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Artemisia annua is the main natural source of artemisinin production. In A. annua , extended drought stress severely reduces its biomass and artemisinin production while short-term water-withholding or abscisic acid (ABA) treatment can increase artemisinin biosynthesis. ABA-responsive transcription factor AabZIP1 and JA signaling AaMYC2 have been shown in separate studies to promote artemisinin production by targeting several artemisinin biosynthesis genes. Here, we found AabZIP1 promote the expression of multiple artemisinin biosynthesis genes including AaDBR2 and AaALDH1 , which AabZIP1 does not directly activate. Subsequently, it was found that AabZIP1 up-regulates AaMYC2 expression through direct binding to its promoter, and that AaMYC2 binds to the promoter of AaALDH1 to activate its transcription. In addition, AabZIP1 directly transactivates wax biosynthesis genes AaCER1 and AaCYP86A1. The biosynthesis of artemisinin and cuticular wax and the tolerance of drought stress were significantly increased by AabZIP1 overexpression, whereas they were significantly decreased in RNAi- AabZIP1 plants. Collectively, we have uncovered the AabZIP1-AaMYC2 transcriptional module as a point of cross-talk between ABA and JA signaling in artemisinin biosynthesis, which may have general implications. We have also identified AabZIP1 as a promising candidate gene for the development of A. annua plants with high artemisinin content and drought tolerance in metabolic engineering breeding. AabZIP1 regulates artemisinin biosynthesis via directly transactivating AaADS and AaCYP71AV1 , and indirectly up-regulating AaDBR2 and AaALDH1 via AaMYC2. Moreover, AabZIP1 improves drought tolerance by promoting wax biosynthesis in Artemisia annua. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Pterocephalus hookeri (C. B. Clarke) Höeck, a Tibetan medicine widely used for treatment of rheumatoid arthritis, was recorded in Chinese Pharmacopoeia (2020 version) with slight toxicity. The liver injury was observed in mice with administration of n-butanol extract (BUE) in our previously study. However, the toxic components and the mechanism were still unrevealed.Purpose: The present study was aimed to isolate and structural elucidate of the toxic compound pterocephin A (PA), as well as evaluate its liver toxicity and investigate its mechanism.Methods: PA was isolated from the BUE of P. hookeri. Its structure was determined by analysis of HRMS, NMR and ECD data. L-02 cellular viability, LDH, ALT, AST, ROS, intracellular Ca2+ and the fluidity of cell membrane were assessed by multifunctional microplate reader. The PI staining, cell membrane permeability assessment, and mitochondrial fluorescence staining analysis were determined through the fluorescence microscope. Liver samples for mice were assessed by pathological and immunohistochemistry analysis. Expression levels of indicated proteins were measured by western blotting assays.Results: PA was determined as a previously undescribed oleanolane-type triterpenoid saponin. In vitro study revealed PA significantly induced hepatotoxicity by inhibition of L-02 cell growth, abnormally elevation of ALT and AST. Mechanically, PA induced the damage of cell membrane, fragmentation of mitochondria, and subsequently increase of intracellular Ca2+ and ROS levels, which trigged by necroptosis with the activation of RIP1 and NF-κB signaling pathways. In vivo study confirmed PA could induce liver injury in mice with observation of the body weight loss, increasing of serum ALT and AST, and the histopathological changes in liver tissues.Conclusion: Our present study indicated that PA was an undescribed toxic constituent in P. hookeri to induce liver injury in mice by activation of necroptosis and inflammation. And the findings are of great significance for the clinical use safely of this herb. [ABSTRACT FROM AUTHOR]

Background: In our previous study, we demonstrated the hepatoprotective effect of Herpetospermum pedunculosum in cholestatic rats. A bioassay-guided study also led to the identification and isolation of a lignan, dihydrodiconiferyl alcohol (DA) from the seeds of H. pedunculosum.Purpose: To investigate whether DA could alleviate cholestasis and determine the mechanisms underlying such action.Methods: Male Sprague-Dawley (SD) rats were administered with DA (10, 20 or 40 mg/kg) intragastrically once daily for 7 days prior to treatment with α-naphthylisothiocyanate (ANIT) (60 mg/kg). We then evaluated the levels of a range of serum indicators, determined bile flow, and carried out histopathological analyses. Western blotting was then used to investigate the levels of inflammatory mediators and the Farnesoid X Receptor (FXR), proteins involved in the downstream biosynthesis of bile acids, and a range of transport proteins. Molecular docking was used to simulate the interaction between DA and FXR. Cell viability of human hepatocytes (L-02) cells was determined by MTT. Then, we treated guggulsterone-inhibited L-02 cells, Si-FXR L-02 cells, and FXR-overexpression cells with the FXR agonist GW4064 (6 μM) or DA (25, 50 and 100 μM) for 24 h before detecting gene and protein expression by RT-PCR and western blotting, respectively.Results: DA significantly attenuated ANIT-induced cholestasis in SD rats by reducing liver function indicators in the serum, increasing bile flow, improving the recovery of histopathological injuries in the liver, and by alleviating pro-inflammatory cytokines in the liver. DA also increased the expression levels of FXR and altered the levels of downstream proteins in the liver tissues, thus indicating that DA might alleviate cholestasis by regulating the FXR. Molecular docking simulations predicted that DA was as an agonist of FXR. In vitro mechanical studies further showed that DA increased the mRNA and protein expression levels of FXR, Small Heterodimer Partner 1/2, Bile Salt Export Pump, Multidrug Resistance-associated Protein 2, and Na+/taurocholate Co-transporting Polypeptide, in both guggulsterone-inhibited and Si-FXR L-02 cells. Moreover, DA enhanced the mRNA and protein expression of FXR, and its downstream genes and proteins, in L-02 cells containing an FXR-overexpression plasmid.Conclusion: DA may represent an effective agonist for FXR has significant therapeutic potential for the treatment of cholestatic liver injury. [ABSTRACT FROM AUTHOR]

Background: Traditionally, seeds of Herpetospermum pedunculosum were used to treat liver disease or cholepathy. Up to date, their protecting effect against cholestasis was remain unclarified.Purpose: To investigate the efficacy, possible mechanisms, and active constituents of the ethyl acetate extract from the seeds of Herpetospermum pedunculosum (HPEAE), studies were carried out using cholestasis rat model induced by α-naphthylisothiocyanate (ANIT).Methods: Male rats were intragastrically treated with HPEAE (100, 200 or 400 mg/kg) once a day for 7 days and were modeled with ANIT (60 mg/kg). The levels of serum indicators, bile flow, and histopathology were evaluated. Indices of oxidative stress and inflammatory mediators were detected using the enzyme-linked immunosorbent assay. Western blotting method was employed for analyzing the protein levels in the signal pathways of farnesoid X receptor (FXR), kelch ech associating protein 1/nuclear factor erythroid 2-related factor 2 (Keap1/Nrf2) and nuclear factor κB (NF-κB). The chemical compositions of HPEAE was analyzed by HPLC, and partially chemical components of HPEAE were identified by comparisons of their retention times with the standards. The FXR agonistic activity of the identified compounds was evaluated in l-02 cells induced by guggulsterone using a high-content screening system.Results: The cholestasis caused by ANIT can be significantly ameliorated by restoring the liver function indexes of alanine transaminase, aspartate transaminase, alkaline phosphatase, gamma-glutamyltransferase, total bilirubin, direct bilirubin and total bile acid, which are dose-dependent, as well as pathological liver injury and bile flow. Mechanical studies suggested that HPEAE can activate the expression of FXR and then up regulate its downstream proteins (multidrug resistance-associated protein 2, bile salt export pump and Na+/taurocholate cotransporting polypeptide). Moreover, the levels of the active oxygen index glutathione, superoxide dismutase, glutathione peroxidase, catalase and malondialdehyde were markedly restored by treatment with HPEAE. Western blotting further confirmed that HPEAE up regulated the expression of quinone oxidoreductase 1, heme oxygenase 1 and Keap1, lowered the expression of Nrf2 and reduced oxidative stress. HPEAE also up regulated P-glycoprotein 65, phosphorylated P-glycoprotein 65 and inhibitor of NF-κB kinase α expression, down regulated inhibitor of NF-κB (IκB), restored inflammatory mediator tumor necrosis factor-α, interleukin-1β (IL-1β), IL-6 and IL-10, and reduced inflammatory response. Fifteen compounds were identified (12 lignans and 3 coumarins). Among them, five lignans exhibited the significant FXR agonistic activity in vitro.Conclusion: HPEAE may alleviate the cholestasis and liver injury caused by ANIT in rats by activating FXR, as well as suppressing the Keap1/Nrf2 and NF-κB signaling pathways and lignans may be its main active components. [ABSTRACT FROM AUTHOR]

Polyamines, including putrescine, spermidine, and spermine, play critical roles in cell physiology by different forms. As a rate-limiting enzyme that converts ornithine to putrescine, ornithine decarboxylase (ODC, EC 1.1.1.37) has been studied in detail in animals and microorganisms, but its specific functions are poorly understood in plants. In this study, the metabolic and developmental roles of the ODC gene were studied through RNAi-mediated suppression of the ODC gene (AbODC) in A. belladonna. Suppression of AbODC reduced the production of precursors of medicinal tropane alkaloids, including putrescine and N -methylputrescine, as well as hyoscyamine and scopolamine. In AbODC -RNAi roots, the production of putrescine and spermidine in free form was reduced, but in the AbODC -RNAi leaves, the content of free polyamines was not altered. In the roots/leaves of AbODC -RNAi plants, the production of conjugated and bound polyamines was reduced. In addition, suppression of the ODC gene resulted in reduction of polyamines and pollen sterility in AbODC- RNAi flowers. In floral organs, GUS-staining results indicated that AbODC was domainantly expressed in pollen. In summary, ornithine decarboxylase not only plays a key role in regulating the biosynthesis of diverse forms of polyamines and medicinal tropane alkaloids, but also participates in pollen development. [Display omitted] • Suppression of AbODC reduced the yield of tropane alkaloids and its precursors. • Inhibition of AbODC expression suppressed the biosynthesis of various polyamines. • In flower, AbODC was dominantly expressed in pollen. • Suppression of the ODC gene resulted in pollen sterility in AbODC- RNAi plants. [ABSTRACT FROM AUTHOR]

Nine previously undescribed iridoids, ptehosides A-I (1 – 9), together with 12 known ones (10 – 21), were isolated from Pterocephalus hookeri (C.B. Clarke) Höeck. Their structures were elucidated using various spectroscopic methods including HR-ESI-MS, NMR, UV, IR and CD, etc. The cytotoxic activities of all isolates were evaluated using MTT method in three human cancer cell lines (Caco2, Huh-7, and SW982). As result, compound 9 exhibited substantial inhibitory activity on Caco2, Huh-7, and SW982 cells with IC 50 values of 1.17 ± 0.05, 1.15 ± 0.05 and 1.14 ± 0.04 μM, respectively. A preliminary mechanism study showed that 9 arrested the cell cycle of SW982 cells in the G0/G1 phase and induced apoptosis by upregulating Bax expression and downregulating Bcl-2 expression. Nine undescribed iridoids, together with twelve known ones were isolated from the whole plant of Pterocephalus hookeri. Among them, seven compounds showed significant cytotoxic activities against SW982 cells in vitro. Mechanically, ptehoside I (9) could arrest the cell-cycle in G0/G1 phase and induce apoptosis. [Display omitted] • Nine undescribed iridoids were isolated from the whole plant of Pterocephalus hookeri. • The stereochemistry was identified by acid hydrolysis, experimental and calculated ECD. • Ptehoside I (9) induced G0/G1 cell cycle arrest against SW982 cells in vitro. • 9 induced apoptosis and regulated the expression levels of Bax and Bcl-2 proteins in SW982 cells. [ABSTRACT FROM AUTHOR]

Putrescine, produced via the arginine decarboxylase (ADC)/ornithine decarboxylase (ODC)-mediated pathway, is an initial precursor for polyamines metabolism and the root-specific biosynthesis of medicinal tropane alkaloids (TAs). These alkaloids are widely used as muscarinic acetylcholine antagonists in clinics. Although the functions of ODC in biosynthesis of polyamines and TAs have been well investigated, the role of ADC is still poorly understood. In this study, enzyme inhibitor treatment showed that ADC was involved in the biosynthesis of putrescine-derived metabolites and root growth in Atropa belladonna. Further analysis found that there were six ADC unigenes in the A. belladonna transcriptome, with two of them, AbADC1 and AbADC2 , exhibiting high expression in the roots. To investigate their roles in TAs/polyamines metabolism and root growth, RNA interference (RNAi) was used to suppress either AbADC1 or AbADC2 expression in A. belladonna hairy roots. Suppression of the AbADC1 expression resulted in a significant reduction in the putrescine content and hairy root biomass. However, it had no noticeable effect on the levels of N -methylputrescine and the TAs hyoscyamine, anisodamine, and scopolamine. On the other hand, suppression of AbADC2 expression markedly reduced the levels of putrescine, N -methylputrescine, and TAs, but had no significant effect on hairy root biomass. According to β -glucuronidase (GUS) staining assays, AbADC1 was mainly expressed in the root elongation and division region while AbADC2 was mainly expressed in the cylinder of the root maturation region. These differences in expression led to functional divergence, with AbADC1 primarily regulating root growth and AbADC2 contributing to TA biosynthesis. • RNAi reduced putrescine biosynthesis by suppressing AbADC1 or AbADC2 in A. belladonna hairy roots. • Knocking down AbADC1 reduced hairy root biomass, while knocking down AbADC2 did not. • Knocking down AbADC2 suppressed the biosynthesis of N -methylputrescine and TAs. • AbADC1 exhibited high expression in the root elongation and division region. • AbADC2 was highly expressed in the cylinder of the root maturation region. [ABSTRACT FROM AUTHOR]

In the present study, an immunological arabinan, LCP70-2A, was isolated from Ligusticum chuanxiong for the first time. The absolute molecular weight of LCP70-2A was determined to be 6.46 × 104 g/mol using the HPSEC-MALLS-RID method. The absolute configuration of arabinose in LCP70-2A was determined to be L-configuration. Physicochemical characterization revealed that LCP70-2A was a homogeneous polysaccharide and had a backbone of (1 → 5)-linked α -L-Ara f with terminal α -L-arabinose residues at position O -2 and O -3. Molecular conformation analysis showed that LCP70-2A was a branching polysaccharide with a compact coil chain conformation in 0.1 M NaCl solution. In addition, in vitro cell assays showed that LCP70-2A can activate macrophages by enhancing the phagocytosis and potentiating the secretion of immunoregulatory factors including NO, TNF- α , IL-6, and IL-1 β. Furthermore, LCP70-2A was proved to promote the production of ROS and NO using the zebrafish model, suggesting that LCP70-2A can be further developed as a candidate supplement for immunological enhancement. Unlabelled Image • A novel polysaccharide (LCP70-2A) was isolated from the rhizome of L. chuanxiong. • LCP70-2A was determined to be an arabinan. • LCP70-2A increased the levels of NO, IL-6, IL-1 β , and TNF- α in RAW264.7 cells. • LCP70-2A was proven to enhance the immunoregulatory activity of zebrafish. [ABSTRACT FROM AUTHOR]

A bioassay-guided chemical investigation on the ethyl acetate extract of the stems of Herpetospermum pedunculosum led to the isolation and identification of 22 lignans including 6 previously undescribed ones, herpetosiols A-F. Their structures including stereochemistries were elucidated by analysis of NMR, HRMS and ECD data. The in vitro cytotoxic activities of all isolates were studied against human gastric carcinoma SGC7901, lung carcinoma A549, breast carcinoma MDA-MB-231 and hepatocellular carcinoma HepG2 cell lines. Among them, eight lignans exhibited anti-proliferative effects against four tumor cell lines with IC 50 ranging from 1.7 ± 0.1 to 32.6 ± 1.1 μM. Hedyotol-B displayed potent inhibitory effect with IC 50 values of 1.7 ± 0.1 μM against SGC7901 and 6.1 ± 0.5 μM against A549, respectively. Image 1 • Six undescribed lignans were obtained from Herpetospermum pedunculosum. • The stereochemistry was elucidated by ECD and 2D-NMR. • Eight compounds selectively inhibited the proliferation of four cancer cell lines. [ABSTRACT FROM AUTHOR]

Mirabilis himalaica is an important Tibetan medicinal plant in China. However, it has become a rare and class I endangered Tibetan medicine plant. Therefore, the use of callus to propagate germplasm resources is of great significance. We found that the flavonoid content of M. himalaica callus increased continuously with the extension of UV-B treatment. Multi-omics profiles were used to reveal the co-expression patterns of gene networks of flavonoid metabolism in M. himalaica callus during UV-B radiation. Results showed that five medicinal metabolics, including geranin, eriodictyol, astragalin, isoquercetin, pyrotechnic acid, and one anthocyanin malvide-3-O-glucoside were identified. The transcriptome data were divided into 46 modules according to the expression pattern by WGCNA (weighted gene co-expression network analysis), of which the module Turquoise had the strongest correlation with six target metabolites. We found that seven structural genes and twenty-five transcription factors were related to the metabolism of flavonoid synthesis, among which the structural genes CHI , C4H and UGT79B6 had strong co-expression relationships with the 6 target metabolites. WRKY42, WRKY7, bHLH128 and other transcription factors had strong co-expression relationships with multiple structural genes. Consequently, these findings suggest callus grown under UV-B treatment could be an effective alternative medical resource of M. himalaica , which is valuable for conservation and usage of this wild and endangered plant. • Six key medicinal metabolic were identified in M. himalaica callus by UV-B radiation. • WGCNA was used to analyze the relationship between gene modules and metabolites. • CHI , C4H and UGT79B6 had strong co-expression relationship with 6 target metabolites. • WRKY42, WRKY7, bHLH128 had strong co-expression relationships with structural genes. [ABSTRACT FROM AUTHOR]

N -methylputrescine is the precursor of nicotine and pharmaceutical tropane alkaloids such as hyoscyamine. Putrescine N -methyltransferase (PMT) catalyzes the N -methylation of putrescine to form N -methylputrescine. While the role of PMT in nicotine biosynthesis is clear, knowledge of PMT in the biosynthesis of tropane alkaloids (TAs) and the regulation of polyamines remains limited. We characterized a PMT gene from Hyoscyamus niger , designated HnPMT that was specifically expressed in roots, especially in the secondary roots and dramatically induced by methyl jasmonate (MeJA). The GUS gene was specifically expressed in Arabidopsis roots or in the vascular tissues, including pericycles and endodermis, of the H. niger hairy root cultures, when it was driven by the 5′-flanking promoter region of HnPMT . The recombinant HnPMT was purified for enzymatic assays. HnPMT converted putrescine to form N -methylputrescine, as confirmed by LC-MS. The kinetics analysis revealed that HnPMT had high affinity with putrescine but low catalytic activity, suggesting that it was a rate-limiting enzyme. When HnPMT was suppressed in the H. niger plants by using the VIGS approach, the contents of N -methylputrescine and hyoscyamine were markedly decreased, but the contents of putrescine, spermidine and a mixture of spermine and thermospermine were significantly increased; this suggested that HnPMT was involved in the biosynthesis of tropane alkaloids and played a competent role in regulating the biosynthesis of polyamines. Functional identification of HnPMT facilitated the understanding of TA biosynthesis and thus implied that the HnPMT-catalyzed step might be a target for metabolic engineering of the TA production in H. niger . [ABSTRACT FROM AUTHOR]

Atropa belladonna is one of the most important plant sources for producing pharmaceutical tropane alkaloids (TAs). T1 progeny of transgenic A. belladonna , in which putrescine N -methyltransferase (EC. 2.1.1.53) from Nicotiana tabacum (NtPMT) and hyoscyamine 6β-hydroxylase (EC. 1.14.11.14) from Hyoscyamus niger (HnH6H) were overexpressed, were established to investigate TA biosynthesis and distribution in ripe fruits, leaves, stems, primary roots and secondary roots under field conditions. Both NtPMT and HnH6H were detected at the transcriptional level in transgenic plants, whereas they were not detected in wild-type plants. The transgenes did not influence the root-specific expression patterns of endogenous TA biosynthetic genes in A. belladonna . All four endogenous TA biosynthetic genes ( AbPMT , AbTRI , AbCYP80F1 and AbH6H ) had the highest/exclusive expression levels in secondary roots, suggesting that TAs were mainly synthesized in secondary roots. T1 progeny of transgenic A. belladonna showed an impressive scopolamine-rich chemotype that greatly improved the pharmaceutical value of A. belladonna . The higher efficiency of hyoscyamine conversion was found in aerial than in underground parts. In aerial parts of transgenic plants, hyoscyamine was totally converted to downstream alkaloids, especially scopolamine. Hyoscyamine, anisodamine and scopolamine were detected in underground parts, but scopolamine and anisodamine were more abundant than hyoscyamine. The exclusively higher levels of anisodamine in roots suggested that it might be difficult for its translocation from root to aerial organs. T1 progeny of transgenic A. belladonna , which produces scopolamine at very high levels (2.94–5.13 mg g −1 ) in field conditions, can provide more valuable plant materials for scopolamine production. [ABSTRACT FROM AUTHOR]

Brugmansia arborea is a woody plant species that produces tropane alkaloids (TAs). The gene encoding tropine-forming reductase or tropinone reductase I (BaTRI) in this plant species was functionally characterised. The full-length cDNA of BaTRI encoded a 272-amino-acid polypeptide that was highly similar to tropinone reductase I from TAs-producing herbal plant species. The purified 29 kDa recombinant BaTRI exhibited maximum reduction activity at pH 6.8–8.0 when tropinone was used as substrate; it also exhibited maximum oxidation activity at pH 9.6 when tropine was used as substrate. The K m, V max and K cat values of BaTRI for tropinone were 2.65 mM, 88.3 nkat mg −1 and 2.93 S −1 , respectively, at pH 6.4; the K m, V max and K cat values of TRI from Datura stramonium (DsTRI) for tropinone were respectively 4.18 mM, 81.20 nkat mg −1 and 2.40 S −1 at pH 6.4. At pH 6.4, 6.8 and 7.0, BaTRI had a significantly higher activity than DsTRI. Analogues of tropinone, 4-methylcyclohexanone and 3-quinuclidinone hydrochloride, were also used to investigate the enzymatic kinetics of BaTRI. The K m, V max and K cat values of BaTRI for tropine were 0.56 mM, 171.62 nkat.mg −1 and 5.69 S −1 , respectively, at pH 9.6; the K m, V max and K cat values of DsTRI for tropine were 0.34 mM, 111.90 nkat mg −1 and 3.30 S −1 , respectively, at pH 9.6. The tissue profiles of BaTRI differed from those in TAs-producing herbal plant species. BaTRI was expressed in all examined organs but was most abundant in secondary roots. Finally, tropane alkaloids, including hyoscyamine, anisodamine and scopolamine, were detected in various organs of B. arborea by HPLC. Interestingly, scopolamine constituted most of the tropane alkaloids content in B. arborea , which suggests that B. arborea is a scopolamine-rich plant species. The scopolamine content was much higher in the leaves and stems than in other organs. The gene expression and TAs accumulation suggest that the biosynthesis of hyoscyamine, especially scopolamine, occurred not only in the roots but also in the aerial parts of B. arborea . [ABSTRACT FROM AUTHOR]

Bioactivity-guided study led to the isolation of a natural phenylpropionate derivative, ( E )-3-(4-hydroxy-2-methoxyphenyl)-propenoic acid 4-hydroxy-3-methoxyphenyl ester from the roots of Mirabilis himalaica . Cellular analysis showed that compound 1 specifically inhibited the cancer cell growth through the S phase arrest. Mechanistically, compound 1 was able to induce the apoptosis in HepG2 cells through mitochondrial apoptosis pathway in which Bcl-2 and p53 were required. Interestingly, the cellular phenotype of compound 1 were shown specifically in cancer cells originated from hepatocellular carcinoma (HepG2) while compromised influence by compound 1 were detected within the normal human liver cells (L-02). Consistently, the in vivo inhibitory effects of compound 1 on tumor growth were validated by the in xenograft administrated with HepG2 cells. Our results provided a novel compound which might serve as a promising candidate and shed light on the therapy of the hepatocellular carcinoma. [ABSTRACT FROM AUTHOR]

The seeds of Herpetospermum pedunculosum (Ser.) C.B. Clarke, a well-known Tibetan medicine in China, are rich in kinds of bioactive lignans. In this phytochemical investigation on H. pedunculosum , sixteen undescribed lignans, named as herpedulins A - P together with 24 known ones were isolated from the ethyl acetate extract of its seeds. Their structures including the absolute configurations were determined by HR MS, 1D and 2D NMR experiments, and comparison of their experimental ECD spectra with calculated ones or literature data. High content screening experiments revealed that 9 compounds could promote the expression of farnesoid X receptor in guggulsterone-induced human normal liver cells L02 cells significantly. Further molecular docking results demonstrated that herpedulin E, J and K exhibited best docking scores (9.70, 9.28 and 10.31, respectively). Hydrogen bonding and hydrophobic interactions might contribute to the main interaction of active compounds with FXR. [Display omitted] • Sixteen undescribed compounds were isolated from Herpetospermum pedunculosum. • The absolute configurations were determined via quantum chemical calculations. • 9 compounds could promote FXR expression in guggulsterone-induced L02 cells. • Molecular interactions of compounds with FXR were analyzed by in silico methods. [ABSTRACT FROM AUTHOR]

[Display omitted] • A tyrosine aminotransferase gene (RcTAT) was cloned from Rhodiola crenulata. • RcTAT catalyzes the formation of 4-hydroxyphenylpyruvate from tyrosine. • Suppression of RcTAT significantly enhances the salidroside production. Rhodiola crenulata is a traditional Tibetan medicinal plant mainly distributed in high altitude areas of Tibet. As the main extract of R. crenulata , salidroside has important medicinal activities in enhancing the body's immunity and resisting microwave radiation by influencing cell metabolism. Tyrosine is the starting amino acid precursor for salidroside biosynthesis. As an aromatic amino acid, tyrosine participates not only in salidroside biosynthesis, but also in other metabolite biosynthesis which might compete against salidroside biosynthetic pathway. In this study, we functionally identified a tyrosine aminotransferase in R. crenulata (RcTAT) that could convert tyrosine into 4-hydroxyphenylpyruvate (4-HPP). The Km and Vmax values of RcTAT for tyrosine were respectively 0.21 mM and 0.17 μmol/min.mg under 9.0 pH and 39 °C. RNAi-mediated suppression of RcTAT expression markedly increased salidroside production in hairy root culture of R. crenulata. In summary, RcTAT is a key gene involved in the metabolic pathway that competes against salidroside biosynthesis, and suppressing its expression is a promising way to elevate salidroside production in planta. [ABSTRACT FROM AUTHOR]

• Glyphosate is used for screening transgenic plants of Atropa belladonna. • Homozygous transgenic plants overexpressing HnH6H and G2-EPSPS are obtained. • Homozygous transgenic plants have high-yield scopolamine and glyphosate resistance. Atropa belladonna , one of the most important medicinal plants in China, is used to produce anticholinergic tropane alkaloids. Weeds severely reduce the agricultural productivity of A. belladonna in fields, and the low content of high-value scopolamine in planta limits its economic value. In this study, homozygous lines of A. belladonna , with glyphosate resistance and high yield of scopolamine, were developed using metabolic engineering technology for the first time. Two homozygous transgenic lines (T2GH03 and T2GH06), harboring G2-EPSPS and HnH6H , were established and tested in the field. Glyphosate resistance assays demonstrated that the two homozygous transgenic lines could resist commercial recommended dose of glyphosate. Alkaloid analysis showed that the transgenic lines produced more scopolamine than wild-type plants. T2GH03 and T2GH06 produced scopolamine at the levels of 5.45 mg/g dry weight (DW) and 7.04 mg/g DW respectively in leaves, and 1.06 mg/g DW to 1.07 mg/g DW respectively in roots. Compared with wild-type plants, the scopolamine contents of homozygous transgenic lines increased by over 10 folds in leaves and nearly 5 folds in roots. To sum up, Atropa belladonna's new varieties with glyphosate resistance and high-yield scopolamine are developed, which are highly valuable for industrial production of scopolamine. [ABSTRACT FROM AUTHOR]

• An arabinofuranan, AQP70-3, was isolated from A. quinata for the first time. • The structure and morphology of AQP70-3 were characterized. • The absolute configuration of monosaccharide of AQP70-3 was characterized. • AQP70-3 showed immunomodulatory effects in cell level. • AQP70-3 was confirmed to possess immunomodulatory effects in zebrafish model. In our continuous searching for natural active polysaccharides with immunomodulatory activity, an arabinofuranan (AQP70-3) was isolated and purified from the fruits of Akebia quinata (Houtt.) Decne. by using ion-exchange chromatography and gel permeation chromatography for the first time. AQP70-3 contained both α - l -Ara f and β - l -Ara f , and the absolute molecular weight was 1.06 × 104 g/mol. The backbone of AQP70-3 comprised →5)- α - l-A ra f -(1→, →3,5)- α - l-A ra f -(1→, and →2,5)- α - l-A ra f -(1→, with branches of →1)- β - l-A ra f and →3)- α - l-A ra f -(1→ residues. Biological assay suggested that AQP70-3 can stimulate phagocytic activity and promote the levels of nitric oxide (NO), interleukin (IL)-6, IL-1 β , and tumor necrosis factor- α (TNF- α) of RAW264.7 cells. Furthermore, AQP70-3 was found to increase the production of reactive oxygen species (ROS) and NO in zebrafish embryo model. [ABSTRACT FROM AUTHOR]

• A root-expressed SAUR gene (AbSAUR1) was cloned from Atropa belladonna. • Overexpression of AbSAUR1 significantly increased the biomass of Atropa belladonna. • Overexpression of AbSAUR1 did not reduce biosynthesis of tropane alkaloids. • The yield of TAs was significantly improved in AbSAUR1 -overexpressing plants. Tropane alkaloids (TAs), including hyoscyamine, anisodamine and scopolamine, are widely used as anticholinergic drugs in the clinic. At present, the production of TAs is completely dependent on extraction from medicinal plants of Solanaceae. Atropa belladonna , commonly known as deadly nightshade, is a major commercial source of TAs. Previous studies have focused on increasing TA content by overexpressing TA biosynthesis genes. However, research on increasing TA yield by increasing the biomass of A. belladonna has not been reported. In this study, a Small Auxin Up-regulated RNA (SAUR) gene from A. belladonna (AbSAUR1) had been cloned for the first time. Based on heat map and tissue expression analysis, it was demonstrated that AbSAUR1 was specifically expressed in roots. Compared to control plants, transgenic lines of A. belladonna overexpressing AbSAUR1 showed a number of phenotypic changes, including increased plant height, thickened stems, increased number of branches, leaves and roots. Meanwhile, the biomass of AbSAUR1 -overexpressing plants also increased significantly, with fresh weight and dry weight being 3.79- and 3.20-fold higher than control plants, respectively. On average, there was no significant change in TA content, but the production of hyoscyamine, anisodamine and scopolamine was slightly enhanced. The overall yield of TAs was significantly improved, reaching 3.55 times that of the control. In summary, the AbSAUR1 gene can be employed as an effective molecular tool to increase the yield of TAs by increasing the biomass of A. belladonna. [ABSTRACT FROM AUTHOR]

AaPIF3, a bHLH transcription factor phylogenetically associated with Arabidopsis PIF3, positively regulates artemisinin biosynthesis in Artemisia annua. Overexpression of AaPIF3 significantly promotes the production of artemisinin and its related metabolites. • AaPIF3 is a bHLH transcription factor that is phylogenetically related with Arabidopsis PIF3. • AaPIF3 is able to transactivate artemisinin biosynthesis genes, according to dual-luciferase assays. • Overexpression of AaPIF3 markedly increased the production of artemisinin in Artemisia annua. Artemisia annua is a Chinese traditional herbal plant that produces artemisinin, the potent anti-malarial drug. It is a common goal for the artemisinin industry to develop plants of A. annua with high yields of artemisinin. In this study, a bHLH transcription factor of A. annua (AaPIF3) was characterized and used to promote the production of artemisinin. AaPIF3 was highly expressed in flower buds and glandular secretory trichomes and its coding protein was localized to the nucleus. Dual-luciferase assays indicated that AaPIF3 was able to significantly enhance the promoter activities of artemisinin biosynthesis genes, including ADS , CYP71AV1 , DBR2 , and ALDH1 , suggesting that AaPIF3 positively regulated artemisinin biosynthesis. Overexpression of AaPIF3 markedly upregulated artemisinin biosynthesis genes at the transcriptional level, and consequently the production of artemisinin was significantly promoted in transgenic A. annua plants. On the contrary, suppression of AaPIF3 led to significantly decreased transcript levels of artemisinin biosynthesis genes, with overall production of artemisinin significantly reduced. In summary, AaPIF3 plays a positive role in regulating artemisinin biosynthesis and transgenic plants of A. annua with high yields of artemisinin have been successfully developed through overexpression of AaPIF3. [ABSTRACT FROM AUTHOR]