Spin filtering through ferromagnetic BiMnO3 tunnel barriers

We report on experiments of spin filtering through ultrathin single-crystal layers of the insulating and ferromagnetic oxide BiMnO3 (BMO). The spin polarization of the electrons tunneling from a gold electrode through BMO is analyzed with a counterelectrode of the half-metallic oxide La2/3Sr1/3MnO3 (LSMO). At 3 K we find a 50% change of the tunnel resistances according to whether the magnetizations of BMO and LSMO are parallel or opposite. This effect corresponds to a spin-filtering efficiency of up to 22%. Our results thus show the potential of complex ferromagnetic insulating oxides for spin filtering and injection.

Effect of chronic ethanol feeding on rat hepatocytic glutathione. Compartmentation, efflux, and response to incubation with ethanol.

Hepatocytes from rats that were fed ethanol chronically for 6-8 wk were found to have a modest decrease in cytosolic GSH (24%) and a marked decrease in mitochondrial GSH (65%) as compared with pair-fed controls. Incubation of hepatocytes from ethanol-fed rats for 4 h in modified Fisher's medium revealed a greater absolute and fractional GSH efflux rate than controls with maintenance of constant cellular GSH, indicating increased net GSH synthesis. Inhibition of gamma-glutamyltransferase had no effect on these results, which indicates that no degradation of GSH had occurred during these studies. Enhanced fractional efflux was also noted in the perfused livers from ethanol-fed rats. Incubation of hepatocytes in medium containing up to 50 mM ethanol had no effect on cellular GSH, accumulation of GSH in the medium, or cell viability. Thus, chronic ethanol feeding causes a modest fall in cytosolic and a marked fall in mitochondrial GSH. Fractional GSH efflux and therefore synthesis are increased under basal conditions by chronic ethanol feeding, whereas the cellular concentration of GSH drops to a lower steady state level. Incubation of hepatocytes with ethanol indicates that it has no direct, acute effect on hepatic GSH homeostasis.

Viologeenit sensorimateriaaleissa

Pro gradu -työn taustalla oli selvittää sähkökemiallisella polymeroinnilla tuotetun viologeenikalvon anioniselektiivisyyttä. Polymerointi toteutettiin sekä staattisella kennosysteemillä että suihkuvirtauskennolla (engl. wall-jet) käyttäen 1,3,5-tris-(N-metyyli-4-syanopyridinium)-2,4,6-trimetyylitribromidi-, trans-1,2-bis-(karbamoyyli-para-metyylisyano-pyridinium)-sykloheksaanidibromidi- ja 1,3-bis-[4-(para-metyylisyanopyridinium)-fenyyli-tioureido]-ksyleenidibromidilähtöaineita. Platina- ja kultasubstraateille muodostettuja viologeenikalvoja tutkittiin voltammetrisesti (CV), kronoamperometrisesti (CA), konduktometrisesta (GA) sekä kvartsikidemikrovaakaa (QCMB) apuna käyttäen. Tulosten perusteella polymeerirakenteet omasivat anionikaviteetteja mutta affiniteetit eri anionien väillä eivät korreloineet täydellisesti sähkökemiallisessa generoinnissa käytettyjen muotti-ionien kanssa. Selektiivisyyteen todennäköisesti vaikuttivat myös liuosfaasissa olleiden ionisten molekyylien ja solvatoituneiden anionien poolisuus ja hydraattiverhon koko. Lisäksi polymeroitujen viologeenien anionivakansseista suurin osa todettiin inaktiivisiksi. Kirjallisuuskatsauksen perusteella substituoidut γ,γ’-bipyridyylit ovat materiaaleina lupaavia ja yleisen sensoriteknologian mielenkiinnon kohteena mm. aurinkokennoissa, biosensoreissa ja elektronin delokalisaatioon perustuvissa värinäytöissä (ECD). Ongelmina löydetyissä sovellutuksissa ovat olleet bipyridyylien vuotaminen liuokseen, katalyyttisesti verraten hitaat elektroninsiirtoreaktiot ja yhdisteiden myrkyllisyys. Vastaavasti etuja ovat olleet polymeerien intensiiviset värit, väriskaalan muokattavuus, sähkökemiallisesti tuotetun radikaalikationin stabiilius vesiliuoksessa, katalyyttinen aktiivisuus ja helppo synteesireitti syanopyridiinilähtöaineista.

Eletrodo íon-seletivo para determinação potenciométrica de alumínio(III) em meio de fluoreto

The construction and analytical evaluation of a coated graphite Al(III) ion-selective electrode, based on the ionic pair formed between the Al(F)n3-n anion and tricaprylylmethylammonium cation (Aliquat 336S) incorporated on a poly(vinylchloride) (PVC) matrix membrane are described. A thin membrane film of this ionic pair and dibutylphthalate (DBPh) in PVC was deposited directly on a cylindric graphite rod (2 cm length x 0.5 cm diameter) attached to the end of a glass tube using epoxy resin. The membrane solution was prepared by dissolving 40% (m/m) of PVC in 10 mL of tetrahydrofuran following addition of 45% (m/m) of DBPh and 15% (m/m) of the ionic pair. The effect of membrane composition, fluoride concentration, and several concomitants as potential interferences on the electrode response were investigated. The aluminium(III) ion-selective electrode showed a linear response ranging from 1.4 x 10-4 to 1.0 x 10-2 mol L-1, a detection limit of 4.0 x 10-5 mol L-1, aslope of -54.3±0.2mV dec-1 and a lifetime of more than 1 year (over 3000 determinations for each membrane). The slope indicates that the ion-selective electrode responds preferentially to the Al(F)4- species. Application of this electrode for the aluminium(III) determination in stomach anti-acid samples is reported.

Síntese, avaliação biológica e modelagem molecular de arilfuranos como inibidores da enzima tripanotiona redutase

Trypanosoma cruzi is a protozoan parasite that causes a severe disease (Chagas'disease) in Central and South America. The currently available chemotherapeutic agents against this disease are still inadequate. The enzyme trypanothione reductase (TR) is considered a validated molecular target for the development of new drugs against this parasite. In this regard, a series of arylfurans based on 2,5-bis-(4-acetamidophenyl)furan was synthesized and tested for their in vitro inhibitory activity against TR. Molecular modeling studies of putative enzyme-inhibitor complexes revealed a possible mechanism of interaction. From synthesized compounds, a benzylaminofuran derivative was found to be more active than the lead compound.

Comportamento eletroquímico da N-nitrosotiazolidina ácido carboxílico sobre eletrodos de ouro e mercúrio

The electrochemical behavior of N-nitrosothiazolidine carboxylic acid (NTAC) on gold and hanging mercury electrodes, using the cyclic and square wave voltammetries, was studied. Whereas NTAC suffer reduction in a single step on the mercury electrode, two peaks appears on the cyclic voltammograms on the gold electrode, one anodic peak overlaying the gold oxide process at 1.2 V and one cathodic peak at -0.41 V vs Ag/AgCl, KCl 3.0 mol L-1. The cathodic peak depends on the previous oxidation of NTAC at the electrode surface, presents irreversible and adsorption controlled characteristics and it is suitable for quantitative purposes.

Determination of traces of nitrate in water samples using spectrophotometric method after its preconcentration on microcrystalline naphthalene

Nitrate is quantitatively retained with 2,6-bis(4-methoxyphenyl)-4-phenyl pyrylium perchlorate (PPP) on microcrystalline naphthalene in the pH range of 6.5-9.0 from a large volume of aqueous solutions of various samples. The method was based on the complexation between PPP and nitrate and then, extraction of the resulted complex from aqueous solution by microcrystalline naphthalene. The solid mass consisting of the nitrate complex and naphthalene was then dissolved in dimethyl formamide (DMF) and absorption of the resulted solution was obtained at 328 nm. The linear calibration range for the determination of nitrate was 15-135 μg L-1 with the detection limit of 10 μg L-1.

Espécies tropicais de pteridófitas em associação com fungos micorrízicos arbusculares em solo contaminado com arsênio

The symbiosis of plants with mycorrhizal fungi represents an alternative to be considered during the processes of revegetation and rehabilitation of arsenic-contaminated soil. The aim of this study was to evaluate under greenhouse conditions the effect of arsenic on the mycorrhizal association of two species of tropical fern (Thelypteris salzmannii and Dicranopteris flexuosa). T. salzmannii had higher rates of colonization and higher density of spores while D. flexuosa showed greater sensitivity to smaller concentrations of arsenic and association with mycorrhizal fungi. Our results indicate that screening and selection of mycorrhizal fungal isolates/species is possible and effective for phytoremediation of arsenic-contaminated soils.

Efeitos da rugosidade superficial nas propriedades de passivação de monocamadas orgânicas automontadas

Precise surface area is needed for accurate characterization of self-assembled monolayers (SAMs) on metallic surfaces. The aim of this manuscript was to emphasize that miscalculation of surface area is the major source of errors in SAM electrochemical characterization. Limitations are discussed and recommendations given for beginners in analyses of SAM functionalized electrodes. The electrochemical measurements and examples were based on bare gold electrode immobilized with dodecanethiol. The degree of compression of the monolayer properties of formation and reproducibility of the electrochemical response depends on roughness factor, with values closer to the unit being better.

Síntese e emprego do [Pd(dmba)(NCO)(PPh3)] em processos catalíticos envolvendo a preparação de derivados da uréia e de alcoxicarbonil complexos

Este trabalho trata do emprego do ciclometalado [Pd(dmba) (NCO)(PPh3)] (dmba = N,N-dimetilbenzilamina; PPh3 = trifenilfosfina) em processos catalíticos em fase homogênea, envolvendo a reação entre p-toluidina e p-nitrotolueno, produzindo N,N'-bis(4-metilfenil)uréia. A reação foi realizada a 140 0C, sob pressão inicial de CO de 60 bar. Empregou-se também o mesmo composto em reações de carbonilação na presença dos álcoois metílico e etílico, obtendo-se os alcoxicarbonil complexos [Pd(NCO)(CO2R)(PPh3)2] (R=Me ou Et). Constatou-se que o emprego do [Pd(dmba)(NCO)(PPh3)] nos referidos processos, propiciou a formação dos produtos com bons rendimentos.

Glyphosate tolerant volunteer corn control at two development stages

The loss of grains during the harvest of glyphosate tolerant corn may generate volunteer plants, which can interfere in the conventional or glyphosate crop in succession. The current work aim to evaluate the control of the volunteer corn glyphosate tolerant under two weed stages. Aimed to evaluate the control of volunteer glyphosate tolerant corn in two stages of development. There were conducted two experiments with hybrid 2B688 HR (lepidoptera and glyphosate tolerant), the application were at V5 and V8 stage. The experiment was randomized block design with four replicates, using the treatments: haloxyfop at 25, 50 and 62 g ha-1 alone and associated with 2,4-D at 670 g ha-1 or fluroxypyr at 200 g ha-1. The standard was clethodim at 84 g ha-1 with 2,4-D and fluroxypyr at same rates. The applications of haloxyfop and clethodim both isolated or in a mixture with 2,4-D and fluroxypyr at V5 stage showed total control (100%) at 32 and 39 days after the application, except for haloxyfop + 2,4-D (25 + 670 g ha-1) mixture, which did not provided adequate control. At V8 stage, haloxyfop + 2,4-D (50 + 670 g ha-1) and haloxyfop + 2,4-D (62 + 670 g ha-1) mixtures took up to 6 and 10 days or longer to reach adequate to excellent control, when compared to haloxyfop isolated applications in the same doses, respectively. Either isolated clethodim or mixed with 2, 4-D and fluroxypyr did not show adequate control. The treatments showed efficient control on volunteer corn plants at V5 stage, except for haloxyfop + 2, 4-D (25 + 670 g ha-1) mixture. At V8 stage applications, haloxyfop either isolated or mixture with fluroxypyr demonstrated excellent control on every evaluated dose. The mixture with 2, 4-D can reduce haloxyfop efficiency at low doses. Clethodim alone or mixed with 2,4-D or furoxypyr did not provide acceptable level of control.

The effect of porphyrins on normal and transformed mouse cell lines in the presence of visible light

Photodynamic therapy consists of the uptake of a photosensitizing dye, often a porphyrin, by tumor tissue and subsequent irradiation of the tumor with visible light of an appropriate wavelength matched to the absorption spectrum of the photosensitizing dye. This class of molecules produces reactive oxygen species when activated by light, resulting in a direct or indirect cytotoxic effect on the target cells. Photodynamic therapy has been used in the treatment of cancer but the technology has a potential for the treatment of several disease conditions mainly because of its selectivity. However, it is not clear why the porphyrins are retained preferentially by abnormal tissue. This paper describes a study of the effect of the association of porphyrin and visible light on two mouse fibroblast cell lines: A31, normal cells and B61, an EJ-ras transformed variant of A31. Two water-soluble porphyrins were used, a positively charged one, tetra(N-methyl-4-pyridyl)porphyrin chloride, and a negatively charged one, tetra(4-sulfonatophenyl)porphyrin-Na salt (TPPS4) in order to assess the effect on cell survival. The results suggest that the B61 cell line is more sensitive to incubation with the anionic porphyrin (TPPS4) followed by light irradiation and that the anionic porphyrin is more efficient in killing the cells than the cationic porphyrin.

Lettres de Jean Du Bellay et pièces relatives à ses ambassades en Angleterre et à Rome (1528-1535).

Contient : 1 « Articles d'instruction à messire Jehan Du Bellay, evesque de Baionne, ambassadeur pour le roy Françoys» Ier « vers le roy Henry » VIII « d'Angleterre, pour traicter une ligue deffensive entre eulx et le roy d'Escosse » Jacques V « y intervenant. 1528 » ; 2 « Double des oblations et offres proposées et ouvertes par le legat en Angleterre, pour parvenir au traicté de paix d'entre l'empereur Charles cinquiesme et le très chrestien roy Françoys, premier du nom, à luy envoyez et portez par le Sr de Morette, le XVIIIe avril 1528 » ; 3 « Memoyres contenans certaines remonstrances et persuasions conceues et proposées par les roy d'Angleterre et cardinal d'Yorth, legat, tendans à faire condescendre le roy très chrestien aux partis par eulx mis en avant pour estre proposez à l'empereur » Charles-Quint « et parvenir au traicté de paix d'entre luy et ledict roy très chrestien envoiés aussy par M. de Morette, le 18 avril 1528 » ; 4 « Discours et advis tenu, le moys de may 1528, entre monseigneur le legat d'Angleterre et le duc de Suffoch, sur le faict de la guerre qui se devoit entreprendre contre l'empereur, au cas que la paix ne se feist entre luy et le roy de France » ; 5 « Forme de traicté de tresve d'entre l'empereur, le roy très chrestien et le roy d'Angleterre, lequel traicté n'a sorty effect ny esté accordé. 14 may 1528 » ; 6 « Autre traicté de tresve, de la forme et manière que les Angloys et Flamens le consentoient, envoyé en France et depuis renvoyé en Angleterre, corrigé par monsieur le chancellier, en juing 1528 » ; 7 « Double du traicté de tresve, d'entre lesdits Srs empereur, roys très chrestien et d'Angleterre, corrigé au vray. Du XVe juing 1528 » ; 8 « Double de la ratiffication que devoit faire madame MARGUERITE, archiduchesse D'AUTRICHE, pour le faict de la tresve ». S. d ; 9 « Forme de ratiffication de ladicte tresve par l'evesque de Baionne JEHAN DU BELLAY ... au nom et comme ambassadeur et procureur dud. Sr roy très chrestien ». S. d ; 10 « Traicté faict par le Sr de Hargerye pour les biens de la duchesse douairière de Vendosme, comprinse au traicté de tresve cy devant ». 28 juillet 1528 ; 11 « Extraict d'un article des lettres du roy très chrestien envoyées à M. de Baionne, son ambassadeur vers le roy d'Angleterre ». S. d ; 12 « Memoyre au Sr de Morette, le secund voiage qu'il fut envoyé vers le roy d'Angleterre ». S. d ; 13 « Obligation d'une contribution accordée par le roy d'Angleterre au roy très chrestien de XXXIIm VIIIe XXVI escus... durant six moys, pour l'entretenement de la guerre contre l'empereur ». S. d. Acte de HENRI VIII ; 14 « Discours des conditions et moiens de paix practiquez par monsieur le legat en Angleterre pour icelle accorder entre l'empereur et le roy très chrestien ». S. d ; 15 « Abregé faict de l'esclarcissement qui se pourroit faire ès articles portez par messire Silvestre pour estre proposez à l'empereur ». S. d ; 16 « Pour respondre à certain advis contenant huict manières pour parvenir à la paix et delivrance de messieurs les enfans du roy très chrestien, dernièrement apporté par reverend père en Dieu monsieur l'evesque de Bade, ambassadeur du roy d'Angleterre, fault considérer ce qui s'ensuyt... » ; 17 « Memoyre de l'advis de monseigneur le legat sur les articles de la dificulté du diferent de Ferrare et de sçavoir si on devra divulguer la capitulation des imperiaulx avec nostre... sainct père » ; 18 « Finales oblatious faictes à l'empereur ». S. d. En latin ; 19 « Lectre de l'empereur, translatée d'espagnol en françoys, à l'ambassadeur estant en Angleterre... Domyngo de Mandoce,... pour luy. Du moys de fevrier 1528 » ; 20 « Pouvoir envoyé par l'empereur à madame Marguerite pour le faict de la paix ». S. d ; 21 « Lettres au roy Françoys, premier du nom, de la part de ses ambassadeurs en Angleterre, c'est asçavoir l'evesque de Bayone » Jean Du Bellay, « ambassadeur ordinaire, et le Sr de Brosse, envoié pour negociation particulière ». 2, 9 et 20 janvier 1528 ; 22 Lettres de JEAN DU BELLAY au grand maître Anne de Montmorency ; 1527 (?) 15 mai (fol. 163) ; 1528. 20 janvier (fol. 44), 6 février (fol. 50), 10 février (fol. 54), 12 mars (fol. 56), 19 mars (fol. 56), 24 mai (fol. 64), 28 mai (fol. 66), 18 juin (fol. 71), 21 juillet (fol. 74), 28 juillet (fol. 81), 8 août (fol. 83), 3 septembre (fol. 85), 20 septembre (fol. 87), 6 octobre (fol. 91), 17 octobre (fol. 92), 1er novembre (fol. 97), 8 novembre (fol. 105), 17 novembre (fol. 108 r° ), 17 novembre (fol. 108 v° ), 20 décembre (fol. 124) ; 1529. 5 mars (fol. 128), 18 mai (fol. 130), 15 juin (fol. 134), 22 juin (fol. 136), 30 juin (fol. 139), 3 juillet (fol. 140), 1er septembre (fol. 141), 17 septembre (fol. 142), 12 octobre (fol. 146), 17 octobre (fol. 147), 22 octobre (fol. 149), 27 octobre (fol. 150), 2 novembre (fol. 98) ; 1533. 8 février (fol. 189), 15 mars (fol. 195) ; 1535. 3 septembre (fol. 220), 23 septembre (fol. 232), 27 novembre (fol. 247) ; 23 Lettres du même au roi ; 1527. 14 décembre (fol. 120) ; 1528. 6 février (fol. 46), 10 février (fol. 52), 26 mars (fol. 57), juillet (?) (fol. 63), 28 juillet (fol. 78), 3 septembre (fol. 84), 24 septembre (fol. 88), 28 octobre (fol. 94) ; 1529. 30 mars (fol. 130), 15 juin (fol. 132), 22 juin (fol. 134), 30 juin (fol. 137 bis), 4 octobre (fol. 143), 12 octobre (fol. 145) ; 1533. 8 février (fol. 189), 24 février (fol. 193), 15 mars (fol. 193), 23 mars (fol. 200), 24 mars (fol. 201), 1er avril (fol. 201) ; 1535. 15 juillet (fol. 203), 18 juillet (fol. 204), 26 juillet (fol. 205), 3 septembre (fol. 215 et 215 bis), 23 septembre (fol. 234), 5 novembre (fol. 238), 5 novembre (fol. 241), 12 novembre (fol. 242 ter), 12 novembre (fol. 245), 27 novembre (fol. 254), 6 décembre (fol. 264), 22 décembre (fol. 267), 31 décembre (fol. 280) ; 1537 (?) 3 septembre (fol 215) ; 24 Lettres du grand maître ANNE DE MONTMORENCY à Jean Du Bellay ; 1527. 21 mai (fol. 164), 30 juillet (fol. 166) ; 1528. 5 janvier (fol. 153), 9 janvier (fol. 154), 20 janvier (fol. 154), 20 janvier (fol. 159), 24 janvier (fol. 159), 3 avril (fol. 161), 19 avril (fol. 162), 10 août (fol. 169), 10 août (fol. 170), 22 août (fol. 171), 24 septembre (fol. 171), 26 octobre (fol. 174), 1er novembre (fol. 175), 24 décembre (fol. 175) ; 1529. 1er septembre (fol. 183 v° ), 9 septembre (fol. 183 r°), 25 octobre (fol. 186) ; 25 Lettres de FRANÇOIS Ier à Jean Du Bellay, son ambassadeur en Angleterre d'abord, et à Rome ensuite ; 1528. 3 janvier (fol. 157), 3 mars (fol. 161), 23 mai (fol. 165), 8 août (fol. 167), 20 octobre (fol. 172) ; 1529. 17 juin (fol. 177), 9 juillet (fol. 179), 13 juillet (fol. 180), 26 juillet (fol. 182), 23 septembre (fol. 185). — Mémoire qu'il lui envoie, le 23 septembre 1529 (fol. 184-185) ; 26 Lettres de JEAN DU BELLAY : ; 27 Lettres diverses :

Reactions of various aromatic nitro-compounds and anthraquinones with selected bases and nucleophiles

The Introducti on deals mainly with hi storical studies on aryne chemi stry and ring closure via arynes , hydride replacement from aromatic rings by nucleophi les, c l eavage of anthr aquinones in basic medium and the Leuckart reaction . This work can be divided into two main s ect i ons. Section I is concerned with the investigation of t he reaction of some aromatic ni t ro-compounds with potassamide in l iquid ammonia. 3-Amino-4- nitrobenzophenone was obtained from the reacti on of 4-nitrobenzophenone with t his reagent, toge t her with benzoic acid formed in a competing Haller-Bauer reaction. Nitrobenzene under these conditions gave a complex mixture from which 2-phenylphenol was isolated; a reaction i nvolving benzyne may be i nvo l ved. 4-Nitrodiphenyl sulfone gave 4-aminodiphenyl sulfone and 4-nitroani l ine. 4-Ethoxydiphenyl sulfone and 4-ethoxynitrobenzene were isolated when ethanol was used as a co-solvent in the reaction. Oxidative coupling reactions were observed with nitrotoluenes. 4-Nitrotoluene gave 4,4t-dinitrobibenzyl which i n a pro longed reaction gave 4,4t-dinitros t ilbene . 2-Nitrotoluene gave 2 , 2 t-dinitrobibenzyl, but not the corresponding stilbene derivative even after a longer time . A rather i nteresting result was obtained with 1-nitro-2,4,6- trimethylbenzene which gave a stilbene derivative only. Also the corresponding stilbene was obtained from bis-(4-nitrophenyl)-methane in a rather slow r eaction with this reagent . Section II deals wi th (i) the preparation of 5-chloro- 1-N-methyl aminoanthraquinone and a new synthesis of N-methyl acridones and (ii) treatment of chloro-anthraquinones with fo rmamide and a new synthesis of chloro-anthracenes . 5-Chloro-1 -N-methylaminoanthraqui none was synthesised f rom 1,5-dichloroanthraquinone by treatment with N-methylformamide. Treatment of 5-chloro-1-N-methylaminoanthraquinone with potassamide in liquid ammonia or with potassium t-butoxide i n t-butylbenzene gave N-methylacridone-1-carboxylic acid. This pleasing result, t he outcome of r i ng opening and alter native ring closure, is being extended to related ring systems.

Studies on the Synthesis and Transformations of a Few 2(3H)- and 3(2H)-Furanones

The thesis entitled studies on the synthesis and transformations of a few 2(3H)- and 3(2H)- furanones. Furanones represent an interesting class of heterocyclic compounds, which constitute the central ring system of many natural products. The derivatives of furan is divided, depending on their structure 2(3H)-furanones(I), 2(5H)-furanones(II), and 3(2H)-furanones(III). Systems I&II are unsatured gama lactones known as ‘butenolides’. Compounds of this type also known as ‘crotonolactones’ based on the parent crotonic acid. In conclusion a number of 2(3H)-and 3(2H)- furanones were synthesized from dibenzoylalkene precursors and were characterized on the basis of spectral analytical and X-ray data. On direct irradiation 3,3-bis(4-chloropheneyl)-5-aryl-3H-furan -2-ones underwent decarbonylation to yield the corresponding alpha, beta- unsaturated carbonyl compounds and upon sensitized irradiation they underwent dimersation arising through a 2+2 cycloaddition reaction. Our studies on 3(2H)-furanones revealed that these compounds are thermally stable, while they undergo extensive decomposition to intractable mixtures under the influence of light. Similarly, the novel dibenzoylalkenes- type systems containing hetroatomatic rings synthesized by us also underwent extensive decomposition under the influence of heat. Some of the 3(2H)-furanones synthesized by us exhibit remarkable anti-proliferative activity.