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 31 毫秒
1.
Separation of the basic fractions from Formosan Fissistigma glaucescens, F. oldhamii and Goniothalamus amuyon afforded one new quaternary phenanthrene alkaloid, N-methylatherosperminium (15), along with the known alkaloids, (?)-discretamine (1), (?)-tetrahydropalmatine (2), palmatine (3), (?)-asimilobine (4), (?)-norannuradhapurine (5), (?)-crebanine (6), (?)-calycinine (fissoldine, fissistigine A) (7a), (?)-anolobine (8), (?)-xylopine (9), (?)-anonaine (10a), oxocrebanine (11), liriodenine (12), atherosperminine (13), N-noratherosperminine (14) and (+)-O-methylflavinantine (O-methylpallidine) (16).  相似文献   

2.
Seventeen quinazoline alkaloids and derivatives, containing two pairs of new epimers, named as (S)- and (R)-1-(2-aminobenzyl)-3-hydroxypyrrolidin-2-one β-d-glucopyranosyl-(1?→?6)-β-d-glucopyranoside (1, 2), (S)- and (R)-vasicinone β-d-glucopyranosyl-(1?→?6)-β-d-glucopyranoside (3, 4), and a new enantiomer (12b), together with six known ones (58, 10, and 12a), and three pairs of known enantiomers (9, 11, and 13), were isolated from the ethanol extracts of the seeds of Peganum harmala L.. Their structures including the absolute configuration were elucidated by using 1D and 2D NMR, and ECD calculation approaches. The cytotoxic activities of all isolated compounds were evaluated. 11 showed moderate cytotoxicity against PC-3 cells with an IC50 value of 15.41?μM.  相似文献   

3.
Five triterpenoid saponins isolated from the flowers, the mature fruits and the leaves of Fatsia japonica were identified as 3-O-[β-d-glucopyranosyl(1→4)-β-d-glucopyranosyl]-hederagenin (1), 3-O-[β-d-glucopyranosyl-(1→4)-α-l-arabinopyranosyl]-oleanolic acid (2), 3-O-[α-l-arabinopyranosyl]-hederagenin (3), 3-O-[β-d-glucopyranosyl]-hederagenin (4) and 3-O-[β-d-glucopyranosyl(1→4)-α-l-arabinopyranosyl]-hederagenin (5). The saponins 1 and 2 are new, naturally occurring, triterpenoid saponins. The distribution of the five saponins in three parts of the plant was investigated. Saponins 2, 3 and 5 were present in the flowers, saponins 1, 3, 4 and 5 were in the mature fruits and saponins 2, 3, 4 and 5 were in the leaves.  相似文献   

4.
Fractionation of the deacetylated acetolyzate of the borate-insoluble fraction of the dextran elaborated by Leuconostoc mesenteroides NRRL B-1299 gave five tetrasaccharide fractions, isolated after chromatography on charcoal—Celite, paper chromatography, and paper electrophoresis. Examination of partial acid hydrolyzates of the tetrasaccharide fractions and their corresponding alditols, the relation between the logarithm of their partition functions (α') and molecular size, and methylation studies, showed them to be (a) 23-α-d-glucosyl-nigerotriose (1), (b) a mixture of 6-α-nigerotriosyl-d-glucose (2) and 61-α-d-glucosyl-nigerotriose (3) and/or 62-α-d-glucosyl-nigerotriose (4), (c) a mixture of 21-α-nigerosyl-isomaltose (5) and 32-α-isomaltosyl-kojibiose (6) and/or 62-α-nigerosyl-kojibiose (7), (d) 2-α-nigerotriosyl-d-glucose (8) and (e) nigerotetraose (9).  相似文献   

5.
Phenolic compounds, named integracin D (1), (7′R, 8′S, 8S)-8-hydroxyisoguaiacin (3), (2R, 3R) pinobanksin-3-caffeoylate (5) and threo-8S-7-methoxysyringylglycerol (6), respectively, were isolated from the Chinese mangrove plant Laguncularia racemosa (L) Gaertn. f. (Combretaceae), together with 23 known phenolic metabolites. Their structures were elucidated on the basis of extensive spectroscopic analyses including that of IR, UV, MS, CD, 1D and 2D NMR spectra as well as by comparison with literature data. Compound 5 showed significant anti-oxidative activity in the DPPH and TEAC free-radical-scavenging assays, while several of the phenolic compounds were tested for protein kinase inhibitory activity in an assay involving 24 different human tumor related protein kinases. Compounds 5, 7, and 23 showed potential inhibition with IC50 values between 2.2 and 3.6 μg/mL toward individual kinases. The ellagic acid derivatives were tested for insecticidal activity.  相似文献   

6.
Photo-oxygenation of 3-hydroxymethyl-5-(2,3-O-isopropylidene-β-d-erythrofuranosyl)-2-methylfuran, 5-(1,2:3,4-di-O-isopropylidene-d-arabino-tetritol-1-yl)-3-(1-hydroxyethyl)-2-methylfuran (8a), and 2-methyl-5-(1,2,3,4-tetra-O-acetyl-d-arabino-tetritol-1-yl)-3-furoic acid (8b) yielded the corresponding endo-peroxides, which were transformed into 4-hydroxymethyl-6-(2,3-O-isopropylidene-β-d-erythrofuranosyl)-3-methylpyridazine, 6-(1,2:3,4-di-O-isopropylidene-d-arabino-tetritol-1-yl)-4-(1-hydroxyethyl)-3-methylpyridazine, and 6-(d-arabino-tetritol-1-yl)-3-methylpyridazine by treatment with hydrazine. The γ-di-ketones (Z)-1-(1,2:3,4-di-O-isopropylidene-d-arabino-tetritol-1-yl)-3-(1-hydroxyethyl)pent-2-ene-1,4-dione and d-arabino-6,7,8,9-tetraacetoxy-4-methoxynonane-2,5-dione can be obtained by reduction of the endo-peroxides 9a and 9b (derived from 8a and 8b, respectively) with dimethyl sulphide. The C → O rearrangement reported for C-glycosyl endo-peroxides was also observed for 9a.  相似文献   

7.
The use of the microorganism Sporotrichum sulfurescens (ATCC 7159) to oxygenate organic molecules has been extended to several dialkylbenzenes. Oxygenation of 1,4-di-t-butylbenzene (1) gave 4-t-butyl(1-hydroxy-2-methyl)isopropylbenzene (2) and 1,4-di-(1-hydroxy-2-methyl)isopropylbenzene (3); of 1,4-diisopropylbenzene (4) gave (R,R)-1,4-di-(1-hydroxy)isopropylbenzene (5); of 1,3-diisopropylbenzene (6) gave 1,3-di-(2-hydroxy)isopropylbenzene (7), 3-(1-hydroxy)isopropyl-(2-hydroxy)isopropylbenzene (8), and 1,3-di-(1-hydroxy)isopropylbenzene (9); and of p-isobutylisopropylbenzene (20) gave 1-(p-2-hydroxyisopropylphenyl)-2-methylpropan-2-ol (15) and 1-(p-1-hydroxyisopropylphenyl)-2-methylpropan-2-ol (16). Monohydroxydialkylbenzenes also served as useful substrates in this reaction as suggested by the fact that 2 is an intermediate in the formation of 3 from 1. Oxygenation of 1-(p-isopropylphenyl)-2-methylpropan-2-ol (14), conveniently prepared from 2-(p-isopropylphenyl)propene (12) via oxygenative isomerization with thallium trinitrate to 13 followed by addition of methyl magnesium bromide, gave 15 and 16. Oxygenation of 2-(p-isobutylphenyl)propan-2-ol (18) gave 15, 2-(p-isobutylphenyl)-propan-1,2-diol (21), and 1-(p-2-hydroxyisopropylphenyl)-2-methylpropan-3-ol (22). Compound 16, obtained from substrate 14, was converted to (2R)-2-[4-(2-hydroxy-2-methylpropyl)phenyl]propionic acid (11), the enantiomer of a metabolite of the antiinflammatory agent, 2-(4-i-butyl)phenylpropionic acid (10).  相似文献   

8.
Five new compounds including two phenyldilactones (1, 2), two coumarins (3, 4) and a dimer of N-E-feruloyl tyramine (5) together with twenty-three known compounds (628) were isolated from a medicinal plant Polygonum chinense. The structures of the new compounds were established by detailed spectral analysis. The absolute configurations of 1 and 5 were elucidated by Mosher’s method, Mo2(OAc)4-induced electronic circular dichroism (ECD) data, and ECD calculation. All the compounds were found to show potent anticomplement activity with CH50 and AP50 values ranging from 0.18 to 1.45?mM, and 0.26 to 2.80?mM, respectively. Phenyldilactones and phenylpropionic tyramines were firstly reported as anticomplement agents. The targets of compounds 1, 3, 5 and 10 in complement activation cascade were identified as well.  相似文献   

9.
6-Deoxy-3-O-methyl-6-nitro-d-allose (5) and -l-talose (6) were synthesized from 1,2-O-isopropylidene-3O-methyl-α-d-allofuranose (1) by the nitromethane method via their furanoid, 1,2-O-isopropylidene derivatives (2 and 3). The barium hydroxide-catalyzed cyclization of the free nitrohexoses (5 and 6) was investigated. Under conditions favoring kinetic control (pH ~8, 0°), 5 gave mainly 1d-5-deoxy-2-O-methyl-5-nitro-allo-inositol (7), with the 1l-epi-1 (8) and epi-6 (9) stereoisomers as minor products. Compound 6 afforded a high yield of the myo-5-isomer (11); the 1l-allo-5 (13) and 1d-epi-1 (14) isomers were formed in small proportions but not isolated. The thermodynamically controlled, mutual interconversion of the stereoisomeric products was studied, as was the formation of nitronate salts and the regeneration of free nitroinositols. Upon immediate acidification, the nitronate obtained from 11 gave 11 and the neo-2 epimer (12) in a ratio of 2:3. The nitronate produced by 7 underwent rapid β-epimerization. The five isolated deoxynitroinositol monomethyl ethers were further characterized as tetra-acetates (7a, 9a, 11a, and 12a) and isopropylidene derivatives (7b, 8b, and 9b).  相似文献   

10.
Reaction of the Schiff base ligands 2-Br-4,5-(OCH2O)C6H2C(H)NCH2CH2NMe2 (a) and 4,5-(OCH2CH2)C6H3C(H)NCH2CH2NMe2 (b) with Pd(OAc)2 or K2[PdCl4] leads to the mononuclear cyclometallated compounds [Pd{2-Br-4,5-(OCH2O)C6HC(H)NCH2CH2NMe2-C6,N,N}(OCOMe)] (1a) and [Pd{4,5-(OCH2CH2)C6H2C(H)NCH2CH2NMe2-C6,N,N}(Cl)] (1b), derived from C-H activation at the C6 carbon. Treatment of a with Pd2(dba)3 gave [Pd{4-5-(OCH2O)C6H2C(H)NCH2CH2NMe2-C2,N,N}(Br)] (2a), via C-Br activation.The metathesis reaction of 1a with aqueous sodium chloride gave [Pd{2-Br-4,5-(OCH2O)C6HC(H)NCH2CH2NMe2-C6,N,N}(Cl)] (3a), with exchange of the acetate group by a chloride ligand. Treatment of the cyclometallated monomers 1a-3a with PPh3 in a 1:1 molar ratio yielded the mononuclear complexes [Pd{2-Br-4,5-(OCH2O)C6HC(H)NCH2CH2NMe2-C6,N}(L)(PPh3)] (L: OAc, 4a; Cl, 5a) and [Pd{4-5-(OCH2O)C6H2C(H)NCH2CH2NMe2-C2,N}(Br)(PPh3)] (6a), with Pd-NMe2 bond cleavage. However, treatment of a solution of 3a or 2a with silver trifluoromethanesulfonate, followed by reaction with PPh3 in acetone yielded the cyclometallated complexes [Pd{2-Br-4,5-(OCH2O)C6HC(H)NCH2CH2NMe2-C6,N,N}(PPh3)][CF3SO3] (7a) and [Pd{4-5-(OCH2O)C6H2C(H)NCH2CH2NMe2-C2,N,N}(PPh3)][CF3SO3] (8a), respectively, where the Pd-NMe2 bond was retained.The reaction of the ligands 2-Br-4,5-(OCH2O)C6H2C(H)N(2′-OH-5′-tBuC6H3) (c) and 4,5-(OCH2CH2)C6H3C(H)N(2′-OH-5′-tBuC6H3) (d) with Pd(OAc)2 gave the tetranuclear complexes [Pd{2-Br-4,5-(OCH2O)C6HC(H)N(2′-O-5′-tBuC6H3)-C6,N,O}]4 (1c) and [Pd{4,5-(OCH2CH2)C6H2C(H)N(2′-O-5′-tBuC6H3)-C6,N,O}]4 (1d), respectively. Treatment of 1c with PPh3 in 1:4 molar ratio, gave the mononuclear species [Pd{2-Br-4,5-(OCH2O)C6HC(H)N(2′-(O)-5′-tBuC6H3)-C6,N,O}(PPh3)] (2c) with opening of the polynuclear structure after P-Obridging bond cleavage.The structure of compounds 2a, 1c and 1d has been determined by X-ray diffraction analysis.  相似文献   

11.
Ligands containing the 2-organochalcogenomethylpyridine motif with substituents in the 4- or 6-position of the pyridyl ring, R4,R6-pyCH2ER1 [R4 = R6 = H, ER1 = SMe (1), SeMe (2), SPh (6), SePh (7); R4 = Me, R6 = H, ER1 = SMe (3), SPh (8), SePh (9); R4 = H, R6 = Me, ER1 = SMe (4), SPh (10), SePh (11); R4 = H, R6 = Ph, ER1 = SMe (5), SPh (12), SePh (13)] are obtained on the reaction of R4,R6-pyMe with LiBun followed by R1EER1. On reaction with PdCl2(NCMe)2, the ligands with a 6-phenyl substituent form cyclopalladated species PdCl{6-(o-C6H4)pyCH2ER1-C,N,E} (5a, 12a, 13a) with the structure of 13a (ER1 = SePh) confirmed by X-ray crystallography; other ligands form complexes of stoichiometry PdCl2(R4,R6-pyCH2ER1). Complexes with R6 = H are monomeric with N,E-bidentate configurations, confirmed by structural analysis for 3a (R4 = Me, ER1 = SMe), 7a (R4 = H, ER1 = SePh) and 9a (R4 = Me, ER1 = SePh). Two of the 6-methyl substituted complexes examined by X-ray crystallography are oligomeric with trans-PdCl2(N,E) motifs and bridging ligands, trimeric [PdCl2(μ-6-MepyCH2SPh-N,S)]3 (10a) and dimeric [PdCl2(μ-6-MepyCH2SePh-N,Se)]2 (11a). This behaviour is attributed to avoidance of the Me···Cl interaction that would occur in the cis-bidentate configuration if the pyridyl plane had the same orientation with respect to the coordination plane as observed for 3a, 7a and 9a [dihedral angles 8.0(2)-16.8(2)°]. When examined as precatalysts for the Mizoroki-Heck reaction of n-butyl acrylate with aryl halides in N,N-dimethylacetamide at 120 °C, the complexes exhibit the anticipated trends in yield (ArI > ArBr > ArCl, higher yield for electron withdrawing substituents in 4-RC6H4Br and 4-RC6H4Cl). The most active precatalysts are PdCl2(R4-pyCH2SMe-N,S) (R = H (1a), Me (3a)); complexes of the selenium containing ligands exhibit very low activity. For closely related ligands, the changes SMe to SPh, 6-H to 6-Me, and 6-H to 6-Ph lead to lower activity, consistent with involvement of both the pyridyl and chalcogen donors in reactions involving aryl bromides. The precatalyst PdCl2(pyCH2SMe-N,S) (1a) exhibits higher activity for the reaction of aryl chlorides in Bun4NCl at 120 °C as a solvent under non-aqueous ionic liquid (NAIL) conditions.  相似文献   

12.
In our search for secondary metabolites regulating the motility behavior of zoospores of the grapevine downy mildew pathogen Plasmopara viticola, we found that extracts from an endophytic fungus Phomopsis sp. CAFT69 and its host plant Endodesmia calophylloides remarkably impaired motility of zoospores followed by lysis. The active principles in the extracts were isolated and identified as two new compounds, namely excelsional (1a) and 9-hydroxyphomopsidin (2a), together with excelsione (1b), phomopsidin (2b), alternariol (3a), alternariol-5-O-methyl ether (3b), the hitherto undescribed 5′-hydroxyalternariol (3c), altenusin (4) from the fungus, xanthochymol (5) and 1,5-dihydroxy-3-methoxyxanthone (mesuaxanthone, 6) from the plant. Bioassays revealed that compounds 1a/b, 2a/b, and 3a6 displayed motility inhibition and lytic activities against zoospores of the grapevine downy mildew pathogen P. viticola in a dose- and time-dependent manner from 1 to 10 μg/mL. Their structures were elucidated by extensive spectroscopic analyses including 2D NMR techniques. This is the first report of an endophyte and its natural products from E. calophylloides and the first isolation of compounds 5 and 6 from this plant.  相似文献   

13.
Iridoid glycosides, 2′,3′,6′-tri-O-acetyl-4′-O-trans-p-(O-β-d-glucopyranosyl)coumaroyl-7-ketologanin (1), 2′-O-caffeoylloganic acid (2), 2′-O-p-hydroxybenzoylloganic acid (3), 2′-O-trans-p-coumaroylloganic acid (4), and 2′-O-cis-p-coumaroylloganic acid (5), were isolated from whole plants of Gentiana loureirii along with six known iridoids, 7-ketologanin (6), loganin (7), loganic acid (8), sweroside, boonein, and isoboonein, and three other known compounds. Their structures were elucidated by spectroscopic means and chemical correlations. The isolated iridoids were evaluated for antibacterial and antioxidant activities, but were either inactive or very weakly active.  相似文献   

14.
Extraction of Millettia pachycarpa Benth. gave 5,7,4′-trihydroxy-6,8-diprenylisoflavone (1a), 5,7,4′-trihydroxy-6,3′-diprenylisoflavone (2a), 5,7,3′,4′-tetrahydroxy-6,8-diprenylisoflavone (3a) and (2R, 3R)-5,4′-dihydroxy-8-prenyl-6″,6″-dimethylpyrano[2″,3″: 7,6]-dihydroflavonol (4a) whose structures were established by chemical transformations and spectroscopic means. Pectolinarigenin and salvigenin were isolated from Buddleia macrostachya Benth.  相似文献   

15.
Two new spirostanoides, filiasparosides E (1) and F (2), one new furostanoside, filiasparoside G (3), and one new ecdysterone, stachysterone A-20, 22-acetonide (4), together with six known steroidal saponins, asparagusin A (5), filiasparoside A (6), filiasparoside B (7), aspafilioside A (8), aspafilioside B (9), and filiasparoside C (10) were isolated from the roots of Asparagus filicinus Buch.-Ham. Their structures were elucidated on the basis of spectroscopic and chemical evidence. Compounds 1-10 were investigated for their cytotoxicities against human breast adenocarcinoma MDA-MB-231 cell line and compounds 8-10 exhibited cytotoxic activities with IC50 values ranging from 3.4 to 6.6 μM.  相似文献   

16.
Treatment of methyl β-d-ribofuranoside with acetone gave methyl 2,3-O-isopropylidene-β-d-ribofuranoside (1, 90%), whereas methyl α-d-ribofuranoside gave a mixture (30%) of 1 and methyl 2,3-O-isopropylidene-α-d-ribofuranoside (1a). On oxidation, 1 gave methyl 2,3-O-isopropylidene-β-d-ribo-pentodialdo-1,4-furanoside (2), whereas no similar product was obtained on oxidation of 1a. Ethynylmagnesium bromide reacted with 2 in dry tetrahydrofuran to give a 1:1 mixture (95%) of methyl 6,7-dideoxy-2,3-O-isopropylidene-β-d-allo- (3) and -α-l-talo-hept-6-ynofuranoside (4). Ozonolysis of 3 and 4 in dichloromethane gave the corresponding d-allo- and l-talo-uronic acids, characterized as their methyl esters (5 and 6) and 5-O-formyl methyl esters (5a and 6a). Ozonolysis in methanol gave a mixture of the free uronic acid and the methyl ester, and only a small proportion of the 5-O-formyl methyl ester. Malonic acid reacted with 2 to give methyl 5,6-dideoxy-2,3-O-isopropylidene-β-d-ribo-trans-hept-5-enofuranosiduronic acid (7).  相似文献   

17.
Chromone glucosides, takanechromones A-C (1, 2 and 5) and chromanone glucosides, named takanechromanones A and B (3 and 4), were isolated from the methanolic extracts of Hypericumsikokumontanum together with 27 known compounds. Their structures were established based on spectroscopic evidence. The isolated compounds and some chromone derivatives were assayed for antimicrobial activity against Helicobacter pylori and cytotoxicity against human cancer cell lines.  相似文献   

18.
Phytochemical investigation of the radix of Angelica sinensis has led to the isolation and identification of a new phthalide dimer, (3Z)-(3aR,6S,3′R,8′S)-3a.8′,6.3′-diligustilide (1), along with three known phthalide dimers, including riligustilide (2), levistolide A (3), senkyunolide O (4), and three known phthalide monomers, including 3,9-dihydroxyl-ligustilide (5), (Z)-butylidene phthalide (6), (Z)-ligustilide (7). Their structures were determined by spectroscopic methods including IR, NMR (1H NMR, 13C NMR, COSY, HSQC, HMBC and NOESY) and MS. Meanwhile, the possible biosynthesis pathways of compounds 1 and 5 were hypothesized.  相似文献   

19.
C20-Phytosphingosine, D(+)-ribo-2-amino-1, 3, 4-trihydroxyeicosane (8a), is synthesized through the following intermediates: 2-Methoxyoctadecanoic acid chloride (1)→Ethyl 2-methoxyoctadecanoylacetoacetate (2)→Ethyl (2-p-nitrophenylhydrazono)-2,3-dioxo-4-methoxyeicosanoate (3)→Ethyl 2-acetamido-3-oxo-4-methoxyeicosanoate (4)→Ethyl 2-acetamido-3-hydroxy-4-methoxyeicosanoate (5)→2-Acetamido-3-hydroxy-4-methoxyeicosanoic acid (6), 2-Amino-3-hydroxyeicosanoic acid 1,4-lactone hydrobromide (7a, b)→DL-ribo (8a) and DL-xylo(?)-2-amino-1,3,4-trihydroxyeicosane (8b). The resolution of the racemic base (8a) has been effected through its salts with D-tartaric acid.  相似文献   

20.
The trunk wood of the Amazonian Aniba ferra Kubitzki contains, besides three benzyl benzoates (1a, b, c) and dillapiol (2), four hydrobenzofuranoid and two bicyclo [3.2.1] octanoid neolignans. The former comprise two representatives (3a, b) of the novel ferrearin- (3a-allyl-2- aryl-7a-hydroxy-3-methyl-3a,4,7,7a-tetrahydro-7-oxobenzofuran type, and two further representatives (4a, b) of the known porosin-(3a-allyl-2-aryl-5-methoxy-3a,4,5,6-tetrahydro-6-oxobenzofuran) type. The latter comprises a new representative (5a) of the known canellin- (1-allyl-6-aryl-7-methylbicyclo [3.2.1] octane) type, and the methyl ether (6a) of a known guianin- (1-allyl-6-aryl-7-methyl-4-oxobicyclo [3.2.1] oct-2-en) type neolignan.  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