Synthesis,characterization, antiproliferative,and antimicrobial activity of osmium(II) half-sandwich complexes

New osmium(II)-arene complexes [(η⁶-C₆H₆)OsCl(C₅H₄N-2-CH=N-C₆H₅X)](PF₆) (X = p-flouro (1), p-chloro (2), p-methyl (3)) were synthesized by reaction of the corresponding bidentate N,N′-ligands with the osmium-arene precursor [(η⁶-C₆H₆)Os(μ-Cl)Cl]₂ in a 2:1 ratio. These complexes were characterized by UV–Vis, IR, ¹H, ¹³C NMR spectroscopy, and elemental analysis and, for compound 1, a single crystal X-ray structure was also obtained. The complexes were investigated for antiproliferative activity in vitro against MCF-7 (human breast adenocarcinoma), Caco-2 (human epithelial colorectal adenocarcinoma), and HepG2 (human hepatocellular carcinoma) tumor cell lines. To test their selectivity, the non-tumor HEK293 (human embryonic kidney) cell line was used. The compounds were selective toward the tumor cell lines when compared to the known anticancer drug 5-fluorouracil which displayed low selectivity. The compounds were substantially more active against Caco-2 than 5-fluorouracil. They also showed moderate activity against the other two tumor cell lines. In addition, the antimicrobial activity of complex 2 was explored against a panel of antimicrobial-susceptible and -resistant Gram-negative and Gram-positive bacteria. Complex 2 showed anti-mycobacterial activity against Mycobacterium smegmatis and bactericidal activity against drug-resistant Enterococcus faecalis and methicillin-resistant Staphylococcus aureus ATCC 43300.     

Synthesis,characterization, and cytotoxic and antimicrobial activities of ruthenium(II) arene complexes with N,N-bidentate ligands

Three new complexes, [(η⁶-C₆H₆)RuCl(C₅H₄N-2-CH=N-Ar)]PF₆ (Ar = phenylmethylene (1), (4-methoxyphenyl)methylene (2), and phenylhydrazone (3)), were prepared by reacting [(η⁶-C₆H₆)Ru(μ-Cl)Cl]₂ with N,N′-bidentate ligands in a 1 : 2 ratio. Full characterization of the complexes was accomplished using ¹H and ¹³C NMR, elemental and thermal analyses, UV–vis and IR spectroscopy and single crystal X-ray structures. Single crystal structures confirmed a pseudo-octahedral three-legged, piano-stool geometry around Ru(II), with the ligand coordinated to the ruthenium(II) through two N atoms. The cytotoxicity of the mononuclear complexes was established against three human cancer cell lines and selectivity was also tested against non-cancerous human epithelial kidney (HEK 293) cells. The compounds were selective toward the tumor cells in contrast to the known anti-cancer drug 5-fluoro uracil which was not selective between the tumor cells and non-tumor cells. All the compounds showed moderate activity against MCF7 (human breast adenocarcinoma), but showed low antiproliferative activity against Caco-2 and HepG2. Also, antimicrobial activities of the complexes were tested against a panel of antimicrobial-susceptible and -resistant Gram-negative and Gram-positive bacteria. Of special interest is the anti-mycobacterial activity of all three synthesized complexes against Mycobacterium smegmatis, and bactericidal activity against resistant Enterococcus faecalis and methicillin-resistant Staphylococcus aureus ATCC 43300.     

Tupisteroide A–C,three new polyhydroxylated steroidal constituents from the roots of Tupistra chinensis

Three new steroidal compounds with polyhydroxy groups, tupisteroide A–C (1–3), were obtained from the roots of Tupistra chinensis, together with one known compound (4) that was isolated from this plant for the first time. The structures of tupisteroide A–C were determined on the basis of one‐ and two‐dimensional NMR spectroscopy, including ¹H–¹H Correlation Spectroscopy, Heteronuclear Multiple Bond Correlation, and Heteronuclear Single Quantum Coherence experiments. The isolated compounds were evaluated for their cytotoxic activities against A549, HepG2, and CaSki cancer cell lines in vitro. Among them, compounds 1, 2, and 4 did not show significant inhibitory activity, but compound 3 showed cytotoxicity against A549 cancer cell lines with IC₅₀ values of 25.0 μM. Copyright © 2012 John Wiley & Sons, Ltd.     

Synthesis and anticancer activity of some novel benzothiazole-thiazolidine derivatives

Sixteen new 2-(benzothiazol-2-ylthio)-N′-(3-substituted-4-(3,4-substitutedphenyl)thiazol-2(3H)-ylidene)acetohydrazide derivatives (4a-4p) were synthesized. The structures of the synthesized compounds were elucidated using FT-IR, ¹H-NMR, ¹³C-NMR, and HRMS spectral data. Anticancer activity of the compounds 4a-4p against C6 (rat brain glioma) and A549 (human lung adenocarcinoma) cell lines was evaluated by using MTT, inhibition of DNA synthesis, and flow cytometric analysis assays. According to MTT assay, 4a and 4d were found to be the most active compounds against C6 cell line with an IC₅₀ value of 0.03 mM. Moreover, IC₅₀ values of 4a (0.2 mM) and 4d (0.1 mM) against NIH3T3 (mouse embryo fibroblast cell line) were higher than their IC₅₀ values (0.03 mM) against C6 cell line. Accordingly, selectivity of compound 4a against C6 cell line was two-fold higher than that of compound 4d. Flow cytometry analysis showed that these compounds display anticancer activity by inducing apoptosis. As a result, compound 4a has a remarkable anticancer activity and a good selectivity towards C6 cell lines.     

Chemical characterization of constituents from Polygonatum cyrtonema Hua and their cytotoxic and antioxidant evaluation

Abstract

Twenty-four compounds were isolated from the roots of Polygonatum cyrtonema Hua, including a new octopamine dimer, named trans-bis(N-feruloyl)octopamine (1). The structure was established on the basis of spectroscopic and chemical methods. All the extracts and compounds were evaluated for cytotoxic and antioxidant activities by using MTT and chemiluminescence assay. The extracts showed activity against MCF-7 and HepG-2 cell lines from IC₅₀ 0.30 to 1.01 mg mL^?1. Compound 3 exhibited activity against HepG-2 cell lines with IC₅₀ 8.99?μM. Compound 7 exhibited activity against Hela cell lines with IC₅₀ 2.53?μM and BGC-823 cell lines with IC₅₀ 7.77?μM. Moreover, compound 7 showed antioxidant with IC₅₀ 12?µM compared to the positive control with IC₅₀ 77?µM. Compound 16 exhibited activity against HepG-2 cell lines with IC₅₀ 1.05?μM and MCF-7 cell lines with IC₅₀ 1.89?μM. These results indicated that this plant might be potential in natural medicine and healthy food.     

Synthesis and in vitro cytotoxicity of platinum(II) complexes with chiral N-monosubstituted 1,2-cyclohexyldiamine derivatives as the carrier groups

Eight platinum(II) complexes with the new chiral ligands, (1R,2R)-N ¹-(pyridine-2-ylmethyl) cyclohexane-1,2-diamine (R) or (1S,2S)-N ¹-(pyridine-2-ylmethyl) cyclohexane-1,2-diamine (S) as the carrier groups were designed, synthesized, and spectrally characterized. All platinum(II) complexes showed much better aqueous solubility than cisplatin and oxaliplatin. In vitro cytotoxicity of the compounds against human HepG-2, MCF-7, A549, and HCT-116 cell lines was evaluated. Results indicate that all compounds with R as the carrier group showed cytotoxicity against HCT-116, A549, and MCF-7 cell lines; however, all compounds with S as carrier group exhibited disappointing cytotoxicity against tested cell lines. Compound R2, bearing ClCH₂COO^- as leaving group, exhibited better cytotoxicity than that of carboplatin against A549 and MCF-7 cell lines and also showed close activity to oxaliplatin against HCT-116 cell line.     

Antiproliferative activities of 2-hydroxyethyl substituted benzimidazolium salts and their palladium complexes against human cancerous cell lines

Abstract

Benzimidazolium salts (1a and 1b) and respective palladium complexes (2a and 2b) were prepared and characterized with ¹H and ¹³C NMR, IR, elemental analysis as well as HRMS (for 2a). All target compounds were screened as potential anticancer agents against human cell lines for assessing their cytotoxicity. Heterocyclic organic compounds (1a and 1b) showed more cytotoxic activity than their complexes (2a and 2b) in the tested two cell lines. Particularly, a benzimidazolium salt including a 4-methylbenzyl group had a high cytotoxic potency towards MDA-MB-231 and DLD-1 cell lines with IC₅₀ values comparable to a well-known anticancer drug cisplatin, which is generally used in clinical studies. Furthermore, a compound namely 1-(2-hydroxyethyl)-3-(2,3,4,5,6-pentamethylbenzyl)-1H-benzo[d]imidazol-3-ium bromide was found to be more cytotoxic activity in MDA-MB-231 cell line compared to cisplatin with following IC₅₀ value of 7.59?±?0.68?μM.     

Synthesis and biological evaluation of 1,2,4-oxadiazole linked 1,3,4-oxadiazole derivatives as tubulin binding agents

As an aspect of our ongoing research in search of new anticancer agents, a series of novel analogs of 1,3,4-oxadiazole embedded with 1,2,4-oxadiazole moieties (11a–j) were synthesized. The structure of the final compounds was confirmed by ¹H NMR, ¹³CNMR and mass spectroscopic techniques and evaluated for their in vitro anticancer activity against three human cancer cell lines (lung, breast). Among the synthesized compounds, 11?b, 11?g, 11?h, and 11i showed potent anticancer activity with IC₅₀ values within the range of 0.34?±?0.025 to 2.45?±?0.23?μM against three human cancer cell lines. Further, these compounds (11a–j) were investigated for molecular docking studies. Among them, compound 11?h showed strong binding affinity on binding sites of target protein EGFR (PDB ID: 4hjo) with highest docking score (-7.028). It revealed that 11?h was a strong tubulin binding agent.     

配合物二乙基锡N-[(2-氧苯基)亚甲基]甘氨酸酯的合成、结构表征和生物活性

合成了5个新的二乙基锡N-[(2-氧苯基)亚甲基]甘氨酸酯(CH3CH2)2Sn(2-O-3-X-5-YC6H2CH=NCH2COO)(X,Y=H,H,1;H,Cl,2;H,Br,3;Cl,Cl,4;Br,Br,5),利用元素分析、IR、1H和129Sn NMR表征了其结构.通过X-射线单晶衍射测定了1和4的晶体结构.化合物1的晶体属单斜晶系,P21空间群;化合物4的晶体属三斜晶系,P1空间群.2个化合物均为由羧基桥联形成的[Sn3O6C3]十二元大环三聚体结构,锡原子的配位构型为六配位[SnC2NO3]畸变八面体.生物活性测试结果表明,化合物5对3种人癌细胞HeLa、CoLo205和MCF-7及大肠杆菌均有抑制活性.     

Four triarylantimony(V) carboxylates: syntheses,structural characterization and in vitro cytotoxicities

Four new organoantimony carboxylates, (R–COO)₂SbR′₃ [R–COOH = (±)-2-phenoxypropionic acid and R′ = phenyl (1), 4-fluorophenyl (2), 3-fluorophenyl (3), 3,4,5-trifluorophenyl (4)], were synthesized and structurally characterized by elemental analysis, ¹H, ¹³C NMR, IR and X-ray single crystal diffraction. Structural analyses reveal that 1–3 show similar five-coordinate trigonal bipyramidal geometries, binding with three aryl groups and two deprotonated unidentate ligands. Unexpectedly, 4 exhibits pentagonal bipyramidal arrangement accompanied by two Sb–O (carbonyl) coordination bonds. In vitro cytotoxic activities of 1–4 have been determined by the MTT method against four cancer cell lines. Studies reveal that 1–4 have an activity similar to cisplatin on lung cancer cell line A549 and but also exhibit excellent cytotoxicity against cisplatin-insensitive colon cancer cell lines HCT-116, Caco-2 and human promyelocytic leukemia cell line HL-60. Additionally, the results showed that most of these triarylantimony(V) complexes exhibited enhanced cytotoxicity compared with the ligand and four triarylantimony dichloride precursors, which clearly implied a positive synergistic effect. Also interestingly, it was found that 3- or 4- mono-fluoro-substituted triphenylantimony, compounds 2 and 3, exhibit higher in vitro cytotoxicities toward the four cancer cell lines than the tri-3,4,5-trifluoro-substituted and without-fluoro-substituted triphenylantimony complexes. The structure-activity relationship of the cytotoxicity of 1–4 is discussed.     

Secondary Metabolites from the Stem Bark of Litsea akoensis and Their Cytotoxic Activity

Six new butanolides, litseadioxanins A and B ( 1 and 2 , resp.) bearing a 1,2‐dioxane moiety, litseatrinolides A and B ( 3 and 4 , resp.), and litseakolides D₁ and D₂ ( 5 and 6 , resp.), were isolated from the stem bark of Litsea akoensis, together with six known compounds. The structures of the new compounds were characterized by in‐depth NMR‐spectroscopic and mass‐spectrometric analyses. Butanolides 1 – 4 , and a mixture of 6 and litsenolide E₂, and litsenolide B₁ were tested against human tumor cells, including MCF‐7 (human breast adenocarcinoma), NCI‐H460 (non‐small‐cell lung cancer), and SF‐268 (glioblastoma) cell lines. Among the tested compounds, litsenolide B₁ exhibited marginal cytotoxic activity against MCF‐7, NCI‐H460, and SF‐268 cell lines in vitro.     

Preparation and in vitro cytotoxicity of oxaliplatin derivatives with chiral amino acid as the carrier group

Eight oxaliplatin derivatives with chiral amino acid, 2-{[(1R,2R)-2-aminocyclohexyl]amino}propanoic acid, as the carrier group, were designed, synthesized, and spectrally characterized by IR, ¹H NMR, MS spectra, and microanalyses. In vitro cytotoxicities against human HepG-2, MCF-7, A549, and HCT-116 cell lines were evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazo-liumbromide assay. Results indicated that all compounds exhibited sensitivity to HepG-2 cell line, and among them, compounds P3 and P4 which have CH₃(CH₂)₆COO^– and CH₃(CH₂)₈COO^– as the leaving groups, respectively, gave better antitumor activity than carboplatin against HepG-2 and A549 cell lines.     

Synthesis and cytotoxic evaluation of novel brominated N-alkyl pyrano[3,2-c]quinolinones

A novel series of 6-alkyl-4-bromopyrano[3,2-c]quinoline-2,5-diones ( 2a–c ), 6-alkyl-3,4-dibromopyrano[3,2-c]quinoline-2,5-diones ( 4a–c ), and 6-alkyl-3-amino-bromopyrano[3,2-c]quinoline-2,5-diones ( 6a–c ) were synthesized via appropriate conventional methods and in good yields. The structures of target compounds were approved by elemental analysis, IR, ¹H NMR, ¹³C NMR, and mass spectrometry. The antitumor inhibitory activities of the new compounds were evaluated on several cancer cell lines, A-549 (human lung cancer), HCT-116 (human colon cancer), MCF-7 (breast cancer), and HePG-2 (human liver cancer). Moreover, 50% inhibitory concentrations, IC₅₀, were established. 5-Fluorouracil was used as a positive control in the viability assay. The screening results showed that most of the examined compounds exposed powerful inhibition activity toward various cell lines. Particularly, Compound 4c exhibited higher cytotoxic activity against four tumor cell lines than the reference drug, 5-fluorouracil, with significantly lower IC₅₀ values. Accordingly, most of the synthesized compounds would be a better prospective growth in the anticancer drug discovery.     

Synthesis,structural characterization,and cytotoxic activity of new spirocyclic octachlorocyclotetraphosphazenes

Octachlorocyclotetraphosphazene, N₄P₄Cl₈, (1) was reacted with N, N′-dibenzylethylenediamine to synthesize partially substituted monospiro- (2), dispiro- (5) and tetraspirocyclotetraphosphazene (8) derivatives. The reactions of 2 and 5 with excess pyrrolidine and morpholine produced fully substituted pyrrolidino (3 and 6) and morpholino (4 and 7) spirocyclotetraphosphazenes. The structures of the compounds were determined with 1D (¹H, ¹³C, ³¹P, and DEPT) NMR, 2D (HSQC) NMR, ESI-MS, FTIR, and elemental analysis. The solid-state structures of 6 and 7 were examined by X-ray crystallography. In 7, intramolecular C-H…O hydrogen bonds link the molecules into centrosymmetric dimmers. The cytotoxic activity of all the compounds against human cervix carcinoma cell lines (HeLa) was investigated. The study showed that these compounds exert limited cytotoxic, apoptotic and necrotic effects on HeLa cancer cell lines.     

Synthesis of 6-oxopyrimidin-1(6H)-yl benzamide derivatives and evaluation of their antibacterial and cytotoxic activity

A series of novel 2-alkylamino and 2, 4-dialkyl amino 6-oxopyrimidin-1(6H)-yl) benzamide derivatives were prepared in good yields from a base-catalyzed ring opening of oxadiazolo[3,2-a]pyrimidin-5-one and evaluated for their antibacterial and cytotoxicity. Most of the compounds exhibited antibacterial activity. In particular, compounds 5b and 5k exhibited considerable antibiotic activity against Klebsiella pneumonia and Bacillus cereus. In addition, compounds 5g and 5i also inhibited the growth of two human tumor cell lines (A549 and H460) at micromolar concentrations.     

(1iR, 1iiR, 2iR, 2iiR)-Ni, Nii-(1,3-亚苯基双(亚甲基))环己烷-1,2-二胺作为配体的双核铂配合物的合成及其抗癌活性

以(1ⁱR,1ⁱⁱR,2ⁱR,2ⁱⁱR)-Nⁱ, Nⁱⁱ-(1,3-亚苯基双(亚甲基))环己烷-1,2-二胺(HL)作为配体,设计并合成了7种双核铂配合物,并利用IR,¹H NMR,¹³C NMR,ESI-MS和元素分析等进行了表征。通过MTT法测定目标双核铂配合物对人类HepG-2,A549,HCT-116和MCF-7四种癌细胞系的细胞毒性。结果表明,所有的化合物对HepG-2,A549和HCT-116细胞系均表现了良好的细胞毒活性,但对MCF-7细胞系均无活性。其中,以3-羟基环丁烷-1,1-二羧酸为离去基团的配合物P7对HepG-2和A549细胞系的活性优于卡铂,对HCT-116细胞系的活性接近于奥沙利铂。     

A new indole-alkaloid and a new phenolic-glycoside with cytotoxic activity from Strychnos fendleri

A new indole alkaloid strychnosinol (1) and a new phenolic-glycoside (2) were isolated from the bark and leaves of Strychnos fendleri Sprague & Sandwith, together with six known compounds reported for the first time in this species. The structures of these compounds were determined on the basis of spectroscopic data; mainly those obtained by using ¹H and ¹³C NMR (1D and 2D) and mass spectrometry. Strychnosinol (1) and the phenolic glycoside (2) together with compounds 3–8 were evaluated for cytotoxicity against a panel of five tumour cell lines; IC₅₀ values between 0.090 and 0.227 μM for the human tumour cell lines were observed for compound 2.     

Amide derivatives of 4-azaindole: Design,synthesis, and EGFR targeting anticancer agents

Abstract

A series of amide derivatives of azaindole-oxazoles (11a-n) were designed and synthesized and their structures were confirmed by ¹HNMR, ¹³CNMR and mass spectral analysis. Further, these derivatives were screened for their anticancer activity against human cancer cell lines viz; MCF7 (breast), A549 (lung) and A375 (melanoma). In vitro anticancer activity screening indicated that most of the hybrids exhibited potent inhibitory activities in a variety of cancer cell lines. Among the compounds 11d, 11e, 11f, 11j, 11k, 11l, 11m, and 11n were exhibited more potent activity than standard, in those mainly two compounds 11m and 11j were exhibited excellent activity in MCF-7 cell line with IC₅₀ values 0.034 and 0.036?µM. Moreover, all these compounds were carried out their molecular docking studies on EGFR receptor results indicated that two potent compounds 11m and 11j were strongly binds to protein EGFR (PDB ID: 4hjo). It was found that the energy calculations were in good agreement with the observed IC₅₀ values.     

In vitro and ex vivo antitubercular activity of diarylheptanoids from the rhizomes of Alpinia officinarum Hance

Phytochemical investigation of methanol extract of the rhizomes of Alpinia officinarum Hance afforded four known diarylheptanoids 1,7-diphenylhept-4-en-3-one (1), 5-hydroxy-1,7-diphenyl-3-heptanone (2), 5-hydroxy-7-(4″-hydroxy-3″-methoxyphenyl)-1-phenyl-3-heptanone (3), and 7-(4″-hydroxy-3″-methoxyphenyl)-1-phenyl heptan-3-one (4).The acetate derivative of (4), 7-(4″-actetate-3″-methoxy phenyl)-1-phenyl heptan-3-one (5), was prepared. These diarylheptanoids exhibited promising in vitro and ex vivo antitubercular activity for the first time against dormant Mycobacterium tuberculosis H37Ra with the IC₅₀ values between 0.34–47.69 and 0.13–22.91 μM, respectively. All compounds showed comparable activity against Mycobacterium bovis BCG (dormant phage) and did not show any activity against two gram + ve and two gram –ve bacterial strains. These compounds were also weakly cytotoxic up to 300 μM against three human cancer cell lines THP-1, Panc-1 and A549.     

(1iR,1iiR,2iR,2iiR)-Ni,Nii-(1,3-亚苯基双(亚甲基))环己烷-1,2-二胺作为配体的双核铂配合物的合成及其抗癌活性

以(1ⁱR,1ⁱⁱR,2ⁱR,2ⁱⁱR)-Nⁱ,Nⁱⁱ-(1,3-亚苯基双(亚甲基))环己烷-1,2-二胺(HL)作为配体,设计并合成了7种双核铂配合物,并利用IR,¹H NMR,¹³C NMR,ESI-MS和元素分析等进行了表征。通过MTT法测定目标双核铂配合物对人类HepG-2,A549,HCT-116和MCF-7四种癌细胞系的细胞毒性。结果表明,所有的化合物对HepG-2,A549和HCT-116细胞系均表现了良好的细胞毒活性,但对MCF-7细胞系均无活性。其中,以3-羟基环丁烷-1,1-二羧酸为离去基团的配合物P7对HepG-2和A549细胞系的活性优于卡铂,对HCT-116细胞系的活性接近于奥沙利铂。