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.
《Tetrahedron: Asymmetry》2004,15(2):323-333
N-Benzyloxycarbonyl-2,5-dideoxy-2,5-imino-3,4-O-isopropylidene-l-ribose 12a has been converted into (1R,2S,6R,7S,7aS)-5 and (1R,2S,6S,7R,7aR)-1,2,6,7-tetrahydroxypyrrolidin-5-ones 6 and (1R,2S,6S,7S,7aS)-7 and (1R,2S,6R,7R,7aS)-1,2,6,7-tetrahydroxypyrrolizidines 8 following stereoselective paths. These new compounds have been assayed for their inhibitory activities towards 25 glycosidases. Pyrrolizidines 7 and 8 are moderate but selective inhibitors of amyloglucosidase from Rhizopus mold (7: IC50=130 μM, Ki=120 μM; 8: IC50=200 μM, Ki=180 μM, mixed type of inhibition).  相似文献   

2.
A new series of pyridothienopyrimidine derivatives was designed and evaluated as antimicrobial and anticancer agents. The target compounds were synthesized starting with 3-aminothieno[2,3-b]pyridine-2-carboxamide derivative 1 which underwent cyclocondensation reaction with aromatic aldehydes to give the key intermediates 2a,b. By further treatment of 2a,b with various reagents, the target 2,4-disubstituted-pyrido[3′,2′:4,5]thieno[2,3-d]pyrimidines 3a,b11a,b were obtained. To evaluate the antimicrobial activity of the new compounds, they were tested against five bacterial and five fungal strains. Compounds 6c, 8b, 9a and 9b revealed the most significant antimicrobial activity against the tested microorganisms with MIC values range (4–16 μg/mL). Also, compounds 2a,b11a,b were screened for their in vitro cytotoxic activity against HepG-2 and MCF-7 cancer cell lines compared with doxorubicin and cisplatin as references drugs. Moreover, compounds (2b, 4a, 6a, 7b, 7c and 9a) which exhibited the most potent anticancer activity, were further subjected to EGFRWT enzyme inhibition assay utilizing erlotinib as a standard drug. The compounds 6a, 7b, 7c and 9a which showed the most promising suppression effects were also evaluated as inhibitors against the mutant forms EGFRL858R and EGFRT790M. The 4-aminopyrazolone analogue 9a showed superior anticancer activity against both HepG-2 and MCF-7 cell lines (IC50 = 1.27, 10.80 μM, respectively) and more potent enzymatic inhibition activity against EGFRWT and its mutant forms EGFRL858R and EGFRT790M than that obtained by erlotinib (IC50 = 0.021, 0.053, 0.081 µM, respectively, IC50erlotinib; 0.027, 0.069, 0.550 µM, respectively). Finally, the molecular docking study showed good binding patterns of the most active compounds with the prospective target EGFRWT.  相似文献   

3.
A series of flavonoids were isolated from Dodonaea Viscosa and tested for inhibition of human neutrophil elastase (HNE), enzyme involved in inflammatory disorders. Isolated compounds were identified as a novel flavonol (1) along with eight known flavonoids (29). Novel flavonol, visconata (1) has a very rare skeleton having odd numbered long chain (C19) fatty acid, which was completely identified by mass fragmentation and 2D NMR analysis. All compounds (19) inhibited HNE in dose dependent manner with IC50s ranging between 2.4 and 150 μM. Visconata (1) emerged to be the most potent compound with 2.4 μM of IC50. In kinetic studies, compound (1) was observed to be reversible, noncompetitive inhibitor having Ki = 1.8 μM, whereas other flavonoids (29) displayed mixed type inhibition.  相似文献   

4.
A series of 30 non-covalent imidazo[1,2-a]quinoxaline-based inhibitors of epidermal growth factor receptor (EGFR) were designed and synthesized. EGFR inhibitory assessment (against wild type) data of compounds revealed 6b, 7h, 7j, 9a and 9c as potent EGFRWT inhibitors with IC50 values of 211.22, 222.21, 193.18, 223.32 and 221.53 nM, respectively, which were comparable to erlotinib (221.03 nM), a positive control. Furthermore, compounds exhibited excellent antiproliferative activity when tested against cancer cell lines harboring EGFRWT; A549, a non-small cell lung cancer (NSCLC), HCT-116 (colon), MDA-MB-231 (breast) and gefitinib-resistant NSCLC cell line H1975 harboring EGFRL858R/T790M. In particular, compound 6b demonstrated significant inhibitory potential against gefitinib-resistant H1975 cells (IC50 = 3.65 μM) as compared to gefitinib (IC50 > 20 μM). Moreover, molecular docking disclosed the binding mode of the 6b to the domain of EGFR (wild type and mutant type), indicating the basis of inhibition. Furthermore, its effects on redox modulation, mitochondrial membrane potential, cell cycle analysis and cell death mode in A549 lung cancer cells were also reported.  相似文献   

5.
Thiosemicarbazones of 2-amino-5-chlorobenzophenone and 3-aminobenzophenone(L1-L4) have been synthesized and their Cu(Ⅱ) complexes(1-4) were afforded via coordination with cupric chloride.All these compounds were characterized by UV-vis and IR spectroscopy together with CHN elemental analysis.NMR spectroscopy was also applied to characterize the ligands.In vitro chohnesterase inhibitory assays for the complexes(1-4) showed IC50 values less than 10μmol/L,with complex 1 exhibiting the most activity,IC50=2.15μmol/L and 2.16μmol/L for AChE and BuChE,respectively. Molecular modeling simulation revealed the binding interaction template for complex 1 with the AChE and BuChE receptors.In DPPH assay,the complexes also showed more in vitro antioxidant activities in comparison to their parent ligands.  相似文献   

6.
A new isocoumarin,tenuissimasatin(1),was isolated from metabolites of the endophytic fungus Alternaria tenuissima(Nees & T.Nees:Fr.) Wiltshire,which was isolated from the bark of Erythrophleum fordii Oliver,together with 11 known compounds(2- 12).The structure and absolute configuration of 1 was determined by means of NMR and CD analysis.Compound 3 shows selective cytotoxic activity on human colon cancer cell HCT-8(IC50 = 1.78μmol/L) by MTT test in vitro.Other compounds show no such activities(IC50>10μmol/L).  相似文献   

7.
A series of novel 2,4-diaminopyrimidine-modified compounds was designed and synthesized. Compound 14 showed micromolar dual inhibitory effect on both FP-2 and PfDHFR, and potential inhibition to the proliferation of P. falciparum 3D7 strain and chloroquine-resistant P. falciparum Dd2 strain.  相似文献   

8.
《Comptes Rendus Chimie》2015,18(2):137-148
Cancer has become a leading cause of death worldwide, which is responsible for 7.6 million cancer deaths according to GLOBOCAN survey conducted in 2008. The exploration of cis-platin analogues (carboplatin, lobaplatin, nedaplatin, oxaliplatin) and their incorporation to the treatment of cancer patients has further led interest in exploring metal-based anticancer drugs. The current study describes the synthesis of two new tetra-coordinated mono- and tetranuclear organotin(IV) carboxylate complexes and their in vitro anticancer studies. Each one of the complexes (1–2) has been characterized by analytical (micro- and gravimetric analysis) and spectroscopic (FTIR, 1H, 13C, 119Sn-NMR) techniques. Furthermore, molecular structures of 1 and 2 were elucidated using X-ray crystallography. The characterization data showed that the coordination took place via oxygen atoms from the carboxylate anions to generate 1 as an organodistannoxane dimer and 2 as a mononuclear complex. Exceptionally, the NMR spectroscopic and X-ray crystallographic study showed that acetone molecules also took part in crystallizing 2. Both complexes were tested against three cancerous (colon cancer HCT 116, breast cancer MCF 7, leukemia K562) and one non-cancerous (3T3-L1) cell lines. Both complexes showed same IC50 value (0.2 μM) against HCT 116, whereas for the other two cancer cell lines (MCF 7 and K562) and a normal cell line (3T3-L1), 2 showed results better than 1. Importantly, the complexes showed exceptional activity against MCF 7 and K562 cell lines and the IC50 values were calculated in nanomoles (MCF 7, IC50s = 86.5 and 53.4 nM; K 562, IC50s = 22.9 and 49.6 nM for 1 and 2, respectively). Both, 1 and 2, showed IC50 values many times better than the standard drugs (5-FU, Tamoxifen, betulinic acid and cis-platin) used. Compared to cancerous cell lines, the complexes showed mild toxicity against normal cells (3T3-L1). Overall, two remained relatively effective.  相似文献   

9.
Alkyl and arylplatinum complexes with 1,5-cyclooctadiene ligand, [PtR2(cod)] (R = Me, Ph, C6H4-p-CF3, C6F5), react with secondary phosphines, PHR′2 (R′ = i-Bu, t-Bu, Ph), to afford the mononuclear platinum complexes, cis-[PtR2(PHR′2)2] (1a: R = Me, R′ = i-Bu; 1b: R = Me, R′ = t-Bu; 1c: R = Me, R′ = Ph; 2a: R = Ph, R′ = i-Bu; 2b: R = Ph, R′ = t-Bu; 2c: R = R′ = Ph; 3a: R = C6H4-p-CF3, R′ = i-Bu; 3b: R = C6H4-p-CF3, R′ = t-Bu; 3c: R = C6H4-p-CF3, R′ = Ph; 4a: R = C6F5, R′ = i-Bu; 4c: R = C6F5, R′ = Ph) in 81–98% yields. Molecular structures of the complexes except for 1a, 1c and 2a were determined by X-ray crystallography. Complex 1b has a square-planar structure with Pt–C(methyl) bonds of 2.083(8) and 2.109(8) Å, while the Pt–C(aryl) bonds of 2bc, 3ac, 4a and 4c (2.055(1)–2.073(8) Å) are shorter than them. Thermal decomposition of 1b, 2ac, and 3ac releases methane, biphenyl or 4,4′-bis(trifluoromethyl)biphenyl as the organic products, which are characterized by NMR spectroscopy. The solid product of the thermal reactions of 2b and 2c were characterized as the metallopolymers formulated as [Pt(PR′2)2]n (5b: R′ = tBu; 5c: R′ = Ph), based on the solid-state NMR and elemental analyses.  相似文献   

10.
The reaction of triethylborane adduct of N-heterocyclic carbene, NHC · BEt3, (NHC = IiPr = 1,3-diisopropylimidazol-2-ylidene (IiPr · BEt3; 1a), NHC = IMes = 1,3-dimesitylimidazol-2-ylidene (IMes · BEt3; 1b)), which was prepared by the reaction of the corresponding imidazolium salt with one equivalent of LiBEt3H, with amidinato(pyridine) complex, [M(η3-allyl){η2-(NPh)2CH}(CO)2(NC5H5)] (M = Mo; 2-Mo M = W; 2-W), was investigated. The reaction of compound 1 with complex 2 under toluene-reflux conditions resulted in the formation of carbene complex [M(η3-allyl){η2-(NPh)2CH}(CO)2(NHC)] (M = Mo, NHC = IiPr; 3a-Mo, M = Mo, NHC = IMes; 3b-Mo, M = W, NHC = IiPr; 3a-W, M = W, NHC = IMes; 3b-W). These complexes were characterized spectroscopically as well as by X-ray analyses. Complex 3a-Mo was formed in various solvents such as 1,2-dimethoxyethane (DME), 1,2-dichloroethane, and acetonitrile under refluxing conditions for 3 h. In toluene, 3a-Mo was obtained in a good yield by heating at 70 °C for only 20 min. Employment of NHC · BEt3 (1) was found to afford convenient route for the introduction of the carbene ligand to the transition metal complexes.  相似文献   

11.
A series of organometallic molybdenum/iron/sulfur clusters of the general formula [Cp1MoFe3S4Ln]m (Cp1 = η5-C5Me5; L = StBu, SPh, Cl, I, n = 3, m = 1−; Ln = I2(PtBu3), m = 0; L = 2,6-diisopropylphenylisocyanide (ArNC), n = 7, m = 1+) have been synthesized. A cubane cluster (PPh4)[Cp1MoFe3S4(StBu)3] (2) was isolated from a self-assembly reaction of Cp1Mo(StBu)3 (1), FeCl3, LiStBu, and S8 followed by cation exchange with PPh4Br in CH3CN, while an analogous cluster (PPh4)[Cp1MoFe3S4(SPh)3] (3) was obtained from the Cp1MoCl4/FeCl3/LiSPh/PPh4Br reaction system or from a ligand substitution reaction of 2 with PhSH. Treatment of 2 with benzoyl chloride gave rise to (PPh4)[Cp1MoFe3S4Cl3] (4), which was in turn converted to (PPh4)[Cp1MoFe3S4I3] (5) by the reaction with NaI. A neutral cubane cluster Cp1MoFe3S4I2(PtBu3) (6) was generated upon treating 5 with PtBu3. Although reduction of 4 by cobaltocene under the presence of ArNC resulted in a disproportionation of the cubane core to give Fe4S4(ArNC)9Cl (7), a similar reduction reaction of 5 produced [Cp1MoFe3S4(ArNC)7]I (8), where the MoFe3S4 core was retained. The crystal structures of 46, and 8 were determined by the X-ray analysis.  相似文献   

12.
Characteristic of Fura-2-Ca~(2 )interaction was studied based on the fluorescence technique.The apparent dissociation constants(K_d)of the Fura-2-Ca~(2 )complex were determined at different temperature.The effect of cefotaxime(CEFA)on intracellular Ca~(2 )concentration([Ca~(2 )]_i)was discussed by using a ratiometric fluorescence dye Fura-2 as a probe.The basal[Ca~(2 )]_i in resting humanperipheral lymphocytes was 100 7 nmol/L but after treatment with cefotaxime,the changes of[Ca~(2 )]_i were observed in differentconditions.In the concentration range of 1-30 μmol/L of cefotaxime[Ca~(2 )]_i increased,as a result of releasing intracellular Ca2 stores.Higher concentration of cefotaxime(50-500 μmol/L)stimulated to decrease of[Ca~(2 )]_i.  相似文献   

13.
Triflate complexes of mono- and diruthenium amidinates, (η6-C6R6)Ru(κ1-OTf){η2-R′NC(R′′)NR′} (1: R = Me; 2: R = H) and (η5-C5Me5)Ru(μ-η2-iPrNC(Me)NiPr)Ru(κ1-OTf)(η5-C5R5) (3: R = Me; 4: R = H), are synthesized, and coordination behavior of the triflate anion to the coordinatively unsaturated ruthenium species is investigated by crystallography and variable temperature (VT) NMR spectroscopy (19F, 1H). The monoruthenium amidinate complexes have three-legged piano-stool structures in single crystals, which include a κ1-OTf ligand with the Ru–O bond of 2.15–2.20 Å. In contrast, reversible dissociation of OTf is observed in variable temperature 1H NMR spectroscopy in liquid states; the activation energy for the dissociation and recombination of the OTf ligand is varied with the substituents on the arene and amidinate ligand in the corresponding ruthenium cation and the solvent used. A typical example of moderately coordinating ability of the OTf ligand is seen in 19F NMR spectra of (η6-C6Me6)Ru(κ1-OTf){η2-iPrNC(Me)NiPr} (1a) and (η6-C6H6)Ru(κ1-OTf){η2-iPrNC(Me)NiPr} (2a) in CD2Cl2 at the temperature range from −90 to 20 °C, in which the OTf anion is dissociated in 1a, whereas 2a has a relatively robust Ru–OTf bond. Combination of crystallography and VT NMR contributes to understanding the difference in coordination behavior of the OTf ligand between two diruthenium amidinates, (η5-C5Me5)Ru(μ-η2-iPrNC(Me)NiPr)Ru(κ1-OTf)(η5-C5Me5) (3) and (η5-C5Me5)Ru(μ-η2-iPrNC(Me)NiPr)Ru(κ1-OTf)(η5-C5H5) (4); the results suggest that the electron-donating and sterically demanding η5-C5Me5 helps for dissociation of the triflate ligand. Moderate coordinating ability of the triflate anion sometimes provides characteristic reactions of mono- and diruthenium amidinates which differ from the corresponding neutral halogeno-compounds or cationic coordinatively unsaturated homologues bearing fluorinated tetraarylborates; a typical example is given by inhibition of coordination of ethylene to the [(η6-C6H6)Ru{η2-tBuNC(Ph)NtBu}]+ species by the OTf ligand.  相似文献   

14.
Bioassay-guided fractionation of the acid hydrolysate of total ginsenosides of Panax ginseng C.A.Meyer (Araliaceae) led to the isolation of a novel ginsengenin(1).The structure of 1 was determined as (20S,22S)-dammar-22,25-epoxy-3β,12β,20-triol by extensive spectroscopy and single-crystal X-ray diffraction analyses.The cytotoxicity of 1 was further tested against SWl 116,HCTl 16,and A549 cells by the MTT method,with IC50 values in the range of 2.96-30.9μmol/L.  相似文献   

15.
Employing the intermediate derivatization method (IDM), a series of 1,3,4-oxadiazole derivatives containing arylpyrazoloxyl moiety were designed and synthesized. In vitro bioassays showed that these compounds have moderate to significant fungicidal activity against rice sheath blight and sorghum anthracnose. Furthermore, compound 20 is a promising fungicide for further development.  相似文献   

16.
Arylselenium(II) derivatives of dithiophosphorus ligands of type ArSeSP(S)R2 [Ar = Ph, R = Ph (1), OPri (2); 2-[MeN(CH2CH2)2NCH2]C6H4, R = Ph (3), OPri (4); 2-[O(CH2CH2)2NCH2]C6H4, R = OPri (6)] were prepared by redistribution reactions between Ar2Se2 and [R2P(S)S]2. The derivative [2-{O(CH2CH2)2NCH2}C6H4]SeSP(S)Ph2 (5) was obtained by the salt metathesis reaction between [2-{O(CH2CH2)2NCH2}C6H4]SeCl and NH4S2PPh2. The compounds were investigated by multinuclear (1H, 13C, 31P, 77Se) NMR and infrared spectroscopy. The crystal and molecular structures of 1, 3, 4 and 6 were determined by single-crystal X-ray diffraction. In compounds 3, 4 and 6 the N(1) atom is intramolecularly coordinated to the selenium center, resulting in a T-shaped geometry (hypervalent 10-Se-3 species). The dithiophosphorus ligands act as anisobidentate in 1 and monodentate in 3, 4 and 6. Supramolecular architectures based on intermolecular S?H and N?H contacts between molecular units are formed in the hypervalent derivatives 3 and 4, while in the compounds 1 and 6 the molecules are associated into polymeric chains through either Se?S or O?H contacts, with no further inter-chain interactions.  相似文献   

17.
Four new natural products, including three arylbenzofurans named heterophyllenes A-C (13), and one stilbene named heterophyllene D (4), together with twenty-one known compounds were isolated from the twigs of Artocarpus heterophyllus and their structures elucidated by spectroscopic methods, mainly 1D and 2D NMR spectroscopy. The cytotoxic activity of selected compounds against KB, MCF-7 and NCI-H187 cell lines was evaluated. Heterophyllene C (3) exhibited cytotoxicity against the MCF-7 cell line with an IC50 value of 12.56 μM. Additionally, the known compounds norartocarpin and artocarpin showed cytotoxic activity against MCF-7 and KB cell lines with IC50 values of 10.04 and 13.57 μM, respectively. Both compounds also displayed cytotoxicity against the NCI-H187 cell line with values of 14.78 and 14.21 μM, respectively.  相似文献   

18.
A series of rigid and chiral C2-symmetric 18-crown-6 type macrocycles (S,S)-4, (S,S)-5, (S,S)-6 and (R,R)-2 bearing diamide–ester groups were synthesized. The binding properties of these macrocycles were examined for α-(1-naphthyl)ethylammonium perchlorates salts by an 1H NMR titration method. Taking into account the host employed, important differences were observed in the Ka values of (R)- and (S)-enantiomers of guests for macrocycles (S,S)-4 and (S,S)-6, KS/KR = 3.6, and KS/KR = 0.1 (KR/KS = 10.3) ΔΔG = 3.19 and ΔΔG = ?5.77 kJ mol?1, respectively. The results indicated excellent enantioselectivity of macrocyclic (S,S)-6 towards the enantiomers of α-(1-naphthyl)ethylammonium perchlorate salts.  相似文献   

19.
《中国化学快报》2020,31(5):1271-1275
Insect chitinase and N-acetyl-β-d-hexosaminidases (Hex) are potential targets for developing new pesticides. Here, a series of thiazolylhydrazones I (with substituted group R1 at N3) and II (with substituted group R1 at N2) were designed, synthesised and evaluated as competitive inhibitors of OfHex1 and OfChi-h, from the agricultural pest Ostrinia furnacalis. Derivatives I-3d and II-3d, with phenoxyethyl group at R1, demonstrated the best inhibitory activities against OfHex1 and OfChi-h. Molecular docking analysis indicated that the branched conformation compound II-3d (Ki = 1.5 μmol/L) formed more hydrogen bonds with OfHex1 than the stretched conformation compound I-3d (Ki = 5.9 μmol/L). The differences in compounds’ binding conformations with OfChi-h explained differences in inhibitory activity of compounds I-3d (Ki = 1.9 μmol/L) and II-3d (Ki = 4.1 μmol/L). This work suggests a novel scaffold for developing specific Hex and Chi-h inhibitors.  相似文献   

20.
The reaction of organoaluminum compounds containing O,C,O or N,C,N chelating (so called pincer) ligands [2,6-(YCH2)2C6H3]AliBu2 (Y = MeO 1, tBuO 2, Me2N 3) with R3SnOH (R = Ph or Me) gives tetraorganotin complexes [2,6-(YCH2)2C6H3]SnR3 (Y = MeO, R = Ph 4, Y = MeO, R = Me 5; Y = tBuO, R = Ph 6, Y = tBuO, R = Me 7; Y = Me2N, R = Ph 8, Y = Me2N, R = Me 9) as the result of migration of O,C,O or N,C,N pincer ligands from aluminum to tin atom. Reaction of 1 and 2 with (nBu3Sn)2O proceeded in similar fashion resulting in 10 and 11 ([2,6-(YCH2)2C6H3]SnnBu3, Y = MeO 10; Y = tBuO 11) in mixture with nBu3SniBu. The reaction 1 and 3 with 2 equiv. of Ph3SiOH followed another reaction path and ([2,6-(YCH2)2C6H3]Al(OSiPh3)2, Y = MeO 12, Me2N 13) were observed as the products of alkane elimination. The organotin derivatives 411 were characterized by the help of elemental analysis, ESI-MS technique, 1H, 13C, 119Sn NMR spectroscopy and in the case 6 and 8 by single crystal X-ray diffraction (XRD). Compounds 12 and 13 were identified using elemental analysis,1H, 13C, 29Si NMR and IR spectroscopy.  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