首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到10条相似文献,搜索用时 109 毫秒
1.
Bioassay-guided fractionation of a phytotoxic extract of Prionosciadium watsoni led to the isolation of three new pyranocoumarins and two pyranochromones. The new compounds were characterized as propionic acid (9R,10R)-9-acetoxy-8,8-dimethyl-9,10-dihydro-2H,8H-benzo[1,2-b:3,4-b']dipyran-2-one-10-yl ester (1), isobutyric acid (9R,10R)-9-hydroxy-8,8-dimethyl-9,10-dihydro-2H,8H-benzo[1,2-b:3,4-b']dipyran-2-one-10-yl ester (2), isobutyric acid (9R)-8,8-dimethyl-9,10-dihydro-2H,8H-benzo[1,2-b:3,4-b']dipyran-2-one-9-yl ester (10), 2-methylbut-(2Z)-enoic acid (3R)-5-methoxy-3,4-dihydro-2,2,8-trimethyl-6-oxo-2H,6H-benzo[1,2-b:5,4-b']dipyran-3-yl ester (11), and isobutyric acid (3R)- 5-methoxy-3,4-dihydro-2,2,8-trimethyl-6-oxo-2H,6H-benzo[1,2-b:5,4-b']dipyran-3-yl ester (12) by spectroscopic and chemical methods. The stereochemistry at the stereogenic centers was established by applying the Mosher ester methodology. The structures of 1 and 2 were corroborated by single-crystal X-ray diffraction studies. The phytotoxic activity of the isolated compounds was assessed on Amaranthus hypochondriacus, Echinochloa crus-galli, and Lemna pausicostata. The phytotoxins also modified the electrophoretic mobility of calmodulin from both bovine-brain and spinach.  相似文献   

2.
Three unique pyrano[4,3-c][2]benzopyran-1,6-dione derivatives and a new furo[3,2-c]pyran-4-one, named phelligridins C-F (2-5), together with hispolon (8), (E)-4-(3,4-dihydroxyphenyl)but-3-en-2-one (9), 4-hydroxybenzaldehyde, protocatechualdehyde, syringic acid, protocatechuic acid, caffeic acid, isoergosterone, and octadecyl ferulate were isolated and identified from the ethanolic extract of Phellinus igniarius. Their structures were determined by spectroscopic methods including IR, MS, and 1D and 2D NMR experiments. The structures of the new compounds were characterized as 3-(4-hydroxystyryl)-8,9-dihydroxypyrano[4,3-c]isochromene-4-one (2), 3-(3,4-hydroxystyryl)-8,9-dihydroxypyrano[4,3-c]isochromene-4-one (3), 8,9-dihydroxy-3-[5',6'-dihydroxy-5' '-methyl-3' '-oxo-spiro[fural-2' '(3' 'H),1'-indene]-2'-yl]-1H,6H-pyrano[4,3-c][2]benzopyran-1,6-dione (4), and (3Z)-3-(3,4-dihydroxybenzylidene)-6-(3,4-dihydroxystyryl)-2,3-dihydro-2-methoxy-2-(2-oxo-propyl)furo[3,2-c]pyran-4-one (5), respectively. Some compounds including 2 and 3 showed in vitro selective cytotoxicity against a human lung cancer cell line (A549) and a liver cancer cell line (Bel7402). Possible biogenetic sequences to the formation of 1-9 are postulated.  相似文献   

3.
New amide alkaloids from the roots of Piper nigrum   总被引:1,自引:0,他引:1  
Seven new amide alkaloids, named N-isobutyl-4-hexanoyl-4-hydroxypyrrolidin-1-one (1), (+/-)-erythro-1-(1-oxo-4,5-dihydroxy-2E-decaenyl)piperidine (2), (+/-)-threo-1-(1- oxo-4,5-dihydroxy-2E-decaenyl)piperidine (3), (+/-)-threo-N-isobutyl-4,5-dihydroxy-2E-octaenamide (4), 1-(1,6-dioxo-2E,4E-decadienyl)piperidine (5), 1-[1-oxo-3(3,4-methylenedioxy-5-methoxyphenyl)-2Z-propenyl]piperidine (6), and 1-[1-oxo-5(3,4-methylenedioxyphenyl)-2Z,4E-pentadienyl]pyrrolidine (7), were isolated from the roots of Piper nigrum, together with 32 known amides. Their structures were elucidated on the basis of spectroscopic analysis and chemical evidence.  相似文献   

4.
??OBJECTIVE To explore the synthesis and acetylcholinesterase inhibitory activity of 6-benzyl-3-aryl-7H-thiazolo[3,2-b]-1,2,4-triazin-7-one derivatives. METHODS Benzaldehyde and acetylglycine were used as raw materials and underwent Erlenmeyer-Pl??chl reaction, condensation reaction, hydrolysis reaction, condensation reaction to obtain 6-benzyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-ones derivatives. The derivatives reacted with substituted ??-phenacyl chlorides to generate 6-benzyl-3-(hydroxylaryl)-7H-thiazolo[3,2-b]-1,2,4-triazin-7-ones derivatives. Then, Williamson reaction was used to yield 6-benzyl-3-aryl-7H-thiazolo[3,2-b]-1,2,4-triazin-7-ones as target compounds. RESULTS Nine 6-benzyl-3-aryl-7H-thiazolo[3,2-b]-1,2,4-triazin-7-ones were prepared as target compounds. All target compounds exhibited inhibitory activities against human AChE in vitro, five of which had inhibitory rates above 50% at 10 ??mol??L-1. CONCLUSION Based on the screening results of AChE inhibitory activity in vitro and docking studies, there are some interactions between 6-benzyl-3-aryl-7H-thiazolo[3,2-b]-1,2,4-triazin-7-one derivatives and the anionic binding site and PAS zones of AChE, and the target compounds have exhibited AChE inhibitory activities.  相似文献   

5.
通过硅胶柱色谱、中压ODS柱色谱和反相HPLC等多种色谱方法对娃儿藤内生真菌Talaromyces purpurogenus的次生代谢产物进行系统分离,运用NMR,MS,CD和旋光等现代波谱技术进行结构鉴定,共分离鉴定了8个化合物:(R)-2-[5-(methoxycarbonyl)-4-methyl-6-oxo-3,6-dihydro-2H-pyran-2-yl]acetic acid (1),(3S,4R)-3,4-dihydro-3,4-epoxy-5-hydroxynaphthalen-1(2H)-one (2),(-)-mitorubrinol (3),(-)-mitorubrin (4),(±)-asperlone A (5),terreusinone (6),verrucisidinol (7)和cerebroside C (8)。化合物1和2是新化合物。体外抗糖尿病试验结果显示,化合物1在浓度为10μmol·L-1时,对XOD酶的抑制率为69.9%。  相似文献   

6.
A novel naphthopyrone derivative, named quinquangulone (1), has been isolated from Cassia quinquangulata, along with the known compounds quinquangulin (2) and its two glycosides (3 and 4), rubrofusarin (5) and its two glycosides (6 and 7), nor-rubrofusarin (8) and its 6-O-glucoside (9), and three stilbenes (10-12). The structure of quinquangulone was established by spectral interpretation as 5,9-dihydroxy-8-methoxy-2,9-dimethyl-6-oxo-4H,6H,9H-naphtho-[2,3-b]pyran-4-one. Reinvestigation of the NMR spectra of quinquangulin led to revision of its structure as 5,6-dihydroxy-8-methoxy-2,9-dimethyl-4H-naphtho[2,3-b]pyran-4-one (2a). The structures of two quinguangulin glycosides, 3 and 4, were also revised accordingly. Compound 2a exhibited activity against Staphylococcus aureus and methicillin-resistant S. aureus (MIC, 3.125 and 6.25 microg/mL, respectively).  相似文献   

7.
Cytotoxic constituents of the roots of Ekmanianthe longiflora   总被引:1,自引:0,他引:1  
Bioactivity-directed fractionation of the CHCl(3) extract of the roots of Ekmanianthe longiflora resulted in the isolation of three new natural products, (2R,3R,4R)-3,4-dihydro-3, 4-dihydroxy-2-(3-methyl-2-butenyl)-1(2H)-naphthalenone (1), (2S,3R, 4R)-3,4-dihydro-3, 4-dihydroxy-2-(3-methyl-2-butenyl)-1(2H)-naphthalenone (2), and (2R, 3aR,9R,9aR)-9-hydroxy-2-(1-hydroxy-1-methylethyl)-2,3,3a,4,9 , 9a-hexahydro-naphtho[2,3-b]furan-4-one (3), together with the known compounds 2-(1-hydroxyethyl)naphtho[2,3-b]furan-4,9-quinone (4), 2-acetylnaphtho[2,3-b]furan-4,9-quinone (5), dehydro-iso-alpha-lapachone (6), alpha-lapachone (7), catalponol, and epi-catalponol. The structures of 1-3 were determined using a combination of NMR spectroscopic techniques, and the absolute configurations of compounds 1 and 2 were obtained using Mosher ester methodology. Compounds 4-6 showed significant cytotoxicity in a panel of human cancer cells. alpha-Lapachone (7) exhibited only marginal activity, and catalponol and epi-catalponol were inactive in this regard. When tested at 72 mg/kg/injection in an in vivo mouse P-388 leukemia system, compound 4 was inactive (110% T/C).  相似文献   

8.
Two new isopropenyl-dihydrofuranoisoflavones exhibiting antimicrobial properties have been isolated along with eight known compounds from the Cameroonian medicinal plant Crotalaria lachnophora. The structures of the new compounds were elucidated by 1D and 2D NMR spectroscopy and high-resolution mass spectrometry as 7,2',4'-trihydroxy-5'-isopropenyl-4',5'-dihydrofurano[2',3':5,6]isoflavone (1) and 4,8-dihydroxy-2-isopropenyl-2,3-dihydro-5H-[1]benzofuro[2,3-b]furo[3,2-g]chromen-5-one (2). The CH(2)Cl(2)/MeOH (1:1) extract and the compounds isolated were subjected to in vitro antimicrobial assays against a panel of pathogenic microorganisms, including Gram-positive and Gram-negative bacteria and fungi. The new compounds, named lachnoisoflavones A (1) and B (2), showed moderate inhibitory activities against Escherichia coli and Klebsiella pneumoniae.  相似文献   

9.
Ma M  Zhao J  Wang S  Li S  Yang Y  Shi J  Fan X  He L 《Journal of natural products》2007,70(3):337-341
Three new bromophenols C-N coupled with nucleoside base derivatives (1-3) and three new brominated 1,2,3,4-tetrahydroisoquinolines (5-7), together with a new brominated tyrosine derivative (4), have been isolated from polar fractions of an ethanolic extract of the red alga Rhodomela confervoides. By spectroscopic and chemical methods including HRMS and 2D NMR data, their structures were determined as 7-[3-bromo-2-(2,3-dibromo-4,5-dihydroxybenzyl)-4,5-dihydroxybenzyl]-3,7-dihydro-1H-purine-2,6-dione (1), 7-(2,3-dibromo-4,5-dihydroxybenzyl)-3,7-dihydro-1H-purine-2,6-dione (2), 9-[3-bromo-2-(2,3-dibromo-4,5-dihydroxybenzyl)-4,5-dihydroxybenzyl]adenine (3), (-)-8S-(3-bromo-5-hydroxy-4-methoxy)phenylalanine (4), (-)-3S-8-bromo-6-hydroxy-7-methoxy-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (5), methyl (-)-3S-8-bromo-6-hydroxy-7-methoxy-1,2,3,4-tetrahydroisoquinoline-3-carboxylate (6), and methyl (-)-3S-6-bromo-8-hydroxy-7-methoxy-1,2,3,4-tetrahydroisoquinoline-3-carboxylate (7). Compounds 5-7 were semisynthesized by using 4 as the starting material.  相似文献   

10.
Lin P  Li S  Wang S  Yang Y  Shi J 《Journal of natural products》2006,69(11):1629-1632
An unusual nitrogen-containing 3-alkyl-1,4-benzoquinone derivative, N-(3-carboxylpropyl)-5-amino-2-hydroxy-3-tridecyl-1,4-benzoquinone (1), and a gomphilactone derivative, 5,6-dihydroxy-7-tridecyl-3-[4-tridecyl-3-hydroxy-5-oxo-2(5H)-furylidene]-2-oxo-3(2H)-benzofuran (2), together with 14 known compounds, as well as the common plant metabolites sitosterol and daucosterol, were isolated from the ethanolic extract of the roots of Embelia ribes. Their structures were elucidated by means of spectroscopic methods. Cytotoxicities of the purified compounds were tested.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号