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ABSTRACT: Stone cells (sclereids) in Norway spruce (Picea abies) bark have been reported to be highly lignified tissues that are important in physical defence against bark beetle invasion. Microchemical analyses of the low-molecular weight compounds in the stone cells of Norway spruce were carried out using laser microdissection in combination with cryogenic nuclear magnetic resonance and mass spectrometry (LMD/NMR/MS). Two phenolic compounds, the stilbene astringin and the dihydroflavonol dihydroxyquercetin 3'-O-beta-D-glucopyranoside, were identified indicating that stone cells are more than just repositories for lignin. Both of these compounds were also found to be present in other phloem tissue at a higher level than in the stone cells based on quantification by cryogenic 1H NMR. Our results suggest that stone cells may be involved in chemical as well as physical defense against bark beetles and their associated microorganisms. This paper reports on the identification of secondary plant metabolites from a single laser-microdissected population of plant cells offering a sensitive new way to determine the chemical profile of specific plant cell types with a high degree of precision.
Planta 03/2007; 225(3):771-9. · 3.00 Impact Factor
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ABSTRACT: The root tubers of Stemona tuberosa, Stemona japonica and Stemona sessilifolia are recognized by the Pharmacopoeia of the People's Republic of China as authentic sources of the herb Radix Stemonae (Baibu). Careful anatomical analyses of these three species, whose identities were confirmed by flowering and fruiting samples, revealed that the root tubers of Stemona tuberosa could be distinguished from those of the other two species by the presence of scattered fibers in the cortex and pith and by the absence of thickened striations on the surface of velamen cells. HPLC analyses demonstrated that the total alkaloid profiles could be grouped into four types represented as the major component by stenine-type Stemona alkaloids such as tuberostemonine (4) and neotuberostemonine (3), or by non-stenine types such as croomine (1) and stemoninine (2). Nevertheless, all these samples demonstrated different degrees of antitussive properties in guinea pigs. These results suggested that non-stenine-type of Stemona alkaloids also contributed to the antitussive properties. The variations in chemical profiles among herb samples add difficulty in ensuring quality control in botanical products.
Journal of Ethnopharmacology 12/2006; 108(1):46-53. · 3.01 Impact Factor
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ABSTRACT: Three new ent-kaurane diterpenoids, parvifoline Z (1), parvifoline AA (2), and parvifoline AB (3), together with 14 known compounds, were isolated from the leaves of Isodon parvifolius. The structures of the new compounds were elucidated by 1D- and 2D-NMR spectroscopy and mass spectrometry, and by comparison with known compounds. These three new diterpenoids included three types of ent-kauranoids, namely, C(20)-non-oxygenated-ent-kauranoid, 7,20-cyclo-ent-kauranoid and 6,7-seco-ent-kauranoid-7,20-olide. Compounds 1 and 2 exhibited significant cytotoxicities against A549, HT-29, and K562 cell lines.
Chemistry & Biodiversity 10/2006; 3(9):1031-8. · 1.80 Impact Factor
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ABSTRACT: Three new prenylated phenolic compounds, fornicins A-C (1-3), were obtained from the fruiting bodies of Ganoderma fornicatum. The structure elucidation was achieved by interpretation of spectroscopic data. These compounds exhibited moderate cytotoxic activity with IC(50) values of 15 to 30 microg/mL in Hep-2 cells.
Journal of Natural Products 10/2006; 69(9):1364-5. · 3.13 Impact Factor
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ABSTRACT: Nine new 7alpha,20-epoxy-ent-kaurane diterpenoids, parvifolines C-K (1-9), together with 12 known analogues, rabdoternin G (10), adenolin E (11), lasiodonin (12), lushanrubescensin F (13), parvifoliside (14), effusanin A (15), effusanin B (16), effusanin E (17), taibaihenryiin A (18), shikokianin (19), maoyecrystal J (20), and the acetonide of lasiodonin (21), were isolated from the leaves of Isodon parvifolius. The structures of compounds 1-9 were determined on the basis of spectroscopic methods including extensive 1D and 2D NMR analysis. The new diterpenoids (1-9) and lasiodonin (12) were evaluated for their inhibitory activity against A549, HT-29, and K562 cell lines.
Journal of Natural Products 05/2006; 69(4):645-9. · 3.13 Impact Factor
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ABSTRACT: [reaction: see text] A phytochemical study of the secondary metabolites produced by the species of Isodon rubescens has led to the isolation of three new dimeric ent-kauranoids and two known ones. The most important of these compounds are bisrubescensin A (1), which contains an unprecedented C(23) ent-kaurane unit, and bisrubescensin C (3), which is the precursor of bisrubescensin B (2) from the viewpoint of biosynthesis. Their structures were determined on the basis of extensive spectroscopic analysis and chemical evidence.
Organic Letters 04/2006; 8(6):1157-60. · 5.86 Impact Factor
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Wei-Lie Xiao,
Ren-Rong Tian,
Jian-Xin Pu,
Xian Li,
Li Wu,
Yang Lu, Sheng-Hong Li,
Rong-Tao Li,
Yong-Tang Zheng,
Qi-Tai Zheng,
Han-Dong Sun
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ABSTRACT: A new trinorcycloartane triterpenoid, lancifodilactone H (1), and a new A ring-secocycloartane triterpenoid, lancifoic acid A (2), together with a known compound, nigranoic acid (3), were isolated from the leaves and stems of Schisandra lancifolia. Their structures were elucidated by spectroscopic data analysis. Compound 1 features a biosynthetically modified seven-membered lactone ring, which was confirmed by single-crystal X-ray diffraction. Compounds 1-3 exhibited weak anti-HIV-1 activity in vitro.
Journal of Natural Products 03/2006; 69(2):277-9. · 3.13 Impact Factor
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ABSTRACT: Fructus Evodiae (Wuzhuyu), the fruits of Evodia rutaecarpa and related varieties, is widely used in traditional Chinese medicine. The bioactive constituents include the indoloquinazoline alkaloids rutaecarpine, evodiamine and dehydroevodiamine. A new assay based on high-performance liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry (HPLC/UV/APCI-MS/MS) was developed for the measurement of the indoloquinazoline alkaloids in commercial Fructus Evodiae products. Initially, the MS/MS fragmentation pathways of indoloquinazoline alkaloids were investigated to identify fragment ions that might be useful for the sensitive and selective detection of trace indoloquinazoline alkaloids during LC/MS/MS. Then, quantitative MS analysis of five indoloquinazoline alkaloids in 12 commercial Fructus Evodiae products from different geographical sources was performed. Analyte recovery was in the range of 97.5-105.3% for all with relative standard deviations (RSDs) below 6%, the intra-assay and inter-assay RSDs were less than 7%, and good linear relationships were shown with correlation coefficients for the analytes exceeding 0.999. Therefore, this LC/MS/MS assay facilitated the rapid quantitative analysis of rutaecarpine, evodiamine, evodiamide, 14-formyldihydrorutaecarpine and dehydroevodiamine in 12 commercial Fructus Evodiae products with excellent recovery, repeatability, accuracy and sensitivity. This method is simple and specific and can be used for identification and quality control of this traditional Chinese remedy.
Rapid Communications in Mass Spectrometry 02/2006; 20(20):3111-8. · 2.79 Impact Factor
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Wei-Lie Xiao,
Hua-Jie Zhu,
Yun-Heng Shen,
Rong-Tao Li, Sheng-Hong Li,
Han-Dong Sun,
Yong-Tang Zheng,
Rui-Rui Wang,
Yang Lu,
Cheng Wang,
Qi-Tai Zheng
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ABSTRACT: [structure: see text]. Lancifodilactone G (1), a novel, highly oxygenated nortriterpenoid featuring a partial enol structure and a spirocyclic moiety, was isolated from the medicinal plant Schisandra lancifolia. Its structure and stereochemistry were determined from extensive one- and two-dimensional NMR and mass spectral data, coupled with single-crystal X-ray analysis. Compound 1 exerted minimal cytotoxicity against C8166 cells (CC50 > 200 microg/mL) and showed anti-HIV activity with EC50 = 95.47 +/- 14.19 microg/mL and a selectivity index in the range of 1.82-2.46.
Organic Letters 05/2005; 7(11):2145-8. · 5.86 Impact Factor
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ABSTRACT: [structures: see text] Lancifodilactone F (1), possessing an unprecedented rearranged pentanortriterpenoid backbone derived from cycloartane, was isolated from the leaves and stems of Schisandra lancifolia (Rehd. et Wils) A. C. Smith. Its structure was established by comprehensive NMR and MS spectroscopic analysis, coupled with single-crystal X-ray experiment. Compound 1 exerted minimal cytotoxicity against C8166 cells (CC50 > 200 microg/mL) and showed anti-HIV activity with EC50 = 20.69 +/- 3.31 microg/mL and a selectivity index > 6.62.
Organic Letters 03/2005; 7(7):1263-6. · 5.86 Impact Factor
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ABSTRACT: Investigation on the anthelminthic bioactive compounds of the ethanol extract of Tadehagi triquetrum resulted in the isolation of three new prenylated isoflavones, triquetrumones A (1), B (2), and C (3), and one new prenylated biisoflavanone, (R)-triquetrumone D (4), along with 16 known compounds, cyclokievitone (5), yukovanol (6), aromadendrin (7), kaempferol (8), astragalin (9), 2-O-methyl-l-chiro-inositol (10), galactitol (11), p-hydroxycinnamic acid (12), ursolic acid (13), betulinic acid (14), beta-sitosterol (15), daucosterol (16), stigmasterol (17), stigmasta-5,22-dien-3-O-beta-d-glucopyranoside (18), saccharose (19), and docosanoic acid (20). The structures of 1-4 were elucidated on the basis of spectroscopic and spectrometric methods. Compounds 1-3 displayed mild anthelminthic bioactivity, and compound 3 showed a significant binding ability to the estrogen receptor.
Journal of Agricultural and Food Chemistry 02/2005; 53(2):267-71. · 2.82 Impact Factor
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Sheng-Hong Li,
Jia Wang,
Xue-Mei Niu,
Yun-Heng Shen,
Hong-Jie Zhang,
Han-Dong Sun,
Ma-Lin Li,
Qin-E Tian,
Yang Lu,
Peng Cao,
Qi-Tai Zheng
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ABSTRACT: Maoecrystal V (1), a novel C(19) diterpenoid possessing a unique 6,7-seco-6-nor-15(8-->9)-abeo-5,8-epoxy-ent-kaurane skeleton, was isolated from the leaves of a Chinese medicinal herb, Isodon eriocalyx. Its structure was determined by comprehensive NMR and MS spectroscopic analysis and confirmed by single-crystal X-ray diffraction study. Compound 1 showed remarkable inhibitory activity toward HeLa cells with IC(50) = 0.02 microg/mL (cis-platin: IC(50) = 0.99 microg/mL).
Organic Letters 11/2004; 6(23):4327-30. · 5.86 Impact Factor
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ABSTRACT: With the flooding of pornographic information on the Internet, how to keep people away from that offensive information is becoming one of the most important research areas in network information security. Some applications which can block or filter such information are used. Approaches in those systems can be roughly classified into two kinds: metadata based and content based. With the development of distributed technologies, content based filtering technologies will play a more and more important role in filtering systems. Keyword matching is a content based method used widely in harmful text filtering. Experiments to evaluate the recall and precision of the method showed that the precision of the method is not satisfactory, though the recall of the method is rather high. According to the results, a new pornographic text filtering model based on reconfirming is put forward. Experiments showed that the model is practical, has less loss of recall than the single keyword matching method, and has higher precision.
Journal of Zhejiang University SCIENCE 10/2004; 5(9):1106-13.
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ABSTRACT: Nine new diterpenoids, melissoidesins M-U (1-9), along with five known analogues, melissoidesin F (10), xindongnin B (11), melissoidesin G (12), melissoidesin E (13), and dawoensin A (14), were isolated from the aerial parts of Isodon melissoides. The structures of new compounds were elucidated by analysis of spectral evidence including extensive 2D NMR data. Compounds 2, 3, 7, 11, 12, and 14 showed cytotoxicity against the human tumor BGC-823 cell line with IC(50) values less than 10 microg/mL, respectively.
Journal of Natural Products 10/2004; 67(9):1441-4. · 3.13 Impact Factor
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ABSTRACT: With the proliferation of harmful Internet content such as pornography, violence, and hate messages, effective content-filtering systems are essential. However, a non-trivial obstacle in good text filtering is the high dimensionality of the data. We introduced a hybrid method to select features more accurately using some feature selection method and rough set theory. We can select features firstly using one of feature selection methods, such as x<sup>2</sup> statistic, mutual information, information gain, and then further select features using rough set. Thus more accurate and less features are extracted. In experiments, we used UCI machine learning dataset as our dataset. We use naive Bayes model to evaluate our feature selection method, the result shows our method has high precision and high recall, and is very effective and efficient.
Machine Learning and Cybernetics, 2004. Proceedings of 2004 International Conference on; 09/2004
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ABSTRACT: The tow novel ent-abietane diterpenoids 1 and 2, named xerophilusins R and S, respectively (=(11β)-6,11-dihydroxy-7,20-dioxo-ent-abieta-5,8(14),15(17)-trien-16-oic acid δ-lactone and (11β,15S)-6,11,17-trihydroxy-7,20-dioxo-ent-abieta-5,8(14)-dien-16-oic acid δ-lactone, resp.), were isolated from Isodon xerophilus (C. J. Wu et H. W. LI) H. Hara. Their structures were established by spectroscopic means.
Helvetica Chimica Acta 07/2004; 87(8):1951 - 1957. · 1.48 Impact Factor
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ABSTRACT: Two new coumarins, 13- O-[ beta- D-apiofuranosyl(1-->6)- beta- D-glucopyranosyl]-(12 R)-heraclenol ( 1) and (12 R,12" R)-diheraclenol ( 2) were isolated from the acetone extract of the fresh roots of Heracleum rapula. Their structures were determined by means of spectroscopic analysis and, in the case of compound 1, the structure elucidation was supported by acid hydrolysis. Compound 1 is a coumarin glycoside while 2 is a coumarin dimer. The inhibitory effects of 1, its aglycone ( 3), and 2 on rabbit platelet aggregation induced by PAF, AA and ADP were tested. Weak activities were observed for each compound with the percentages of inhibition in the range of 0.7 - 24.8 %.
Planta Medica 06/2004; 70(6):578-81. · 2.15 Impact Factor
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ABSTRACT: Both coriatone (1). a novel highly oxygenated picrotoxane-type sesquiterpene, and corianlactone (2). with an unprecedented sesquiterpene basic skeleton, named coriane, were isolated from Coriaria nepalensis Wall. The structures of 1 and 2 were determined by analysis of their two-dimensional NMR data, and the structure of 2 was confirmed by X-ray analysis. Compounds 1 and 2 showed no remarkable inhibitory activity toward K(562) cells. They are cytotoxic with IC(50) > 50 microg/mL (cis-platinim: IC(50) = 0.49 microg/mL).
Organic Letters 06/2004; 6(10):1593-5. · 5.86 Impact Factor
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ABSTRACT: Three new ent-kaurene diterpenoids, oreskaurins A-C (1-3), together with ten known ent-kaurene diterpenoids, enmenin monoacetate (4), effusanin E (5), adenolin B (6), maoecrystal G (7), enmelol (8), trichokaurin (9), sodoponin (10), trichorabdal A (11), nodosin (12), enmein (13), and a flavonoid, vitexin (14), were isolated from Isodon oresbius. Their structures were determined by spectroscopic means. Compound 12 showed inhibitory activity toward K562 cells with IC(50)=1.43 microg/ml.
Phytochemistry 05/2004; 65(8):1173-7. · 3.35 Impact Factor
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ABSTRACT: Four new nortriterpenes, lancifodilactones B-E (1-4), were isolated from the leaves and stems of Schisandra lancifolia. Their structures were determined by analysis of 1D and 2D NMR spectroscopic data. These compounds are members of a new highly oxygenated cycloartane skeletal class with a biosynthetically modified eight-membered ring D.
Journal of Natural Products 02/2004; 67(1):94-7. · 3.13 Impact Factor
