Molecules, Volume 13, Issue 3 (March 2008) – 13 articles , Pages 488-715

Water soluble homo-base polynucleotide analogues were synthesized in whichpolyvinyl alcohol and partially phosphonated polyvinyl alcohol constituted the backbones,onto which were grafted uracil or adenine via 1,3-dioxane spacers formed by acetalformation with the 1,3-diol moieties in PVA. The resulting adenine-PVA polynucleotideanalogs exhibited hyperchromic effects, which was not the case for the correspondinguracil compounds. Mixtures of the adenine- and aracil PVA-phosphate polynucleotideanalogs in solutions exhibited characteristic S-shaped UV-absorbance vs temperature andmelting curves with melting points at approximately 40 ^oC. Full article

We have synthetized medium-sized cyclophanes and macrocycles containingphosphonic groups, directly linked to the aromatic rings of the phanes or as pendant arms,for use as specific receptors for the selective complexation of neutral guests or forcomplexing lanthanides, as luminescent sensors and for diagnostic bioassays in medicine.Furthermore, because it would be of great interest for biochemistry as well as forpharmacological studies to dispose of preorganized rigid chiral hosts for biorelevantmolecules we designed inter alia, some new chiral macrocycles capable of a triple bindingmode and we used them for constructing macrocycles that could also be of interest forchiral recognition and chiral separations. Thus, in this paper we shall review the salientaspects of some macrocycles synthetized in our laboratory, all possessing the phosphonatemoiety and a spirobisindanol scaffold and able to act as complexing agents for cations andorganic substrates. In particular, we shall describe their NMR characterization, theirstereochemistry in solution and in the solid state, and their use as chiral receptors forbiorelevant molecules. Chiral HPLC resolution of some of them is also reported. Full article

Recently, World Health Organization (WHO) and Medicins San Frontieres (MSF) proposed a classification of diseases as global, neglected and extremely neglected. Global diseases, such as cancer, cardiovascular and mental (CNS) diseases represent the targets of the majority of the R&D efforts of pharmaceutical companies. Neglected diseases affect millions of people in the world yet existing drug therapy is limited and often inappropriate. Furthermore, extremely neglected diseases affect people living under miserable conditions who barely have access to the bare necessities for survival. Most of these diseases are excluded from the goals of the R&D programs in the pharmaceutical industry and therefore fall outside the pharmaceutical market. About 14 million people, mainly in developing countries, die each year from infectious diseases. From 1975 to 1999, 1393 new drugs were approved yet only 1% were for the treatment of neglected diseases [3]. These numbers have not changed until now, so in those countries there is an urgent need for the design and synthesis of new drugs and in this area the prodrug approach is a very interesting field. It provides, among other effects, activity improvements and toxicity decreases for current and new drugs, improving market availability. It is worth noting that it is essential in drug design to save time and money, and prodrug approaches can be considered of high interest in this respect. The present review covers 20 years of research on the design of prodrugs for the treatment of neglected and extremely neglected diseases such as Chagas’ disease (American trypanosomiasis), sleeping sickness (African trypanosomiasis), malaria, sickle cell disease, tuberculosis, leishmaniasis and schistosomiasis. Full article

The article describes a two-step synthesis of diastereomeric 3-hydroxy-2-methyl-3-(4-biphenylyl)butanoic acids. In the first step an intermediate α-bromo propanoicacid 1-ethoxyethyl ester was synthesized. The second step is a new modified Reformatskyreaction in presence of Zn in tetrahydrofuran (THF) at –5 to 10 °C between the previouslysynthesized intermediate and 4-acetylbiphenyl. Synthesis of the other studied β-hydroxy-β-arylpropanoic acids has already been reported. These β-hydroxy-β-arylpropanoic acidsbelong to the arylpropanoic acid class of compounds, structurally similar to the NSAIDssuch as ibuprofen. The anti-inflammatory activity and gastric tolerability of thesynthesized compounds were evaluated. Molecular docking experiments were carried outto identify potential COX-2 inhibitors among the β-hydroxy-β-aryl-alkanoic acids class.The results indicate that all compounds possess significant anti-inflammatory activity afteroral administration and that the compounds 2-(9-(9-hydroxy-fluorenyl))-2-methylpropanoic acid (5) and 3-hydroxy-3,3-diphenyl-propanoic acid (3) possess thestrongest anti-inflammatory activity, comparable to that of ibuprofen, a standard NSAID,and that none of tested substances or ibuprofen produced any significant gastric lesions. Full article

The unstable isomeric compounds 5-hydroxy-7-prop-2-en-(E)-ylidene-7,7adihydro-2H-cyclopenta[b]pyran-6-one (1) and 5-hydroxy-7-prop-2-en-(Z)-ylidene-7,7adihydro-2H-cyclopenta[b]pyran-6-one (2), previously described as antimicrobialmetabolites from the sponge Ulosa sp., were isolated and identified as major componentsof the ascidian Diplosoma virens. In this paper, full spectral data for 2 and complete ¹³CNMRdata for 1, based on 2D NMR measurements, are provided for the first time.Compounds 1 and 2 showed cytotoxity against HCT116 cells (human colorectal cancercells) by triggering apoptotic cell death. Full article

A total of fourteen (14) species of wild edible fruits from Burkina Faso wereanalyzed for their phenolic and flavonoid contents, and their antioxidant activities usingthe DPPH, FRAP and ABTS methods. The data obtained show that the total phenolic andtotal flavonoid levels were significantly higher in the acetone than in the methanol extracts.Detarium microcarpum fruit had the highest phenolic and the highest flavonoid content,followed by that of Adansonia digitata, Ziziphus mauritiana, Ximenia americana andLannea microcarpa. Significant amounts of total phenolics were also detected in the otherfruit species in the following order of decreasing levels: Tamarindus indica > Sclerocaryabirrea > Dialium guineense > Gardenia erubescens > Diospyros mespiliformis > Parkiabiglobosa > Ficus sycomorus > Vitellaria paradoxa. Detarium microcarpum fruit alsoshowed the highest antioxidant activity using the three antioxidant assays. Fruits with highantioxidant activities were also found to possess high phenolic and flavonoid contents.There was a strong correlation between total phenolic and flavonoid levels and antioxidantactivities. Full article

We report here the characterisation of eight newly synthesized thioureides of 2-(4-chlorophenoxymethyl)-benzoic acid and the evaluation of the in vitro antimicrobialactivity of the new compounds against Gram-positive [Listeria monocytogenes,Staphylococcus aureus, Bacillus subtilis], Gram-negative [Psedomonas aeruginosa,Escherichia coli, Salmonella enteritidis], as well as Candida spp., using both reference andclinical multidrug resistant strains to establish the minimal inhibitory concentration (MIC)values. Our results showed that the tested compounds exhibited specific antimicrobialactivities, both concerning the spectrum of antimicrobial activity and the correspondingMIC values, which ranged widely between 1024 and 32 μg/mL, depending on the natureand position of the substituents on the benzene ring. The most active compounds were N-[2-(4-chlorophenoxymethyl)-benzoyl]-N'-(2,6-dichlorophenyl)-thiourea (5g) and N-[2-(4-chlorophenoxymethyl)-benzoyl]-N'-(4-bromophenyl)-thiourea (5h), which showed a broadspectrum of antimicrobial activity against enterobacterial strains (E. coli and S. enteritidis),P. aeruginosa, S. aureus and Candida spp. All the tested compounds except 5f were highly active against S. aureus (MIC=32 μg/mL), suggesting their possible use in the treatment ofMRSA infections. Four of compounds also exhibited antifungal activity (MIC =256-32μg/mL) against C. albicans, but L. monocytogenes as well as B. subtilis were resistant toall tested compounds. Our studies thus demonstrated that among other biological activities,the thioureides of 2-(4-chlorophenoxymethyl)-benzoic acid also exhibit selective andeffective antimicrobial properties that could lead to the selection and use of thesecompounds as efficient antimicrobial agents, especially for the treatment of multidrugresistant infections. Full article

A new and efficient method for the synthesis of 1-(2,6-dichloro-4-trifluoromethylphenyl)-4-alkyl-1H-[1,2,3]-triazoles by the room temperature 1,3-dipolarcycloaddition of (2-azido-1,3-dichloro-5-trifluoromethyl)benzene with terminal alkynes inthe presence of Cu (I) salt as catalyst is reported. All the reactions gave 1,4-disubstitutedproducts with high regioselectivity, as no 1,5-disubstituted product was formed. Thestructures of all the title compounds have been confirmed by elemental analysis, ¹H- and¹³C-NMR and in addition, the structure of compound 5a was investigated by X-raycrystallography. Full article

The purpose of this work is to review the published strategies for the productionof prodrugs of amines. The review is divided in two main groups of approaches: those thatrely on enzymatic activation and those that take advantage of physiological chemicalconditions for release of the drugs. A compilation of the most important approaches ispresented in the form of a table, where the main advantages and disadvantages of eachstrategy are also referred. Full article

A series of 1-acyl-4-phenyl/(acridin-9-yl)thiosemicarbazides 3, including fournew compounds, were prepared in order to study substituent effects on cyclizationreactions with oxalyl chloride (producing imidazolidine-4,5-diones 4), dimethylacetylenedicarboxylate (to give thiazolidin-4-ones 7 and 8) and autocondensation underalkaline conditions (to yield 1,2,4-triazoles 9). A positional isomer, 10 of compound 3f wasalso prepared. Altogether, twenty new compounds characterized and identified by IR, UV,¹H, ¹³C and 2D NMR and quantum chemical calculations are described. The tautomerismof the products and regioselectivity of the reactions were evaluated. Compounds 3f−h,3h·2HCl, 7b,d and 10 were screened for cytotoxic activity against the L1210 leukemia cellline and all compounds, except for 3f, exhibited promising inhibitions of cell growth. Full article

The synthesis of konjac glucomannan-graft-polyacrylamide (KGM-g-PAM) wascarried out at 25°C by γ-irradiation under a N₂ atmosphere. The effects of absorbedradiation dosage and monomer concentration on grafting yield and water absorbency werestudied. The grafted copolymers were characterized using Fourier Transform Infrared(FTIR) spectroscopy, nuclear magnetic resonance (NMR), x-ray diffraction (XRD),thermogravimetric analysis (TGA) and gel permeation chromatography (GPC). Thegrafting yield was observed to increase with increasing absorbed dosage and monomerconcentration. Compared with the original KGM, the grafted copolymers exhibited betterthermal stability and water absorbency. The results suggest that γ-irradiation is convenientand efficient for inducing graft copolymerization of KGM and acrylamide (AM). Full article