Methylenecyclopropane Analogues of Nucleosides: Synthesis,Absolute Configuration,and Enantioselectivity of Antiviral Effect of (R)-(-)- and (S)-(+)-Synadenol

Abstract

Synthesis, absolute configuration and antiviral activity of enantiomeric antiviral agents (R)-(-)- and (S)-(+)-synadenol (2 and 3a) are described.     

Syntheses of Phosphonate Analogues of Dideoxyadenosine (DDA)-, Dideoxycytidine (DDC)-, Dideoxyinosine (DDI)-, and Deoxythymidine (DDT)-5′-Monophosphates

Abstract

Phosphonate derivatives of ddA, ddC, ddI and ddT (5f, 5e, 5c, and 5a) were prepared by condensing the 5′-aldehydes with diphenyl triphenylphosphoranylidenemethylphosphonate, reducing the resultant olefins and hydrolyzing the phosphonate phenyl esters, sequentially, with base and then C. atrox phosphodiesterase.     

The Synthesis and Antiviral Activity of (E)-5-(2-Nitrovinyl)uridine and (E)-5-(2-Nitrovinyl)-2′-deoxyuridine

Abstract

The protection of the sugar moiety of a 5-formyluracil nucleoside with acid-labile protecting groups allows for the deprotection of the sugar of a subsequently formed nucleoside possessing a 5-nitrovinyl side-chain. The synthesis and antiviral activity of (E) -5-(2-nitrovinyl)-uridine and (E)-5-(2-nitrovinyl)-2′-deoxyuridine are reported.     

Synthesis of AZT analogues: 7-(3-azido-2hydroxypropyl)-, 7-(3-amino-2-hydroxypropyl)-, 7-(3-triazolyl-2-hydroxypropyl)theophyllines

Nucleophilic displacement of the tosyloxy group in 7-(2-hydroxy-3-p-toluenesulfonyloxypropyl)theophylline (1) with azide anion afforded 7-(3-azido-2-hydroxypropyl)theophylline (2). Reduction of the 3-azido group in 2 with Ph₃P/Py/NH₄OH afforded the 3-amino derivative 4, alternatively obtained by regioselective amination of 7-(2,3-epoxypropyl)theophylline (3). Selective acetylation of 4 gave the N-acetyl derivative 5. 1,3-Dipolar cycloaddition of the azide group in 2 with N¹-propargyl thymine (6) afforded the regioisomeric triazole 7.     

3,5-Bis(Phenylmethylene)-1-(N-arylmaleamoyl)-4-piperidones: A Novel Group of Cytotoxic Agents

A series of novel 3,5-bis(phenylmethylene)-1-(N-arylmaleamoyl)-4-piperidones 3 have been synthesized which displayed potent cytotoxicity towards human Molt 4/C8 and CEM T-lymphocytes as well as murine P388 and L1210 leukemic cells. In contrast, the related N-arylmaleamic acids 4 possessed little or no cytotoxicity in these four screens. Molecular modeling revealed certain interplanar and bond angles and interatomic distances which were perceived to contribute to the observed bioactivity as well as providing suggestions for future structural modifications of the piperidones 3. Evaluation of representative compounds in series 3 and 4 on the activity of human N-myristoyltransferase revealed that, at the maximum concentration utilized, namely 250?μM, only weak inhibiting properties were displayed by some of the compounds in series 4. Various members of series 3 and 4 were well tolerated in mice.     

Synthesis and Hybridization Properties of Oligonucleotides Containing (2 S ,3 R )-9-(2,3,4-Trihydroxybutyl)Adenine

The synthesis and properties of oligonucleotides (ONs) containing 9-(2,3,4-trihydroxybutyl)adenine, A ^C2 and A ^C3, are described. The ON containing A ^C2 involves the 3′ → 4′ and 3′ → 5′ phosphodiester linkages in the strand, whereas that containing A ^C3 possesses the 3′ → 4′ and 2′ → 5′ phosphodiester linkages. It was found that incorporation of the analogs, A ^C2 or A ^C3, into ONs significantly reduces the thermal and thermodynamic stabilities of the ON/DNA duplexes, but does not largely decrease the thermal and thermodynamic stabilities of the ON/RNA duplexes as compared with the case of the ON/DNA duplexes. It was revealed that the base recognition ability of A ^C2 is greater than that of A ^C3 in the ON/RNA duplexes.     

Synthesis of Base Substituted 2-Hydroxy-3-(purin-9-yl)-propanoic Acids and 4-(Purin-9-yl)-3-butenoic Acids

Abstract

Alkylation of 6-chloropurine and 2-amino-6-chloropurine with bromoacetaldehyde diethyl acetal afforded 6-chloro-9-(2,2-diethoxyethyl)purine (3a) and its 2-amino congener (3b). Treatment of compounds 3 with primary and secondary amines gave the N⁶-substituted adenines (5a–5c) and 2,6-diaminopurines (5d–5f). Hydrolysis of 3 resulted in hypoxanthine (6a) and guanine (6b) derivatives, while their reaction with thiourea led to 6-sulfanylpurine (7a) and 2-amino-6-sulfanylpurine (7b) compounds. Treatment with diluted acid followed by potassium cyanide treatment and acid hydrolysis afforded 6-substituted 3-(purin-9-yl)- and 3-(2-aminopurin-9-yl)-2-hydroxypropanoic acids (8–10). Reaction of compounds 3 with malonic acid in aqueous solution gave exclusively the product of isomerisation, 6-substituted 4-(purin-9-yl)-3-butenoic acids (15).     

Synthesis,characterization and preliminary screening of regioisomeric 1-(3-pyridazinyl)-3-arylpyrazole and 1-(3-pyridazinyl)-5-arylpyrazole derivatives towards cyclooxygenase inhibition

In a search for novel compounds with analgesic and anti-inflammatory activity, a series of regioisomeric 1-(3-pyridazinyl)-3-arylpyrazole (5a–f, 6a–f) and 1-(3-pyridazinyl)-5-arylpyrazole (7a–f, 8a–f) derivatives were synthesized. The structure of these regioisomers was confirmed by spectral techniques. The compounds were preliminarily screened at 8 μM concentration for their inhibitory activity against cyclooxygenase enzymes, COX-1 and COX-2, using a human whole blood test. The tested derivatives showed inhibitory activity for both enzymes and are worthy of further investigation for developing better leads.     

2-(R-1H-Benzoimidazol-2-yl)-6-(1-aryliminoethyl)pyridyliron(II) dichlorides: Synthesis, characterization and the ethylene oligomerization behavior

Iron(II) dichloride complexes bearing 2-(methyl-substituted 1H-benzoimidazol-2-yl)-6-(1-aryliminoethyl)pyridines (Fe1–Fe6) or 2-(chloro-substituted 1H-benzoimidazol-2-yl)-6-(1-aryliminoethyl)pyridines (Fe7–Fe12) were synthesized and characterized by FT-IR and elemental analysis. Single crystal X-ray crystallographic analyses revealed that complexes Fe2 and Fe3 possessed a distorted square-pyramidal geometry at iron. Upon activation with either MAO or MMAO, all iron pro-catalysts showed good activities toward ethylene oligomerization with high selectivity for α-olefins and high K values. The influence of the reaction conditions and the nature of the ligands on the catalytic performance of these iron complexes were investigated.     

Synthesis and anticonvulsant activity of some 2-(2-{1-[substituted phenyl]ethylidene}hydrazinyl)-4-(4-methoxy-phenyl)-6-oxo-1,6-dihydro-pyrimidine-5-carbonitrile

A series of dihydro-pyrimidine-5-carbonitrile derivatives (3–16) were synthesized and evaluated for their anticonvulsant activity against MES and scPTZ models. Motor impairment screening was carried out by rotarod test method and CNS depressant effect was determined by Porsolt’s force swim pool method. Compounds 4 and 9 having p-substituted bromo and m-substituted nitro groups, respectively, were found to be most active showing activity both in MES and scPTZ screen at lower doses of 30 mgkg^?1 at 0.5?h and 100 mgkg^?1 at 4?h. In the rotarod motor impairment screen, compound 4 did not show any motor impairment even at the maximum dose of 300 mgkg^?1; however, compound 9 showed motor impairment at 300 mgkg^?1 dose after 4.0?h. The compounds were also tested for their CNS depression effect. The compounds 4 and 9 showed 41.38 and 43.44% increase in immobility time with respect to control. The pharmacophore hypothesis also fits best for compounds 4 and 9.     

Synthesis,spectral characterisation and cytotoxic effect of metal complexes of 2-(2-(4-carboxyphenyl)guanidino) acetic acid ligand

Abstract

A new series of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Sr(II), Hg(II), Ag(I), Tl(I) and UO₂(II) complexes of 2-(2-(4-carboxyphenyl)guanidino)acetic acid ligand have been synthesised and characterised by elemental analyses, IR, UV-Vis spectra, mass spectra (ligand and its zinc(II) complex), ¹H NMR spectra (ligand and its mercury(II) complex), magnetic moments, conductances, thermal analyses (DTA and TGA) and ESR measurements. The IR data show that, the ligand behaves as neutral tridentate, (2), [(H_{2 L}L)_{3 C}Cu_{2 (}(OAc)_{4 (}(H_{2 O}O)_{2 ]} ], neutral bidentate, (3), [(H_2LL)Cu(OAc)_2]].1/2H_2OO, (13), [(HL)_2CCuCl₂₍(H_2OO)_2]], (17), [(H_2LL)Cu(OOSO₂₎)(H_2OO)J,dibasic hexadentate, (4), [(L) Ni₄₍(OAc)₆₍(H_2OO)J.4H_2OO, (5), [(L)Mn4(OAc)6(H2O)10]. 4H2O, (6), [(L)Co4(OAc)6(H2O)10] . 4H2O, monobasic bidentate, (7), [(HL)(UO2)(OAc)(H2O)3], (12), [(HL)2Cu], (15), [(HL)2Fe2(Cl4)(H2O)2]. 7H2O, (16), [(HL)2Cr2(Cl4)(H2O)2]. 7H2O, (21 ), [(H2L)Cd (OOSO2)(H2O)3]. 2H2O, monobasic tridentate, (8), [(L)_2HHg₂₍(OAc)₂ (H2O)6].H2O, (9), [(L)2Zn2(OAc)2(H2O)6].H2O, (10), [(L) _2ZZn₂₍(OAc)₂₍(H_2OO)_6]].H_2OO, (11), [(L)Tl4(OAc)3 (H2O)6], (18), [(HL)(OH)Cr2(SO4)2(H2O)5]. H2O, (19), [(HL)3Ag3NO3], or dibasic tridentate, (14), [(L) Sr(Cl)_{20 (}(H_{2 O}O)_{24 ]}], (20), [(L)_{3 C}Cu (H_{2 O}O)_{2 ]} ]. Molar conductances in DMF indicate that, the complexes are non-electrolyte. The ESR spectra of Cu(II) complexes (2), (3) and (20) at room temperature show axial type symmetry with g_// > g_-> 2.00, indicating a d_(x2-y2) ground state with significant covalent bond character in an octahedral or square planar geometry. However, Cu(II) complexes (12) and (13) show isotropic type, indicating square planar and octahedral structure. Complexes Mn(II) (5) and Co(II) (6) show broad signals in the low field region indicating spin exchange interaction take place between metal(II) ion. Hg(II) complex (9), Tl(I) complex (11), Cr(III) complex (16), Cu(II) complex (17) and Cd(II) complex (21) showed potential antiproliferative activity where they showed inhibitory effect on breast carcinoma (MCF-7 cell line) in comparing with the standard drug.     

Synthesis and Biological Evaluation of 3-Chloro-4-(D-Ribofuranosyl)-Pyridine and 3-(D-Ribofuranosyl)-2- Pyridone

Abstract

Condensation of 2-fluoro-3-lithio pyridine and 3-chloro-4-lithio pyridine with 2,4:3,5-di-O-benzylidene-alde-hydo-D-ribose gives the corresponding D-allo- and D-altro-addition products. These were converted into the corresponding mesylates and cyclized to the ribofuranosyl nucleosides with an overall yield of 60–70 %. Both nucleosides did not show any inhibitory effect on L-₁₂₁₀-cells.     

Synthesis and Biological Properties of (+) and (-)-(E)-5-(2-bronovinyl)-21 -deoxy-11 a-Carbauridine

Abstract

Carbocyclic (+)- and (-)-(E)-5- (2-bromovinyl)-2′-deoxyuridlne have been prepared from (+)- and (-)-endo-norborn-5-en-2-y1 butyrate. In cell cultures both (+)- and (-)-C-BVDU showed activity against herpes simplex virus types 1 and 2, (+)-C-BVDU being only slightly less active than BVDU itself. (-)-C-BVDU gave a smaller but still significant antiviral effect. A nomenclature for carbocyclic nucleosides is proposed.     

Synthesis of the Nucleotide Analogue: (R,S)-9-[1-(2-Hydroxyethylthio)-2-phosphonylethyl] Adenine

Abstract

The acyclic nucleotide analogue (R,S)-9-[1-(2-hydroxyethylthio)-2-phosphonylethyl] adenine [HETPEA, 4] was prepared by coupling the adenine potassium salt with diethyl ethynylphosphonate followed by condensation of the product with 2-mercaptoethanol.     

Synthesis of trans-L/D-2-(Tert-butoxycarbonyl- aminomethyl)-4-(thymin-1-yl) Pyrrolidin-1-yl Acetic Acid

Abstract

To delineate the binding preferences of stereochemically divergent pyrrolidine PNAs, synthesis of all four diastreomeric monomers of I and the systematic complexation studies of the resultant PNAs with complementary DNA/RNA is essential. We herein report the synthesis of trans-L/D-2-(tert-butoxycarbonylaminomethyl)-4-(thymin-1-yl) pyrrolidin-1-yl acetic acids I, their incorporation in PNA oligomers and DNA binding studies will be presented.     

Synthesis of 9-[1-(1-Hydroxyethyl)-3-(Phosphonomethoxy)Propyl] Adenine and Prodrug as Possible Antiviral Agents

The appropriately protected C-1′-hydroxyethyl-3-hydroxypropyl-N⁹-adenine nucleoside was prepared from 1-pivaloyloxy-5-tert-butyldiphenylsilyloxy-3-pentanol and adenine through the Mitsunobu reaction. One of the terminal hydroxyls was converted to the phosphonomethoxy derivative and the prodrug.     

Synthesis of Optically Pure (R)-4a-Methyl-4,4a,5,6,7,8-hexahydro-2(3H)-naphthalenone and Its Transformation into (+)-7-Hydroxycostal

A novel synthesis of the enone 12 starting from (+)-dihydrocarvone (3) and its transformation into (+)-7-hydroxycostal (1) are described. The ketone 10, obtained from 4 through a four-step sequence was converted to 12 by acid-catalyzed elimination and subsequent regioselective hydrogenation. Alternatively, the methoxyhydroperoxide 13 generated by the ozonolysis of 4 was subjected to the Criegee rearrangement, providing a mixture of 10 and 14, which on acid treatment, gave 11. Transformation of 12 into 19 was accomplished via a five-step reaction sequence. The reaction of 19 with the lithium alkoxide of 2-lithio-2-propenol afforded (+)-7-hydroxycostol (2), whose oxidation with manganese dioxide gave rise to (+)-7-hydroxycostal (1).     

Synthesis and Biological Evaluation of 9-(f-2, c-3-Bishydroxymethyl-r-cyclopropylmethyl)-9H-adenine (A Lower Methylene Homolog of Carbocyclic Oxetanocin) and Related Compounds

Abstract

Adenine (7 and 16), thymine (9a and 18a), and 5-fluorouracil (9b and 18b) involving f-2, c-3-bishydroxymethyl-r-1-cyclopropylmethyl- and t-2 t-3-bishydroxymethyl-r-1-cyclopropylmethyl residues were synthesized, starting from trans-1, 4-dibenzyloxy-2-butene and its cis isomer, respectively. These compounds were evaluated for anti HSV-1 activity.     

SYNTHESIS AND BIOLOGICAL ACTIVITY OF 4-SUBSTITUTED 1-[1-(2-HYDROXYETHOXY)- METHYL-1,2,3-TRIAZOL-(4 & 5)-YLMETHYL]-1H-PYRAZOLO[3,4-d]PYRIMIDINES

The chemical synthesis of some 4-substituted 1-[1-(2-hydroxyethoxy)methyl-1,2,3-triazol-(4 and 5)-ylmethyl]-1H-pyrazolo[3,4-d]pyrimidines 12a,b, 13a,b and 14–23 as acyclic nucleosides is described. Treatment of (2-acetoxyethoxy)methylbromide with sodium azide afforded (2-acetoxyethoxy)methylazide 9. The heterocycles 6a,b were alkylated, separately, with propargyl bromide to obtain, regioselectively, 4-(methyl and benzyl)thio-1-(prop-2-ynyl)-1H-pyrazolo[3,4-d]pyrimidines 7a,b. These N₁-alkylated products were condensed with compound 9 via a 1,3-dipolar cycloaddition reaction to obtain, after separation and deprotection, 1,4 and 1,5-regioisomers 12a,b and 13a,b. The deprotected acyclic nucleosides 12a and 13a served as precursors for the preparation of 4-amino (14 and 15), 4-methylamino (16 and 17), 4-benzylamino (18 and 19), 4-methoxy (20 and 21) and 4-hydroxy (22 and 23) analogues. Compounds 7a,b and all deprotected acyclic nucleosides were evaluated for their inhibitory effects against the replication of HIV-1(III_B) and HIV-2(ROD) in MT-4 cells and for their anti-tumor activity. No marked activity was found. However, initial evaluation of 6a,b, 7a,b, 12a,b, 13a,b and 14–23 showed that compound 7b has marked activity against M. tuberculosis.     

3-Arylidene-5-(4-isobutylphenyl)-2(3H)-furanones: a new series of anti-inflammatory and analgesic compounds having antimicrobial activity

An ideal anti-inflammatory drug should have the desired effect in minimum dose with minimum side effects. Antimicrobial actions associated with such agents will be an added advantage as they broaden the spectrum of the compounds. Promising anti-inflammatory and antimicrobial activity together with low ulcerogenic properties of some 2(3H)-furanones, synthesized in our previous study, prompted us to investigate the effect of the isobutyl group on their pharmacological profile. Since compounds 3, 9, 13, and 14 have both anti-inflammatory and analgesic effects in addition to low ulcerogenic incidence, they were selected for investigation of their inhibitory effects on various cyclo-oxygenase enzymes. It was found that they were more selective toward COX-2 enzymes. An MIC of 6.25 μg/mL was recorded for compounds 3, 13, and 14 against S. aureus, E. coli, R. oryza, and P. citrum. The study supports the development of furanone derivatives as potential anti-inflammatory agents with antimicrobial activity.