首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 250 毫秒
1.
Acetone extraction of cultures of the marine ascomycete Leptosphaeria oraemaris (LINDER) on cornmeal disk gave the novel polyketide derivative leptosphaerolide ( = (+)-7-[(1E)-l,3-dimethylpent-1-enyl]-10-hydroxy-3-methoxybenzo[1,2-b:5,4-c′]dipyran-2(9H)-one; (4+)-8) besides the o-dihydroquinone 3-[(1E)-1,3-dimethylpent-1-euyl]-8,10-dihydroxy-7-methoxy-8-(2-oxopropyl)-1H-naphtho[2,3-c]pyran-9(8H)-one ( 1 ) as a 10:9 mixture of epimers. retro-Aldol reaction of 1 gave leptosphaerodione ( = (?)-3-[(1E)-1,3-dimethylpent-1-enyl]-10-hydroxy-7-methoxy-1H-naphtho[2,3-c]pyran-8,9(8H)-dione; (?)-6) which was also present in small amounts in the extracts and which gave 1 on reaction with acetone. It is thus likely that 1 is an artefact of the extraction by acetone. Biogenetically (+)-8 might derive from (?)-6 via an unusual oxidation with loss of CO2.  相似文献   

2.
Three novel conjugated long-chain fatty acids (1-3) were obtained from aqueous methanol extracts of Pleurocybella porrigens together with nine known constituents including (8E,10E)-7,12-dioxo-8,10-octadecadienoic acid (ostopanic acid) (4). The structures of the new fatty acids were characterized as (14RS)-(10E,12E)-14-hydroxy-9-oxo-10,12-octadecadienoic acid (1), (12RS)-(8E,10E)-12-hydroxy-7-oxo-8,10-octadecadienoic acid (2), and (10E,12E)-9,14-dioxo-10,12-octadecadienoic acid (3) by spectroscopic methods.  相似文献   

3.
A further investigation of the leaves and stems of Saprosma scortechinii afforded 13 compounds, of which 10 are new compounds. These were elucidated as the bis-iridoid glucosides, saprosmosides G (1) and H (2), the iridoid glucoside, 6-O-epi-acetylscandoside (3), and the anthraquinones, 1-methoxy-3-hydroxy-2-carbomethoxy-9,10-anthraquinone (4), 1-methoxy-3-hydroxy-2-carbomethoxy-9,10-anthraquinone 3-O-beta-primeveroside (5), 1,3-dihydroxy-2-carbomethoxy-9,10-anthraquinone 3-O-beta-primeveroside (6), 1,3,6-trihydroxy-2-methoxymethyl-9,10-anthraquinone (7), 1-methoxy-3,6-dihydroxy-2-hydroxymethyl-9,10-anthraquinone (8), 1,3,6-trihydroxy-2-hydroxymethyl-9,10-anthraquinone 3-O-beta-primeveroside (9), and 3,6-dihydroxy-2-hydroxymethyl-9,10-anthraquinone (10). Structure assignments for all compounds were established by means of mass and NMR spectroscopies, chemical methods, and comparison with published data. The new anthraquinones were derivatives of munjistin and lucidin.  相似文献   

4.
Four new flavonoids, 3,5-dihydroxy-7,8-dimethoxy-3',4'-methylenedioxyflavone (1), 3,5-dihydroxy-7-methoxy-3',4'-methylenedioxyflavone (2), 3,5-dihydroxy-7-isopentenyloxy-8-methoxy-3',4'-methylenedioxyflavone (3) and 5-hydroxy-3-isopentenyloxy-7-methoxy-3',4'-methylenedioxyflavone (4), were isolated from the leaves of Melicope triphylla. In addition, two known flavonoids were detected including 5-hydroxy-3,7-dimethoxy-3',4'-methylenedioxyflavone (5) and 5-hydroxy-7-isopentenyloxy-3,8-dimethoxy-3',4'-methylenedioxyflavone (6). The structures of the new compounds were established by spectroscopic methods.  相似文献   

5.
Six new flavonoids-5-hydroxy-3,8-dimethoxy-3',4':6,7-bismethylenedioxyflavone (1), 3,3',4',5-tetramethoxy-7-(3-methylbut-2-enyloxy)flavone (2), 7-(2-hydroxy-3-methylbut-3-enyloxy)-3,3',4',5-tetramethoxyflavone (3), 7-(2-hydroxy-3-methylbut-3-enyloxy)-3,5-dimethoxy-3',4'-methylenedioxyflavone (4), 7-(2-hydroxy-3-methylbut-3-enyloxy)-3,3',4',5,8-pentamethoxyflavone (5), and 7-(2-hydroxy-3-methylbut-3-enyloxy)-3,5,8-trimethoxy-3',4'-methylenedioxyflavone (6)-were isolated from the leaves of Melicope triphylla. In addition, six already known flavonoids were also detected: 5-hydroxy-3,6,7-trimethoxy-3',4'-methylenedioxyflavone (7), 5,7-dihydroxy-3,3',4',8-tetramethoxyflavone (8), 4',5-dihydroxy-3,3',7,8-tetramethoxyflavone (9), 3,5,6,7,8-pentamethoxy-3',4'-methylenedioxyflavone (10), 3,5,6,7-tetramethoxy-3',4'-methylenedioxyflavone (11), and 3,3',4',5,6,7,8-heptamethoxyflavone (12). The structures of the new compounds were established by spectroscopic methods. Compound 2 displayed ichthyotoxic activity against Japanese killifish (medaka in Japanese) (Oryzias latipes var.) at 10?ppm.  相似文献   

6.
A novel anthraquinone, 1,3-dihydroxy-5,6-dimethoxy-2-methoxymethyl-9,10-anthraquinone (9) and a new natural product, 2-hydroxymethyl-1-methoxy-9,10-anthraquinone (8) were isolated from the roots of Prismatomeris malayana together with seven known anthraquinones, tectoquinone (1), 1-hydroxy-2-methyl-9,10-anthraquinone (2), rubiadin (3), rubiadin-1-methyl ether (4), 1,3-dihydroxy-5,6-dimethoxy-2-methyl-9,10-anthraquinone (5), nordamnacanthal (6), and damnacanthal (7). Their structures were determined on the basis of spectroscopic data. Some of the anthraquinones were tested for anticancer, antifungal, and antimalarial activities.  相似文献   

7.
A new dihydrochalcone 4',6'-dihydroxy-2',3',4-trimethoxydihydrochalcone (1) along with nine known compounds, pashanone (2), dihydropashanone (3), pinostrobin (4), 5-hydroxy-7,4'-dimethoxyflavanone (5), 5-hydroxy-6,7-dimethoxyflavanone (6), 5-hydroxy-7,8-dimethoxyflavanone (7), 24-methylencycloartane-3β,21-diol (8), liriodenine (9) and 3,5-dihydroxy-7,3',4'-trimethoxyflavone (10), were isolated from the extracts, exhibiting cytotoxic activity (n-hexane and ethyl acetate extracts) of Miliusa sinensis. The structure of (1) was elucidated by the analysis of spectral data (IR, HR-MS, EI-MS, 1D and 2D NMR).  相似文献   

8.
Stereo- and regioselective hydroxylation of grindelane derivatives on position 3beta was catalyzed by cultures of Aspergillus niger. Grindelic acid (1), methyl grindelate (2), 15-hydroxy-7(8)-en-9alpha,13(S)-oxide-ent-labdane (3) and 7alpha,8alpha-epoxymethylgrindelate (4) were bioconverted into the corresponding 3beta-hydroxy derivatives as the only biotransformation products. 13(S),15-dihydroxy-8(9)-en-ent-labdane (5) remained unreacted under the same conditions. The conformational and electronic studies of the substrates are discussed.  相似文献   

9.
Five new monoterpene glycosides, rhodiolosides A-E (1-5), were isolated from the roots of Rhodiola rosea (Crassulaceae). Their structures were elucidated as (2E,6E,4R)-4,8-dihydroxy-3,7-dimethyl-2,6-octadienyl beta-D-glucopyranoside (1), (2E,4R)-4-hydroxy-3,7-dimethyl-2,6-octadienyl alpha-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside (2), (2E,4R)-4-hydroxy-3,7-dimethyl-2,6-octadienyl beta-D-glucopyranosyl(1-->3)-beta-D-glucopyranoside (3), (2E,4R)-4,7-dihydroxy-3,7-dimethyl-2-octenyl beta-D-glucopyranoside (4), and (2E)-7-hydroxy-3,7-dimethyl-2-octenyl alpha-L-arabinopyranosyl(1-->6)-beta-D-glucopyranoside (5), on the basis of various spectroscopic analyses and chemical degradation.  相似文献   

10.
Two new polyketides: 2Z-(heptadec-12-enyl)-4-hydroxy-3,4,7,8-tetrahydro-2H-chromen-5(6H)-one (1) and 2-(heptadec-12-enyl)-5-hydroxy-5,6,7,8-tetrahydrochromen- 4-one (2), together with eleven known compounds: 4-hydroxy-2-[(3,4-methylenedioxy- phenyl)tridecanoyl] cyclohexane-1,3-dione (3), oleiferinone (4), 4-hydroxy-2-[(3,4- methylenedioxyphenyl)undecanoyl]cyclohexane-1,3-dione (5), 4-hydroxy-2-[(11-phenyl- undecanoyl)cyclohexane-1,3-dione (6), proctorione C (7), surinone C (8), 5-hydroxy- 7,8,4'-trimethoxyflavone (9), 5-hydroxy-7,8,3',4'-tetramethoxyflavone (10), 5-hydroxy- 7,3',4'-trimethoxyflavone (11), 5,8-dihydroxy-7,3',4'-trimethoxyflavone (12) and cepharanone B (13) were isolated from the whole plant of Peperomia dindygulensis Miq. Their structures were elucidated by spectroscopic methods, including 2D-NMR techniques. Compounds 2, 3, 5 and 8 inhibited human umbilical vein endothelial cell (HUVEC) proliferation and compounds 5 and 8 sharply suppressed HUVEC tube formation.  相似文献   

11.
Isoprenylated flavonoids 5,7-dihydroxy-3'-(2-hydroxy-3-methyl-3-butenyl)-3,6,4'-trimethoxyflavone (1), 3,7-dihydroxy-3'-(2-hydroxy-3-methyl-3-butenyl)-5,6,4'-trimethoxyflavone (2) and an isoprenylated acetophenone derivative (3) have been isolated from Duranta repens along with known compounds, 5-hydroxy-3,6,7,4'-tetramethoxyflavone (4), rosenonolactone (5), 6,7-dimethoxycoumarin (6), 5alpha,8alpha-epidioxyergosta-6,22-dien-3beta-ol (7) and 5alpha,8alpha-epidioxyergosta-6,9(11),22-trien-3beta-ol (8), isolated for the first time from this species. Their structures and the relative configuration were determined by spectroscopic methods (1H- and 13C-NMR, IR, UV and MS) and two-dimensional (2D)-NMR experiments. The compounds 1-5 showed inhibitory activity against prolyl endopeptidase while 4 and 5 were also active against thrombin.  相似文献   

12.
黑紫橐吾化学成分的分离与鉴定   总被引:2,自引:0,他引:2  
利用各种色谱技术对黑紫橐吾的乙酸乙酯萃取部位进行分离纯化, 并且根据一维和二维波谱数据进行结构鉴定. 共分离得到4个呋喃雅槛蓝型倍半萜: 1α-氯-6β-异丁酰基-9-酮-10β-羟基-呋喃雅槛蓝烷(1), 1α-羟基-6β-异丁酰基-9-酮-10β-氢-呋喃雅槛蓝烷(2), 1α-羟基-6β-异丁酰基-9-酮-10α-氢-呋喃雅槛蓝烷(3)和1α,10β-二羟基-6β-当归酰基-9-酮-呋喃雅槛蓝烷(4). 其中化合物1为新化合物, 并且通过X射线单晶衍射确定了绝对构型; 化合物2~4为首次从该植物中分离得到.  相似文献   

13.
Four new pyrrolidine alkaloids, broussonetines R, S, T, and V and a new pyrroline alkaloid, broussonetine U were isolated from the branches of Broussonetia kazinoki SIEB. (Moraceae) in low yield. Broussonetines R, S and T were formulated as (2R,3R,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(1R)-1-hydroxy-3-[6-(4-hydroxybutyl)-cyclohexy-2-on-1(6)-enyllpropyl] pyrrolidine (1), (2R,3R,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(1R,10S)-1,10,13-trihydroxytridecyl] pyrrolidine (2), (2R,3R,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(1R,5S)-1,5, 13-trihydroxy-10-oxo-tridecyl] pyrrolidine (3). And broussonetines U and V were proposed to be (2S,3S,4S)-2-hydroxymethyl-3, 4-dihydroxy-5-(9-oxo-13-hydroxytridecyl)-5-pyrroline (4), (2R,3S,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(E)-9-oxo-13-hydroxy-3-tridecenyl] pyrrolidine (5), respectively, by spectroscopic and chemical methods.  相似文献   

14.
Eight phenanthrenes, 7-carboxy-2-hydroxy-1-methyl-5-vinyl-phenanthrene (1); 2,7-dihydroxy-1-methyl-5-aldehyde-9,10-dihydrophenanthrene (2); dehydroeffusol (3); dehydrojuncusol (4); 7-carboxy-2-hydroxy-1-methyl-5-vinyl-9,10-dihydrophenanthrene (5); 8-carboxy-2-hydroxy-1-methyl-5-vinyl-9,10-dihydrophenanthrene (6); effusol (7) and juncusol (8), were isolated from the aerial part of Juncus effusus. Compounds 1 and 2 were identified as new constituents. Compounds 7 and 8 showed anxiolytic and sedative activities.  相似文献   

15.
Four new pyrrolidine alkaloids, broussonetines M, O, P, and Q, were isolated from the branches of Broussonetia kazinoki SIEB, (Moraceae). Broussonetines M, O, P, and Q were formulated as (2R,3R,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(10S)-10,13-dihydroxy-tri decyl]pyrrolidine (1), (2R,3R,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(E)9-oxo-13-hydroxy-3- tridecenyl]pyrrolidine (2), (2R,3R,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(E)10-oxo-13-hydroxy-3-++ +tridecenyl]pyrrolidine (3), and (2R,3S,4R,5R)-2-hydroxymethyl-3-hydroxy-4-(beta-D-glucopyranosyloxy++ +)-5-[10-oxo-13-(beta-D-glucopyranosyloxy)tridecyl]pyrrolidine (4) respectively, by spectroscopic and chemical methods. 1-4 inhibited beta-glucosidase, beta-galactosidase and beta-mannosidase.  相似文献   

16.
Six podocarpane-type trinorditerpenes were isolated from the bark of Taiwania cryptomerioides. Their structures, 14-hydroxy-13-methoxy-8,11,13-podocarpatrien-7-one (1), 13-hydroxy-12-methoxy-8,11,13-podocarpatriene (2), 12-hydroxy-13-methoxy-8,11,13-podocarpatriene (3), 14-hydroxy-13-methoxy-8,11,13-podocarpatriene (4), 13-hydroxy-8,11,13-podocarpatriene (5), and 13,14-dihydroxy-8,11,13-podocarpatrien-7-one (6), were determined principally from spectral evidence.  相似文献   

17.
Three new podocarpane-type diterpenoids, 3beta,12-dihydroxy-13-methyl-6,8,11,13-podocarpatetraen (1), 3beta,12-dihydroxy-13-methyl-5,8,11,13-podocarpatetraen-7-one (2), and 1-(7-hydroxy-2,6-dimethyl-1-naphthyl)-4-methyl-3-pentanone (3) (20(10-->5)-abeo-4,5-seco-5(10),6,8,11,13-podocarpapentaen-3-one) were isolated from callus of Securinega suffruticosa. The structures were elucidated by spectroscopic methods. Compounds 1, 2, and 3 showed cytotoxic activity against five human cancer cell lines (A549, BEL 7402, BGC-823, HCT-8, A2780).  相似文献   

18.
Six new 2-(2-phenylethyl)chromones from Agarwood   总被引:1,自引:0,他引:1  
Six new chromones, 6-methoxy-2-[2-(3-methoxy-4-hydroxyphenyl)ethyllchromone (2), 6,8-dihydroxy-2-(2-phenylethyl)chromone (3), 6-hydroxy-2-[2-(4-hydroxyphenyl)ethyl]chromone (4), 6-hydroxy-2-[2-(2-hydroxyphenyl)ethyl]chromone (5), 7-hydroxy-2-(2-phenylethyl)chromone (6), and 6-hydroxy-7-methoxy-2-(2-phenylethyl)chromone (7) were isolated from the ether extract of agarwood in addition to a known compound, 2-(2-phenylethyl)chromone or flidersiachromone (1). Their structures were determined by spectroscopic methods including UV, IR, and NMR spectral data and comparisons with the calculated values using the hydroxyl and methoxyl substituent increments of the chromone ring.  相似文献   

19.
A new xanthone-O-glycoside, the 1,7-dihydroxy-3-methoxyxanthone-8-O-β-D-glucopyranoside ( 7 ), has been isolated from the leaves of Gentiana verna L. by means of column chromatography on polyamid. Six known xanthones: 1-hydroxy-3,7,8-trimethoxyxanthone-1-O-primerveroside ( 2 ); 1,7,8-trihydroxy-3-methoxyxanthone ( 3 ); 7-hydroxy-3,8-dimethoxyxanthone-1-O-primeveroside ( 4 ); 7,8-dihydroxy-3-methoxyxanthone-1-O-primeveroside ( 5 ); mangiferin 6 and the flavone C-glycoside isoorientin 8 have also been isolated and identified.  相似文献   

20.
Diethyl 6-amino-2-hydroxyazulene-1,3-dicarboxylate ( 6a ) and 2-acetoxyl derivative ( 6b ) were synthesized by reduction of the 6-azido derivatives ( 5a,b ) with zinc/acetic acid in excellent yields. 5a and 5b were prepared by azidation of diethyl 2-acetoxy-6-bromoazulene-1,3-dicarboxylate (4). Diazotization of 6a with sodium nitrite in the presence of concentrated sulfuric acid in dioxane gave diethyl 2-hydroxy- ( 7a ), 2,6-dihydroxy- ( 8a ), and 2-hydroxy-6-[2-(2-hydroxyethoxy)ethoxy]-azulene-1,3-dicarboxylates ( 9a ), in 5, 35 and 20% yields, respectively. Similar reaction of 6b gave the corresponding acetates 7b, 8b , and 9b , compounds of the same type from 6a . No evidence for the formation of 6-diazo-1,3-diethoxycarbonyl-2(6H) azulenone ( 2b ) was obtained in the employed reaction conditions.  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