Publications by authors named "Frederico L Reis"

This study aimed to identify the chemical composition resulting from the chemical interaction between calcium hypochlorite [Ca(OCl)] and chlorhexidine (CHX) using different H and C nuclear magnetic resonance spectrometry (NMR), correlated two-dimensional spectroscopy (2D COSY), heteronuclear single quantum coherence (HSQC), and Fourier Transform Infrared Spectroscopy (FTIR) experiments. The 5.25% Ca(OCl) was mixed with 2% CHX in a 1:1 ratio, obtaining an orange-brown precipitate that was filtered, washed in ultrapure water, dried and characterized by H and C NMR, 2D COSY, HSQC and FTIR.

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In this work, four alkaloids from the stem bark of were isolated, namely: voacangine (); ethyl apovincaminate (); affinisine () and voachalotine (). The alkaloids were tested for antiproliferative capacity in eight tumor cell lines: U251 (glioma), MCF-7 (breast), NCI-ADR/RES (drug resistant ovary), 786-0 (kidney), NCI-H460 (lung), HT-29 (colon), K562 (leukemia) and PC-3 (prostate) and a non-tumor keratinocyte cell line (HaCat). Antiproliferative activity was observed after 48 hours and results expressed as the concentration needed to induce 50% growth inhibition (GI50) in µM.

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A reinvestigation of the chemical constituents of the stem barks of Scutia buxifolia, a member of the Rhamnaceae, resulted, along with the known alkaloids scutianine C and scutianene L, in the isolation of three undescribed diastereoisomeric alkaloids - scutianine N, 27-epi-scutianine N and 3, 4, 7-tri-epi-scutianine N -, one undescribed non macrocyclic alkaloid - scutianine Q - and a neutral compound -scutianene M. Their structures were determined using extensive NMR techniques and HRMS. The absolute configurations of the stereogenic centers of the three diastereoisomeric alkaloids have been assigned by gas chromatography employing modified cyclodextrins as chiral stationary phases.

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