Pteris Semipinnata Research Articles

Natural diterpenoid EKO activates deubiqutinase ATXN3 to preserve vascular endothelial integrity and alleviate diabetic retinopathy through c-fos/focal adhesion axis

Diabetic retinopathy (DR) is one of the most prevalent severe diabetic microvascular complications caused by hyperglycemia. Deciphering the underlying mechanism of vascular injury and finding ways to alleviate hyperglycemia induced microvascular complications is of great necessity. In this study, we identified that a compound ent-9α-hydroxy-15-oxo-16-kauren-19-oic acid (EKO), the diterpenoid isolated and purified from Pteris semipinnata L., exhibited good protective roles against vascular endothelial injury associated with diabetic retinopathy in vitro and in vivo. To further uncover the underlying mechanism, we used unbiased transcriptome sequencing analysis and showed substantial impairment in the focal adhesion pathway upon high glucose and IL-1β stimulation. EKO could effectively improve endothelial focal adhesion pathway by enhancing the expression of two focal adhesion proteins Vinculin and ITGA11. We found that c-fos protein was involved in regulating the expression of Vinculin and ITGA11, a transcription factor component that was downregulated by high glucose and IL-1β stimulation and recovered by EKO. Mechanically, EKO facilitated the binding of deubiquitylation enzyme ATXN3 to c-fos protein and promoted its deubiquitylation, thereby elevating its protein level to enhance the expression of Vinculin and ITGA11. Besides, EKO effectively suppressed ROS production and restored mitochondrial function. In vivo studies, we confirmed EKO could alleviate some of the indicators of diabetic mice. In addition, protein levels of ATXN3 and focal adhesion Vinculin molecule were also verified in vivo. Collectively, our findings addressed the endothelial protective role of natural diterpenoid EKO, with emphasize of mechanism on ATXN3/c-fos/focal adhesion signaling pathway as well as oxygen stress suppression, implicating its therapeutic potential in alleviating vascular endothelium injury and diabetic retinopathy.

Three new pterosins from Pteris semipinnata

Three new pterosins, named as semipterosin A (1), B (2) and C (3), together with 11 known pterosins (4–14), were isolated from the aerial parts of Pteris semipinnata. Their structures were elucidated by HRESI-MS, NMR spectral data, CD and literature comparisons. Three new pterosins were assessed for their anti-inflammatory activity. Compounds 1–3 inhibited the NF-kB induction by 40.7%, 61.9% and 34.0%, respectively. This is the first report of the isolation of compounds 6–14 from this plant.

Ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic acid loaded onto fluorescent mesoporous silica nanoparticles for the location and therapy of nasopharyngeal carcinoma.

Ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic acid (5F) is a diterpenoid that is isolated and purified from the Chinese herbal medicine Pteris semipinnata L., and is known to exert antitumour activity in several kinds of malignant cancer cells by leading cancer cells to apoptosis. However, the antitumour effect of 5F in vivo is rarely reported due to the complexity of the physiological environment and limitations of 5F as a small anticancer drug. In the present study, we utilized FITC-doped nanoparticles for the accumulation and delivery of 5F in nasopharyngeal carcinoma CNE2 tumours transplanted in nude mice by the enhanced permeation and retention (EPR) effect. In vivo studies demonstrated that nanoparticles could efficiently deliver 5F in CNE2 transplanted tumours, and the tumour growth was effectively inhibited by the drug-loaded nanoparticles with minimal side effects. The study indicated the benefits of combining well-studied nanoparticles with traditional herbal medicine treatment and establishes a delivery platform for 5F chemotherapy.

The High Content of Ent-11α-hydroxy-15-oxo-kaur- 16-en-19-oic Acid in Adenostemma lavenia (L.) O. Kuntze Leaf Extract: With Preliminary in Vivo Assays.

Background: Ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic acid (11αOH-KA) is a multifunctional biochemical found in some ferns, Pteris semipinnata, and its congeneric species. Although a number of therapeutic applications of 11αOH-KA have been proposed (e.g., anti-cancer, anti-inflammation, and skin whitening), the content of 11αOH-KA in these ferns is not high. Adenostemma lavenia (L.) O. Kuntze, an Asteraceae, has also been reported to contain 11αOH-KA. The decoction (hot water extract) of whole plants of A. lavenia is used as a folk remedy for inflammatory disorders, such as hepatitis and pneumonia, suggesting that 11αOH-KA may be the ingredient responsible for the medicinal properties of this plant. Methods: The anti-melanogenic activities of the water extracts of A. lavenia leaves and Pteris dispar Kunze (a cognate of P. semipinnata) leaves were compared in mouse B16F10 melanoma cells. The amount of 11αOH-KA was measured by using liquid chromatography spectrometry. C57BL/6J mice were treated with the water extract of A. lavenia leaf, and the blood concentration of 11αOH-KA was measured. The in vivo efficacy of the water extract of A. lavenia leaf was evaluated according to tis anti-melanogenic activity by monitoring hair color. Results: Although both the extracts (A. lavenia and P. dispar Kunze) showed high anti-melanogenic activities, only A. lavenia contained a high amount of 11αOH-KA, approximately 2.5% of the dry leaf weight. 11αOH-KA can be purified from A. lavenia leaves in two steps: water extraction followed by chloroform distribution. The treatment of mice with the water extract of A. lavenia leaf suppresses pigmentation in their hairs. Conclusions: Despite the small number of mice examined, the present preliminary result of the suppressed hair pigmentation suggests that the water extract of A. lavenia leaf and the ingredient that is possibly responsible for this—11αOH-KA—are new materials for oral cosmetics. The results may also be helpful in the future development of functional foods and methods to treat patients suffering from hyperpigmentation disorders, such as melasma.

Inhibition of breast cancer cell growth by the Pteris semipinnata extract ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid.

Previous studies have demonstrated strong anti-tumor effects of ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid (5F), an extract from Pteris semipinnata, in liver, lung, stomach and anaplastic thyroid cancer cells. However, whether 5F inhibits the growth of breast cancer cells remains unclear. The present study assessed the effect of 5F on breast cancer cells. The breast cancer cell lines MCF-7, MDA-MB-231 and SK-BR-3 were each treated with 0, 5, 10, 20 and 40 µg/ml 5F. Morphological changes in the breast cancer cells were assessed using fluorescence microscopy. The proliferation and apoptosis of the breast cancer cells were also examined using Cell Counting Kit-8 and flow cytometry. The levels of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X apoptosis regulator (Bax), Bcl-2 antagonist/killer (Bak) 1 and caspase-3 in the breast cancer cells were assessed. The results of the present study demonstrated that 5F inhibited the proliferation of MCF-7, MDA-MB-231 and SK-BR-3 breast cancer cells in a concentration- and time-dependent manner. Treatment with 5F also induced the apoptosis of breast cancer cells. MDA-MB-231, MCF-7, and SK-BR-3 cells exhibited apoptotic rates of 40.13, 60.44, and 70.49%, respectively, following incubation with 5F for 24 h. Furthermore, 5F significantly decreased the expression of Bcl-2 and increased the expression of Bax, Bak, and caspase-3 in a concentration-dependent manner. The results of the present study revealed that the P. semipinnata extract 5F inhibited the growth of human breast cancer cells in a time- and concentration-dependent manner, and that 5F induced apoptosis of human breast cancer cells.

Pteisolic acid G, a novel ent-kaurane diterpenoid, inhibits viability and induces apoptosis in human colorectal carcinoma cells.

Human colorectal cancer (CRC) is a major cause of cancer morbidity and mortality, and its incidence rates are increasing in economical transitioning areas globally. To develop efficient chemotherapy drugs for CRC, the present study isolated and identified a novel ent-kaurane diterpenoid from Pteris semipinnata, termed pterisolic acid G (PAG). This ent-kaurane diterpenoid was demonstrated to significantly inhibit the growth of human CRC HCT116 cells in a time- and dose-dependent manner, determined using the Cell Counting Kit-8 assay. Additionally, western blot analysis, Hoechst 33342 staining and cytometry analysis revealed that PAG not only inhibited the viability of HCT116 cells by suppressing the dishevelled segment polarity protein 2/glycogen synthase kinase 3 β/β-catenin pathway, but also induced the apoptosis of HCT116 cells by downregulating nuclear factor-κB p65 activity, stimulating p53 expression and promoting the generation of intracellular reactive oxygen species. These results suggest that PAG, a novel inhibitor of the Wnt/β-catenin pathway and inducer of apoptosis, should be investigated in more detail using in vivo experiments and comprehensive mechanistic studies in order to examine the potential use of PAG as a novel therapeutic agent for the treatment of CRC.

Synergistic anti-proliferative and pro-apoptotic activities of 5F and cisplatin in human non-small cell lung cancer NCI-H23 cells.

Two-drug combination chemotherapy, often including cisplatin and one other drug, remains the standard of care for patients with advanced non-small cell lung cancer (NSCLC). To improve the treatment of late-stage NSCLC and decrease the toxicity of combination chemotherapy, the search for novel drugs remains vigorous. Ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic acid (5F), a bioactive compound isolated from the herb Pteris semipinnata L., has previously been shown to induce apoptosis and inhibit proliferation in various cancer cells. One outstanding property of 5F is its minimal side effects. In the present study, 5F was combined with cisplatin to treat NCI-H23 cells; proliferation, apoptosis and cell cycle arrest were measured by an MTT assay, Annexin V staining/flow cytometry and propidium iodide staining/flow cytometry, respectively. The messenger RNA levels of β-catenin, glycogen synthase kinase (GSK)-3β, c-Myc and cyclin D1 were determined by reverse transcription-quantitative polymerase chain reaction, and the protein levels of β-catenin and GSK-3β were measured by western blot analysis. The results revealed that 5F and cisplatin synergistically induced apoptosis and inhibited cell growth, arrested cell cycles in the G0/G1 phase, downregulated β-catenin, c-Myc and cyclin D1, and upregulated GSK-3β. These findings merit in vivo studies using animal models of NSCLC to confirm the addition of 5F as a third drug to cisplatin-based combination therapy for late-stage NSCLC.

Report of the Nomenclature Committee for Vascular Plants: 69

SummaryThe following ten generic names are recommended for conservation: Brachypterum against Solori, Casearia against Laetia and Samyda, Cathaya Chen & Kuang against Cathaya Karav., Forsteronia with a conserved type, Iochroma against Acnistus and Pederlea, Miconia againstMaieta and Tococa, Pinochia, Scytophyllum Bernem. against Scytophyllum Eckl. & Zeyh., SeleniaNutt. against Selenia Hill, and Stellaria with a conserved type. The nothogeneric name ×Brassolaeliocattleya is recommended for conservation with that spelling and against ×Brasso-catt-laeliaand ×Laelia-brasso-cattleya. The nothogeneric name ×Laburnocytisusis recommended for rejection. The generic name Trisetum is not recommended to be conserved against Trisetaria. The following 13 species names are recommended for conservation: Acalypha brasiliensis against A. subsana, Acalypha communis against A. hirsuta, Andropogon caricosus with a conserved type, Astragalus membranaceus Fisch. ex Bunge against A. membranaceus Moench, Carex rostrata against C. inflata and with a conserved type, Chalcas paniculata with a conserved type, Drynaria fortunei with a conserved type, Hymenaea stigonocarpa with a conserved type, Malus domestica against M. pumila and six other synonyms (contradicting a previously published recommendation), Myriophyllum spicatum with a conserved type, Odontarrhena obovata against O. microphylla, Selinum microphyllum with a conserved type, and Sobralia infundibuligera against S. aurantiaca. The following three species names are not recommended for conservation: Dalbergia polyphylla Benth. against D. polyphylla Poir., Drosera ×belezeana with a conserved type, and Macroclinidium trilobum with that spelling. The following eight species names are recommended for rejection: Aloe obscura, Aloe picta, Aristolochia cordata, Cereus cubensis, Cereus subrepandus, Chenopodium caudatum, Corylus virginiana, and Crocuspurpureus. The species name Aloe perfoliata is not recommended for rejection. The varietal name Aloe perfoliata var. saponaria is recommended for rejection. It is recommended that the conserved author, place and date of publication of Actinidiaceae, Lardizabalaceae, Melanthiaceae, and Primulaceae, and the conserved place and date of Eucommiaceae, be changed. It is recommended that Andinia and Andina be treated as homonyms. It is not recommended that Huperzia rubricaulis and H. rubicaulis, Pittosporum napaulense and P. napaliense, or Senecio petasioides and S. petasitoides, be treated as homonyms. It is recommended that “Euonymus bullatus Wall. ex G. Lodd.” and “Thea piquetiana Laness.” be treated as not validly published. It is recommended that Der sichere Führer in der Obstkunde, Miller’s Gardeners Dictionary abridged edition 4 [species and infraspecific taxa], and Glaziou’s Plantae Brasiliae centralis a Glaziou lectae be added to the list of “Suppressed Works”. After two ballots, no vote of at least eleven either for or against has been obtained for proposals to reject Alyssum hyperboreum or Pteris semipinnata or to conserve Rhaponticoides against Bielzia, Rhaponticum with a conserved type, Aloe parvibracteata against A. monteiroae, Dyschoriste humilis with a conserved type, Pteris semipinnata with a conserved type, or Salvia cruikshanksii with that spelling, or for requests to determine whether the descriptive texts of “Erica longipedunculata G. Lodd.”, “Goodyera tesselata G. Lodd.”, “Pittosporum angustifolium G. Lodd.”, or “Tillandsia amoena G. Lodd.” were adequate for valid publication.

Two new hydroxylated ent-kauranoic acids from Pteris semipinnata

Two new hydroxylated ent-kauranoic acids, pterisolic acid G (1) and pterisolic acid H (3), together with five known ent-kaurane-type diterpenoids (2 and 4–7) were isolated from the whole plant of Pteris semipinnata L. The structures of compounds 1–3 were elucidated on the basis of HR-MS, 1D and 2D NMR analysis, and the absolute configuration of compounds 1 and 2 were determined by the results of single crystal X-ray diffraction experiment. Compounds 1–4 and 6–7 were evaluated in vitro cytotoxicity against the A549, CT26.WT, and Hep G2 cells, and compounds 4 and 6 possessed varying degrees of activity.

A preliminary study on inhibitory effect of ent-11α-hydroxy-15-oxo-aur-16-en-19-olic acid from pteris semiinnata L.on triple-negative human breast cancer cells and its mechanisms

Objective To explore the anti-cancer effects and its mechanisms of ent-11 α-hydroxy-15-oxo-kaur-16-en-19-oic-acid (5F),a compound isolated from pteris semipinnata L (PsL),on human triple-negative breast cancer cells.Methods Triple-negative human breast cancer cells were treated with different concentrations of 5F (0,5,10,20,40 mg/L) for different periods respectively.Cell viability was detected by a cell counting kit-8 (CCK-8).Morphologic changes were examined under a fluorescence microscope after treatment with 5F for 24 h.The appotosis rate of cells was examined by flow cytomety.The expression of representative apoptosis-related proteins was detected by Western blotting.Results 5F inhibited the proliferation of triple-negative breast cancer cells in a concentration-and time-dependent manner (P ＜ 0.05).The appotosis rate of malondialdehyde (MDA)-MB-231 was 40.13％,significantly higher than the control group (P ＜ 0.05).Western blotting revealed that after treatment with 5 F,the expression of anti-appototic protein B cell lymphoma/leukemia-2 (bcl-2) in breast cancer cells was decreased,and that of pro-appototic protein bcl-2 associated X protein (bax) and Caspase-3 was increased.Conclusion 5F could inhibit the proliferation of triple-negative breast cancer cells in a concentration-and timedependent manner probably by inducing cell apoptosis. Key words: Pteris semipinnata L; Triple-negative breast cancer; Apoptosis

Two new ent-kaurane diterpenoids from Pteris semipinnata

In this study, two new compounds and six known compounds were isolated from the aerial parts of Pteris semipinnata. The chemical structures of these two new compounds were elucidated as 6β,11α-dihydroxy-15-oxo-ent-kaur-16-en-19-oic acid (1) and 7α,11α-dihydroxy-15-oxo-ent-kaur-16-en-19-oic acid (2) by the extensive spectral methods including 2D NMR and HR-MS techniques.

Ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid induces apoptosis and cell cycle arrest in CNE-2Z nasopharyngeal carcinoma cells

Ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid (5F), a compound isolated from Pteris semipinnata L. (PsL), inhibits cell proliferation and induces cell apoptosis in several cancer lines. We found that 5F induced apoptosis and G2 phase cell cycle arrest in the CNE-2Z nasopharyngeal carcinoma (NPC) cells, accompanied by a decrease of NF-κB expression. 5F suppressed the viability of CNE-2Z cells in a time- and dose-dependent manner. 5F induced G2/M phase cell cycle arrest, but did not induce p21. Further analysis revealed that CNE-2Z cells harbored two p53 mutations. 5F treatment resulted in mitochondrial apoptosis, associated with increased Bax/Bcl-2 ratio, upregulation of cytochrome c in the cytosol, decreased NF-κB-p65 and increased IκB. Of note, 5F significantly sensitized CNE-2Z cells to cisplatin. 5F did not increase ROS, but reduced ROS production alone or in combination with cisplatin. Our data suggest that 5F is a potential anti-NPC drug for the development of single agent therapy and therapy in combination with cisplatin.

Ent-11α-Hydroxy-15-Oxo-Kaur-16-en-19-Oic-Acid Induces Apoptosis of Human Malignant Cancer Cells

Ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid (5F) is a chemical compound isolated from Pteris semipinnata L (PsL), a Chinese traditional herb. 5F has been known to exert antitumor activity in several kinds of human malignant cancer cells by leading cancer cell to apoptosis. 5F translocated Bax into the mitochondria, down-regulated Bcl-2, activated caspase-9 and caspase-3, released cytochrome c into the cytosol and translocated AIF from the mitochondria to the nucleus. The presentation of a wild-type p53 in the cancer cells facilitated cancer cells sensitive to the 5F treatment. 5F induces apoptosis of cancer cells by inhibiting NF-κB activation/induction, which leading to the decrease of Bcl-2 but the increase of Bax and Bak. MAPK kinases and Akt are also involved in process of 5F inducing cancer cell apoptosis. In lung cancer, 5F activated ERK1/2 and the inhibition of ERK1/2 suppressed 5F-mediated changes in apoptotic molecules. 5F activated Akt and suggested that Akt activation was anti-apoptotic rather than pro-apoptotic. However, in anaplastic thyroid carcinoma, JNK activation was related to cell death induced by 5F. ERK and p38 were also activated but as survival signals in response to 5F treatment to counteract the induction of cell death. Collectively, 5F is effective against several malignant cancers both in vivo and in vitro with minimal side effects. It induces apoptosis through the mitochondrialmediated pathway, in which regulation of Bcl-2 family proteins expression, the activation of MAPK and inactivation of NF-κB are critical. The good ability of 5F to inhibit cancer cells makes it in line with the successful development of other anti-tumor agents.

Ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid inhibits growth of human lung cancer A549 cells by arresting cell cycle and triggering apoptosis

To examine the apoptotic effect of ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid (5F), a compound isolated from Pteris semipinnata L (PsL), in human lung cancer A549 cells. A549 cells were treated with 5F (0-80 μg/ml) for different time periods. Cytotoxicity was examined using a MTT method. Cell cycle was examined using propidium iodide staining. Apoptosis was examined using Hoechst 33258 staining, enzyme-linked immunosorbent assay (ELISA) and caspase-3 activity analysis. Expression of representative apoptosis-related proteins was evaluated by Western blot analysis. Reactive oxygen species (ROS) level was measured using standard protocols. Potential interaction of 5F with cisplatin was also examined. 5F inhibited the proliferation of A549 cells in a concentration- and time-dependent manner. 5F increased the accumulation of cells in sub-G1 phase and arrested the cells in the G2 phase. Exposure to 5F induced morphological changes and DNA fragmentation that are characteristic of apoptosis. The expression of p21 was increased. 5F exposure also increased Bax expression, release of cytochrome c and apoptosis inducing factor (AIF), and activation of caspase-3. 5F significantly sensitized the cells to cisplatin toxicity. Interestingly, treatment with 5F did not increase ROS, but reduced ROS production induced by cisplatin. 5F could inhibit the proliferation of A549 cells by arresting the cells in G2 phase and by inducing mitochondrial-mediated apoptosis.

Ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid inhibits hepatocellular carcinoma in vitro and in vivo via stabilizing IkBα

Ent-11-hydroxy-15-oxo-kaur-16-en-19-oic-acid (5F) isolated from Pteris Semipinnata L is known to inhibit certain tumor cells in vitro. The information on the in vivo effect of 5F is limited and its effect on hepatocellular carcinoma (HCC) is unknown. In this study, the anti-tumor effect of 5F was investigated in a diethylnitrosamine (DEN)-induced mouse HCC model. In addition to therapeutic effect, the potential side effect was monitored. A panel of cultured HCC cells was used to confirm the in vivo data and explore the responsible molecular pathway. The result showed that 5F significantly inhibited the DEN-induced HCC tumors by reducing the number of tumor foci and the volume of tumors. Furthermore, 5F induced the death of cultured HCC cells in dose- and time-dependent manners. The cell death was confirmed to be apoptotic by in vivo and in vitro TUNEL assays. 5F inhibited NF-kB by stabilizing its inhibitor IkBα, reducing the nuclear p65 and inhibiting NF-kB activity. Subsequently it affected the NF-kB downstream molecules with a decrease in anti-apoptotic Bcl-2 and increase in pro-apoptotic Bax and Bak. During the whole period of the experiment, mice receiving 5F appeared to be healthy, though they suffered from a mild degree of hair loss. 5F did not damage liver and renal functions. In conclusion, 5F is effective against HCC with minimal side effects. It induces apoptosis in HCC cells via inhibiting NF-kB, leading to the decrease of Bcl-2 but the increase of Bax and Bak.

Comparison of Supercritical Fluid Extraction and Liquid Solvent Extraction on Antitumor Diterpenoid from Pteris semipinnata L.

Extraction techniques using Supercritical Fluid Extraction (SFE) and Liquid Solvent Extraction (LSE) were evaluated for the extraction of Ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid (5 F), the antitumor diterpenoid from Pteris semipinnata L. The extracts were analyzed by high performance liquid chromatography (HPLC). SFE experiments showed that many factors had a great impact on the yield and purity of the diterpenoid, such as extraction temperature, pressure, fluid flow rate, extraction time, and modifier. For the SFE process, the optimum operation conditions were as follows: extraction temperature of 328.15 K, extraction pressure of 30 MPa, supercritical CO2 flow rate of 160 kg/h, extraction time of 4 h, and 10% ethanol as the modifier. Under such a condition, the diterpenoid was almost completely extracted from the material and the yield was approximately 0.504 g/kg dry herb by HPLC analysis. The yield was approximately 3 fold higher than that by liquid solvent extraction. The purity of 5F was 5.148 g/kg dried extract with SFE, it was about 9 fold higher than that by LSE. Mass spectrum data indicated there were two correlative compounds, 5F and its derivative with glycose, in both the extracts, and the ratio of the signal strength of 5F and its derivative was about 3:1 in the SFE extract while that ratio was 1:3 in the LSE extract. The results demonstrated that the supercritical fluid extraction was selective, highly efficient, and with less consumption of organic solvents.

Analysis of operation conditions for a pilot-scale supercritical CO2extraction of diterpenoid fromPteris semipinnataL.

A pilot-scale supercritical CO2 extraction process with extraction volume of 20 L was established with which the antitumor diterpenoid, ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid, was extracted from the medicinal herb Pteris semipinnata L. The experiments showed that many factors had great impacts on yields of the diterpenoid, such as extraction temperature, pressure, fluid flow rate, extraction time and modifier. For the extraction process of the diterpenoid from Pteris semipinnata L, the optimum operation conditions were as follows: extraction temperature of 55 °C, extraction pressure of 30 MPa, supercritical CO2 flow rate of 160 kg/h, extraction time of 4 h, and 10% ethanol as the modifier. Under such a condition, the diterpenoid was almost completely extracted from the material, and the yield was approximately 0.504 g/kg dry herb by high-performance liquid chromatography analysis. The yield was approximately 2.8-fold more than that of the normal solvent extraction. The experimental results demonstrate that the supercritical CO2 extraction process is rapid, highly efficient and with less consumption of organic solvents. © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.

ChemInform Abstract: Pterisolic Acids A—F, New ent‐Kaurane Diterpenoids from the Fern Pteris semipinnata.

Six new ent-15-oxokauran-19-oic acid derivatives, named pterisolic acids A-F (1-6), were isolated from the ethanol extract of the fern Pteris semipinnata (Pteridaceae), and the structures of these new ent-kauranoids were elucidated on the basis of extensive spectroscopic studies and single crystal X-ray diffraction analysis.

The effects of arsenic and induced-phytoextraction methods on photosynthesis in Pteris species with different arsenic-accumulating abilities

Arsenic (As) accumulation and photosynthesis occur simultaneously in plants under As exposure. We investigated the effects of As and induced-phytoextraction methods on photosynthesis in two As hyperaccumulators ( Pteris vittata and Pteris cretica var. nervosa) and two non-hyperaccumulators ( Pteris semipinnata and Pteris ensiformis) under soil culture conditions. Chlorophyll fluorescence parameters (the maximum [ F v/ F m] and actual quantum efficiency [ F PSII]) and the activities of three photosynthetic enzymes (ATPase, ribulose-1, 5-bisphosphate carboxylase [RuBPC] and glyceraldehyde-3-phosphate dehydrogenase [GAPDH]) were measured. Arsenic accumulation and photosynthetic behaviours in response to enhanced-phytoextraction methods (trans-1, 2-cyclobexylenedinitrilotetraacetic acid [CDTA] and phosphorous [P] addition and soil pH adjustment) of P. cretica and P. semipinnata were monitored and compared under conditions of 100 mg As kg −1. Significant decreases in the F v/ F m (19.9%) and F PSII (36.1%) were observed in P. vittata when exposed to 100 mg As kg −1 in comparison to the control (0 mg As kg −1). Compared to the control (0 mg As kg −1), the activities of GAPDH increased by 0.5% in P. cretica var. nervosa and decreased by only 8.3% in P. vittata even when both of them were treated with 200 mg As kg −1, whereas a significant decrease, 56.1% and 51.7%, of this enzyme was observed in P. semipinnata and P. ensiformis, respectively, when exposed to 50 mg As kg −1. Compared to the control (0 mg CDTA kg −1 or 0 mg P kg −1), the activities of ATPase increased by 53.7% and 82.7% in P. cretica when exposed to 0.5 g CDTA kg −1 and 50 mg P kg −1, respectively, and an increase of up to 175% was also observed in P. semipinnata when exposed to 600 mg P kg −1. The activities of GAPDH increased by 68.9% and 90.7% in P. cretica when exposed to 2 g CDTA kg −1 and 600 mg P kg −1, respectively, but a decrease of up to 60% was observed in P. semipinnata when exposed to 2 g CDTA kg −1. The uptake of As in P. semipinnata increased by 80.9% and 73.3% when 1 g CDTA kg −1 and 600 mg P kg −1 were added, respectively, compared to the control (0 g CDTA kg −1 or 0 mg P kg −1). It was concluded that GAPDH played an important role in the photosynthesis of As hyperaccumulators under As treatments.

Organic acids in two arsenic hyperaccumulators and a non-hyperaccumulator of Pteris exposed to elevated arsenic concentrations

Six organic acids (oxalic, malonic, malic, citric, palmitic and linolenic acid) in two arsenic (As) hyperaccumulators (Pteris multifida and Pteris vittata) and a non-hyperaccumulator fern (Pteris semipinnata) exposed to different As concentrations (0, 5, 20 and 40 mg As L−1) under hydroponic conditions were determined using gas chromatography-mass spectrometry (GC-MS). Three fern species were collected from an uncontaminated site, but two As-hyperaccumulators were also collected from an As-contaminated site. Furthermore, the time-course effect of organic acid production in P. multifida and P. semipinnata collected from the uncontaminated site were also studied under 0 and 20 mg As L–1 treatments with a sampling interval at 0, 6, 12, 24 and 36 h. After esterifying (H2SO4–CH3OH), extracting (CH2Cl2), washing (saturated NaCl) and drying (anhydrous Na2SO4), these organic acids were isolated (Column: HP Ultra 2, 50 m × 0.2 mM × 0.33 µM; Carrier gas: He). There was no significant increase in the concentrations of the six organic acids in the fronds and roots of the three fern species sampled from an uncontaminated site under 5 or 40 mg As L−1 treatments. In addition, there were also no significant differences in the concentrations of organic acids among the three fern species under the same As concentration treatments. Concentrations of malic, oxalic and linolenic acids in the fronds and roots of two As hyperaccumulators collected from an As-contaminated or uncontaminated site and the non-hyperaccumulator collected from an uncontaminated site followed the sequence of malic acid > oxalic acid > linolenic acid. As for time-course effect, compared to P. semipinnata, a significant increase was observed in concentrations of oxalic and linolenic acid in P. multifida over time under 20 mg As L−1 treatment. In general, the changes of organic acid concentrations in As hyperaccumulators did not directly contribute to As accumulation.