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1.
Two new cyclic diarylheptanoids named ostryopsitrienol(1) and ostryopsitriol(2),together with six known compounds,were isolated from the stems of endemic medicinal plant of Ostryopsis nobilis (Betulaceae).The structures of the new compounds were elucidated by means of HRMS,~1D NMR,~2D NMR and X-ray crystallography analysis.  相似文献   

2.
Phytochemical investigation of EtOH extract of NIRAM, natural dye from Polygonum tinctorium, resulted in the purification of nine alkaloid compounds (19) including four new compounds (14). Structures of these new compounds were elucidated by 1D and 2D NMR (1H and 13C NMR, 1H–1H COSY, 1H–13C HSQC, 1H–13C HMBC), IR, UV, HR-ESI-MS, and ECD spectra. Isolated compounds (19) were tested for their inhibitory effects on nitric oxide (NO) production in lipopolysaccharide (LPS)-activated BV-2 cells. Compounds 13, 5, and 7 showed potent NO production inhibitory activities, with IC50 values of 3.88–22.87 μM.  相似文献   

3.
(1R,2S,6R)-2-Amino-6-hydroxycyclooctanecarboxylic acid (?)-10 was synthesized from (1R,2S)-2-aminocyclooct-5-enecarboxylic acid (+)-2 via an iodolactone intermediate, while (1R,2S,3R,4S)-2-amino-5,6-dihydroxycyclooctanecarboxylic acid (?)-12 was prepared by using the OsO4-catalyzed oxidation of Boc-protected amino ester (?)-5. The stereochemistry and relative configurations of the synthesized compounds were determined by 1D and 2D NMR spectroscopy (based on 2D NOE cross-peaks and 3J(H,H) coupling constants) and X-ray crystallography.  相似文献   

4.
Two new spiroketals, didemnaketals D (1) and E (2) were isolated from a marine ascidian species belonging to the genus Didemnum. The structures of the compounds were elucidated by extensive 1D (1H, 13C, and DEPT) and 2D (COSY, TOCSY, HSQC, HMBC, NOESY, and ROESY) NMR studies and high-resolution mass spectroscopic data. The new didemnaketals differ from the reported ones in which that they lack the methyl functionality at C-6 and the hydroxy moiety at C-21. Instead, they possess an ester moiety at C-6 in addition to new oxygen functionality at C-20 of the didemnaketals. Compounds 1 and 2 were evaluated for their protein kinase inhibitory activity against different kinases (CDK5, CK1, DyrK1A, and GSK3) at 10 μg/mL. Compounds 1 and 2 showed moderate activity against these kinases. In addition, the compounds displayed moderate antimicrobial activity against Staphylococcus aureus and Bacillus subtilis, respectively.  相似文献   

5.
Two novel cucurbitane triterpenoid glycosides, named saxifraganoids A (1) and B (2), were isolated from Saxifraga umbellulata var. pectinata. Their structures including absolute configurations were elucidated based on the analysis of spectroscopic data (1D, 2D NMR and HRMS), and single-crystal X-ray diffraction. Compound 1 represents the first example of cucurbitane triterpenoid with a Δ17(20), and compound 2 contained an unusual N-acetylglucosamine at C-16. The protective effects against liver injury induced by carbon tetrachloride (CCl4) in the human embryonic-liver L-02 cells of these two compounds were evaluated.  相似文献   

6.
A series of (E)-2-[5-chloro-1-(1H-benzo[d]imidazol-2-yl)ethylidene] N-(substituted) hydrazine carbothioamide (7a7t) and (E)-2-[1-(1H-benzo[d]imidazol-2-yl)ethylidene] N-(substituted) hydrazine carbothioamide (8a8t) were prepared via the synthesis of 1-(substituted-1H-benzimidazol-2-yl) ethanol (3a3b) which was synthesized by the condensation of substituted o-phenylenediamine (2a2b) with dl-lactic acid (1) followed by oxidation with sodium hypochlorite in mild acidic condition to form the corresponding ketones 4a4b. Final compounds were formed by condensation of 4a4b with different thiosemicarbazides 6a6t. A total of 40 compounds were synthesized and characterized by FT-IR, 1H NMR, 13C NMR, Mass spectral technique and elemental analysis, in addition they were evaluated for anti-malarial properties. Among the compounds tested 7o, 7p, 7q, 7r, 7s, 8e and 8h exhibited good antimalarial activity in vitro.  相似文献   

7.
《Tetrahedron letters》2019,60(51):151325
Three new polyketides, phomopones A−C (13), one new cyclic tetrapeptide, 18-hydroxydihydrotentoxin (4), and a new amide, 6-hydroxyenamidin (5) together with a known derivative, enamindin (6) were obtained from the endophytic fungus Phomopsis sp. D15a2a isolated from the plant Alternanthera bettzickiana. The structures of the new compounds were elucidated by 1D, 2D NMR and HRMS data. The absolute configurations of the isolated metabolites were determined either by X-ray crystallography, Marfey’s method or by converting the compounds to Mosher esters.  相似文献   

8.
The synthesis of a number of novel, fully conjugated, planar pentacyclic 5H-indolo[3′,2′:4,5]pyrido[1,2-a][1,3]benzimidazoles (8) and 11H-pyrido[3″,2″:4′,5′]imidazo[1′,2′:1,6]pyrido[3,4-b]indoles (12) by a one-pot reaction of pyranoindolones with substituted o-phenylenediamines or 2,3-diaminopyridines is described. In the case of 2,3-diaminopyridines the reaction proceeds regioselectively affording only regioisomers 12. Structural assignments of the new compounds as well as complete assignment of 1H and 13C NMR signals were based on the analysis of their 1H and 13C NMR (1D and 2D), IR, MS and elemental analysis data. Plausible mechanisms are proposed.  相似文献   

9.
A Streptomyces sp. Lv3-13, isolated from the rhizosphere soil of the plant Mespilus germanica, has yielded three new pimprinine derivatives, named pimprinols A–C (13) and the unknown (2-aminophenyl)(2-ethyloxazol-5-yl) methanone (4) along with the known compounds 2-ethyl oxazole pimprinine and 2-propyl oxazole pimprinine. The structures of the compounds were elucidated based on spectroscopic methods including UV, HR-ESIMS and 1D, 2D NMR data. Compounds 14 were screened for antimicrobial and cytotoxic activities.  相似文献   

10.
A series of 4-(1-aryl-2-oxo-1,2-dihydro-indol-3-ylideneamino)-N-substituted benzenesulfonamide derivatives (132) was synthesized and evaluated for its in vitro antimicrobial, antiviral and cytotoxic activities. Antimicrobial results indicated that compounds (11) and (18) were found to be the most effective ones. In general, the synthesized compounds were bacteriostatic and fungistatic in their action. The cytotoxic screening results indicated that the compounds were less active than the standard drug 5-fluorouracil (5-FU). None of the compounds inhibited viral replication at subtoxic concentrations. In general, the presence of a pyrimidine ring with electron releasing groups and an ortho- and para-substituted benzoyl moiety favored antimicrobial activities. The results of QSAR studies demonstrated the importance of topological parameters, valence zero order molecular connectivity index (0χv) and valence first order molecular connectivity index (1χv) in describing the antimicrobial activity of synthesized compounds.  相似文献   

11.
《Tetrahedron: Asymmetry》2006,17(6):916-921
A series of new compounds, (1R,2R)-1-(1′,8′-naphthalimide)-2-aminocyclohexane 1 and its 4′-derivatives 2 and 3 derived from (1R,2R)-1,2-diaminocyclohexane have been synthesized conveniently and efficiently. 1H NMR spectroscopy was employed to investigate their enantiodiscriminating ability. Compared with α-phenylethylamine, a commercially available chiral solvating agent (CSA), these compounds exhibited better enantiodiscriminating ability toward the chiral carboxylic acids we had chosen, distinguishing them as promising and practical CSAs.  相似文献   

12.
Two new compounds, (2S,3R)-methyl 7-hydroxy-2-(4-hydroxy-3-methoxy-phenyl)-3-(hydroxymethyl)-2,3-dihydrobenzofuran-5-carboxylate (1) and (4R,5S)-5-(3-hydroxy-2,6-dimethylphenyl)-4-isopropyldihydrofuran-2-one (2), tentatively named norcurlignan and limlactone, respectively, were isolated from Liriope muscari, together with the known compound (-)-pinoresinol (3). The structures of these compounds were elucidated and characterized on the basis of 1D NMR, 2D NMR, CD and MS data. The in vitro antioxidant activities of compounds 1-3 were assessed by the DPPH and ABTS scavenging methods.  相似文献   

13.
This study aimed to characterize and evaluate the cytotoxicities of ellagitannins from S. praecox fruit. Fractionation of an acetone extract of the fruit led to isolation of five new ellagitannins—stachyuranin D (15), stachyuranin E (16), stachyuranin F (17), stachyugluconin (18), and stachyuglyconin (19)—along with seven ellagitannins previously isolated from S. praecox leaves and seven known ellagitannins isolated from Stachyuraceae for the first time. Two-dimensional NMR and other spectroscopic methods enabled complete elucidation of the structures of the new compounds. Structure of flavanoellagitannin (16) was confirmed by 1H NMR comparison with synthetic analogs. The configuration of stachyuglyconin (19) with a C8-aldonic acid core was established with the aid of density functional theory calculations. A MTT assay revealed 5-desgalloylpterocarinin A (11) and hippophaenin B (9) had the highest cytotoxicities among the compounds against HeLa (IC50 = 35.35 μM) and HepG2 (IC50 = 60.00 μM) cells, respectively.  相似文献   

14.
Within the study covering the search for new methods of synthesis of rifamycin antibiotics, the reactions of 3-formylrifamycin SV (2) with primary amines or ammonia were studied. In the reaction of 2 with methylamine, unstable 3-methyliminomethylrifamycin SV (8) was formed, which was further oxidised to stable 3-methyliminomethylrifamycin S (9). In the reaction of 2 with ammonia, N,15-didehydro-15-deoxo-pyrimido-(4,5-b)rifamycin SV (10), a new compound with a chromophore system enlarged by a pyrimidine ring, was obtained. The product of its reduction with sodium borohydride—(11)—was also isolated. The structures of the compounds and an explanation of the synthesis mechanism have been proposed on the basis of mass spectrometry results as well as (1D) and (2D) 1H- and 13C NMR analysis. In vitro antituberculous activity of the new compounds have been investigated.  相似文献   

15.
A series of 4-(1-aryl-5-chloro-2-oxo-1,2-dihydro-indol-3-ylideneamino)-N-substituted benzenesulfonamide derivatives (1–20) was synthesized and evaluated for its in vitro antimicrobial and anticancer activities. Antimicrobial results indicated that compounds N-(4-(1-benzoyl-5-chloro-2-oxoindolin-3-ylideneamino) phenylsulfonyl)-4-isopropoxy benzamide (9) and N-(4-(5-chloro-1-(2-chlorobenzoyl)-2-oxoindolin-3-ylideneamino) phenylsulfonyl)-4-isopropoxybenzamide (19) were found to be the most effective ones. The anticancer results indicated that almost all the synthesized compounds were more active than the standard drug carboplatin but less active than the standard drug 5-fluorouracil (5-FU) against both the cell lines (HCT116 and RAW 264.7). 4-(1-Benzoyl-5-chloro-2-oxoindolin-3-ylideneamino)-N-(pyrimidin-2-yl) benzenesulfonamide (3) was found to be most potent and exhibited selectivity toward HCT 116. QSAR studies indicated that antimicrobial activity of isatin derivatives against different microbial strains was governed by lipophilic parameter, log P and topological parameters valance zero and third order molecular connectivity indices (0χv and 3χv).  相似文献   

16.
Three new polyacetylenic alcohols, pellynols M?O (13), along with two known ones, melyne A (4) and melyne B (5), were isolated from a Niphates sp. marine sponge collected off the South China Sea. The structures of new compounds were determined based on a combination of 1D and 2D NMR analysis, ESI-MSn fragmentation, and chemical (ozonolysis) method. Their absolute configurations were assigned by modified Mosher's method. All the isolates showed potent cytotoxic activity against PC9 and HepG2 human cancer cell lines with IC50 values of 2.9–7.6?μM.  相似文献   

17.
《Tetrahedron: Asymmetry》2007,18(4):464-475
In CDCl3 solution, enantiopure (S)-1-benzyl-6-methylpiperazine-2,5-dione (S)-1a formed diastereomeric COH–N hydrogen-bonded associates with racemic (RS,Z)-1-benzyl-3-[(dimethylamino)methylidene]piperazine-2,5-diones 2a and 2b, (RS)-tert-butyl pyroglutamate (RS)-2c and (RS)-N-benzoylalanine methyl ester (RS)-2d. This resulted in splitting (doubling) of the characteristic signals in the 1H NMR and 13C spectra of racemic compounds 2ad in the presence of 1 equiv of (S)-1a. The formation of hydrogen-bonded dimers in CDCl3 solution was studied by 1H NMR, 13C NMR and 2D NMR and confirmed by the intermolecular NOE observed between the hydrogen-bonded amide protons from each of the monomeric units, (S)-1a and 2ac. On the other hand, a slightly different binding mode was proposed for association of (S)-1a with alaninamide (RS)-2d. Enantiomer compositions of known (weighed) mixtures of both enantiomers of tert-butyl pyroglutamate 2c were re-determined by 1H NMR in the presence of (S)-1a in CDCl3. The experimental values were in good agreement with the theoretical values, thus indicating the potential applicability of (S)-1a and related diketopiperazines as chiral solvating agents in NMR spectroscopy.  相似文献   

18.
Two new compounds, designated as itampolins A (1) and B (2) were isolated from the sponge Iotrochota purpurea collected at Itampolo, southwest of Tuléar, Madagascar. The structures of the compounds were elucidated mainly on the basis of 1D and 2D NMR and mass spectroscopic data and, in the case of 1, also by chemical degradation.  相似文献   

19.
Four new diterpenes (14) together with six known members of this family were isolated from the brown alga Bifurcaria bifurcata collected off the coast near Roscoff, France. The structures of the new compounds were established in a comprehensive study on the basis of 1D and 2D NMR spectroscopic and mass spectrometric (ESI-MS) analyses. Our assignment is supported by a comparison of the 13C NMR chemical shifts to known compounds and predicted values. The new diterpenes are derivatives of the diterpene eleganolone (5). The structural relation and hypothetical metabolic pathway of the new diterpenes (14) with the co-isolated known diterpenes are discussed.  相似文献   

20.
A marine fungal isolate, identified as Chaetomium sp., was cultivated and found to produce a novel benzonaphthyridinedione derivative, chaetominedione (1). In addition to the known fungal metabolites, 2-furancarboxylic acid (2) and 5-(hydroxymethyl)-2-furancarboxylic acid (3) were obtained. The structures of all the compounds were determined based on extensive spectroscopic measurements (1D and 2D NMR, MS, UV, and IR). The total extract and compound 1 had significant inhibitory activity toward p56lck tyrosine kinase (18.7% and 93.6% enzyme inhibition at 200 μg/mL, respectively).  相似文献   

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