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Paulo C. Vieira

Bio: Paulo C. Vieira is an academic researcher from Federal University of São Carlos. The author has contributed to research in topics: Atta sexdens & Limonoid. The author has an hindex of 34, co-authored 307 publications receiving 4764 citations. Previous affiliations of Paulo C. Vieira include Universidade Estadual de Londrina & Universidade Estadual de Maringá.


Papers
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TL;DR: Three anacardic acids have been isolated as cytotoxic agents against BT-20 breast carcinoma cells from the cashew Anacardium occidentale (Anacardiaceae) apple juice.
Abstract: Three anacardic acids (1-3) have been isolated as cytotoxic agents against BT-20 breast carcinoma cells from the cashew Anacardium occidentale (Anacardiaceae) apple juice. In addition to these anacardic acids, the cytotoxicity of their 13 congeners (4-16) isolated from the cashew nut and nut shell oil has also been examined. Anacardic acids (1-4), cardols (5-8), and methylcardols (9-12) have been found to exhibit moderate cytotoxic activity against both BT-20 breast and HeLa epithelioid cervix carcinoma cells

162 citations

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TL;DR: The results of this study help to understand the mechanism of inhibition of the Dengue virus serine protease by flavonoids, which is essential for the development of improved inhibitors.

111 citations

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TL;DR: The main compounds responsible for activity against the fungus and ant in leaf extracts of R communis were found to be fatty acids for the former and ricinine for the ants.
Abstract: The focus of this study was the identification of compounds from plant extracts for use in crop protection. This paper reports on the toxic activity of fractions of leaf extracts of Ricinus communis L (Euphorbiaceae) and isolated active compounds in the leaf-cutting ant Atta sexdens rubropilosa Forel and its symbiotic fungus Leucoagaricus gongylophorus (Singer) Moller. The main compounds responsible for activity against the fungus and ant in leaf extracts of R communis were found to be fatty acids for the former and ricinine for the ants.

95 citations

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TL;DR: In this paper, nine limonoids were isolated from Carapa guianensis and Cedrela fissilis and were assayed on Atta sexdens rubropilosa workers showing moderate insecticidal activities.
Abstract: Nine limonoids were isolated from Carapa guianensis and Cedrela fissilis Among them, 1,2-dihydro-3b-hydroxy-7-deacetoxy-7-oxogedunin is a new compound Moreover, the assignments of some chemical shifts of xyloccensin k have been corrected and 1H NMR data of 7-deacetylgedunin have been assigned for the first time These isolated limonoids were assayed on Atta sexdens rubropilosa workers showing moderate insecticidal activities

75 citations

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TL;DR: The fruits of Neoraptua magnifica afforded three new flavonoids: 2'-hydroxy-4,4',-dimethoxy-5',6'-(2'',2''-dimethylpyrano)chalcone, and 3',4'-methylenedioxy-5,6,7-trimethoxyflavone, which were identified on the basis of spectroscopic methods.

74 citations


Cited by
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Journal ArticleDOI
TL;DR: This review covers the isolation, structure determination, synthesis and biological activity of quinoline, quinazoline and acridone alkaloids from plant, microbial and animal sources.

1,687 citations

Journal ArticleDOI
TL;DR: Progress made during the last two decades in producing transgenic lines of different C3 crops with enhanced photosynthetic performance is discussed, which was reached by either the overexpression of C3 enzymes or transcription factors or the incorporation of genes encoding C4 enzymes into C3 plants.
Abstract: Stressful environments such as salinity, drought, and high temperature (heat) cause alterations in a wide range of physiological, biochemical, and molecular processes in plants. Photosynthesis, the most fundamental and intricate physiological process in all green plants, is also severely affected in all its phases by such stresses. Since the mechanism of photosynthesis involves various components, including photosynthetic pigments and photosystems, the electron transport system, and CO2 reduction pathways, any damage at any level caused by a stress may reduce the overall photosynthetic capacity of a green plant. Details of the stress-induced damage and adverse effects on different types of pigments, photosystems, components of electron transport system, alterations in the activities of enzymes involved in the mechanism of photosynthesis, and changes in various gas exchange characteristics, particularly of agricultural plants, are considered in this review. In addition, we discussed also progress made during the last two decades in producing transgenic lines of different C3 crops with enhanced photosynthetic performance, which was reached by either the overexpression of C3 enzymes or transcription factors or the incorporation of genes encoding C4 enzymes into C3 plants. We also discussed critically a current, worldwide effort to identify signaling components, such as transcription factors and protein kinases, particularly mitogen-activated protein kinases (MAPKs) involved in stress adaptation in agricultural plants.

1,435 citations

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TL;DR: A number of methods using various copper complexes and salts to carry out cross-coupling reactions leading to the formation of C heteroatom (C N, C O, C S, C P, C Se), C C, and C metal bonds have been proposed as discussed by the authors.

1,361 citations

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TL;DR: The ability of luteolin to inhibit angiogenesis, to induce apoptosis, to prevent carcinogenesis in animal models, to reduce tumor growth in vivo and to sensitize tumor cells to the cytotoxic effects of some anticancer drugs suggests that this flavonoid has cancer chemopreventive and chemotherapeutic potential.
Abstract: Epidemiological evidence suggests that flavonoids may play an important role in the decreased risk of chronic diseases associated with a diet rich in plant-derived foods. Flavonoids are also common constituents of plants used in traditional medicine to treat a wide range of diseases. The purpose of this article is to summarize the distribution and biological activities of one of the most common flavonoids: luteolin. This flavonoid and its glycosides are widely distributed in the plant kingdom; they are present in many plant families and have been identified in Bryophyta, Pteridophyta, Pinophyta and Magnoliophyta. Dietary sources of luteolin include, for instance, carrots, peppers, celery, olive oil, peppermint, thyme, rosemary and oregano. Preclinical studies have shown that this flavone possesses a variety of pharmacological activities, including antioxidant, anti-inflammatory, antimicrobial and anticancer activities. The ability of luteolin to inhibit angiogenesis, to induce apoptosis, to prevent carcinogenesis in animal models, to reduce tumor growth in vivo and to sensitize tumor cells to the cytotoxic effects of some anticancer drugs suggests that this flavonoid has cancer chemopreventive and chemotherapeutic potential. Modulation of ROS levels, inhibition of topoisomerases I and II, reduction of NF-kappaB and AP-1 activity, stabilization of p53, and inhibition of PI3K, STAT3, IGF1R and HER2 are possible mechanisms involved in the biological activities of luteolin.

898 citations