Coelonin protects against PM2 .5 -induced macrophage damage via suppressing TLR4/NF-κB/COX-2 signaling pathway and NLRP3 inflammasome activation in vitro.

One of the important monitoring indicators of the air pollution is atmospheric fine particulate matter (PM2.5 ), which can induce lung inflammation after inhalation. Coelonin can alleviate PM2.5 -induced macrophage damage through anti-inflammation. However, its molecular mechanism remains unclear. We hypothesized that macrophage damage may involve the release of inflammatory cytokines, activation of inflammatory pathways, and pyrosis induced by inflammasome. In this study, we evaluated the anti-inflammation activity of coelonin in PM2.5 -induced macrophage and its mechanism of action. Nitric oxide (NO) and reactive oxygen species (ROS) production were measured by NO Assay kit and dichlorofluorescein-diacetate (DCFH-DA), and apoptosis were measured by Flow cytometry and TUNEL staining. The concentration of inflammatory cytokines production was measured with cytometric bead arrays and ELISA kits. The activation of NF-κB signaling pathway and NLRP3 inflammasome were measured by immunofluorescence, quantitative reverse transcription-polymerase chain reaction and western blot. As expected, coelonin pretreatment reduced NO production significantly as well as alleviated cell damage by decreasing ROS and apoptosis. It decreased generation of interleukin (IL)-6 and tumor necrosis factor (TNF)-α in PM2.5 -induced RAW264.7 and J774A.1 cells. Moreover, coelonin markedly inhibited upregulating the expression of toll-like receptor (TLR)4 and cyclo-oxygenase (COX)-2, blocked activation of p-nuclear factor-kappa B (NF-κB) signaling pathway, and suppressed expression of NLRP3 inflammasome, ASC, GSDMD, IL-18 and IL-1ß. In conclusion, the results showed that coelonin could protect against PM2.5 -induced macrophage damage via suppressing TLR4/NF-κB/COX-2 signaling pathway and NLRP3 inflammasome activation in vitro.

Pseudomonas aeruginosa isolation is an important predictor for recurrent hemoptysis after bronchial artery embolization in patients with idiopathic bronchiectasis: a multicenter cohort study.

BACKGROUND: Nearly half of bronchiectasis patients receiving bronchial artery embolization (BAE) still have recurrent hemoptysis, which may be life-threatening. Worse still, the underlying risk factors of recurrence remain unknown. METHODS: A retrospective cohort was conducted of patients with idiopathic bronchiectasis who received BAE from 2015 to 2019 at eight centers. Patients were followed up for at least 24 months post BAE. Based on the outcomes of recurrent hemoptysis and recurrent severe hemoptysis, a Cox regression model was used to identify risk factors for recurrence. RESULTS: A total of 588 individuals were included. The median follow-up period was 34.0 months (interquartile range: 24.3-53.3 months). The 1-month, 1-year, 2-year, and 5-year cumulative recurrent hemoptysis-free rates were 87.2%, 67.5%, 57.6%, and 49.4%, respectively. The following factors were relative to recurrent hemoptysis: 24-h sputum volume (hazard ratio [HR] = 1.99 [95% confidence interval [95% CI]: 1.25-3.15, p = 0.015]), isolation of Pseudomonas aeruginosa (HR = 1.50 [95% CI: 1.13-2.00, p = 0.003]), extensive bronchiectasis (HR = 2.00 [95% CI: 1.29-3.09, p = 0.002]), and aberrant bronchial arteries (AbBAs) (HR = 1.45 [95% CI: 1.09-1.93, p = 0.014]). The area under the receiver operating characteristic curve of the nomogram was 0.728 [95% CI: 0.688-0.769]. CONCLUSIONS: Isolation of Pseudomonas aeruginosa is an important independent predictor of recurrent hemoptysis. The clearance of Pseudomonas aeruginosa might effectively reduce the hemoptysis recurrence rate.

[Pleurodesis with an Autologous Blood Patch in the Treatment of Persistent Air Leak after Lung Resection].

Objective To evaluate the efficacy and risks of autologous blood patch pleurodesis in patients with persistent air leak(PAL)after lung resection. Methods A total of 97 patients with PAL after lung resection in Beijing Shijitan Hospital from October 2014 to October 2019 were retrospectively reviewed,including 53 treated by autologous blood patch pleurodesis and 44 by the conventional way.The therapeutic effect,adverse reactions and complications were analyzed. Results All the patients with PAL were cured with autologous blood patch pleurodesis.Most air leaks(81.1%)ceased within 48 hours after treatment,and the left 18.9% patients got cured after a repeat.The mean tube retention time and the mean in-hospital stay were 8.4 days and 10.0 days in the autologous blood patch pleurodesis group and 13.5 days and 15.3 days in the conventional treatment group.A prolonged drainage time(P=0.00)and in-hospital stay(P=0.00)were observed in the conventional treatment group.No severe complications were observed except two patients developed slight fever and cutaneous emphysema. Conclusion In our experience,the autologous blood patch pleurodesis is an effective way with low risk of adverse reactions in the treatment of PAL.

Effective fraction of Bletilla striata reduces the inflammatory cytokine production induced by water and organic extracts of airborne fine particulate matter (PM2.5) in vitro.

BACKGROUND: Bletilla striata is a traditional Chinese medicine used to treat hemorrhage, scald, gastric ulcer, pulmonary diseases and inflammations. In this study, we investigated bioactivity of the effective fraction of B. striata (EFB) in reducing the inflammatory cytokine production induced by water or organic extracts of PM2.5. METHODS: PM2.5 extracts were collected and analyzed by chromatographic system and inductively coupled plasma mass spectrometer. Cell viability was measured using MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay, and cell supernatant was analyzed by flow cytometry, ELISA, and qRT-PCR in cultured mouse macrophage cell line RAW264.7 treated with EFB and PM2.5 extracts. Expressions of nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathway were measured by Western blot. RESULTS: PM2.5 composition is complex and the toxicity of PM2.5 extracts were not noticeable. The treatment of EFB at a wide dose-range of 0-40 µg/mL did not cause significant change of RAW264.7 cell proliferation. EFB pretreatment decreased the inflammatory cytokines in the macrophage. Further analysis showed that EFB significantly attenuated PM2.5-induced proinflammatory protein expression and downregulated the levels of phosphorylated NF-κBp65, inhibitor of kappa B (IκB)-α, c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and p38. CONCLUSIONS: Our study demonstrated the potential effectiveness of B. striata extracts for treating PM2.5-triggered pulmonary inflammation.

[Comparison of contents of three active ingredients in Bletilla striata from different sources].

In order to understand the difference of contents of coelonin,batatasin Ⅲ and 3'-O-methylbatatasin Ⅲ in 60 different sources of Bletilla striata planted under the same conditions. UPLC method was used and the analysis was performed on a Waters ACQUITY UPLC BEH C18 column( 2. 1 mm×100 mm,1. 7 µm),eluted with acetonitril-0. 1% formic acid solution by gradient. The flow rate was 0. 208 m L·min-1,the detection wavelength was 270 nm,the column temperature was 35 ℃ and the injection volume was 4µL. Under the above chromatographic conditions,the three components can be separated well with good linearity in the range of 0. 156-5. 000 mg·L-1. The average contents of coelonin,batatasin Ⅲ and 3'-O-methylbatatasin Ⅲ were( 0. 116 ± 0. 071) %,( 0. 386 ±0. 185) % and( 0. 086±0. 034) %,respectively. After planting for two years under the same conditions,there was no significant difference in chemical composition among different sources and varieties,but the contents of the three components had some regional differences,which indicated that the western region was higher than the eastern region,while the contents of coelonin and batatasin Ⅲ in B.sinensis were slightly higher than those in B. striata. The chromatographic method above is simple,stable and reproducible,and can be used for quantitative analysis of three components. The content analysis of different sources of B. striata can provide reference for future B. striata breeding and quality control.

[Effects of Stored Apheresis Platelet Apoptosis on Aggregation Function].

OBJECTIVE: To investigate the effects of storage lesion in apheresis platelets on platelet apoptosis and the changes of aggregation function, and analyze the relationships between the apoptosis and aggregation function. METHODS: Platelet samples were collected from 10 healthy donors with O blood group. Firstly, the effects of storage lesion in platelets on the platelet apoptosis were detected by flow cytometry. Then, using a multiplate analyzer, individual-donor Plt aggregation response to stimulation by the agonists ADP, Collagen, TRAP and ASPI was examined. Finally, the relationships between its apoptosis and aggregation function was analyzed by correlation regression analysis. RESULTS: By flow cytometry it was found that with the prolonging of storage time, the apoptosis ratio of platelets significantly increased in a time-dependent manner, the apoptosis rates of platelets on 2nd, 5th and 8th day were (2.87±0.31)%, (11.08±1.54)% and (27.99±2.76)% respectively (P<0.01). Compared with Day 2 platelets, the d 5 platelets stored for 5 d significantly decrease the aggregation response to stimnlation of collagen, TRAP, and ASPI. Compared with platelets stored for 5 d, platelets stored for 8 d significantly decreased the aggregation response to stimnlation of collagen, TRAP and ASPI (P<0.01). However, when stimulated by ADP, the aggregation response was similar among Day 2, Day 5 and Day 8 platelets. The rate of the aggregation function was also declined significantly when stimulated by collagen, TRAP, and ASPI, but not ADP. Further regression analysis showed that the aggregation function of apheresis platelet negatively correlated with the apoptosis (r=-0.9497, r=-0.9527, r= -0.9707 and r= -0.9352 respectively), and the correlation is very strong. CONCLUSION: With the prolonging of storage time, the apoptosis ratio in platelets significantly increased. The aggregation function also is declined significantly when stimulated by collagen, TRAP, and ASPI, but not ADP. The aggregation function of apheresis platelets closly correlats with the apoptosis.

The anti-Staphylococcus aureus activity of the phenanthrene fraction from fibrous roots of Bletilla striata.

BACKGROUND: Bletillae Rhizoma, the tuber of Bletilla striata, has been used in Chinese traditional medicine to treat infectious diseases. Chemical studies indicated that phenanthrene was one of the most important components of the herb, with a broad spectrum of antibiotic activity against Gram-positive bacteria. The objective of this study was to further characterize the antibacterial activity of the phenanthrene fraction from the fibrous root of the pseudobulb of B. striata. METHODS: The phenanthrene fraction (EF60) from the ethanol extract of fibrous roots of Bletilla striata pseudobulbs was isolated using polyamide column chromatography. The antibacterial activity of the fraction was evaluated in vitro using a 96-well microtiter plate and microbroth dilution method. The cytotoxicity of EF60 against mammalian cells was tested by hemolysis and MTT assays. RESULTS: EF60 was obtained using alcohol extraction and polyamide column chromatography, with a yield of 14.9 g per 1 kg of the fibrous roots of B. striata. In vitro tests indicated that EF60 was active against all tested strains of Staphylococcus aureus, including clinical isolates and methicillin-resistant S. aureus (MRSA). The minimum inhibitory concentration (MIC) values of EF60 against these pathogens ranged from 8 to 64 µg/mL. Minimum bactericidal concentration tests demonstrated that EF60 was bactericidal against S. aureus 3304 and ATCC 29213 and was bacteriostatic against S. aureus 3211, ATCC 25923, and ATCC 43300. Consistently, the time-kill assay indicated that EF60 could completely kill S. aureus ATCC 29213 at 2× the MIC within 3 h but could kill less than two logarithmic units of ATCC 43300, even at 4× the MIC within 24 h. The postantibiotic effects (PAE) of EF60 (4× MIC) against strains 29213 and 43300 were 2.0 and 0.38 h, respectively. Further studies indicated that EF60 (160 µg/mL) showed no cytotoxicity against human erythrocytes, and was minimally toxic to Human Umbilical Vein Endothelial Cells with an IC50 of 75 µg/mL. CONCLUSIONS: Our studies indicated that EF60 is worthy of further investigation as a potential phytotherapeutic agent for treating infections caused by S. aureus and MRSA.

[Antibacterial Activity of Chemical Constituents Isolated from Fibrous Roots of Bletilla striata].

Objective: To investigate the chemical constituents isolated from the fibrous roots of Bletilla striata, and to research their antibacterial activities. Methods: The native products were isolated and purified by silica gel, Sephadex LH-20 column chromatography and preparative HPLC. Their structures were elucidated on the basis of various spectroscopic analysis, and their antibacterial activities were tested by microbroth dilution method in a 96-well microtiter plate. Results: Seven compounds were isolated from the ethanol extract of the fibrous roots of Bletilla striata, and identified as p-hydroxybenzaldehyde( 1),2,7-dihydroxy-4-methoxy-9,10-dihydrophenanthrene( 2),4,5-dihydroxy-2-methoxy-9,10-dihydrohenanthrpene( 3),2-dihydroxy-4,7-dimethoxyphenan-threne( 4), militarine( 5), dactylorhin A( 6) and gastrodin( 7). Among them, compounds 2 ~ 4 showed moderate antibacterial activities against several Gram-positive bacterial strains( MIC 8 ~ 128 µg / m L),such as Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis and Bacillus subtilis. Conclusion: The fibrous roots and tubers of Bletilla striata contain similar compounds, including glucosyloxybenzyl 2-isobutylmalates,and phenanthrene compounds, which showed antimicrobial activities against Gram-positive bacterial strains. And compounds 3,4 are isolated from Bletilla genus for the first time.

[Research on the Anti-Pulmonary Fibrosis Effect of the Bletilla striata Polysaccharide in Rat Silicosis Model].

Objective: To investigate the anti-pulmonary fibrosis effect and the possible molecular mechanism of the Bletilla striata polysaccharide. Methods: Polysaccharide was prepared by water reflux extraction plus ethanol precipitation method, and following deproteinization process by Sevage method. Rat silicosis model was established by invasive intratracheal instillation method. The effect and molecular mechanism of the polysaccharide was evaluated by lung indexes, lung pathological change, serum levels of SOD,MDA,NF-κB,IL-1ß,PDGF,TGF-ß1,TNF-α,HYP were detected, and the contents of CD3~+,CD4~+,CD8~+T lymph cells and CD4~+/ CD8~+ratio were detected by flow cytometry. Results: Both low( 100 mg / kg) and high( 400 mg / kg) dosage polysaccharide treatment could remarkably elevate the serum SOD level and reduce the MDA,NO level, and effectively reverse the CD4~+/ CD8~+ratio comparing with the model group( P < 0. 01). Except the TNF-α level was significantly lower in the high dosage treatment group, there was no other effect in inflammatory cytokines and HYP content in serum. HE pathological section confirmed that the Bletilla striata polysaccharide treatment group can not effectively prevent lung fibrosis. Conclusion: The Bletilla striata polysaccharide has remarkable regulation effect on antioxidation system and immune system, but can not effectively prevent lung fibrosis, more effort should be made to study the active antipulmonary fibrosis components of Bletilla striata.

Cardamonin Regulates miR-21 Expression and Suppresses Angiogenesis Induced by Vascular Endothelial Growth Factor.

Cardamonin has promising potential in cancer prevention and therapy by interacting with proteins and modifying the expressions and activities, including factors of cell survival, proliferation, and angiogenesis. In our precious study, we have demonstrated that cardamonin suppressed vascular endothelial growth factor- (VEGF-) induced angiogenesis as evaluated in the mouse aortic ring assay. It is also known that microRNAs (miRNAs) play important roles in angiogenesis. Herein, we hypothesized whether antiangiogenesis effect of cardamonin in human umbilical vein endothelial cells (HUVECs) triggered by VEGF was associated with miRNAs. We found that cardamonin reduced the miR-21 expression induced by VEGF in HUVECs. Treatment with miR-21 mimics abolished the effects of cardamonin on VEGF-induced cell proliferation, migration, and angiogenesis in HUVECs. However, treatment with miR-21 inhibitors presented the opposite effects, indicating the vital role of miR-21 in this process. Our study provides a new insight of the preliminary mechanism of anti-VEGF-induced angiogenesis by cardamonin in HUVECs.

Antibacterial Biphenanthrenes from the Fibrous Roots of Bletilla striata.

Four new 9',10'-dihydro-biphenanthrenes, including an unprecedented 1,2'-linked biphenanthrene, 4,7,3',5'-tetramethoxy-9',10'-dihydro(1,2'-biphenanthrene)-2,7'-diol (1), a new 1,3'-linked biphenanthrene, 4,7,7'-trimethoxy-9',10'-dihydro(1,3'-biphenanthrene)-2,2',5'-triol (2), and two new 1,1'-linked biphenanthrenes, 4,7,4'-trimethoxy-9',10'-dihydro(1,1'-biphenanthrene)-2,2',7'-triol (3) and 4,7,3',5'-tetramethoxy-9',10'-dihydro(1,1'-biphenanthrene)-2,2',7'-triol (4), as well as two known biphenanthrenes (5, 6), were isolated from a 95% ethanol extract of the fibrous roots of Bletilla striata. Their structures were determined by spectroscopic and spectrometric methods. Atropisomerism of these compounds was considered based on their chiral optical properties and potential energy surface scans at the ab initio HF/3-21G level, which revealed their racemic mixture form. Compounds 2-6 showed potent antibacterial activities against six Gram-positive bacterial strains.

Lasiodiplodia sp. ME4-2, an endophytic fungus from the floral parts of Viscum coloratum, produces indole-3-carboxylic acid and other aromatic metabolites.

BACKGROUND: Studies on endophytes, a relatively under-explored group of microorganisms, are currently popular amongst biologists and natural product researchers. A fungal strain (ME4-2) was isolated from flower samples of mistletoe (Viscum coloratum) during a screening program for endophytes. As limited information on floral endophytes is available, the aim of the present study is to characterise fungal endophytes using their secondary metabolites. RESULTS: ME4-2 grew well in both natural and basic synthetic media but produced no conidia. Sequence analysis of its internal transcribed spacer rDNA demonstrated that ME4-2 forms a distinct branch within the genus Lasiodiplodia and is closely related to L. pseudotheobromae. This floral endophyte was thus identified as Lasiodiplodia sp. based on its molecular biological characteristics. Five aromatic compounds, including cyclo-(Trp-Ala), indole-3-carboxylic acid (ICA), indole-3-carbaldehyde, mellein and 2-phenylethanol, were found in the culture. The structures of these compounds were determined using spectroscopic methods combined with gas chromatography. To the best of our knowledge, our work is the first to report isolation of these aromatic metabolites from a floral endophyte. Interestingly, ICA, a major secondary metabolite produced by ME4-2, seemed to be biosynthesized via an unusual pathway. Furthermore, our results indicate that the fungus ME4-2 is a potent producer of 2-phenylethanol, which is a common component of floral essential oils. CONCLUSIONS: This study introduces a fungal strain producing several important aromatic metabolites with pharmaceutical or food applications and suggests that endophytic fungi isolated from plant flowers are promising natural sources of aromatic compounds.

[Protoplasts isolation, purification and plant regeneration of Pinellia cordata].

The main factors which affected the isolation, purification and cultivation of Pinellia cordata protoplasts from leaves were studied. The results indicated that the optimum enzyme solution for P. cordata leaves was 13% CPW + 1.0% Cellulose +0.1% Pectolase, at pH 6.0, temperature (25-28 degrees C ) for 4 h. The sucrose density gradient centrifugation was adopted to purificate the protoplasts collected, when 25% sucrose was used as mediator, centrifugating at 500 rpm for 10 min. When the protoplasts were shallow liquid and liquid-solid double layer cultured on the medium of MS + 0.5 mg x L(-1) 6-BA + 0.25 mg x L(-1) NAA + 13% mannitol at the density of 2.5 x 104 protoplasts/mL, or fed and nursed cultured at the density of 100-500 protoplasts/mL, cell division could be observed for 3 days; granular calli appeared for 30 days. Calli was proliferated on the medium of MS + 0.5 mg x L(-1) 6-BA + 0.25 mg x L(-1) NAA solidified by 0.55% agar, and differentiated and regenerated after 5-6 months. Plant generation of P. cordata is successfully established.

Flavonoids from the leaves of Carya cathayensis Sarg. inhibit vascular endothelial growth factor-induced angiogenesis.

The total flavonoids (TFs) were isolated from the leaves of Carya cathayensis Sarg. (LCC), a well-known Chinese medicinal herb commercially cultivated in Tianmu Mountain district, a cross area of Zhejiang and Anhui provinces in China. Five flavonoids, i.e. cardamonin, pinostrobin chalcone (PC), wogonin, chrysin, and pinocembrin were the main components of the TFs. The TFs and these pure compounds suppressed vascular endothelial growth factor (VEGF)-induced angiogenesis as detected in the mouse aortic ring assay, and cardamonin showed the best effect among them. To further elucidate the mechanisms for suppressing angiogenesis of these flavonoids, assays of VEGF-induced proliferation and migration in human umbilical vein endothelial cells (HUVECs) were performed. The TFs, cardamonin, pinocembrin, and chrysin obviously suppressed both VEGF-induced HUVEC proliferation and migration. However, PC and wogonin not only slightly inhibited VEGF-induced proliferation but also remarkably suppressed those of migration in HUVECs. Our further study showed that cardamonin decreased the phosphorylation of ERK and AKT induced by VEGF with a dose-dependent manner in HUVECs. Our findings indicate that the TFs and these pure flavonoids may become potential preventive and/or therapeutic agents against angiogenesis-related diseases.

[Surgical approach for lung cancer larger than 10 cm].

OBJECTIVE: To discuss the surgical techniques for lung cancer larger than 10 cm. METHODS: Via a modified anterolateral thoracotomy entered through the 4th or 5th intercostal space, intrapericardial access to pulmonary vessels was obtained for pneumonectomy or extended pneumonectomy in all patients, after excluding the feasibility of lobectomy. RESULTS: From March 2009 to October 2011, 13 consecutive patients with lung cancer larger than 10 cm, were admitted to surgical resection via this approach for intrapericardial pneumonectomy/extending pneumonectomy. The whole processes were smooth and without any major morbidity. CONCLUSIONS: The main approach for lung cancer larger than 10 cm is pneumonectomy. The key to surgical success is intrapericardial controlling of the hilum vascular. The modified anterolateral thoracotomy may facilitate this procedure.

Antitumor constituents from the leaves of Carya cathayensis.

This study aimed to find cytotoxic chemical constituents from Carya cathayensis leaves (LCC) by using various chromatographic procedures. Identification of the chemical constituents was carried out by various spectroscopic techniques and classical chemical methods. The cytotoxic activity of the constituents was assayed on HeLa and HepG2 cell lines by staining with 3-(4,5-dimethylthiahiazol-2-y1)-2,5-di-phenytetrazolium bromide (MTT). Six flavanoids, namely (1) pinostrobin, (2) pinostrobin chalcone, (3) wogonin, (4) cardamonin, (5) alpinetin and (6) tectochrysin were identified from this species. Compounds 2-6 were isolated from this kind of plant for the first time. MTT results showed that wogonin has a moderate cytotoxic activity with IC(50) values of 17.03 ± 2.41 and 44.23 ± 3.87 µM against HeLa and HepG2 cell lines, respectively. According to the correlation of primary the structure and activity, 8-methoxy substituent in these flavones may be a major factor of the antitumor activity.

[Rapid propagation of Bletilla striata by synthetic seeds technology].

OBJECTIVE: To establish a new manufacturing method for Bletilla striata synthetic seeds, and provided a new way for rapid propagation of B. striata, the correlated influential factors were studied. METHOD: The synthetic seeds were manufactured by taking seeds of B. striata as materials which were beforehand germinated in 1/2 MS medium for 10 days, and the influential factors such as artificial endosperm components, episperm substances, storage conditions and germination groundmass impact on the germination rate and seedling rate of the synthetic seeds were evaluated. RESULT: Compound 4.0% sodium alginate + 0.2 mol x L(-1) CaCl2 + 0.4 mg x L(-1) penicillin + 0.3% carbendazim powder + 0.2% sodium benzoate served as the best episperm substances while MS + 1.0 mg x L(-1) NAA + 2.0 mg x L(-1) KT as the best endosperm components, in which, high germination rate and seedling rate were obtained. The synthetic seeds storing in the 4 degrees C for a long time was able to have still high vitality. CONCLUSION: The B. striata synthetic seeds manufacturing system was established successfully, while efforts should be taken to improve the sowing technique of the synthetic seeds in non-sterile conditions.

2-Meth-oxy-naphthalene-1,4-dione.

The title compound, C(11)H(8)O(3), was isolated from Impatiens balsamina plants (balsam, LIB) grown in our laboratory. The two six-membered rings of the naphthalene-1,4-dione unit are coplanar [maximum deviation = 0.009 (1) Å]. The O and C atoms of the meth-oxy substituent also lie close to the naphthalene plane, with deviations of 0.0090 (2) and 0.047 (2) Å, respectively.

[Study on sequence characterized amplified region (SCAR) markers in Dendrobium candidum].

OBJECTIVE: To establish an effective way for rapid identification of Dendrobium candidum based on DNA molecular marker. METHODS: The genetic diversity among 11 wild species of Dendrobium was studied by using the random amplification polymorphism DNA. The special segment with random primer in Dendrobium candidum was recovered, cloned and sequenced. According to its sequence, a pair of specific primers was synthesized and tested for the specific detection of Dendrobium candidum. RESULTS: The results of PCR showed that only a 302 bp electrophoresis band of Dendrobium candidum named DS-302 was found. According to the result of sequence analysis in the Genbank databases, no distinct comparability was found. And a specific primer was designed and used to identify Dendrobium candidum from other Dendrobium species effectively. There was a same band like DS-302 in Dendrobium candidum, but not be discovered in other species of Dendrobium. CONCLUSIONS: The RAPD marker DS-302 was successfully converted into SCAR marker. It was an effective way to identify Dendrobium candidum more rapidly.

[Study function of endophytic fungus in parasitism process of mistletoe].

OBJECTIVE: To research the function of endophytes of mistletoe in parasitism process of mistletoe in Pterocarya stenoptera. METHOD: Endophytes from eight different parts of the mistletoe were separated by explant culture, and further screened by different CMC plates culture and DNS method to get cellulase high productive strains. The distribution of the endophytic fungus parasitized in mistletoe were prepared and stained to demonstrate by histological section of the intumescentia part of the P. stenoptera. RESULT: The histological section indicated that aboundent of hyphasma were distributed around the haustorium of the mistletoe. Eighty three strains of endophytic fungus were separated, 38 of them were able to degrade cellulose, 19 strains showed high cellulase activity and 10 of which were separated from the parasitic position. CONCLUSION: Endophytic fungus of mistletoe can secrete cellulase and assist the haustorium of mistletoe to breakthrough the cell walls as well as intercellular space tissues of the P. stenoptera, thus, the endophytic fungus plays an important role in the parasitism process of mistletoe in P. stenoptera.