RESUMO
Essential oils from aerial parts of six aromatic plants were analysed by GC-MS. The major compounds identified were γ-terpinene (11.5%), cuminaldehyde (26.6%) and γ-terpinen-7-al (40.6%) in Cuminum cyminum, trans-anethol (95.2%) in Pimpinella anisum, α-pinene (11.6%), limonene (21.0%), ß-caryophyllene (22.3%) and α-humulene (16.7%) in Lippia integrifolia, limonene (40.8%) and artemisia ketone (19.3%) in Lippia junelliana, trans-ß-ocimene (15.6%), 4-ethyl-4-methyl-1-hexene (24.5%), trans-tagetone (20.5%) and verbenone (27.2%) in Tagetes minuta, 1,8-cineole (17.9%),elixene (10.3%) and spathulenol (13.8%) in Aloysia gratissima. Oils with strong insecticidal activity on Carpophilus dimidiatus and Oryzaephilus mercator were from P. anisum (LC50 = 4 µl/L; LC100 = 10 µl/L) and T. minuta (LC50=10.19-12.57 µl/L; LC100=20 µl/L). Scents of C. cyminum and L. junelliana were strong insecticides on O. mercator (LC50=7.02-7.17 µl/L; LC100=10.00-20.00 µl/L). The insecticidal activity was associated to the whole content of C10 molecules and oxygenated constituents. The P. anisum oil is promising as protective agent of nut products.
Assuntos
Besouros , Inseticidas , Óleos Voláteis , Animais , Óleos Voláteis/farmacologia , Limoneno , Inseticidas/farmacologia , ArgentinaRESUMO
Essential oils from six species of aromatic plants collected in the Catamarca Province of Argentina were evaluated for their chemical composition and repellent and insecticidal activities against beetles of the genus Carpophilus (Coleoptera: Nitidulidae) and Oryzaephilus (Coleoptera: Silvanidae) that infest the local walnut production. Experimental data were analyzed using generalized estimating equations, with normal distribution and the identity link function. From the spectral information from the tested essential oils, we worked their molecular modeling as mixtures by developing mixture descriptors ( Dmix) that combined the molecular descriptor of each component in the mixture ( d i) and its relative concentration ( x i), i.e., Dmix = f( d i, x i). The application of chemoinformatic approaches determined that a combination of mixture descriptors related to molecular size, branchedness, charge distribution, and electronegativity were useful to explain the bioactivity profile against Carpophilus spp. and Oryzaephilus spp. The reported models were rigorously validated using stringent statistical parameters and essential oils reported with repellent activity against other beetle species from the Nitidulidae and Silvanidae families. This model confirmed each essential oil as a repellent with a comparable performance to the experimental reports.
Assuntos
Besouros/efeitos dos fármacos , Repelentes de Insetos/química , Repelentes de Insetos/farmacologia , Juglans/parasitologia , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Doenças das Plantas/parasitologia , Animais , Argentina , Besouros/fisiologia , Nozes/parasitologia , Doenças das Plantas/prevenção & controle , Óleos de Plantas/química , Óleos de Plantas/farmacologia , Relação Quantitativa Estrutura-AtividadeRESUMO
In our continuing efforts to find out acceptable Absorption, Distribution, Metabolization, Elimination and Toxicity (ADMET) properties of organic compounds, we establish linear QSAR models for the carcinogenic potential prediction of 1464 compounds taken from the "Galvez data set", that include many marketed drugs. More than a thousand of geometry-independent molecular descriptors are simultaneously analyzed, obtained with the softwares E-Dragon and Recon. The variable subset selection method employed is the Replacement Method, and also the improved version Enhanced Replacement Method. The established models are properly validated through an external test set of compounds, and by means of the Leave-Group-Out Cross Validation method. In addition, we apply the Y-Randomization strategy and analyze the Applicability Domain of the developed model. Finally, we compare the results obtained in present study with the previous ones from the literature. The novelty of present work relies on the development of an alternative predictive structure-carcinogenicity relationship in a large heterogeneous set of organic compounds, by only using a reduced number of geometry independent molecular descriptors.
Assuntos
Carcinógenos/toxicidade , Modelos Moleculares , Compostos Orgânicos/efeitos adversos , Testes de Carcinogenicidade , Carcinógenos/química , Humanos , Modelos Lineares , Compostos Orgânicos/química , Relação Quantitativa Estrutura-Atividade , SoftwareRESUMO
The conformational and electronic characteristics of the polar O(9)âC(8)-X(10) moiety in the anticonvulsant valproic acid (Vpa) drug and some of their amides and ester derivatives are analyzed at the B3LYP level using the 6-31+G(d,p) and 6-311++G(d,p) 6d,10f basis sets. Exploring the delocalization of the electron density of the O(9)âC(8)-X(10) moiety by means of ELF, NBO, and AIM calculations, we found that the bending away from coplanarity of the atoms in O(9)âC(8)-X(10) is accompanied by a three-dimensional arrangement of donor and acceptor proton units closing nearly planar pseudorings of four, five, and six members arising from stabilizing interactions around the O(9)âC(8)-X(10) backbone. From the structure-property relationship analysis, we explain the origin of the change in the structural parameters and atomic charges in the polar moiety.
Assuntos
Anticonvulsivantes/química , Elétrons , Ácido Valproico/química , Anticonvulsivantes/farmacologia , Eletrochoque , Modelos Moleculares , Conformação Molecular , Relação Estrutura-Atividade , Ácido Valproico/análogos & derivados , Ácido Valproico/farmacologiaRESUMO
The equilibrium structures, the planarity of the C(=O)X linkage and the nature of the chemical bond in the Y-C(=O)-XR(1)R(2) [where: Y= -CH-(CH(2)-CH(2)-CH(3))(2), X=N,O and R(1), R(2)= H; alkyl and aryl groups and lone pair electrons (lp)] molecular fragment of derivates of Valproic acid (Vpa) with antiepileptic activity were studied systematically by means of B3LYP calculations and topological analysis of the electron localization function (ELF). The covariance parameter cov[Omega(i), Omega(j)] reveals a dominating delocalization effect between the lone pair V(O(1)), V(X) and the electron density of the H-C and H-X(1) bonds resulting from the existence of not only non-conventional intramolecular hydrogen bonding patterns as C-H...O/N but also a weak closed-shell stabilizing interaction type arising from a dihydrogen bonding as C-H...H-N, where H...H contacts at a significantly shorter distance than twice the hydrogen atom van der Waals radius. The analyzed data derived from ELF domains were found to be in agreement with the known features and properties of the hydrogen bonding interactions discussed in this work.