Prediction of Gas Chromatographic Retention Indices of Coumarins

Quantitative structure-retention relationships (QSRR) were used in this study to relate the chromatographic retention of different substituted coumarins to molecular structure. Different structural parameters were selected, such as topological, geometric, electronic, quantum-chemical and physico-chemical descriptors, in order to find an equation that fitted the chromatographic retention of these compounds. The method proposed by Dimov that classifies the descriptors in different groups in agreement with their values of correlation coefficients was analysed. Significant correlation equations were obtained with the following molecular descriptors: the total surface area (A T), the electrotopological state index (S(-o-)) of the oxygen in position 1 of coumarin, and the highest occupied molecular orbital energy (E HOMO), showing that the experimental retention, using stationary phases with low polarity, was related with the shape and electronic factors of the solutes. The models found have a good predictive ability as established by cross-validation r²cv values and thus, can be used to aid in the elucidation of the structure or the chromatographic retention of similar coumarins. O estudo de correlação entre estrutura-retenção (QSRR) foi usado para relacionar a retenção cromatográfica de diferentes cumarinas substituídas as suas características estruturais. Diferentes parâmetros estruturais foram selecionados tais como: descritores topológicos, geométricos, eletrônicos, químico-quânticos e físico-químicos para encontrar uma equação que melhor explique o comportamento cromatográfico destes compostos. O método proposto por Dimov que classifica os descritores em diferentes grupos de acordo com seus valores de coeficientes de correlação foi utilizado neste estudo. As melhores equações de correlação linear múltipla foram obtidas com os seguintes descritores: área total (A T), índice do estado eletrotopológico (S-O-) e orbital molecular ocupado de maior energia (E HOMO), mostrando que a retenção experimental, usando fase estacionária de baixa polaridade está relacionada principalmente com fatores relacionados a forma e também eletrônicos. Os modelos selecionados apresentaram uma boa predictabilidade, a qual foi estabelecida através dos valores do coeficiente de correlação de validação cruzada (r²cv). As equações encontradas podem ser utilizadas para auxiliar na elucidação da estrutura ou retenção cromatográfica de cumarinas similares às estudadas

Biochemical evaluation of a series of synthetic chalcone and hydrazide derivatives as novel inhibitors of cruzain from Trypanosoma cruzi

Chagas’ disease, a parasitic infection widely distributed throughout Latin America, is a major public health problem with devastating consequences in terms of human morbidity and mortality. The enzyme cruzain is the major cysteine protease from Trypanosoma cruzi, the etiologic agent of American trypanosomiasis or Chagas’ disease, and has been selected as an attractive target for the development of novel trypanocidal drugs. In the present work, we describe the synthesis and inhibitory effects of a series of thirty-three chalcone and seven hydrazide derivatives against the enzyme cruzain from T. cruzi. Most of the compounds showed promising in vitro inhibition (IC50 values in the range of 20-60 μM), which suggest the potential of these compounds as lead candidates for further development. Twelve compounds have not been reported before, and four of them (7, 13, 16 e 18) are among the most potent inhibitors of the series.A doença de Chagas, uma infecção parasitária amplamente distribuída na América Latina, é um problema grave de saúde pública com conseqüências devastadoras em termos de morbidade e mortalidade humana. A enzima cruzaína é a principal cisteíno protease do Trypanosoma cruzi, agente etiológico da tripanossomíase Americana ou doença de Chagas, e foi selecionada como alvo atrativo para o desenvolvimento de novos fármacos tripanocidas. No presente trabalho, a síntese e os efeitos inibitórios de uma série de trinta e três chalconas e sete hidrazidas são descritos contra a enzima cruzaína de T.cruzi. A maioria dos compostos mostraram inibição promissora in vitro (valores de IC50 na faixa de 20-60 μM), o que sugere o potencial desses compostos como candidatos a líderes para contínuo desenvolvimento. Doze compostos são inéditos, sendo que quatro destes (7, 13, 16 e 18) estão entre os inibidores mais potentes da série.CNPqFAPESPCAPE

SB225002 induces cell death and cell cycle arrest in acute lymphoblastic leukemia cells through the activation of GLIPR1

Acute Lymphoblastic Leukemia (ALL) is the most frequent childhood malignancy. In the effort to find new anti-leukemic agents, we evaluated the small drug SB225002 (N-(2-hydroxy-4-nitrophenyl)-N'-(2-bromophenyl)urea). Although initially described as a selective antagonist of CXCR2, later studies have identified other cellular targets for SB225002, with potential medicinal use in cancer. We found that SB225002 has a significant pro-apoptotic effect against both B- and T-ALL cell lines. Cell cycle analysis demonstrated that treatment with SB225002 induces G2-M cell cycle arrest. Transcriptional profiling revealed that SB225002-mediated apoptosis triggered a transcriptional program typical of tubulin binding agents. Network analysis revealed the activation of genes linked to the JUN and p53 pathways and inhibition of genes linked to the TNF pathway. Early cellular effects activated by SB225002 included the up-regulation of GLIPR1 , a p53-target gene shown to have pro-apoptotic activities in prostate and bladder cancer. Silencing of GLIPR1 in B- and T-ALL cell lines resulted in increased resistance to SB225002. Although SB225002 promoted ROS increase in ALL cells, antioxidant N-Acetyl Cysteine pre-treatment only modestly attenuated cell death, implying that the pro-apoptotic effects of SB225002 are not exclusively mediated by ROS. Moreover, GLIPR1 silencing resulted in increased ROS levels both in untreated and SB225002-treated cells. In conclusion, SB225002 induces cell cycle arrest and apoptosis in different B- and T-ALL cell lines. Inhibition of tubulin function with concurrent activation of the p53 pathway, in particular, its downstream target GLIPR1 , seems to underlie the anti-leukemic effect of SB225002

Fármacos e fitoterápicos: a necessidade do desenvolvimento da indústria de fitoterápicos e fitofármacos no Brasil Pharmaceutics and phytotherapics: the need for development of the industry of phytopharmaceutics and phytotherapics in Brazil

<abstract language="eng">We discuss briefly the development and the present status of medicinal chemistry. In this context, we consider the therapeutic possibilities of the phytotherapy. On the basis of this analysis, the development of the phytopharmaceutical industry in Brazil is shown to be of essential importance for both the university and the Country due to the human and technological resources involved