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1.
A new compound, subglain B, was isolated from the stems of Uvaria tonkinensis var.subglabra and its structure was identified as 1S, 2R, 3S, 6R-1-benzoyloxymethylene-1,2-dihydroxy-3-benzoyloxy-6-chlorocyclohex-4-ene (1), by spectral evidences.  相似文献   

2.
A new compound from the leaves of Diospyros mollis Griff. was elucidated as diospyrol 8,8′-di-O-(6-β-D-apiofuranosyl-β-D glucopyranoside) by spectroscopic methods.  相似文献   

3.
A formal total synthesis of (-)-cephalotaxine (1) has been achieved. The key step is an intramolecular aldol condensation of the diketone 9, which in turn was obtained in three steps from the azabicyclic compound 6 derived from D-proline according to Seebach's procedure. Treatment of 9 with a catalytic amount of sodium 2-methyl-2-butanolate in benzene at room temperature gave the alpha, beta-unsaturated ketone 8 in 43% yield. Catalytic hydrogenation of 8 followed by reduction of the ketone 22 with sodium borohydride and acetylation of the resulting alcohol 23 gave the acetoxy derivative 24, which, after deprotection, was acylated with (methylthio)acetic acid to give the amide 26. Compound 26 was converted into optically active ketolactam 4 following the synthetic operations developed for the synthesis of the racemic compound.  相似文献   

4.
The new compounds, epoxydines A and B ( 1 and 2 , resp.), along with the known and related metabolites, 3 – 6 , were isolated from the fungal endophyte Phoma sp. The structures of the new compounds were elucidated by detailed spectroscopic analysis, and the relative configuration of 1 was confirmed by ROESY experiments. Preliminary studies indicated that compounds 2 – 5 possess good antibacterial, antifungal, and algicidal properties. Similarly, compound 1 showed antifungal and algicidal, and compound 6 antibacterial and algicidal properties.  相似文献   

5.
CGS 21680 (2-[p-(2-carboxyethyl)phenylethylamino]-5'-N- ethylcarboxamidoadenosine, I) is a highly A2-selective (A2/A1 = 140), high-affinity adenosine agonist. A method has been devised to extract the compound from biological matrices with automated solid-phase extraction using C18 bonded silica columns. This is followed by reversed-phase, paired-ion chromatography on a Supelco LC-18-S column with fluorescence detection. The limit of quantitation is 5 ng/ml, but 1 ng/ml (five times the signal-to-noise ratio) can readily be detected. Tritium-labeled compound was used to study the pharmacokinetics in rats. After an intravenous dose of 0.3 mg/kg, biphasic elimination kinetics were observed for parent I, characterized by half-lives of 1.8 min (distribution) and 15 min (elimination). The volume of distribution in the terminal phase (V beta) was low (0.27 l/kg) and plasma clearance was moderate (0.83 l/kg/h). Although the compound was rapidly absorbed (mean Tmax = 13 min), low concentrations (mean Cmax = 94 ng/ml) were observed after an oral dose of 3.0 mg/kg, and bioavailability was only approximately 1.4%. Radioactivity persisted in plasma longer than parent compound after either dose, but levels were too low for isolation and structure identification of drug-derived compounds.  相似文献   

6.
[reaction: see text] In this, the second of two Letters, the optimization of the pyrrolidine-5,5-trans-lactam template (exemplified by 1a) as a mechanism-based inhibitor of hepatitis C NS3/4A protease is described. "Right Box" analysis of cassette dosing screening pharmacokinetic data was used to rapidly categorize the compounds. GW0014 (compound 4d) emerged as the compound displaying an optimal balance of biochemical and replicon potency, along with low i.v. clearance in the dog.  相似文献   

7.
A new cyanogenic glycoside, sutherlandin-5-trans-p-coumarate was isolated along with a known cardiosdiospermin-5-(4-hydroxy) benzoate fr the aerial parts of Sorbaria sorbifolia (L.) A. Br. var. stellipila MAX. (Rosaceae). The structure of the new compound was established based on spectral evidence.  相似文献   

8.
A new cafferic ester, (+)-2-(1-hydroxyl-4-oxocyclohexyl) ethyl caffeate, was isolated from the 80% ethanol extract of the whole plants of Incarvillea mairei var. granditlora (Wehrhahn) Grierson. The structure of the compound was established by spectroscopic methods.  相似文献   

9.
A four-step preparation of 1-methyl-5-p-totylpyrrole-2-acetic acid (Tolmetin) is reported starting from 1-methyl-2-p-tolylpyrrole. Formylation of this compound followed by condensation with methyl(methylthio)-methyl sulfoxide furnished 1-(methylsulfinyl)-1-methylthio-2-(1-methyl-5-p-tolyl-2-pyrrolyl)ethylene. Pummerer rearrangement of the latter compound gave ethyl 1-methyl-5-p-tolylpyrrole-2-acetate, which was hydrolyzed in alkaline medium to afford Tolmetin.  相似文献   

10.
A novel butanolide, named virginaebutanolide F (1), was isolated from the lyophilized culture broth of Slreptomyces sp., along with a known compound virginaebutanolide C (2). Their structures including the stereochemistry were elucidated on the basis of extensive 1D and 2D NMR as well as HRESI-MS and CD spectroscopic analysis.  相似文献   

11.
Na Z  Xu YK 《Natural product research》2010,24(17):1648-1653
A new prenylated xanthone, named bannaxanthone I, has been isolated from the leaves of Garcinia xipshuanbannaensis, along with five other known compounds, bannaxanthone E, mangostinone, tovophyllin A, garcinone E, and γ-mangostin. The structure of the new compound was elucidated on the basis of high-resolution fast atom bombardment mass spectra (HRFABMS), 1D-and 2D-NMR experiments, including heteronuclear multiple bond connectivity (HMBC), heteronuclear single quantum coherence (HSQC) and 1H-1H-COSY (correlated spectroscopy, COSY).  相似文献   

12.
A new ellagitannin along with eight known compounds has been isolated from the ethanol extract of the fruit of Phyllanthus emblica L. The chemical structure of the new compound was established as Phyllanthunin (1) by HR‐ESI‐MS, 1D and 2D NMR spectroscopic analysis.  相似文献   

13.
A new phenolic compound was isolated from the ethanol extract of the bulbs of Crinum asiaticum L.var.sinicum Baker.Its structure was defined as 1-(2-hydroxy-4-hydroxymethyl)phenyl-6-O-caffeoyl-β-D-gluco-pyranoside on the basis of spectroscopic evidences.  相似文献   

14.
<正>A new flavonoidic glycoside,tricin-4'-O-β-L-arabinoside(1) was isolated from the leaves of Alstonia macrophylla along with two known flavonoids,vitexin and myricetin-3′-rhamnoside-3-O-galactoside.Their structures were established by chemical and spectral evidences.The known compounds were reported for the first time from this plant.Moreover compound 1 was tested for antifungal and antibacterial activities.  相似文献   

15.
A new ent-kaurane diterpenoid, lophanthodin G (1) and one known abietanoid, 6alpha-hydroxyferruginol (2), were isolated from the leaves of Isodon lophanthoides var. geradianus. The structure of the new compound 1 was established using spectroscopic methods including extensive 1D and 2D NMR analysis.  相似文献   

16.
A macrocyclic polyketide with novel carbon skeleton, namely hainanmycin A, was isolated from the mangrove-derived Streptomyces sp. 219807. This polycyclic compound featured a cyclo-heptadeca framework possessing a 5,6-disubstituted-4-hydroxy-2-pyrone moiety in conjunction with a 2-cyclopentenone residue. The structure was established by spectroscopic analyses, and the stereochemistry was determined by NMR chemical shifts calculations and time-dependent density functional theory (TDDFT) calculation of electronic circulardichroism (ECD). A possible biogenetic pathway for hainanmycin A was proposed.  相似文献   

17.
[structure: see text] A structurally unique hydrophobic compound, biyouyanagin A, was isolated from the MeOH extract of the leaves of Hypericum chinense L. var. salicifolium. The structure of biyouyanagin A was elucidated on the basis of spectroscopic evidence. Biyouyanagin A showed a significant activity against HIV and inhibited cytokine production.  相似文献   

18.
The plant Dalbergia odorifera T. Chen (Leguminosae) is a high tree, the root and heartwood of this plant is a Chinese traditional medicine named Jiangxiang. It is indigenous to Guangdong province.Compound 1 was isolated from the EtOAc extract of plant Dalbergia odorifera T. Chen as yellow crystalline powder, mp: 191.2-192.5 ℃. EI-MS (m/z): 244 (96), 243 (92), 167 (100), 166 (65), 123 (23), 105 (55), 77 (95). IR ν(KBr) cm-1 : 3300 (hydryoxy), 1637 (β-unsaturated carbonyl), 1597, 1571…  相似文献   

19.
A new method for analysis of the active compound in a commercial pharmaceutical formulation in different steps of the production cycle, based on near-infrared diffuse reflectance spectroscopy, is proposed. The analysis includes three different steps of the production cycle: granules ready for compression (mixed phase), cores (intermediate) and coated tablets (final product). Satisfactory predictive results for production samples, independently of its origin in the production cycle, require calibration with laboratory-made samples covering the concentration range involved in the manufacturing process, and also production samples from various production batches and different steps, which introduce the variation sources inherent in such a process. A global and sole model was found to determine the active compound during the production cycle, with errors of prediction less than 1.8% in all cases. Tablets can be individually analysed with high accuracy and precision, so a content uniformity analysis may be performed.  相似文献   

20.
A novel lignan glysocide, namely sagitiside A (1), together with two known ones, (+)-lyoniresinol-2α-O-β-D-glucopyranoside (2) and (+)-5'-methoxyisolariciresinol 3α-O-β-D-glucopyranoside (3), was isolated from the 95% ethanol extract of dry roots of Tinospora sagittata var. yunnanensis. The structure of the new compound (1) was determined based on MS, 1D and 2D NMR spectral data. Compounds 1-3 showed antioxidant activity with EC(50) values 55, 75 and 80?μM by 1,1-diphenyl-2-picryhydrazyl (DPPH) radical-scavenging assay.  相似文献   

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