Antonieta Taddei

Antibacterial and Cytotoxic Activity of Leaf Essential Oil of Croton malambo

Abstract The composition of the essential oil obtained from leaves of Croton malambo was determined by means of GC-MS analysis. The major compound present in the oil was found to be: methyl eugenol (94.2 %); γ-bisabolene (1.3 %), isoelemicin (0.8 %) and γ-curcumene (0.8 %) were the minor compounds. The antibacterial activities of the oil from leaf were assessed against Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginose, Escherichia coli and Candida tropicalis. A significant antibacterial activity was determined with the agar diffusion method. In vitro cytotoxic activity of C. malambo essential oil was tested against, human breast cancer cell line MCF-7, on prostate cancer cell line PC 3, on colon carcinoma LoVo and on normal human fibroblasts. The results indicated a moderate activity on MCF-7 cancer cell line.

4,6-Diamino-5-(4-methylbenzylidene)pyrimidin-2(5H)-one

Abstract: A new compound, 4,6-diamino-5-(methylbenzylidene)pyrimidin-2(5 H )-one, was synthesized and its IR, 1 H NMR, 13 C NMR and MS spectroscopic data are presented. Keywords: 4,6-diamino-5-(4-methylbenzylidene)pyrimidin-2(5 H )-one; urea; antimicrobial activity Pyrimidines and their derivatives are considered an important group of compounds because of the diversity of biological activities associated with these systems. Among the activities reported for pyrimidines have been found antifolate [1], antimicrobial [2], leishmanicidal [3], anticonvulsant [4], anti-rubella [5], anti-HIV [6], calcium channel modulation [7], and selective hepatitis B virus inhibition [8]. In the specialized literature, we can find different articles on the synthesis of substituted pyrimidines and many detailed reviews have appeared [9–12]. Recently, the Biginelli reaction is a well-known multicomponent reaction involving a one-pot cyclocondensation of an aldehyde, a methylene active compound and urea/thiourea for the synthesis of pyrimidine derivatives [13–15]. Nevertheless, little attention is given to the synthesis and biological activity of the pyrimidine nucleus having the benzylidene group in position 5, close to amino groups at positions 4 and 6. We report here the synthesis and biological activity of 4,6-diamino-5-(4-methylbenzylidene)pyrimidin-2(5

Synthesis of 2-(4-nitrophenoxy)quinoxaline and its reactions with hydroxide ion in micellar systems

Abstract The synthesis of 2-(4-nitrophenoxy)quinoxaline (3) is described. The reaction of (3) with hydroxide ion was studied in the presence and absence of micellar systems. Cationic micelles of cetyltrimethylammonium chloride and bromide (CTACl and CTABr) and tetradecyltrimethylammonium chloride and bromide (MTACl and MTABr) speed the reaction of (3) with hydroxide ion. The second-order rate constants at the micellar pseudophase are smaller than the second-order rate constant in water.

Synthesis and biological evaluation of caracasine acid derivatives.

A series of caracasine acid (1) derivatives were synthesized and evaluated for their in vitro cytotoxicity on human cancer-derived cell lines MCF-7 and PC-3, as well as for other activities such as antibacterial, antileishmanial and antitrypanosomal activity. Compound 1 was more effective than any of its derivatives against tested human cancer cell lines. PC-3 cells were more sensitive than MCF-7 to all compounds, particularly the methyl ester (2), the amide (9) and the epoxide (10). The evaluation of antiparasitic activity revealed that ester derivatives (2-8) and the amide derivative (9) were the most effective antileishmanial and antitrypanosomal compounds, even though their effect on Trypanosoma cruzi was modest. Finally, compound 1 and the derivatives evidenced a broad spectrum of antibacterial activity, as assayed against Gram-positive and Gram-negative bacteria.

Photosensitizing properties of Actarit, an antirheumatic drug.

The photobiological properties of 4-acetylaminophenylacetic acid (Actarit, ACT, MS-932, CAS 18699-02-0) were studied using in vitro phototoxicity assays: photohemolysis, photoperoxidation of linoleic acid and Candida sp phototoxicity test. ACT reduced nitro blue tetrazolium (NBT) when irradiated with lambda > or = 300 nm in deoxygenated aqueous buffer solution (pH 7.4). The photohemolysis rate and photoperoxidation of linoleic acid were inhibited significantly by reduced glutathione. ACT was phototoxic to Candida sp. The isolation and identification of the photodegradation products of ACT in phosphate buffered saline solution (pH 7.4) and methanol were studied under aerobic conditions. Four compounds were identified and two of them isolated and characterized by spectroscopic methods. A photodecarboxylation with the participation of oxygen via a type I mechanism was proposed for the photodegradation of ACT which undergoes direct electron transfer from the excited state of ACT carboxylate and homolytic rupture of the alpha-carbon bond. A photodynamic mechanism involving radicals and electron transfer reactions was suggested for the observed in vitro phototoxicity.

4,6-Diamino-5-[4-(dimethylamino)benzylidene]pyrimidin-2(5H)-one

A new compound, 4,6-diamino-5-[4-(dimethylamino)benzylidene]pyrimidin-2(5H)-one, was synthesized and its IR, 1H NMR and 13C NMR and MS spectroscopic data are presented.

4,6-Diamino-5-(3,4-dichlorobenzylidene)pyrimidin-2(5H)-one

A new compound, 4,6-diamino-5-(3,4-dichlorobenzylidene)pyrimidin-2(5H)-one, was synthesized and its IR, 1H NMR,13C NMR, MS spectroscopic data and elemental analysis are presented.