Organocatalytic entry to chiral bicyclo[3.n.1]alkanones via direct asymmetric intramolecular aldolization

[reaction: see text] The facile stereoselective syntheses of endo-8-hydroxybicyclo[3.3.1]nonan-2-one and endo-7-hydroxybicyclo[3.2.1]octan-2-one, featuring an alpha-amino acid catalyzed intramolecular aldolization of sigma-symmetric substrates, are described. A high enantioselectivity and a high catalytic efficiency have been exhibited by (4R,2S)-tetrabutylammonium 4-TBDPSoxy-prolinate in the aldolization of 3-(4-oxocyclohexyl)propionaldehyde to give highly enantiomerically enriched (1S,5R,8R)-8-hydroxybicyclo[3.3.1]nonan-2-one.     

Synthesis and study on 2,4,6,8-tetraaryl- 3,7-diazabicyclo[3.3.1]nonanes and their derivatives

1-Carbethoxy-2,4,6,8-tetraaryl-3,7-diazabicyclo[3.3.1] nonan-9-ones (1, 2) were synthesized and their 1H and 13C NMR data are reported. Chemical shifts and spectral assignments for 2,4,6,8-tetrakis(4-chlorophenyl)-3,7-diazabicyclo[3.3.1]nonan-9-one (3), 2,4,6,8-tetraphenyl-3-thia-7-azabicyclo[3.3.1]nonan-9-one (4) and 2,4,6,8-tetraaryl-3,7-diazabicyclo[3.3.1]nonanes (5-7) are also included.     

Bicyclo[3.3.1]nonanes as synthetic intermediates XIII. : Novel transannular hydride shifts enforced by relief of the steric constraint in the bicyclo[3.3.1]nonane system bearing endo-substituents at position 7

The Huang-Minlon reduction of 7α-hydroxymethylbicycl4o[3.3.1]- nonan-3-one (1) gave 7β-methylbicyclo[3.3.1]nonan-3 β-ol (2), a product formed as a result of the transannular 1,6-hydride shift enforced by relief of the stenc constraint in the system. Another example of the intramolecular hydride transfer on the same basis was observed in the deketalization of 9,9-disubstituted 7,7-ethylenedioxybicyclo[3.3.1 ]- nonan-3 β-ol (13 and 18) resulting in the formation of 7 β-(2-hydroxyethoxy) bicyclo[3.3.1]nonan-3-one (15 and 20).     

基于半刚性乳酸衍生物的单一手性配位聚合物的合成、 结构与性质

在溶剂热反应条件下, 用预先合成的乳酸衍生物(R)-H₂CBA和(S)-H₂CBA分别与含氮辅助配体(E)-1,2-二(4-吡啶基)乙烯(DPEE)和1,4-二(1H-咪唑-1-基)苯(1,4-DIB)组合, 制备出2对不同结构的单一手性配位聚合物[Cd₂((R)-CBA)₂(DPEE)(H₂O)₂]_n(1-D), [Cd₂((S)- CBA)₂(DPEE)(H₂O)₂]_n(1-L), [Cd((R)-CBA)(1,4-DIB)]·H₂O(2-D)和[Cd((S)-CBA)(1,4-DIB)]·H₂O(2-L). 其中1-D和1-L是由梯形Cd-CBA链和DPEE配体连接成的二维框架结构; 而2-D和2-L是三维超分子框架结构, 包含3种不同类型的对映手性螺旋链. 对上述化合物进行了粉末X射线衍射、 热重分析和圆二色谱分析, 并对其荧光性质进行了讨论.     

Synthesis and properties of 3-substituted 3-azabicyclo-[3.3.1]nonan-9-amines

Catalytic hydrogenation of 3-benzyl- and 3-tert-butoxycarbonyl-3-azabicyclo[3.3.1]nonan-9-one oximes over Raney nickel gave the corresponding 3-substituted 3-azabicyclo[3.3.1]nonan-9-amines which were converted into amides via reactions with acetyl and chloroacetyl chlorides and maleic and succinic anhydrides, into Schiff bases by condensation with benzaldehyde and 4-chlorobenzaldehyde, and into isothiocyanates by treatment with thiophosgene in the presence of K₂CO₃. 3-Benzyl- and 3-tert-butoxycarbonyl-3-azabicyclo-[3.3.1]nonan-9-yl isothiocyanates readily reacted with methanol, aniline, and sodium azide to produce methyl thiocarbamate, thiourea, and dihydrotetrazole-5-thione derivatives having a 3-azabicyclo[3.3.1]nonane fragment.     

Comparison of various density functional methods for distinguishing stereoisomers based on computed (1)H or (13)C NMR chemical shifts using diastereomeric penam beta-lactams as a test set

Full (1)H and (13)C NMR chemical shift assignments were made for two sets of penam beta-lactams: namely, the diastereomeric (2S, 5S, 6S)-, (2S, 5R, 6R)-, (2S, 5S, 6R)-, and (2S, 5R, 6S)-methyl 6-(1,3-dioxoisoindolin-2-yl)-3,3-dimethyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylates (1-4) and (2S, 5R, 6R)-, (2S, 5S, 6R)-, and (2S, 5R, 6S)-6-(1,3-dioxoisoindolin-2-yl)-3,3-dimethyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylic acids (6-8). Each penam was then modeled as a family of conformers obtained from Monte Carlo searches using the AMBER* force field followed by IEFPCM/B3LYP/6-31G(d) geometry optimization of each conformer using chloroform solvation. (1)H and (13)C chemical shifts for each conformer were computed at the WP04, WC04, B3LYP, and PBE1 density functional levels as Boltzmann averages of IEFPCM/B3LYP/6-311 + G(2d,p) energies over each family. Comparisons between experimental and theoretical chemical shift data were made using the total absolute error (|Deltadelta| (T)) criterion. For the (1)H shift data, all methods were sufficiently accurate to identify the proper stereoisomers. Computed (13)C shifts were not always successful in identifying the correct stereoisomer, regardless of which DFT method was used. The relative ability of each theoretical approach to discriminate among stereoisomers on the basis of proton shifts was also evaluated.     

Polymethylated DOTA ligands. 1. Synthesis of rigidified ligands and studies on the effects of alkyl substitution on acid-base properties and conformational mobility

This work describes the synthesis and the conformational properties of new polymethylated macrocyclic ligands of potential interest for magnetic resonance imaging. M4cyclen, (2S,5S,8S,11S)-2,5,8,11-tetramethyl-1,4,7,10-tetraazacyclododecane, was obtained by cyclotetramerization of (2S)-1-benzyl-2-methylaziridine followed by catalytic hydrogenation. The ligands M4DOTA, [(2S,5S,8S,11S)-4,7,10-tris-carboxymethyl-2,5,8,11-tetramethyl- 1,4,7,10-tetraazacyclododecan-1-yl]acetic acid, and M4DOTMA, (R)-2-[(2S,5S,8S,11S)-4,7,10-tris-((R)-1-carboxyethyl)-2,5,8,11-tetramethyl-1,4,7,10-tetraazacyclododecan-1-yl]propionic acid, were prepared by carboxyalkylation of M4cyclen in the presence of Na(2)CO(3). The triacetic ligand M4DO3A, [(2S,5S,8S,11S)-4,7-bis-carboxymethyl-2,5,8,11-tetramethyl-1,4,7,10-tetraazacyclododecan-1-yl]acetic acid, was obtained in good yields without traces of M4DOTA if NaHCO(3) was the acid scavenger when adding the carboxylic arms. In the same conditions, cyclen yielded M4DOTA in 82% yield. The difference between the reactivity of cyclen and M4cyclen is assigned to the high basicity of the substituted tetraamine as estimated by NMR titration. The one- and two-dimensional (1)H and (13)C NMR spectra of M4DOTA and M4DOTMA in the H(4)L or H(6)L(2+) forms are interpreted as arising from a slow exchange between two elongated geometries in which the methyl substituents are in one of the two possible equatorial-like positions, either close to or away from the carboxylic arms. The axial-like positions are sterically too crowded and cannot be occupied by the methyl groups. An elongated conformation is also adopted by DOTMA, (R)-2-[4,7,10-tris-((R)-carboxyethyl)-1,4,7,10-tetraazacyclododecan-1-yl]propionic acid, in the H(6)L(2+) form. The rigidification of the polymethylated ligands allows a detailed NMR analysis that cannot be carried out on the parent unsubstituted ligand DOTA.     

Synthesis and Properties of 3-Thia-9-azabicyclo[3.3.1]nonan-7-one

N-Benzyl-3-thia-9-aza-bicyclo[3.3.1]nonan-7-one has been prepared from methyl 4-bromocrotonate by reaction sequence involving sodium sulfide, benzylamine, and Dieckmann condensation. Some spectral and chemical properties of this system are also reported.     

Rigid Scaffolds: Synthesis of 2,6-Bridged Piperazines with Functional Groups in all three Bridges

The activity of pharmacologically active compounds can be increased by presenting a drug in a defined conformation, which fits exactly into the binding pocket of its target. Herein, the piperazine scaffold was conformationally restricted by substituted C₂- or C₃-bridges across the 2- and 6-position. At first, a three-step, one-pot procedure was developed to obtain reproducibly piperazine-2,6-diones with various substituents at the N-atoms in high yields. Three strategies for bridging of piperazine-2,6-diones were pursued: 1. The bicyclic mixed ketals 8-benzyl-6-ethoxy-3-(4-methoxybenzyl)-6-(trimethylsilyloxy)-3,8-diazabicyclo[3.2.1]octane-2,4-diones were prepared by Dieckmann analogous cyclization of 2-(3,5-dioxopiperazin-2-yl)acetates. 2. Stepwise allylation, hydroboration and oxidation of piperazine-2,6-diones led to 3-(3,5-dioxopiperazin-2-yl)propionaldehydes. Whereas reaction of such an aldehyde with base provided the bicyclic alcohol 9-benzyl-6-hydroxy-3-(4-methoxybenzyl)-3,9-diazabicyclo[3.3.1]nonane-2,4-dione in only 10 % yield, the corresponding sulfinylimines reacted with base to give N-(2,4-dioxo-3,9-diazabicyclo[3.3.1]nonan-6-yl)-2-methylpropane-2-sulfinamides in >66 % yield. 3. Transformation of a piperazine-2,6-dione with 1,4-dibromobut-2-ene and 3-halo-2-halomethylprop-1-enes provided 3,8-diazabicyclo[3.2.1]octane-2,4-dione and 3,9-diazabicyclo[3.3.1]nonane-2,4-dione with a vinyl group at the C₂- or a methylene group at the C₃-bridge, respectively. Since bridging via sulfinylimines and the one-pot bridging with 3-bromo-2-bromomethylprop-1-ene gave promising yields, these strategies will be exploited for the synthesis of novel receptor ligands bearing various substituents in a defined orientation at the carbon bridge     

A new, non-iterative asymmetric synthesis of long-chain 1,3-polyols

A new approach to the asymmetric synthesis of pentadeca-1,3,5,7,9,11,13,15-octols and their derivatives is presented. It is based on the Sharpless asymmetric dihydroxylation (AD) of 4,4'-methylene[(1R,1'S,6R,6'S)-6-acetoxycyclohept-3-en-1-yl]bis(4-methoxybenzoate) (9), derived from a double [3+4] cycloaddition of the 1,1,3-trichloro-2-oxyallyl cation with 2,2'-methylenedifuran (1). The diol (-)-10, obtained in 98.4% ee from 9 with "AD-mix-beta(5x), was oxidised into (2R and 2S,4S,6R)-tetrahydro-2-hydroxy-6-((4S,6S)-(6-hydroxy-4-[(4-methoxybenzoyl)oxy]cyclohept-1-en-1-yl)-2-oxopropyl)-2H-pyran-4-yl 4-methoxybenzoates ((-)-18). By the combinations of Evans' anti and Nasaraka's syn reductions of aldol (-)-18 with the double Mitsunobu reaction, 16 diastereomeric pentadeca-1,3,5,7,9,11,13,15-octols and analogues can be obtained, in principle, with high enantio- and diastereoselectivities.     

New forced degradation products of vildagliptin: Identification and structural elucidation using LC-MS,with proposed formation mechanisms

Abstract

A new and simple RP-HPLC-UV method was developed for well-separation of vildagliptin raw material and its degradation products at different conditions; it uses of ammonium acetate buffer at pH= 7.5 and methanol with Athena C18 -WP (250?mm) column. Results show that six degradants have been identified using LC–MS technique, in addition to the NMR approach in some cases. One degradant at relative retention time (RRT) 1.3 was formed under acidic condition and designated as 2-((1R, 3S, 5R, 7S)-3-hydroxyadamantan-1-yl) hexahydropyrrolo[1,2-a]pyrazine-1,4-dione at m/z = 304. Three degradants were formed under various conditions of basic hydrolysis at RRTs 1.2, 0.6 and 0.4 with following names and molar masses (m/z), respectively: 1-(((1S, 3S, 5S, 7S)-1,3-dihydroxyadamantan-2-yl)glycyl)pyrrolidine-2-carboxamide at m/z = 337.2, 1-(((1R, 3S, 5R, 7S)-3-hydroxyadamantan-1-yl)glycyl)pyrrolidine-2-carboxamide at m/z = 321.1 and (1,4-dioxo-1,4,6,7,8,8a-hexahydropyrrolo[1,2-a]pyrazin-3-yl)glycylproline at m/z = 322.6. Another three degradants were also formed under oxidative oxidations of vildagliptin, one at RRT 0.38 and designated as N-hydroxy-N-((1R, 3S, 5R, 7S)-3-hydroxyadamantan-1-yl) glycinate with m/z 241.1, the second one was identical to that formed under basic hydrolysis at RRT 0.6 and the last one has RRT 0.8 and was identified as (1S, 3R, 5R, 7S)-3-(hydroxyamino)adamantan-1-ol at m/z 183.1. Formation mechanisms for the degradation products were described.     

Lone pairs vs. covalent bonds: conformational effects in bicyclo[3.3.1]nonane derivatives

Structural Chemistry - Investigations on the relative energy of two least-strain conformers for bicyclo[3.3.1]nonane 1, bicyclo[3.3.1]nonan-9-one 2, and their heteroanalogues:...     

新型Bluco类β-内酰胺酶分子探针的合成

以2-氰基-6-羟基苯并噻唑为原料,与溴乙醛缩二乙醇缩合制得缩醛后再水解合成中间体6-(2-羰乙基)苯并[d]噻唑-2-甲腈(2);7-苯乙酰氨基-3-氯甲基头孢菌烷酸二苯甲酯依次经碘代和Wittig反应得(Z)-3-[3-(2-氰基苯并[d]噻唑-6-氧)丙-1-烯]-8-羰基-7-(2-苯乙酰氨基)-5-噻-1-氮[4.2.0]辛-2-烯-2-甲酸二苯甲酯(5);5经脱保护、缩合和氧化反应合成了3个新的Bluco类似物,其结构经1H NMR,13C NMR和HR-MS(ESI)表征。     

具有四连接网络的单一手性螺旋配位聚合物的合成与结构表征

在水热反应条件下,使用乳酸衍生物[(R)-H2CBA和(S)-H2CBA]和辅助配体1,4-DIB与Ni2+组合,制备出一对具有dia拓扑网络的单一手性框架材料[Ni2((R)-CBA)2(1,4-DIB)3(H2O)2]·x H2O(1-D)和[Ni2((S)-CBA)2(1,4-DIB)3(H2O)2]·x H2O(1-L).配合物1-D和1-L具有2种由1,4-DIB与Ni2+组构建而成的螺旋链以及二重穿插的结构特征.此外,对上述配合物进行了粉末X射线衍射、热失重和圆二色谱测试并对结果进行了分析.     

Design and synthesis of novel dinucleotide analogs

Syntheses of dinucleotide analogs, (S,R) cis-(4-((4-amino-2-oxopyrimidin-1(2H)-yl)methyl)-1,3-dioxolan-2-yl)methyl (2R,3R,5R)-2-(hydroxymethyl)-5-(5-methyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-tetrahydrofuran-3-yl hydrogen phosphate (5a) and (S,R) cis-(5-((4-amino-2-oxopyrimidin-1(2H)-yl)methyl)-1,3-oxathiolan-2-yl)methyl (2R,3R,5R)-2-(hydroxymethyl)-5-(5-methyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-tetrahydrofuran-3-yl hydrogen phosphate (5b), were accomplished by the use of a new strategy. The use of phenyldichlorophosphate (Method A) as the coupling reagent was shown to possess superiority relative to the reported use of di(1H-benzo[d][1,2,3]triazol-1-yl)phenyl phosphonate (Method B).     

Diastereoselective cyclization in chiral diarylethene crystals: polymorphism and selectivity

[structure: see text] An optically active photochromic diarylethene, (S)-1-(2-methyl-5-phenyl-3-thienyl)-2-[2-methyl-5-(4-(3-methyl-1-penten-1-yl)phenyl)-3-thienyl]perfluorocyclopentene ((S)-1a), was synthesized. (S)-1a formed two crystalline phases, alpha- and beta-phases. The diarylethene underwent a photochromic reaction in solution and even in the single-crystalline phase. In solution, no diastereoselection was observed. On the other hand, in the beta-crystalline phase, only one diastereomer (S,R,R)-1b was produced. No such diastereoselection was observed in the alpha-crystalline phase.     

New benzimidazole derivatives: Design,synthesis, docking,and biological evaluation

The aim of this study was to synthesize novel enaminonitrile derivatives starting from 2-aminobenzimidazole and utilize this derivative for the preparation of novel heterocyclic compounds and assess their function for biological activity screening. The key precursor N-(1H-benzo[d]imidazol-2-yl)carbonohydrazonoyl dicyanide (2) was prepared in pyridine by coupling of diazotized 2-aminobenzimidazole (1) with malononitrile. Compound 2 was subjected to react with various secondary amines such as piperidine, morpholine, piperazine, diphenylamine, N-methylglucamine, and diethanolamine in boiling ethanol to give the acrylonitriles (2Z)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-3-amino-3-(piperidin-1-yl)acrylonitrile (3), (2Z)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-3-amino-3-morpholinoacrylonitrile (4), (2Z)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-3-amino-3-(piperazin-1-yl)acrylonitrile (5), (2Z)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-3-amino-3-(diphenylamino)acrylonitrile (6), (2Z)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-3-amino-3-(methyl((2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl)amino)acrylonitrile (7), and (2Z)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-3-amino-3-(bis(2-hydroxyethyl)amino)acrylonitrile (8), respectively. It has been found that the behaviour of nitrile derivative 2 towards hydrazine hydrate to the creation of 4-((1H-benzo[d]imidazol-2-yl)diazenyl)-1H-pyrazole-3,5-diamine (9). The reaction of malononitrile with compound 2 in an ethanolic solution catalyzed with sodium ethoxide afforded 4-amino-1-(1H-benzo[d]imidazol-2-yl)-6-imino-1,6-dihydropyridazine-3,5-dicarbonitrile (11). Moreover, malononitrile reacted with 7 in a boiling ethanolic sodium ethoxide solution to give 2-(5-((1H-benzo[d]imidazol-2-yl)diazenyl)-4-amino-6-(methyl((2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl)amino)pyrimidin-2-yl)acetonitrile (14). Heating 7 in boiling acetic anhydride and pyridine afforded (2R,3R,4R,5S)-6-(((1E)-2-((1-acetyl-1H-benzo[d]imidazol-2-yl)diazenyl)-1-(N-acetylacetamido)-2-cyanovinyl)(methyl)amino)hexane-1,2,3,4,5-pentayl pentaacetate (15). When compound 15 is heated for a long time in refluxing DMF including a catalytic of TEA, cyclization occurs to give the corresponding (2R,3R,4R,5S)-6-((1-acetyl-3-((1-acetyl-1H-benzo[d]imidazol-2-yl)diazenyl)-4-amino-6-oxo-1,6-dihydropyridin-2-yl)(methyl)amino)hexane-1,2,3,4,5-pentayl pentaacetate (16). In addition, triethyl orthoformate was reacted with compound 7 in the presence of acetic anhydride to afford the corresponding ethoxymethyleneamino derivative (2R,3R,4R,5S)-6-(((1E)-2-((1-acetyl-1H-benzo[d]imidazol-2-yl)diazenyl)-2-cyano-1-(((E) ethoxymethylene)amino)vinyl)(methyl)amino)hexane-1,2,3,4,5-pentayl pentaacetate (17). Also, it has been found that heating a mixture of 7 with DMF/DMA in anhydrous xylene yielded compound (1E)-N'-((1E)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-2-cyano-1-(methyl((2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl)amino)vinyl)-N,N-dimethylformimidamide (18). In addition, compound 7, when reacted with several acid anhydrides, allowed the matching phthalimide derivatives 19–26. The results showed that compound 14 has significantly higher ABTS and antitumor activities than the other compounds. Molecular modelling was also studied for compounds 22 and 24. The viability of four many cell lines—the African green monkey kidney epithelial cells (VERO), human breast adenocarcinoma cell line (MCF-7), human lung fibroblast cell line (WI-38), and human hepatocellular liver carcinoma cell line (HepG2) was examined to determine the antitumor activities of the newly synthesized compounds. Also, it was found that compounds 9, 11, 15, 16, 22, 23, 24 and 25 are strong against HepG2 cell lines, while 16, 22, and 25 are strong against WI-38 cell lines. Moreover, it was also found that compounds 16 and 22 are strong against VERO cell lines. On the other hand, compounds 7, 14, 15, 16, and 22 are strong while the rest of the other compounds are moderate against the MCF-7 cell line. The result of docking showed that compound 24 got stabilized inside the pocket with a very promising binding score of ? 8.12 through hydrogen bonds with Arg184 and Lys179, respectively.     

Anticancer Cytotoxic Activity of Bispidine Derivatives Associated with the Increasing Catabolism of Polyamines

Polyamine (PA) catabolism is often reduced in cancer cells. The activation of this metabolic pathway produces cytotoxic substances that might cause apoptosis in cancer cells. Chemical compounds able to restore the level of PA catabolism in tumors could become potential antineoplastic agents. The search for activators of PA catabolism among bicyclononan-9-ones is a promising strategy for drug development. The aim of the study was to evaluate the biological activity of new 3,7-diazabicyclo[3.3.1]nonan-9-one derivatives that have antiproliferative properties by accelerating PA catabolism. Eight bispidine derivatives were synthetized and demonstrated the ability to activate PA catabolism in regenerating rat liver homogenates. However, only three of them demonstrated a potent ability to decrease the viability of cancer cells in the MTT assay. Compounds 4c and 4e could induce apoptosis more effectively in cancer HepG2 cells rather than in normal WI-38 fibroblasts. The lead compound 4e could significantly enhance cancer cell death, but not the death of normal cells if PAs were added to the cell culture media. Thus, the bispidine derivative 4e 3-(3-methoxypropyl)-7-[3-(1H-piperazin-1-yl)ethyl]-3,7-diazabicyclo[3.3.1]nonane could become a potential anticancer drug substance whose mechanism relies on the induction of PA catabolism in cancer cells.     

Synthesis,characterization and antitumor activities of some novel thiazinones and thiosemicarbazones derivatives

Abstract

Two series of thiazinone and thiosemicarbazone derivatives (1-12) were synthesized using 2,4-diaryl-3-azabicyclo[3.3.1]nonan-9-ones (ABNs) and 3–alkyl–2,6–diarylpiperidin–4–ones as the starting materials. The structures of newly synthesized compounds were established on the basis of FT–IR, NMR spectroscopy and mass spectrometry. From the spectroscopic data, we identified that the cyclization reaction of thioamide with dialkyl acetylenedicarboxylate selectively gives six membered methyl 2-(2-(2,4-disubstituted-3-azabicyclo[3.3.1]nonan-9-ylidene)hydrazinyl)-4-oxo-4H-1,3-thiazine-6-carboxylates (1-6). In order to investigate the antitumor activities of the synthesized compounds, in vitro cytotoxicity studies were carried out using human prostate cancer cell lines. Tested compounds showed good/moderate activities against cancer cell lines and further investigation carried out by live/dead assay.     

Three new diterpenes and the biological activity of different extracts of Jasonia montana

Three new diterpenes, namely jasonin-a (1), jasonin-b (2), and jasonin-c (3) were isolated from the aerial parts of Jasonia montana (Asteraceae). Their structures were elucidated on the basis of spectral data as [(1E)-2-((2S)-1,2,5-trimethylbicyclo[3.2.l]octan-8-yl)vinyl] benzene-3-carboxylic acid (1), [3-((2S, 5S)-1,2, 5-trimethylcycloheptanyl)propyl]benzene-3-carboxylic acid (2), and [(1E)-3-((7R)-1,7-dimethy-4-methylenecycloheptanyl)prop-1-enyl] benzene-3-carboxylic acid (3). In addition, the previously reported 5,7,3'-trihydroxy-3,6,4'-trimethoxy flavone designated as centaureidin (4), was also isolated and characterized from this source. The different extracts of the plant were also screened for hypoglycemic, antidiabetic, and antimicrobial activities, wherein the petroleum ether and ethanolic extracts exhibited hypoglycemic and antidiabetic activity, and the petroleum ether and chloroform extracts showed antimicrobial activity.