which catalyzes HMBPP to form IPP and DMAPP. In this study, we isolated the full-length cDNA of HDR from Artemisia annua L. (AaHDR2) and performed functional analysis. According to gene expression analysis of AaHDR2 (GenBank:KX058541) and AaHDR1 reported ever (GenBank:ADC84348.1) by qPCR, we found that AaHDR1 and AaHDR2 had much higher expression level in trichomes than that in roots, stems, leaves and flowers. AaHDR2 had much higher expression level in flowers than that in leaves. Further, the plant hormones such as MeJA and ABA respectively up-regulated the expression level of AaHDR1 and AaHDR2 significantly, but GA3 up-regulated the expression level of AaHDR2 only. The gene expression analysis of AaHDR1 and AaHDR2 showed that AaHDR2 had a greater contribution than AaHDR1 to isoprenoid biosynthesis (including artemisinin). We used AaHDR2 for the following experiments. Bioinformatic analysis indicated that AaHDR2 belonged to the HDR family and the functional complementation assay showed that AaHDR2 did have the enzymatic function of HDR, using E. coli mutant MG1655araHDR as host cell. The subcellular localization assay showed that AaHDR2 fused with GFP at its N-terminal specifically targeted in chloroplasts. Finally, AaHDR2 was overexpressed in Arabidopsis thaliana. The AaHDR2-overexpressing plants produced the isoprenoids including chlorophyll a, chlorophyll b and carotenoids at significantly higher levels than the wild-type Arabidopsis plants. In summary, AaHDR2 might be a candidate gene for genetic improvement of the isoprenoid biosynthesis.

Overexpression of NtPMT and HnH6H changed hyoscyamine-rich Atropa belladonna to scopolamine-rich varieties / 药学学报

Atropa belladonna L. is the commercial plant material for production of tropane alkaloids, including hyoscyamine and scopolamine. The wild-type Atropa belladonna is characterized by the hyoscyaminerich chemotype, in which the hyoscyamine content is much higher than the scopolamine content. It is the common goal for the pharmaceutical industry to increase the content of scopolamine in A. belladonna. Based on the T0 progeny of transgenic A. belladonna with NtPMT and HnH6H overexpression, T1 progeny of transgenic A. belladonna were obtained through self-pollination and used in a field trial. The 461 bp fragment of NtPMT and the 1 077 bp HnH6H were simultaneously expressed from T1 progeny of transgenic A. belladonna, but were not obtained from the wild-type A. belladonna. At the transcription level, the expression of NtPMT and HnH6H were detected in T1 progeny of transgenic A. belladonna, but were not detected in the wild-type plants. Further, the alkaloids were analyzed by HPLC. In the stems and leaves of T1 progeny of transgenic A. belladonna, hyoscyamine was not detected and scopolamine was detected at very high levels; in the stems and leaves of wild-type A. belladonna, hyoscyamine was detected at much higher levels. In the leaves of T1 progeny of transgenic A. belladonna, the content of scopolamine was 15-36 folds higher than that of wildtype leaves; in the stems of T1 progeny of transgenic A. belladonna, the scopolamine content was 37-108 folds higher than that of wild-type stems. In conclusion, overexpression of NtPMT and HnH6H greatly enhanced conversion of hyoscyamine into high-value scopolamine and improved the commercial value of A. belladonna.

Molecular cloning and characterization of the 2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase gene from Artemisia annua L / 药学学报

The plastidial methylerythritol phosphate (MEP) pathway provides 5-carbon precursors to the biosynthesis of isoprenoid (including artemisinin). 2-C-Methyl-D-erythritol-4-phosphate cytidylyltransferase (MCT) is the third enzyme of the MEP pathway, which catalyzes 2-C-methyl-D-erythritol-4-phosphate to form 4-(cytidine 5'-diphospho)-2-C-methyl-D-erythritol. The full-length MCT cDNA sequence (AaMCT) was cloned and characterized for the first time from Artemisia annua L. Analysis of tissue expression pattern revealed that AaMCT was highly expressed in glandular secretory trichome and poorly expressed in leaf, flower, root and stem. AaMCT was found to be a methyl jasmonate (MeJA)-induced genes, the expression of AaMCT was significantly increased after MeJA treatment. Subcellular localization indicated that the GFP protein fused with AaMCT was targeted specifically in chloroplasts. The transgenic plants of Arabidopsis thaliana with AaMCT overexpression exhibited a significantly increase in the content of chlorophyll a, chlorophyll b and carotenoids, demonstrating that AaMCT kinase plays an influential role in isoprenoid biosynthesis.

Herpetolide C: one new 7H-dibenzoc,eoxepin-5-one from Herpetospermum caudigerum / 药学学报

The chemical constituents of Herpetospermum caudigerum were investigated using chromatographic methods, including silica gel column chromatography, Sephadex LH-20 and semi-preparative HPLC. Four compounds were isolated and their structures were elucidated by spectral data and physicochemical properties, which were identified as 2,11-dimethoxy-3,9-dihydroxy-7H-dibenzo[c,e]oxepin-5-one (1), 7,8'-didehydroherpetotriol (2), herpetotriol (3) and kaempferitrin (4). Among those, compound 1 is one new 7H-dibenzo[c,e] oxepin-5-one, named as herpetolide C.

Chamerilactone A: one new isocoumarin isolated from Chamerion angustifolium / 药学学报

A new isocoumarin, chamerilactone A (1) was isolated from the ethanol extract of Chamerion angustifolium with normal phase silica column chromatography, Sephadex LH-20, MCI CHP-20 and semipreparative HPLC methods. Its structure and stereochemistry were elucidated by spectroscopic methods, including 2D-NMR and optical rotation techniques.

Study on medicinal plant resources and diversity in Rhinopithecus bieti national natural reserve of Markam in Tibet / 中国中药杂志

This research was a part of the investigation of traditional Chinese medicine resources survey in Markam. The medicinal plants in natural reserve were studied for the first in this paper. There were 300 species in 202 genera of 54 families, among them there were 7 species of ferns in 5 genera of 5 families, 6 species of gymnosperms in 4 genera of 3 families, and 287 species of angiosperms in 194 genera of 61 families. There were 166 species Tibetan medicinal plants in 102 genera of 47 families. Quantitative analysis was carried out in 6 aspects of family and genus composition, medicinal parts, drug properties, flavour of a drug, Tibetan medicine, toxicity and new plants. The concrete suggestions of protection and exploitation were put forward, which provided scientific basis for the sustainable utilization of medicinal plants in this area.

Cloning and expression of the key enzyme hyoscyamine 6 beta-hydroxylase gene (DaH6H) in scopolamine biosynthesis of Datura arborea / 药学学报

Hyoscyamine 6 beta-hydroxylase (H6H) is the last rate-limiting enzyme directly catalyzing the formation of scopolamine in tropane alkaloids (TAs) biosynthesis pathway. It is the primary target gene in the genetic modification of TAs metabolic pathway. Full-length cDNA and gDNA sequences of a novel H6H gene were cloned from Datura arborea (DaH6H, GenBank accession numbers for cDNA and gDNA are KR006981 and KR006983, respectively). Nucleotide sequence analysis reveals an open reading frame of 1375 bp encoding 347 amino acids in the cDNA of DaH6H, while the gDNA of DaH6H contains four exons and three introns, with the highest similarity to the gDNA of H6H from D. stramonium. DaH6H also exhibited the most identity of 90.5% with DsH6H in amino acids and harbored conserved 2-oxoglutarate binding motif and two iron binding motifs. The expression level of DaH6H was highest in the mature leaf, followed by the secondary root, and with no expression in the primary root based on qPCR analysis. Its expression was inhibited by MeJA. DaH6H was expressed in E. coli and a 39 kD recombinant protein was detected in SDS-PAGE. Comparison of the contents of scopolamine and hyoscyamine in various TAs-producing plants revealed that D. arborea was one of the rare scopolamine predominant plants. Cloning of DaH6H gene will allow more research in the molecular regulatory mechanism of TAs biosynthesis in distinct plants and provide a new candidate gene for scopolamine metabolic engineering.

Cloning and functional characterization of a cDNA encoding isopentenyl diphosphate isomerase involved in taxol biosynthesis in Taxus media / 药学学报

Taxol is one of the most potent anti-cancer agents, which is extracted from the plants of Taxus species. Isopentenyl diphosphate isomerase (IPI) catalyzes the reversible transformation between IPP and DMAPP, both of which are the general 5-carbon precursors for taxol biosynthesis. In the present study, a new gene encoding IPI was cloned from Taxus media (namely TmIPI with the GenBank Accession Number KP970677) for the first time. The full-length cDNA of TmIPI was 1 232 bps encoding a polypeptide with 233 amino acids, in which the conserved domain Nudix was found. Bioinformatic analysis indicated that the sequence of TmIPI was highly similar to those of other plant IPI proteins, and the phylogenetic analysis showed that there were two clades of plant IPI proteins, including IPIs of angiosperm plants and IPIs of gymnosperm plants. TmIPI belonged to the clade of gymnosperm plant IPIs, and this was consistent with the fact that Taxus media is a plant species of gymnosperm. Southern blotting analysis demonstrated that there was a gene family of IPI in Taxus media. Finally, functional verification was applied to identify the function of TmIPI. The results showed that biosynthesis of β-carotenoid was enhanced by overexpressing TmIPI in the engineered E. coli strain, and this suggested that TmIPI might be a key gene involved in isoprenoid/terpenoid biosynthesis.

Enhancement of artemisinin biosynthesis in transgenic Artemisia annua L. by overexpressed HDR and ADS genes / 药学学报

Artemisnin is a novel sesquiterpene lactone with an internal peroxide bridge structure, which is extracted from traditional Chinese herb Artemisia annua L. (Qinghao). Recommended by World Health Organization, artemisinin is the first-line drug in the treatment of encephalic and chloroquine-resistant malaria. In the present study, transgenic A. annua plants were developed by overexpressing the key enzymes involved in the biosynthetic pathway of artemisinin. Based on Agrobacterium-mediated transformation methods, transgenic plants of A. annua with overexpression of both HDR and ADS were obtained through hygromycin screening. The genomic PCR analysis confirmed six transgenic lines in which both HDR and ADS were integrated into genome. The gene expression analysis given by real-time quantitative PCR showed that all the transgenic lines had higher expression levels of HDR and ADS than the non-transgenic control (except ah3 in which the expression level of ADS showed no significant difference compared with control); and the HPLC analysis of artemisinin demonstrated that transgenic A. annua plants produced artemisinin at significantly higher level than non-transgenic plants. Especially, the highest content of artemisinin was found in transgenic line ah70, in which the artemisinin content was 3.48 times compared with that in non-transgenic lines. In summary, overexpression of HDR and ADS facilitated artemisinin biosynthesis and this method could be applied to develop transgenic plants of A. annua with higher yield of artemisinin.

Renchangianin E: a new dibenzocyclooctadiene lignan from Kadsura renchangiana / 药学学报

A new dibenzocyclooctadiene lignan, renchangianin E (1) was isolated from the stems of Kadsura renchangiana. Its structure and stereochemistry were elucidated by spectroscopic methods, including 2D-NMR techniques.

Expression pattern of genes involved in tropane alkaloids biosynthesis and tropane alkaloids accumulation in Atropa belladonna / 中国中药杂志

Atropa belladonna is a medicinal plant and main commercial source of tropane alkaloids (TAs) including scopolamine and hyoscyamine, which are anticholine drugs widely used clinically. Based on the high throughput transcriptome sequencing results, the digital expression patterns of UniGenes representing 9 structural genes (ODC, ADC, AIH, CPA, SPDS, PMT, CYP80F1, H6H, TRII) involved in TAs biosynthesis were constructed, and simultaneously expression analysis of 4 released genes in NCBI (PMT, CYP80F1, H6H, TRII) for verification was performed using qPCR, as well as the TAs contents detection in 8 different tissues. Digital expression patterns results suggested that the 4 genes including ODC, ADC, AIH and CPA involved in the upstream pathway of TAs, and the 2 branch pathway genes including SPDS and TRII were found to be expressed in all the detected tissues with high expression level in secondary root. While the 3 TAs-pathway-specific genes including PMT, CYP80F1, H6H were only expressed in secondary roots and primary roots, mainly in secondary roots. The qPCR detection results of PMT, CYP80F1 and H6H were consistent with the digital expression patterns, but their expression levels in primary root were too low to be detected. The highest content of hyoscyamine was found in tender stems (3.364 mg x g(-1)), followed by tender leaves (1.526 mg x g(-1)), roots (1.598 mg x g(-1)), young fruits (1.271 mg x g(-1)) and fruit sepals (1.413 mg x g(-1)). The highest content of scopolamine was detected in fruit sepals (1.003 mg x g(-1)), then followed by tender stems (0.600 mg x g(-1)) and tender leaves (0.601 mg x g(-1)). Both old stems and old leaves had the lowest content of hyoscyamine and scopolamine. The gene expression profile and TAs accumulation indicated that TAs in Atropa belladonna were mainly biosynthesized in secondary root, and then transported and deposited in tender aerial parts. Screening Atropa belladonna secondary root transcriptome database will facilitate unveiling the unknown enzymatic reactions and the mechanisms of transcriptional control.

Enhancement of tropane alkaloids production in transgenic hair roots of Atropa belladonna by overexpressing endogenous genes AbPMT and AbH6H / 药学学报

Atropa belladonna L. is the officially medicinal plant species and the main commercial source of scopolamine and hyoscyamine in China. In this study, we reported the simultaneous overexpression of two functional genes involved in biosynthesis of scopolamine, which respectively encoded the upstream key enzyme putrescine N-methyltransferase (PMT; EC 2.1.1.53) and the downstream key enzyme hyoscyamine 6beta-hydroxylase (H6H; EC 1.14.11.11) in transgenic hair root cultures of Atropa belladonna L. HPLC results suggested that four transgenic hair root lines produced higher content of scopolamine at different levels compared with nontransgenic hair root cultures. And scopolamine content increased to 8.2 fold in transgenic line PH2 compared with that of control line; and the other four transgenic lines showed an increase of scopolamine compared with the control. Two of the transgenic hair root lines produced higher levels of tropane alkaloids, and the content increased to 2.7 fold in transgenic line PH2 compared with the control. The gene expression profile indicated that both PMT and H6H expressed at a different levels in different transgenic hair root lines, which would be helpful for biosynthesis of scopolamine. Our studies suggested that overexpression of A. belladonna endogenous genes PMT and H6H could enhance tropane alkaloid biosynthesis.

Enhanced biosynthesis of scopolamine in transgenic Atropa belladonna by overexpression of h6h gene / 中国中药杂志

Transgenic Atropa belladonna with high levels of scopolamine was developed by metabolic engineering. A functional gene involved in the rate limiting enzyme of h6h involved in the biosynthetic pathway of scopolamine was over expressed in A. belladonna via Agrobacterium-mediation. The transgenic plants were culturing till fruiting through micropropogating and acclimating. The integration of the h6h genes into the genomic DNA of transgenic plants were confirmed by genomic polymerase chain reaction (PCR) analysis. Analysis of the difference of plant height, crown width, stem diameter, leaf length, leaf width, branch number and fresh weight was carried out using SPSS software. The content of hyoscyamine and scopolamine in roots, stems, leaves and fruits was determined by HPLC. The investigation of the expression levels of Hnh6h by qPCR. Both Kan(r) and Hnh6h genes were detected in five transgenic lines of A. belladonna plants (A8, A11, A12, C8 and C19), but were not detected in the controls. The plant height, crown width, stem diameter, leaf length, leaf width, branch number and fresh weight of transgenic plants did not decrease by comparison with the non-transgenic ones, and furthermore some agronomic characters of transgenic plants were better than those of the controls. The highest level of scopolamine was found in leaves of transgenic A. belladonna, and the content of scopolamine was also higher than that of hyoscyamine in leaves. The contents of scopolamine of leaves in different transgenic lines were listed in order: C8 > A12 > C19 > A11 > A8, especially, the content of scopolamine in transgenic line C8 was 2.17 mg x g(-1) DW that was 4.2 folds of the non-transgenic ones (0.42 mg x g(-1) DW). The expression of transgenic Hnh6h was detected in all the transgenic plants but not in the control. The highest level of Hnh6h expression was found in transgenic leaves. Overexpression of Hnh6h is able to break the rate limiting steps involved in the downstream pathway of scopolamine biosynthesis, and thus promotes the metabolic flux flowing toward biosynthesis of scopolamine to improve the capacity of scopolamine biosynthesis in transgenic plants. As a result, transgenic plants of A. belladonna with higher level of scopolamine were developed.