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Malaria is still the most destructive and dangerous parasitic infection in many tropical and subtropical countries. The burden of this disease is getting worse, mainly due to the increasing resistance of Plasmodium falciparum against the widely available antimalarial drugs. There is an urgent need for new, more affordable and accessible antimalarial agents possessing original modes of action. Natural products have played a dominant role in the discovery of leads for the development of drugs to treat human diseases, and this fact anticipates that new antimalarial leads may certainly emerge from tropical plant sources. This present review covers most of the recently-published non-alkaloidal natural compounds from plants with antiplasmodial and antimalarial properties, belonging to the classes of terpenes, limonoids, flavonoids, chromones, xanthones, anthraquinones, miscellaneous and related compounds, besides the majority of papers describing antiplasmodial crude extracts published in the last five years not reviewed before. In addition, some perspectives and remarks on the development of new drugs and phytomedicines for malaria are succinctly discussed.

The conformation of the title molecule, C17H17N3S, is stabilized by an intramolecular N—H...N hydrogen bond involving the azometinic group. The dihedral angle between the two aromatic rings is 36.49 (06)°. The non-aromatic ring of the tetralone substituent adopts a sofa conformation. In the crystal, molecules are linked by pairs of N—H...S hydrogen bonds relatedviacentres of symmetry, forming dimers.

The reaction of 2-(1,2,3,4-tetrahydronapthalen-1-ylidene)hydrazinecarbothioamide (TTSC) with pyrazine-2,3,5,6-tetracarbonitrile (tetracyanopyrazine, TCNP) yields the title 2:1 charge-transfer adduct, 2C11H12N3S·C6N8. The complete TCNP molecule is generated by a crystallographic inversion centre and the non-aromatic ring in the TTSC molecule adopts an envelope conformation with a methylene C atom as the flap. In the crystal, the thiosemicarbazone molecules are connected through inversion-related pairs of N—H...S interactions, building a polymeric chain along theb-axis direction. The TCNP molecules are embedded in the structure, forming TTSC–TCNP–TTSC stacks with the aromatic rings of TTSC and the molecular plane of TCNP in a parallel arrangement [centroid–centroid distance = 3.5558 (14) Å]. Charge-transfer (CT)viaπ-stacking is indicated by a CT band around 550 cm−1in the single-crystal absorption spectrum.

Made available in DSpace on 2022-04-28T19:00:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-08-06 The title compound, C11H21N3S, consists of a menthone moiety attached to an extended thiosemicarbazone group with the N - N - C - N torsion angle being 11.92 (16)°. The cyclohexane ring has a chair conformation and the conformation about the C=N bond is E. In the crystal, molecules are linked via pairs of N - H⋯S hydrogen bonds, forming chains along the a axis. The absolute structure could be assigned with reference to the starting material, i.e. enantiopure (-)-menthone [Flack parameter = 0.05 (5)]. Departamento de Química Universidade Federal de Sergipe, Av. Marechal Rondon s/n Institut für Anorganische Chemie Universität Bonn, Gerhard-Domagk-Strasse 1 Instituto de Química Universidade Estadual Paulista, Rua Francisco Degni s/n Instituto de Química Universidade Estadual Paulista, Rua Francisco Degni s/n

Foi comparada, em laboratório, a atividade moluscicida do extrato hexânico da casca da castanha do caju - Anacardium occidentalel L. (EHCCC), do complexo de cobre (II), docomplexo de chumbo (II) e do ácido anacárdico com objetivo de encontrar entre eles um produto que apresentasse maior estabilidade que o ácido anacárdico. Este foi preparado tratando o EHCCC com hidróxido de chumbo (II) ou com o sulfato de cobre mais hidróxido de sódio ou com hidróxido de cobre (II). Em seguida, o complexo de chumbo (II) ou os complexos de cobre (II)preparados foram tratados com uma solução de ácido sulfúrico diluída. As misturas dos dez produtos obtidos foram testadas sobre caramujos adultos de Biomphalaria glabrata nas concentrações de la 10 ppm. Os mais ativos foram o complexo de cobre (II), obtido com sulfato de cobre mais hidróxido de sódio, e o ácido anacárdico (hidróxido de chumbo) que apresentaram atividade a partir da concentração de 4 ppm. O teor de chumbo do ácido anacárdico (hidróxido de chumbo) foi acima das normas recomendadas pelos Padrões de Saúde Pública dos Estados Unidos.The molluscicide activity of hexanic extract from Anacardium occidental L. (cashew) nutshell, of copper (II) complex, of lead (II) complex and anacardic acid has been compared in the laboratory in an attempt to obtain better stability than anacardic acid. This was obtained from the hexanic extract of the cashew nut shell by precipitation with lead (II) hydroxide or cupric sulfate plus sodium hydroxide or (II) cupric hydroxide followed by treatment of lead (II) complex with a diluted solution of sulfuric acid. Ten products of the mixture obtained were tested on adults snails of Biomphalaria glabrata at I to 10 ppm. The most active products were copper (II) complex, obtained by cupric sulfate plus sodium hydroxide, and anacardic acid (sodium hydroxide) which presented activity at 4ppm. The anacardic acid's lead content was above the limits accepted by the United States standards.

In the title compound, [Ni(C15H14N3O2S)2], the NiIIatom lies on a center of symmetry. The deprotonated ligands act asN,S-donors, forming five-membered metalla-rings. The NiIIatom is four-coordinated in a slightly distorted square-planar environment. In the crystal, the discrete complex molecules are linked by weak N—H...O hydrogen bonds, generating chains along [110]. The chains are further connectedviaweak O—H...N interactions into a layered network extending parallel to (001).