ICEN - Instituto de Ciências Exatas e Naturais

URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/2435

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Agora exibindo 1 - 19 de 19

Acesso aberto (Open Access)
Ab Initio correlated all electron Dirac-Fock calculations for eka-francium fluoride (E119F)
(2012-06) MIRANDA, Patrícia S.; MENDES, Anna Paula S.; GOMES, José da Silva; ALVES, Claudio Nahum; SOUZA, Aguinaldo R. de; SAMBRANO, Julio Ricardo; GARGANO, Ricardo; MACEDO, Luiz Guilherme Machado de
Results obtained with correlated 4-component Dirac-Fock calculations for element E119 (eka-francium) fluoride with stable and accurate basis set (prolapse-free) are reported in this work. At CCSD(T) level, the equilibrium distance Re, harmonic frequency ωe and dissociation energy De are 2.432 Å, 354.97 cm-1 and 116.92 kcal mol-1, respectively. A 4-component prolapse free basis set for E119, an accurate analytical potential energy curve and vibrational spectra from CCSD(T) data are also reported. Our results suggest that E119F should be less ionic than lighter alkaline fluoride homologues, in contrast to the common chemical belief based on periodic trends - it would be expected in this molecule the most ionic bond possible. We also found that the charge model correction to neglect SS integrals leads to negligible errors and speed up calculations close to three times at CCSD(T) level and close to 4 times at DFT/B3LYP level.
Acesso aberto (Open Access)
Ácidos fenólicos, flavonoides e atividade antioxidante em méis de Melipona fasciculata, M. flavolineata (Apidae, Meliponini) e Apis mellifera (Apidae, Apini) da Amazônia
(2012) OLIVEIRA, Patricia Sertão; MÜLLER, Regina Celi Sarkis; DANTAS, Kelly das Graças Fernandes; ALVES, Claudio Nahum; VASCONCELOS, Marcus Arthur Marçal de; VENTURIERI, Giorgio Cristino
Honey produced by three stingless bee species (Melipona flavolineata, M. fasciculata and Apis mellifera) from different regions of the Amazon was analyzed by separating phenolic acids and flavonoids using the HPLC technique. Data were subjected to multivariate statistical analysis (PCA, HCA and DA). Results showed the three species of honey samples could be distinguished by phenolic composition. Antioxidant activity of the honeys was determined by studying the capacity of inhibiting radicals using DPPH assay. Honeys with higher phenolic compound contents had greater antioxidant capacity and darker color.
Acesso aberto (Open Access)
Assessment of surface water in two Amazonian rivers impacted by industrial wastewater, Barcarena City, Pará State (Brazil)
(2011-08) LIMA, Marcelo de Oliveira; SANTOS, Elisabeth Conceição de Oliveira; JESUS, Iracina Maura de; MEDEIROS, Adaelson Campelo; FAIAL, Kelson do Carmo Freitas; ALVES, Claudio Nahum
In 2007, surface waters were collected from 21 sampling points in Barcarena City in Northern Region of Brazil: one sampling point located in a stream that receives discharge of wastewater from a kaolin processing industry and flows into the Curuperê River, three sampling points located near sources that emerge on the left bank and flow into the Curuperê River, nine sampling points in Curuperê River, which flows into the Dendê River, and eight in Dendê River, a tributary on the right bank of the Pará River. For all water samples were quantified 14 physicochemical variables and levels of 12 metals. The results in the points near the sources of the Curuperê River presented physicochemical profile and metal levels which are typical of surface waters being used as reference to compare and identify possible changes in the chemical characteristics of the other sampling points. The comparison between the results obtained for the sources of the Curuperê River and the ones for the point near the discharge of industrial wastewater revealed strong changes in the values of 6 physicochemical variables (pH, electrical conductivity (EC), total dissolved solids (TDS), sulfate (SO4), ammoniacal nitrogen (NH4-N) and salinity) and an increase in magnitude of the levels of four metals (Al, Fe, Mn and Zn). These facts characterized that the wastewaters were discharged into the environment without adequate treatment. Results in other sampling sites showed that these anomalous conditions were also found along the Curuperê and Dendê Rivers, especially during low tide. This chemical characterization of the waters allowed to identify harmful conditions to aquatic ecosystems and potential health risk for the local people, who use the rivers for drinking water, recreation and transportation.
Acesso aberto (Open Access)
Avaliação de minerais em plantas medicinais amazônicas
(2009-06) MARTINS, Alexsandro Sozar; ALVES, Claudio Nahum; LAMEIRA, Osmar Alves; SANTOS, Alberdan Silva; MÜLLER, Regina Celi Sarkis
The Amazonian Brazilian offers an appreciable potential of plants with therapeutic properties, although most are little known. In this way, with the objective of verifying the potentiality nutritional of medicinal herbs, a work was developed to determine the concentration of Ca, Mg, Fe, Cu and Zn in the leaves and in the teas of these species: Piper callosum Ruiz & Pav., Piperaceae, Mikania lindleyana DC., Asteraceae e Arrabidaea chica (Humb. & Bonpl.) B. Verl., Bignoniaceae. After the plants samples have been processed, they were submitted to digestion and soon afterwards the metals were analyzed in an spectrophotometer of Atomic Absorption. The results showed the follow yields: for the tea of Arrabidaea chica Ca were detected (6955 to 20058 mg/L), Mg (2390 to 3094 mg/L) and Fe (40 to 61 mg/L). For the tea of Mikania lindleyana besides the presence of high values of Ca (17722 to 22336 mg/L), Mg (4531 to 9370 mg/L) and Fe (20 to 87 mg/L) they were found from 7 to 16 mg/L of Cu and 9 to 41 mg/L of Zn. The tea of the Piper callosum presented 2036 to 4344 mg/L of Ca, 618 to 4023 mg/L of Mg and 39 to 60 mg/L of Fe. Being compared the results of the minerals with the values recommended by the Health World Organization, is possible that the present metals in the teas of the plants could contribute in the complementation of the people's alimentary diets that use these medicinal plants.
Acesso aberto (Open Access)
Avaliação do efeito antifúngico do óleo resina e do óleo essencial de copaíba (Copaifera multijuga Hayne)
(2011) DEUS, Ricardo Jorge Amorim de; ALVES, Claudio Nahum; ARRUDA, Mara Silvia Pinheiro
Copaifera multijuga Hayne oil in natura and its fractions were evaluated as to their fungitoxic activities against five filamentous fungus species belonging to the genus Aspergillus and three yeast species of the genus Candida. Oleoresin and essential oil concentrations ranging from 0.08 mg mL-1 to 1.6 mg mL-1 were used for qualitative and quantitative analyses. The samples were placed onto 5mm-diameter paper discs distributed on Sabouraud's medium in Petri dishes inoculated with spores of the microorganisms and incubated at 28ºC for 10 days. A solution containing 1.6 mg mL-1 miconazole nitrate was used as positive control. Qualitative results showed that the oleoresin presented good activity, while a fraction of the essential oil was highly effective against Candida parapsilosis IOC-2882, Aspergillus flavus IOC-3874 and A tamarii IOC-187 with 16.0±1.4 mm, 19.5±2.1 mm and 12.5±3.5 mm inhibition halos, respectively. The quantitative evaluation showed that 0.3 mg mL-1 oleoresin inhibited the growth of Aspergillus flavus and Candida parapsilosis, while 0.08 mg mL-1 of the essential oil fraction reached this same activity.
Acesso aberto (Open Access)
Biotransformation of chalcones by the endophytic fungus Aspergillus flavus isolated from Paspalum maritimum trin
(2011-07) CORRÊA, Marivaldo José Costa; NUNES, Fátima Miranda; BITENCOURT, Heriberto Rodrigues; BORGES, Fábio Cardoso; GUILHON, Giselle Maria Skelding Pinheiro; ARRUDA, Mara Silvia Pinheiro; MARINHO, Andrey Moacir do Rosário; SANTOS, Alberdan Silva; ALVES, Claudio Nahum; BRASIL, Davi do Socorro Barros; SANTOS, Lourivaldo da Silva
The fungus Aspergillus flavus isolated as endophytic of the plant Paspalum maritimum Trin. was evaluated for its potential application in biotransformation reactions. The compounds chalcone (1), 3,4,5-trimethoxychalcone (2) and 2,3,4,4'-tetramethoxychalcone (3) were biotransformed, respectively, in dihydrochalcone (4), 3,4,5-trimethoxydihydrochalcone (5) and 2,3,4,4'-tetramethoxydihydrochalcone (6). The structures were elucidated by spectroscopic methods including 1D and 2D NMR techniques, and MS analysis. The dihydrochalcones 5 and 6 are new compounds.
Acesso aberto (Open Access)
Biotransformation of sucrose into 5-hydroxy-2-hydroxymethyl-γ-pirone by Aspergillus flavus
(2010-09) FERREIRA, Nelson Rosa; SARQUIS, Maria Inez de Moura; ALVES, Claudio Nahum; SANTOS, Alberdan Silva
The sucrose hydrolysis and the preference of consumption of glucose instead of fructose were investigated for the production of 5-hydroxy-2-hydroxymethyl-γ-pyrone (HHMP) in the presence of Aspergillus flavus IOC 3974 cultivated in liquid Czapeck medium. Standardized 0.5g of pellets were transferred as inoculum into twelve conical flasks of 250 ml containing 100 ml of medium with different sucrose concentration, which was kept at 120 rpm and 28"C for 16 days without pH adjustment. Aliquots of 500μl of the broth culture were withdrawn at 24 h intervals and analyzed. The major yield of HHMP was 26g l-1 in 120g l-1 of sucrose. At these conditions, A. flavus produced an invertase capable of hydrolyzing 65% of total sucrose concentration in 24h, and an isomerase capable of converting fructose into glucose. In this work, it focused the preference for glucose and, then, of fructose by A. flavus and the strategy used to produce HHMP.
Acesso aberto (Open Access)
Characterization of the Fruit Pulp of Camu-Camu (Myrciaria dubia) of Seven Different Genotypes and Their Rankings Using Statistical Methods PCA and HCA
(Universidade Federal do Pará, 2016-10) FREITAS, Camila Auad Beltrao de ; SILVA, Antonio dos Santos; ALVES, Claudio Nahum; NASCIMENTO, Walnice Maria Oliveira do; LOPES, Alessandra Santos; LIMA, Marcelo de Oliveira; MÜLLER, Regina Celi Sarkis
Due to the economic potential of camu-camu, considering its high concentration of vitamin C, the aim of this work was to evaluate the quality and genetic variability seven accessions of camu-camu conserved in genebank (BAG) of Embrapa Amazônia Oriental, in the state of Pará, Amazon region, Brazil. The fruits of camucamuzeiro were analyzed for physicochemical characterization (standard methodologies) and mineral composition. The data were subjected to multivariate statistical analysis, using the techniques of cluster analysis and principal component analysis. The formation of different groups for each genotype, which shows the genetic variability and the dissimilarity of the genotypes in the species data, may be used to guide the selection of promising genotypes to enrich the programs of genetic improvement of the camucamuzeiro. Ascorbic acid showed levels above 1000 mg 100 g-1, however, genotypes 4, 1 and 2 show the highest potential and the most promising nutritional capacity, but genotype 4 showed good characteristics for the moisture, acidity, carbohydrates, Cu and Zn and differs totally from others about the total soluble solids (TSS) and flavon-3-ol, features that make it the most promising genotype. It was possible to separate the seven different genotypes using multivariate analysis (hierarchical cluster analysis-HCA and principal component analysis-PCA).
Acesso aberto (Open Access)
Classification of honeys from Pará State (Amazon region, Brazil) produced by three different species of bees
(2013-07) SILVA, Antonio dos Santos; ALVES, Claudio Nahum; DANTAS, Kelly das Graças Fernandes; MÜLLER, Regina Celi Sarkis
Twenty seven samples of honey produced in ten cities of Pará State (Amazon region, North of Brazil) by three different species of bee (Apis mellifera, Melipona fasciculata and Melipona flavoneata) were characterized based on mineral composition (Al, As, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Sr and Zn), and some physicochemical parameters, namely color, moisture, density, pH, total soluble solids, insoluble solids, ash, electrical conductivity, formol index, free acidity, hydroxymethylfurfural, reducing sugars, total sugars and sucrose. The mineral content was determined using inductively coupled plasma-optical emission spectrometry (ICP OES), and the physicochemical parameters were determined according to officially approved methods. The results of the physicochemical analysis were in agreement with national and international regulations, and with the results of similar studies from around the world. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied in the study of the results of the mineral contents and physicochemical parameters, and it was possible to distinguish the honey samples produced by each of the three different species of bee.
Acesso aberto (Open Access)
Composição química e valor nutricional para grandes herbívoros das folhas e frutos de Aninga (Montrichardia linifera, Araceae)
(Instituto Nacional de Pesquisas da Amazônia, 2010-12) AMARANTE, Cristine Bastos do; MÜLLER, Regina Celi Sarkis; DANTAS, Kelly das Graças Fernandes; ALVES, Claudio Nahum; MÜLLER, Adolfo Henrique; PALHETA, Dulcidéia da Conceição
The aninga (Montrichardia linifera, Araceae) is often found in the floodplain ecosystems of the Amazon and is the natural diet of animals such as manatees, turtles, fish, buffalo and cattle. Aiming to contribute to the chemical knowledge and nutritional value of this plant, leaves and fruits of M. linifera were collected on the banks of the Guama and Maratauira rivers, Para State, Brazil. We determined the moisture content, ash mineral composition, lipids, protein, fiber, carbohydrate and caloric value of the fruits and leaves. The mineral composition (Ca, Mg, Cu, Fe, Zn and Mn) was obtained by flame atomic absorption spectrometry. The leaves and the fruits of M. linifera had caloric values of 289.75 kcal and 355.12 kcal, respectively; and a low protein concentration, 0.44% for leaves and 0.24% for fruits. Manganese concentrations were 3279.46 mg kg-1 for leaves and 18151.53 mg kg-1 for fruits. These Mn concentrations are considered toxic, as they exceed the maximum tolerable for the ruminants (1000 mg kg-1). The M. linifera has the capacity to absorb and bioaccumulate large amounts of Ca, Mg and Mn in the soil, which makes it inappropriate for exclusive use as food for turtles, cattle and buffaloes, requiring more studies for its application as part of the diet.
Acesso aberto (Open Access)
Dados espectroscópicos de diterpenos labdânicos: uma análise teórica via RMN e DFT
(2015-06) SOUZA, Fabrine Silva de; SILVA, Silvana de Oliveira; FARIA, Lênio José Guerreiro de; ALVES, Claudio Nahum; MÜLLER, Adolfo Henrique; GUILHON, Giselle Maria Skelding Pinheiro; BRASIL, Davi do Socorro Barros
Labdane diterpenes exhibit important bioactivities such as cardiovascular effects in rats as well as effects in the treatment of autoimmune diseases and Alzheimer syndrome. Recently, the labdane diterpenes ent-13-epi-manoil oxide, ribenone and ribenol were isolated from Croton palanostigma. The computational method DFT/B3LYP/cc-pVDZ was used to optimize the structures of these diterpenes and to calculate infrared data. Chemical shifts (δH and δC) of the minimum energy structures (local minimum) were calculated and compared with the experimental data. Comparison of the NMR data by simple linear regression (SLR) showed satisfactory statistical results with a correlation coefficient (R2) and predictive ability (Q2) of over 98%. The predicted NMR data were used to confirm the δH values that have not been published.
Acesso aberto (Open Access)
Efeito fungitóxico in vitro do óleo resina e do óleo essencial de copaíba (Copaifera multijuga Hayne)
(2009) DEUS, Ricardo Jorge Amorim de; CARVALHO, Antonio Sergio Costa; BANNA, Débora Ariane Dornelas da Silva; ARRUDA, Mara Silvia Pinheiro; ALVES, Claudio Nahum; SANTOS, Alberdan Silva
In vitro fungitoxic effect of the oil-resin and the essential oil of copaiba (Copaifera multijuga Hayne). Copaifera multijuga Hayne oil, crude and fractions, was evaluated for its in vitro fungitoxic activities against five species of filamentous fungi belonging to the genus Aspergillus and three yeast species of the genus Candida. Oil-resin and essential oil concentrations ranging from 0.008 mg mL-1 to 1.6 mg mL-1 were used in qualitative and quantitative analyses. Samples were placed onto 5mm-diameter paper disks and distributed on Saboraud culture medium in Petri dishes inoculated with conidia and incubated at 28ºC during 10 days. A solution with 1.6 mg mL-1 of miconazole nitrate was used as positive control. Qualitative results indicated that the oil-resin presented good fungistatic activity; however, one of the essential oil fractions was highly effective against Candida parapsilosis IOC-2882, Aspergillus flavus IOC-3874 and A. tamarii IOC- 187, with inhibition halos of 16.0±1.4 mm, 19.5±2.1 mm and 12.5±3.5 mm, respectively. The quantitative evaluation indicated that 0.3 mg mL-1 of the oil-resin inhibited Aspergillus flavus and Candida parapsilosis growth, whereas 0.08 mg mL-1 of the essential oil fraction reached this same activity.
Acesso aberto (Open Access)
Essential oil composition of Croton palanostigma Klotzsch from north Brazil
(2009) BRASIL, Davi do Socorro Barros; MÜLLER, Adolfo Henrique; GUILHON, Giselle Maria Skelding Pinheiro; ALVES, Claudio Nahum; ANDRADE, Eloisa Helena de Aguiar; SILVA, Joyce Kelly do Rosário da; MAIA, José Guilherme Soares
The essential oils of leaves, twigs, branches, trunk bark and fruits of Croton palanostigma were analyzed by GC and GC-MS. The main compounds found in the oil of the leaves were linalool (25.4%), (E)-caryophyllene (21.0%), methyleugenol (17.2%) and β-elemene (6.0%); in the oil of the twigs were α-pinene (41.4%), limonene (29.0%), sabinene (11.5%) and β-pinene (5.7%); in the oil of the branches were methyleugenol (24.1%), (E)-methylisoeugenol (15.3%), α-pinene (11.2%) and (E)-caryophyllene (8.5%); in the oil of the trunk bark were a-pinene (31.6%), methyleugenol (25.6%) and (E)-methylisoeugenol (23.7%); and in the oil of the fruits were linalool (42.7%), methyleugenol (16.3%) and β-elemene (6.4%). Statistical analysis showed that the leaves and fruit, and the branches and trunk bark, have significant similarities between them. In addition, the trunk bark oil has high brine shrimp larvicidal activity (LC50, 3.71 ± 0.01 mg mL-1).
Acesso aberto (Open Access)
Isolation, X-ray crystal structure and theoretical calculations of the new compound 8-Eepicordatin and identification of others terpenes and steroids from the bark and leaves of Croton palanostigma Klotzsch
(2010) BRASIL, Davi do Socorro Barros; MÜLLER, Adolfo Henrique; GUILHON, Giselle Maria Skelding Pinheiro; ALVES, Claudio Nahum; PERIS, Gabriel; LLUSAR, Rosa; MOLINER, Vicent
Phytochemical studies of the bark and leaves of Croton palanostigma Klotzsch (Euphorbiaceae) led to the isolation of a new clerodane diterpene, 8-epicordatin (2), in addition to 12-oxohardwickiic acid methyl ester (3), aparisthman, cordatin (1), ent-trachyloban-18-oic acid, ent-13-epimanoyl oxide, ent-3-oxo-13-epimanoyl oxide, ent-3β-hydroxy-13-epimanoyl oxide, sitosterol, stigmasterol, stigmastan-3-one, 6β-hydroxystigmast-4-en-3-one, 6β-hydroxystigmasta-4,22-dien-3-one, stigmast-4-en-3-one, stigmasta-4,22-dien-3-one, 3-O-acetylaleuritolic acid, 11α-hydroxyurs-12-en-3-one, α-amyrenone, 24-methylenecycloartenone and lupenone. These compounds were isolated using typical phytochemical procedures and the structures were deduced from spectroscopic studies, including 2D NMR experiments. In addition, the crystalline structure of 8-epicordatin (2) was determined by X-ray diffraction. NMR theoretical calculations at the B3PW91/DGDZVP level were used to confirm the assignment of the chemical shifts of the H-7α and H-7β hydrogens of 8-epicordatin.
Acesso aberto (Open Access)
Levels of As, Cd, Pb and Hg found in the hair from people living in Altamira, Pará, Brazil: environmental implications in the Belo Monte area
(2009) CARVALHO, Antonio Sergio Costa; SANTOS, Alberdan Silva; PEREIRA, Simone de Fátima Pinheiro; ALVES, Claudio Nahum
Human hair was used as a bioindicator to evaluate the levels of As, Cd, Pb and Hg in the resident population of the "Volta Grande" area of the Xingu river, in the North of Brazil. The concentrations of As and Cd are in agreement with the values found in the literature, however, the Pb and Hg concentration is very different, which can suggest an inter-regional variation. Moreover, the high values found for these elements in the residents of the Canteiro Island can be attributed to environmental exposure of this population in an area with environmental impact from activities of gold mining. The application of these methods showed that the concentrations of the metals studied in this work can correctly classify two different localities in the Altamira district. The results reflect the impact of these elements on the health of the inhabitants of this auriferous area.
Acesso aberto (Open Access)
A structure-activity relationship (SAR) study of neolignan compounds with anti-schistosomiasis activity
(2002-06) ALVES, Claudio Nahum; MACEDO, Luiz Guilherme Machado de; HONORIO, Kathia Maria; CAMARGO, Ademir João; SANTOS, Lourivaldo da Silva; JARDIM, Iselino Nogueira; BARATA, Lauro Euclides Soares; SILVA, Alberico Borges Ferreira da
A set of eighteen neolignan derivative compounds with anti-schistosomiasis activity was studied by using the quantum mechanical semi-empirical method PM3 and other theoretical methods in order to calculate selected molecular properties (variables or descriptors) to be correlated to their biological activities. Exploratory data analysis (principal component analysis, PCA, and hierarchical cluster analysis, HCA), discriminant analysis (DA) and the Kth nearest neighbor (KNN) method were employed for obtaining possible relationships between the calculated descriptors and the biological activities studied and predicting the anti-schistosomiasis activity of new compounds from a test set. The molecular descriptors responsible for the separation between active and inactive compounds were: hydration energy (HE), molecular refractivity (MR) and charge on the C19 carbon atom (Q19). These descriptors give information on the kind of interaction that can occur between the compounds and their respective biological receptor. The prediction study was done with a new set of ten derivative compounds by using the PCA, HCA, DA and KNN methods and only five of them were predicted as active against schistosomiasis.
Acesso aberto (Open Access)
Structure-activity relationship of compounds which are anti-schistosomiasis active
(1998-12) ALVES, Claudio Nahum; BARROSO, Lucia Pereira; SANTOS, Lourivaldo da Silva; JARDIM, Iselino Nogueira
The molecular orbital method AM1 was employed to calculate a set of molecular descriptors for twenty synthetic neolignan derivatives with anti-schistosomiasis activity. The pattern recognition method (principal component analysis PCA and cluster analysis CA and discriminant analysis methods) have been employed to obtain the relationship between the molecular descriptors and biological activity. The set of molecules was classified into two groups according to their degree of biological activity. These results allow us to rationally project new compounds, potential candidates for synthesis and biological evaluation.
Acesso aberto (Open Access)
A study of neolignan compounds with biological activity against Paracoccidioides brasiliensis by using quantum chemical and chemometric methods
(2003-10) CAMARGO, Ademir João; HONORIO, Kathia Maria; MERCADANTE, Ricardo; MOLFETTA, Fábio Alberto de; ALVES, Claudio Nahum; SILVA, Alberico Borges Ferreira da
Chemometric (statistical) methods are employed to classify a set of neolignan compounds with activity against Paracoccidioides brasiliensis. The AM1 (Austin Model 1) method was used to calculate a set of molecular descriptors (properties) of the neolignan compounds under study. The descriptors were further analyzed using Principal Components Analysis (PCA), Hierarchical Cluster Analysis (HCA) and K-Nearest Neighbor (KNN) chemometric methods. The PCA and HCA methods were quite efficient to classify the compounds into two groups (active and inactive) and three descriptors were found to be important in the classification: the highest occupied molecular orbital energy (EHOMO), the bond order between C1'-R7 atoms (L14) and the bond order between C5' -R6 atoms (L22). The three variables responsible for the separation between active and inactive compounds are all electronic descriptors, therefore we can conclude that electronic effects should have an important role when one is trying to understand the activity of neolignan compounds against Paracoccidioides brasiliensis.
Acesso aberto (Open Access)
Synthesis, X-ray crystal structure and theoretical calculations of antileishmanial neolignan analogues
(2010) NASCIMENTO, Josenaide Pereira do; SANTOS, Lourivaldo da Silva; SANTOS, Regina Helena de Almeida; TOZZO, Érica; FERREIRA, Janaina Gomes; CARMO, Maria Carolina Lima do; BRASIL, Davi do Socorro Barros; ALVES, Claudio Nahum
The synthesis and X-ray crystal diffraction structure of two analogues of neolignans, 2-(4-chlorophenyl)-1-phenylethanone (20) and 2-[(4-chlorophenyl)thio]-1-(3,4-dimethoxyphenyl)propan-1-one (12) is described. The compound 12 presents activity against intracellular Leishmania donovani and Leishmania amazonensis amastigotes that cause cutaneous and visceral leishmaniasis. In addition, the density functional theory (DFT) with the B3LYP hybrid functional was employed to calculate a set of molecular descriptors for nineteen synthetic analogues of neolignans with antileishmanial activities. Afterwards, the stepwise discriminant analysis was performed to investigate possible relationship between the molecular descriptors and biological activities. Through this analysis the compounds were classified into two groups active and inactive according to their degree of biological activities, and the more important properties were charges on some key atoms, electronic affinity and ClogP.