Publications by authors named "Helvecio M Dos Santos Junior"

The new heterocyclic derivative LQFM048 (3) (2,4,6-tris ((E)-ethyl 2-cyano-3-(4-hydroxy-3-methoxyphenyl)acrylate)-1,3,5-triazine) was originally designed through the molecular hybridization strategy from Uvinul® T 150 (1) and (E)-ethyl 2-cyano-3-(4hydroxy-3-methoxyphenyl)acrylate (2) sunscreens, using green chemistry approach. This compound was obtained in global yields (80%) and showed an interesting redox potential. In addition, it is thermally stable up to temperatures around 250°C.

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Rationale: The study of natural products by electrospray ionization tandem mass spectrometry (ESI-MS/MS) is an important strategy for the characterization of the major fragmentation reactions which can then help to determine the composition of complex mixtures. Application of ESI-MS/MS to a series of isopimarane diterpenes from Velloziaceae allowed the rationalization of their fragmentation mechanisms.

Methods: Velloziaceae diterpenes were isolated by silica gel column chromatography and investigated by ESI-MS/MS analysis.

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To contribute to the development of products to control Meloidogyne exigua, the bacteria Bacillus cereus and B. subtilis were cultivated in liquid medium to produce metabolites active against this plant-parasitic nematode. Fractionation of the crude dichloromethane extracts obtained from the cultures afforded uracil, 9H-purine and dihydrouracil.

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New oxirane derivatives were synthesized using six naphthoquinones as the starting materials. Our biological results showed that these oxiranes acted as trypanocidal agents against Trypanosoma cruzi with minimal cytotoxicity in the VERO cell line compared to naphthoquinones. In particular, oxirane derivative 14 showed low cytotoxicity in a mammalian cell line and exhibited better activity against epimastigote forms of T.

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Native and exotic Brazilian plants collected in the State of Minas Gerais were evaluated for their anticancer potential. Methanol extracts from leaves of 51 plant species were tested for cytotoxicity against four tumor cell lines: B16 (murine skin), HL-60 (human leukemia), MCF-7 (human breast), and HCT-8 (human colon). Plant extracts that exhibited IC(50) values less than 30 microg/ml against any tumor cell line were tested on sea urchin egg development and mouse erythrocytes.

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