Moxibustion prevents tripterygium glycoside-induced oligoasthenoteratozoospermia in rats via reduced oxidative stress and modulation of the Nrf2/HO-1 signaling pathway

Oligoasthenoteratozoospermia (OAT) decreases male fertility, seriously affecting the production of offspring. This study clarified the preventive impact of different moxibustion frequencies on OAT and selected the optimal frequency to elucidate the underlying mechanism. An OAT rat model was constructed by gavage of tripterygium glycosides (TGS) suspension. Daily moxibustion (DM) or alternate-day moxibustion (ADM) was administered on the day of TGS suspension administration. Finally, we selected DM for further study based on sperm quality and DNA fragmentation index, testicular and epididymal morphology, and reproductive hormone level results. Subsequently, the oxidative stress (OS) status was evaluated by observing the OS indices levels; malondialdehyde (MDA), 8-hydroxy-deoxyguanosine (8-OHdG), total antioxidant capacity (T-AOC), and total superoxide dismutase (T-SOD) in testicular tissue using colorimetry and enzyme-linked immunosorbent assay. Furthermore, heme oxygenase 1 (HO-1) and nuclear factor erythropoietin-2-related factor 2 (Nrf2) were evaluated using Western blotting. Immunohistochemistry was employed to locate and assess the expression of HO-1 and Nrf2 protein, while quantitative real-time polymerase chain reaction was utilized to detect their mRNA expression. MDA and 8-OHdG levels decreased following DM treatment, while T-SOD and T-AOC increased, suggesting that DM may prevent TGS-induced OAT in rats by decreasing OS in the testis. Furthermore, protein and mRNA expression of Nrf2 and HO-1 in the testis were elevated, indicating that DM may reduce OS by activating the signaling pathway of Nrf2/HO-1. Therefore, DM could prevent OAT in rats via the Nrf2/HO-1 pathway, thereby presenting a promising therapeutic approach against OAT.

Tripterygium wilfordii Hook.f. ameliorates paraquat-induced lung injury by reducing oxidative stress and ferroptosis via Nrf2/HO-1 pathway

Paraquat (PQ) poisoning can induce acute lung injury and fibrosis and has an extremely high mortality rate. However, no effective treatments for PQ poisoning have been established. In this study, the potential efficacy of Tripterygium wilfordii Hook.f. (TwHF) in alleviating PQ-induced lung injury and fibrosis was investigated in a mouse model. Mice were randomly assigned to the control, PQ, PQ + TwHF1 (pretreatment before inducing poisoning), and PQ + TwHF2 (treatment after poisoning) groups. The mice in the PQ + TwHF1 group were pretreated with TwHF for 5 days before receiving one dose of PQ (120 mg/kg) and then received a daily oral gavage of the indicated dosages of TwHF until sacrifice. The mice in the PQ + TwHF2 group were treated with TwHF 2 h after PQ exposure until sacrifice. The pathological analysis and Fapi PET/CT showed that treatment with TwHF attenuated lung injury. And TwHF reduced pulmonary oxidative stress, as indicated by the reduction in, malondialdehyde (MDA), glutathione (GSH), and reactive oxygen species (ROS) levels, as well as by the increase in superoxide dismutase (SOD) levels. Accordingly, the Perls DAB staining showed increased iron concentrations and western blotting revealed a decreased GPX4 expression after PQ exposure, as well as the mitigation of the overexpression of Nrf2 and HO-1 induced by PQ. In conclusion, our study demonstrated the potential of TwHF as a treatment for PQ-induced lung injury and fibrosis. The protective mechanism of this medicinal herb may involve the regulation of ferroptosis.

Probing the functions of friedelane-type triterpene cyclases from four celastrol-producing plants

Triterpenes are among the most diverse plant natural products, and their diversity is closely related to various triterpene skeletons catalyzed by different 2,3-oxidosqualene cyclases (OSCs). Celastrol, a friedelane-type triterpene with significant bioactivities, is specifically distributed in higher plants, such as Celastraceae species. Friedelin is an important precursor for the biosynthesis of celastrol, and it is synthesized through the cyclization of 2,3-oxidosqualene, with the highest number of rearrangements being catalyzed by friedelane-type triterpene cyclases. However, the molecular mechanisms underlying the catalysis of friedelin production by friedelane-type triterpene cyclases have not yet been fully elucidated. In this study, transcriptome data of four celastrol-producing plants from Celastraceae were used to identify a total of 21 putative OSCs. Through functional characterization, the friedelane-type triterpene cyclases were separately verified in the four plants. Analysis of the selection pressure showed that purifying selection acted on these OSCs, and the friedelane-type triterpene cyclases may undergo weaker selective restriction during evolution. Molecular docking and site-directed mutagenesis revealed that changes in some amino acids that are unique to friedelane-type triterpene cyclases may lead to variations in catalytic specificity or efficiency, thereby affecting the synthesis of friedelin. Our research explored the functional diversity of triterpene synthases from a multispecies perspective. It also provides some references for further research on the relative mechanisms of friedelin biosynthesis.

Triptolide: pharmacological spectrum, biosynthesis, chemical synthesis and derivatives

Triptolide, an abietane-type diterpenoid isolated from Tripterygium wilfordii Hook. F., has significant pharmacological activity. Research results show that triptolide has obvious inhibitory effects on many solid tumors. Therefore, triptolide has become one of the lead compounds candidates for being the next "blockbuster" drug, and multiple triptolide derivatives have entered clinical research. An increasing number of researchers have developed triptolide synthesis methods to meet the clinical need. To provide new ideas for researchers in different disciplines and connect different disciplines with researchers aiming to solve scientific problems more efficiently, this article reviews the research progress made with analyzes of triptolide pharmacological activity, biosynthetic pathways, and chemical synthesis pathways and reported in toxicological and clinical studies of derivatives over the past 20 years, which have laid the foundation for subsequent researchers to study triptolide in many ways.

Identification and functional characterization of a PDR transporter in Tripterygium wilfordii Hook.f. that mediates the efflux of triptolide

KEY MESSAGE

TwPDR1, a PDR transporter from Tripterygium wilfordii Hook.f., was proved to efflux triptolide and its stability could be enhanced by A1033T mutation. Triptolide, an abietane-type diterpene in Tripterygium wilfordii Hook.f., possesses many pharmacological activities. However, triptolide is in short supply and very expensive because it is present at low amounts in natural plants and lack alternative production methods. Transporter engineering, which increases the extracellular secretion of secondary metabolites in in vitro culture systems, is an effective strategy in metabolic engineering but is rarely reported. In this study, TwPDR1, a pleiotropic drug resistance-type ATP binding cassette transporter, was identified as the best efflux pump candidate for diterpenoids through bioinformatics analysis. TwPDR1 was located in the plasma membrane, highly expressed in adventitious roots, and induced by methyl jasmonate. The triptolide efflux function of TwPDR1 was confirmed by transient expression in tobacco BY-2 cells and by downregulation via RNA interference in the native host. However, the overexpression of TwPDR1 had a limited effect on the secretion of triptolide. As shown by previous studies, a single amino acid mutation might increase the abundance of TwPDR1 by increasing protein stability. We identified the A1033 residue in TwPDR1 by sequence alignment and confirmed that A1033T mutation could increase the expression of TwPDR1 and result in the higher release ratio of triptolide (78.8%) of the mutants than that of control (60.1%). The identification and functional characterization of TwPDR1 will not only provide candidate gene material for the metabolic engineering of triptolide but also guide other transporter engineering researches in the future.

Integrating pathway elucidation with yeast engineering to produce polpunonic acid the precursor of the anti-obesity agent celastrol

BACKGROUND

Celastrol is a promising anti-obesity agent that acts as a sensitizer of the protein hormone leptin. Despite its potent activity, a sustainable source of celastrol and celastrol derivatives for further pharmacological studies is lacking.

RESULTS

To elucidate the celastrol biosynthetic pathway and reconstruct it in Saccharomyces cerevisiae, we mined a root-transcriptome of Tripterygium wilfordii and identified four oxidosqualene cyclases and 49 cytochrome P450s as candidates to be involved in the early steps of celastrol biosynthesis. Using functional screening of the candidate genes in Nicotiana benthamiana, TwOSC4 was characterized as a novel oxidosqualene cyclase that produces friedelin, the presumed triterpenoid backbone of celastrol. In addition, three P450s (CYP712K1, CYP712K2, and CYP712K3) that act downstream of TwOSC4 were found to effectively oxidize friedelin and form the likely celastrol biosynthesis intermediates 29-hydroxy-friedelin and polpunonic acid. To facilitate production of friedelin, the yeast strain AM254 was constructed by deleting UBC7, which afforded a fivefold increase in friedelin titer. This platform was further expanded with CYP712K1 to produce polpunonic acid and a method for the facile extraction of products from the yeast culture medium, resulting in polpunonic acid titers of 1.4 mg/L.

CONCLUSION

Our study elucidates the early steps of celastrol biosynthesis and paves the way for future biotechnological production of this pharmacologically promising compound in engineered yeast strains.

A class I TGA transcription factor from Tripterygium wilfordii Hook.f. modulates the biosynthesis of secondary metabolites in both native and heterologous hosts

Class I TGA transcription factors (TFs) are known to participate in plant resistance responses, however, their regulatory functions in the biosynthesis of secondary metabolites were rarely revealed. In this study, a class I TGA TF, TwTGA1, from Tripterygium wilfordii Hook.f. was cloned and characterized. Overexpression of TwTGA1 in T. wilfordii Hook.f. cells increased the production of triptolide and two sesquiterpene pyridine alkaloids, which was further enhanced by methyl jasmonate (MeJA) treatment. RNA interference of TwTGA1 showed no significant effects on the production of these metabolites, indicating the existence of other TGA partner(s) with overlapping functions. Heterologous expression of TwTGA1 in tobacco By-2 cells promoted the biosynthesis of pyridine alkaloids. Under the elicitation of MeJA, the contents of nonpyrrolidine alkaloids further increased but not for nicotine. TwTGA1 could induce the expression of Putrescine N-methyltransferase (PMT) and N-methylputrescine oxidase 1 (MPO1) through binding to their promoters. Finally, transient expression of TwTGA1 in leaves of Catharanthus roseus changed both the profiles of vinca alkaloids (increased contents of serpentine and catharanthine, but decreased that of vinblastine) and the expressions of biosynthesis-related genes. The metabolic and transcriptional data indicated a relationship between jasmonic acid signaling pathway and the functions of TwTGA1.

Analysis of the role of geranylgeranyl diphosphate synthase 8 from Tripterygium wilfordii in diterpenoids biosynthesis

Tripterygium wilfordii is known to contain various types of bioactive diterpenoids that exhibit many remarkable activities. Many studies have recently been targeted toward the elucidation of the diterpenoids biosynthetic pathways in attempts to obtain these compounds with a view to solving the dilemma of low yield in plants. However, the short-chain prenyltransferases (SC-PTSs) responsible for the formation of geranylgeranyl diphosphate (GGPP), a crucial precursor for synthesizing the skeleton structures of diterpenoids, have not been characterized in depth. Here, T. wilfordii transcriptome data were used to identify eight putative GGPPSs, including two small subunits of geranyl diphosphate synthase (GPPS.SSU). Of them, GGPPS1, GGPPS7, GGPPS8, GPPS.SSU II and GPPS.SSU were translocated mainly into chloroplasts, and GGPPS8 exhibited the optimal catalytic efficiency with respect to catalyzing the formation of GGPP. In addition, the expression pattern of GGPPS8 was similar to that of downstream terpene synthase genes that are directly correlated with triptolide production in roots, indicating that GGPPS8 was most likely to participate in triptolide biosynthesis in roots among the studied enzymes. GPPS.SSU was inactive alone but interacted with GGPPS1, GGPPS7 and GGPPS8 to change the product from GGPP to GPP. These findings implicate that these candidate genes can be regulated to shift the metabolic flux toward diterpenoid formation, increasing the yields of bioactive diterpenoids in plants.

Friedelane-type triterpene cyclase in celastrol biosynthesis from Tripterygium wilfordii and its application for triterpenes biosynthesis in yeast

Celastrol is a promising bioactive compound isolated from Tripterygium wilfordii and has been shown to possess many encouraging preclinical applications. However, the celastrol biosynthetic pathway is poorly understood, especially the key oxidosqualene cyclase (OSC) enzyme responsible for cyclisation of the main scaffold. Here, we report on the isolation and characterisation of three OSCs from T. wilfordii: TwOSC1, TwOSC2 and TwOSC3. Both TwOSC1 and TwOSC3 were multiproduct friedelin synthases, while TwOSC2 was a β-amyrin synthase. We further found that TwOSC1 and TwOSC3 were involved in the biosynthesis of celastrol and that their common product, friedelin, was a precursor of celastrol. We then reconstituted the biosynthetic pathway of friedelin in engineered yeast constructed by the CRISPR/Cas9 system, with protein modification and medium optimisation, leading to heterologous production of friedelin at 37.07 mg l^-1 in a shake flask culture. Our study was the first to identify the genes responsible for biosynthesis of the main scaffold of celastrol and other triterpenes in T. wilfordii. As friedelin has been found in many plants, the results and approaches described here have laid a solid foundation for further explaining the biosynthesis of celastrol and related triterpenoids. Moreover, our results provide insights for metabolic engineering of friedelane-type triterpenes.

Rapid identification of "mad honey" from Tripterygium wilfordii Hook. f. and Macleaya cordata (Willd) R. Br using UHPLC/Q-TOF-MS

Cases of honey poisoning have been reported widely, meaning there is a need for methods that detect "mad honey" or honey contaminated with plant-derived toxins to protect human health. In this study, we compared whole flower extracts and honey from Tripterygium wilfordii Hook. f. (TwHf) and Macleaya cordata (Willd) R. Br (McRB) using QuEChERS (quick, easy, cheap, effective, rugged, and safe) and ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF-MS). The results revealed several compounds common to whole flowers and honey samples. Triptolide and protopine were selected as potential markers for identifying "mad honeys" from these plants. The developed method can easily detect different honey varieties that were spiked with 5% TwHf and McRB honey samples. Additionally, 90 commercial honey samples were analyzed and determined as free from contamination. The method described in this report could be useful for studies on honey from other poisonous nectar and pollen plants.

Biosynthesis of Diterpenoids in Tripterygium Adventitious Root Cultures

Adventitious root cultures were developed from Tripterygium regelii, and growth conditions were optimized for the abundant production of diterpenoids, which can be collected directly from the medium. An analysis of publicly available transcriptome data sets collected with T. regelii roots and root cultures indicated the presence of a large gene family (with 20 members) for terpene synthases (TPSs). Nine candidate diterpene synthase genes were selected for follow-up functional evaluation, of which two belonged to the TPS-c, three to the TPS-e/f, and four to the TPS-b subfamilies. These genes were characterized by heterologous expression in a modular metabolic engineering system in Escherichia coli Members of the TPS-c subfamily were characterized as copalyl diphosphate (diterpene) synthases, and those belonging to the TPS-e/f subfamily catalyzed the formation of precursors of kaurane diterpenoids. The TPS-b subfamily encompassed genes coding for enzymes involved in abietane diterpenoid biosynthesis and others with activities as monoterpene synthases. The structural characterization of diterpenoids accumulating in the medium of T. regelii adventitious root cultures, facilitated by searching the Spektraris online spectral database, enabled us to formulate a biosynthetic pathway for the biosynthesis of triptolide, a diterpenoid with pharmaceutical potential. Considering the significant enrichment of diterpenoids in the culture medium, fast-growing adventitious root cultures may hold promise as a sustainable resource for the large-scale production of triptolide.

A MDR transporter contributes to the different extracellular production of sesquiterpene pyridine alkaloids between adventitious root and hairy root liquid cultures of Tripterygium wilfordii Hook.f

TwMDR1 transports sesquiterpene pyridine alkaloids, wilforine and wilforgine, into the hairy roots of T. wilfordii Hook.f. resulting in low secretion ratio of alkaloids. Hairy roots (HRs) exhibit high growth rate and biochemical and genetic stability. However, varying secondary metabolites in HR liquid cultures mainly remain in root tissues, and this condition may affect cell growth and cause inconvenience in downstream extraction. Studies pay less attention to adventitious root (AR) liquid cultures though release ratio of some metabolites in AR liquid cultures is significantly higher than that of HR. In Tripterygium wilfordii Hook.f., release ratio of wilforine in AR liquid cultures reached 92.75 and 13.32% in HR on day 15 of culture. To explore potential roles of transporters in this phenomenon, we cloned and functionally identified a multidrug resistance (MDR) transporter, TwMDR1, which shows high expression levels in HRs and is correlated to transmembrane transportation of alkaloids. Nicotiana tabacum cells with overexpressed TwMDR1 efficiently transported wilforine and wilforgine in an inward direction. To further prove the feasibility of genetically engineered TwMDR1 and improve alkaloid production, we performed a transient RNAi experiment on TwMDR1 in T. wilfordii Hook.f. suspension cells. Results indicated that release ratios of wilforine and wilforgine increased by 1.94- and 1.64-folds compared with that of the control group, respectively. This study provides bases for future studies that aim at increasing secretion ratios of alkaloids in root liquid cultures in vitro.

Molecular Analysis of Chinese Celastrus and Tripterygium and Implications in Medicinal and Pharmacological Studies

Celastrus and Tripterygium species, which are used in traditional Chinese medicine, have attracted much attention due to their anti-tumor promoting and neuroprotective activities, in addition to their applications in autoimmune disorders. However, systematic relationships between them and among species are unclear, and it may disturb their further medicinal utilization. In the present study, the molecular analysis of combined chloroplast and nuclear markers of all Chinese Celastrus and Tripterygium was performed, and clear inter- and intra-genus relationships were presented. The result suggests that Tripterygium constitute a natural monophyletic clade within Celastrus with strong support value. Fruit and seed type are better than inflorescence in subgeneric classification. Chinese Celastrus are classified for three sections: Sect. Sempervirentes (Maxim.) CY Cheng & TC Kao, Sect. Lunatus XY Mu & ZX Zhang, sect. nov., and Sect. Ellipticus XY Mu & ZX Zhang, sect. nov. The phylogenetic data was consistent with their chemical components reported previously. Owing to the close relationship, several evergreen Celastrus species are recommended for chemical and pharmacological studies. Our results also provide reference for molecular identification of Chinese Celastrus and Tripterygium.

Integrative Approaches for the Identification and Localization of Specialized Metabolites in Tripterygium Roots

Members of the genus Tripterygium are known to contain an astonishing diversity of specialized metabolites. The lack of authentic standards has been an impediment to the rapid identification of such metabolites in extracts. We employed an approach that involves the searching of multiple, complementary chromatographic and spectroscopic data sets against the Spektraris database to speed up the metabolite identification process. Mass spectrometry-based imaging indicated a differential localization of triterpenoids to the periderm and sesquiterpene alkaloids to the cortex layer of Tripterygium roots. We further provide evidence that triterpenoids are accumulated to high levels in cells that contain suberized cell walls, which might indicate a mechanism for storage. To our knowledge, our data provide first insights into the cell type specificity of metabolite accumulation in Tripterygium and set the stage for furthering our understanding of the biological implications of specialized metabolites in this genus.

[Different metabolites of leaves between Tripterygium wilfordii and Tripterygium hypoglaucum based on UPLC-Q-TOF-MS]

To analysis the differences between Tripterygium wilfordii and T. hypoglaucum, specimens of their leaves were collected from five production regions and analyzed by ultra performance liquid chromatography coupled with quadrupole time of flight mass spectrometry (UPLC-Q-TOF-MS). The data were analyzed by multivariate statistical method, such as hierarchical cluster analysis (HCA) principal component analysis (PCA) and orthogonal signal correction partial least square discrimination (OPLS-DA). Potential markers with VIP values above 5.0 and corresponding r values above 0.85, were selected and further tested by combining mann-Whitney nonparametric. Those with P < 0.001 and AUC = 1 were confirmed as metabolite markers to discriminate them from each other. Results revealed that the two species were obviously different in their leaf metabolites. Based on their mass spectra, 23 potential metabolite markers were identified to distinguish T. wilfordii from T. hypoglaucum.

[Effects of elicitors on growth of adventitious roots and contents of secondary metabolites in Tripterygium wilfordii Hook. f]

To study the effects of the extract of fungal elicitor, AgNO3, MeJA and yeast on the growth and content of secondary metabolites of adventitious roots in Tripterygium wilfordii. The above elicitors were supplemented to the medium, the growth and the content of secondary metabolites were measured. When the medium was supplemented with the elicitor Glomerella cingulata or Collectotrichum gloeosporioides, the content of triptolide was increased by 2.24 and 1.93-fold, the alkaloids content was increased by 2.02 and 2.07-fold, respectively. The optimal concentration of G. cingulata was 50 μg/mL for accumulation of triptolide, alkaloids and for the growth of adventitious roots. AgNO3 inhibited the growth of adventitious roots and the accumulation of the alkaloids, whereas it (at 25 μmol/L) increased the accumulation of triptolide by 1.71-fold compared to the control. The growth of adventitious roots, the contents of triptolide and alkaloids were increased 1.04, 1.64 and 2.12-folds, respectively when MeJA was at 50 μmol/L. When the concentration of yeast reached 2 g/L, the content of triptolide increased 1.48-folds. This research demonstrated that supplementation of AgNO3 and yeast enhanced the biosynthesis of triptolide in adventitious roots and the synergism of G. cingulata and MeJA could promote the biosynthesis of both triptolide and alkaloids.

Anti-inflammatory effects of triptolide in LPS-induced acute lung injury in mice

Triptolide is one of the main active components of Chinese herb Tripterygium wilfordii Hook F, which has been demonstrated to have anti-inflammatory properties. The aim of this study was to investigate the effects of triptolide on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and to clarify the possible mechanisms. Mice were administered intranasally with LPS to induce lung injury. Triptolide was administered intraperitoneally 1 h before LPS challenge. Triptolide-treated mice exhibited significantly reduced leukocyte, myeloperoxidase (MPO) activity, edema of the lung, as well as TNF-α, IL-1β, and IL-6 production in the bronchoalveolar lavage fluid compared with LPS-treated mice. Additionally, Western blot analysis showed that triptolide inhibited the phosphorylation of inhibitor-kappa B kinase-alpha (IκB-α), p65, nuclear factor kappa B (NF-κB), p38, extracellular receptor kinase (ERK), and Jun N-terminal kinase (JNK) and the expression of Toll-like receptor 4 (TLR4) caused by LPS. In conclusion, our results suggested that the promising anti-inflammatory mechanism of triptolide may be that triptolide activates peroxisome proliferation-activated receptor gamma (PPAR-γ), thereby attenuating an LPS-induced inflammatory response. Triptolide may be a promising potential therapeutic reagent for ALI treatment.

[Establishment of adventitious root culture system and scale-up fermentation of Tripterygium wilfordii]

Using MS as basic medium, supplemented with 1.0 mg · L(-1) IBA, the adventitious roots of Tripterygium wilfordii were induced, and the good adventitious root culture system was established by leaves or callus induced by leaves as explants. The adventitious roots were also induced with 2.0-4.0 mg · L(-1) NAA and the good adventitious root culture system established by using suspension cells from callus as materials to induce adventitious root. The content of triptolide of three adventitious roots culture system were exceeded in the natural root bark. The content of triptolide of AR3 adventitious roots was the highest about 5.3 times as that in the natural root bark. By using 5 L stirred fermentor during pilot enlarge cultivation, compared with 250 mL flask cultivation, the adventitious roots increment and secondary metabolites content per liter medium showed no significant difference. The accomplishment of this analysis laid a foundation by tissue culture production of the secondary metabolites of T. wilfordii.

[Effects of amino acid on growth and secondary metabolites contents of adventitious roots of Tripterygium wilfordii]

The adventitious root of Tripterygium wilfordii was used as experiment material to study effects of various concentration of aspartic acid, isoleucine, cysteine and arginine in MS medium on the growth and triptolide, wilforgine, wilforine contents of the adventitious roots. The results showed that compared with the control, supplemented with 0.25 mmol x L(-1) aspartic acid at 3rd week, the growth of the adventitious roots only accounted for 80%, but the content of triptolide of the adventitious roots and the medium was 1.36, 1.30 times, the content of wilforgine was 1.16, 1.37 times, the content of wilforine was 1.22, 1.63 times, respectively. At 3rd week 0.05 mmol x L(-1) isoleucine, the growth of adventitious roots was 97.3%, wilforgine of adventitious roots and medium 1.02, 1.27 times, wilforine 1.36 times and 1.15 times. At 1st week 0.25 mmol x L(-1) cysteine, the growth of the adventitious roots comprised 77.5% of the control, while content of triptolide of adventitious roots reached 1.87 times. At 2nd week 1.00 mmol x L(-1) cysteine, the growth of adventitious roots was 44.6% of the control, the content of wilforine in medium was 2.97 times. At 3rd week 0.50 mmol x L(-1) arginine, the growth of adventitious roots was 124.2%, the content of wilforgine and wilforine was 1.3, 1.4 times, respectively.

Elicitation and in situ adsorption enhanced secondary metabolites production of Tripterygium wilfordii Hook. f. adventitious root fragment liquid cultures in shake flask and a modified bubble column bioreactor

The experiments of elicitation and in situ adsorption were conducted in shake flasks and then tested in a modified bubble column bioreactor for enhancing the productions of three active metabolites in Tripterygium wilfordii Hook. f., triptolide, wilforgine and wilforine. Methyl jasmonate was screened out as the elicitor and the non-ionic polymeric ion-exchange resin of Amberlite(®) XAD-7 was used for in situ product removal and protecting the alkaloids from degradation in the medium. In shake flask experiments, 3.55-fold, 49.11-fold, and 10.40-fold of triptolide, wilforgine, and wilforine, respectively, could be recovered from the medium and XAD-7 resin by elicitation and in situ product removal, compared with the control. The modified 10 L bubble column bioreactor had similar productions of the three active metabolites but needed a further optimization of parameters for better growth of adventitious roots.

[Chemical constituents from root bark of Tripterygium hypoglaucum]

OBJECTIVE

To investigate chemical constituents of the root bark of Tripterygium hypoglaucum.

METHOD

Compounds were isolated by column chromatography on silica gel and Sephadex LH-20, and their structures were identified on the basis of spectral data (MS, 1H-NMR and 13C-NMR).

RESULT

Twelve compounds were isolated and identified as friedelin (1), 3-oxo-olean-9(11),12-diene (2), canophyllal (3), 3-acetoxy oleanolic acid (4), triptophenolide (5), triptonoterpene methyl ether (6), tricosanoic acid (7), beta-sitosterol (8), stearic acid (9), glut-5-en-3beta,28-diol (10), palmitic acid (11) and daucostorol (12).

CONCLUSION

Compounds 1, 2, 3, 7 and 10 were isolated from T. hypoglaucum and 7 from the genus Tripterygium for the first time.

A novel method to convert triptolide into tripchlorolide in Tripterygium wilfordii

A new method has been established to convert triptolide (1) into tripchlorolide (2) directly in the Chinese herbal drug Tripterygium wilfordii Hook F. and the influences of reaction times and pH values have been investigated. It was found that 1 could be most efficiently converted into 2 using a hydrochloric acid-acetic acid system. An HPLC method was devised in order to monitor the conversion and ESI-MS was used to identify the synthetic product 2. The sensitivity of the assay was sufficient to monitor the conversion of the main active components in T. wilfordii.