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| Silva,Tania M.S.; Camara,Celso A.; Lins,Antonio C.S.; Agra,Maria de Fátima; Silva,Eva M.S.; Reis,Igor T.; Freitas,Breno M.. |
| Stingless bees in Brazil are indigenous and found all over the country. Bee pollen is used for its nutritional value in the human diet. It is made up of natural flower pollen mixed with nectar and bee secretions. In order to evaluate the chemical composition, free radical scavenging activity, and botanical origin, sample of pollen loads from stingless bee, Melipona rufiventris (Uruçu amarela) was studied. The EtOAc extract of pollen of Melipona rufiventris yielded the following compounds: p-hydroxycinnamic acid, dihydroquercetin, isorhamnetin, isorhamnetin3-O-(6"-O-E-p-coumaroyl)-β-D-glucopyranoside, luteolin, and quercetin. This is the first report of the isolation of isorhamnetin3-O-(6"O-E-p-coumaroyl)β-D-glucopyranoside from pollen. The free... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antioxidant activity; Bee pollen; Flavonoids; Melipona rufiventris; Uruçu amarela. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652009000200003 |
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| Camara,Celso A.; Silva,Tania M.S.; da-Silva,Thiago G.; Martins,Rodrigo M.; Barbosa,Ticiano P.; Pinto,Angelo C.; Vargas,Maria D.. |
| The toxic profile of lawsone (2-hydroxy-[1,4]naphthoquinone) and a series of [1,4]naphthoquinone derivatives was evaluated against the brine shrimp Artemia salina and against the mollusk Biomphalaria glabrata, the main transmitting vector of schistosomiasis in Brazil. Of the seventeen compounds tested nine fell below the threshold of 100 µg/mL set for potential molluscicidal activity by the World Health Organization. As a general rule derivatives with non-polar substituents presented the highest molluscicidal activities. These substances showed significant toxicity in A. salina lethality bioassay. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biomphalaria glabrata Artemia salina toxicity quinones schistosomiasis molluscicidal activity lawsone 1; 4-naphthoquinone. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652008000200011 |
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| Carvalho,Mário G. de; Silva,Virginia C. da; Silva,Tânia M.S. da; Camara,Celso A.; Braz-Filho,Raimundo. |
| The reaction of the flavonol 3,7,3', 4'-tetra-O-methylquercetin (1) and of the isoflavone 7,4'-di-O-methylgenistein (2) with alkaline iodine in methanol afforded four new iodine derivatives: 8-iodo-5-hydroxy-3,7,3', 4'-tetramethoxy- flavone (1a) and 6-iodo-5-hydroxy-3,7,3', 4'-tetramethoxyflavone (1b) from 1; 2 afforded a mixture of two compounds, identified as a racemic mixture of (±)-trans-5-hydroxy-2,3,7,4'-tetramethoxy-8-iodo-isoflavanone (2a) and (±)-trans-5-hydroxy-2,3,7,4'-tetramethoxy-6,8-diiodo-isoflavanone (2b). The formation of these different products reveals a significant difference involving the chemical interaction between the reactive site of α, β-unsaturated ketones of flavonol and isoflavone under the tested reaction conditions (using... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Flavonol; Isoflavone; Iodoflavonoid; Iodoisoflavonoid; Iodine derivatives. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652009000100004 |
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