Two epimeric friedelane triterpenes isolated from Maytenus truncata Reiss : 1H and 13C chemical shift assignments.

An NMR study of 3˛- and 3ˇ-friedelinol is described. In addition to conventional 1D NMR methods, 2D shift-correlated NMR experiments HMQC [(1J(C,H)], HMBC [nJ(C,H); n D 2 and 3] and 2D 1H,1H-NOESY were used for 1H and 13C chemical shift assignments of these triterpenes

Total assignment of 1H and 13C NMR spectra of two 3,4-secofriedelanes from Austroplenckia populnea.

Two new 3,4-secofriedelanes, 3,4-seco-28-hydroxyfriedelan-3-oic acid (1) and 3,4-secofriedelan-3-oic acid (2),were isolated from the leaves of Austroplenckia populnea (Celastraceae).The structureswere established by 2D NMR spectroscopic techniques (COSY, HMQC, HMBC and NOESY)

Complete assignment of the 1H and 13C NMR spectra of the tetraisoprenylated benzophenone 15-epiclusianone.

An NMR study of 15-epiclusianone, 1-benzoyl-6-hydroxy-14,14-dimethyl-3,5,15-tri(3-methyl-2-butenyl)- bicyclo[3.3.1]non-1-ene-4,6-dione (1), a novel tetraisoprenylated benzophenone isolated from pericarp of fruits of Rheedia gardneriana, is described. In addition to conventional 1D NMR techniques, 2D shiftcorrelated NMR experiments [1H 1H-COSY, 1H 13C-HMQC-1J(C,H), 1H 13C-HMBC-nJ(C,H) (n = 2 and 3) and 1H 1H-NOESY] were used for 1H and 13C chemical shift assignments of this natural product. The 1D 13C NMR spectrum of 1 in the solid state was also obtained

3-beta-(Stearyloxy)olean-12-ene from Austroplenckia populnea : structure elucidation by 2D-NMR and quantitative 13C-NMR spectroscopy.

3 -(Stearyloxy)olean-12-ene was isolated from a hexane extract of Austroplenckia populnea Reiss (Celastraceae) leaves. The structure was solved by means of quantitative 13C-NMR, HMBC, HMQC, COSY, NOESY, and NOE difference spectra. The mass spectrum showed an [M 1] ion peak at m/z 693, and the molecular formula C48H84O2 was confirmed by combustion analysis

Improvement of genistein content in solid genistein/β-cyclodextrin complexes

Genistein: β-cyclodextrin complexes with high drug loading (19.22%) were prepared by freeze-drying and characterized by differential scanning calorimetry and hydrogen nuclear magnetic resonance spectroscopy. The spatial configuration of the complex was proposed by means of 2D-NOESY experiment combined with molecular modeling. According to the results obtained, the interaction of genistein with β-cyclodextrin in a 1:1 complex is supposed to occur mainly through the insertion of the guest A-ring in cyclodextrin cavity, without rule out the possibility of inclusion through the B-ring, as previously reported in the literature

Chemical constituents from branches of Maytenus gonoclada (Celastraceae) and evaluation of antimicrobial activity

Six pentacyclic triterpenes were isolated from branches of Maytenus gonoclada (Celastraceae) and all NMR data of a new compound 3-oxo-12α,29-dihydroxyfriedelane are herein reported. The stereochemistry of the new friedelane was established by bidimensional NMR (HSQC, HMBC and NOESY) data, and its molecular weight confirmed by ESI mass spectrometry. Antimicrobial activity assays using the method of disk diffusion and macrodilution were carried out against the bacteria Escherichia coli, Citrobacter freundii, and Bacillus cereus, and against the fungi Candida albicans. The triterpene 3-oxo-12α-hydroxyfriedelane showed positive result against C. albicans

Complete assignment of the 1H and 13C NMR spectra of a new polyester sesquiterpene from Austroplenckia populnea.

new polyester sesquiterpene (4-hydroxy-1,2,6,15-tetraacetyl-9-benzoylagarofuran), together with known friedelane triterpenes (friedelin, -friedelinol and 28-hydroxyfriedelin), was isolated from the leaves of Austroplenckia populnea. The structure and relative stereochemistry of the new ester were based on 2D NMR spectroscopic techniques including HMBC, HMQC and NOESY

Development of Sulfadiazine-Decorated PLGA Nanoparticles Loaded with 5-Fluorouracil and Cell Viability

The aim of this work was to synthesize sulfadiazine-poly(lactide-co-glycolide) (SUL-PLGA) nanoparticles (NPs) for the efficient delivery of 5-fluorouracil to cancer cells. The SUL-PLGA conjugation was assessed using FTIR, 1H-NMR, 13C-NMR, elemental analysis and TG and DTA analysis. The SUL-PLGA NPs were characterized using transmission and scanning electron microscopy and dynamic light scattering. Additionally, the zeta potential, drug content, and in vitro 5-FU release were evaluated. We found that for the SUL-PLGA NPs, Dh = 114.0 nm, ZP = −32.1 mV and the encapsulation efficiency was 49%. The 5-FU was released for up to 7 days from the NPs. Cytotoxicity evaluations of 5-FU-loaded NPs (5-FU-SUL-PLGA and 5-FU-PLGA) on two cancer cell lines (Caco-2, A431) and two normal cell lines (fibroblast, osteoblast) were compared. Higher cytotoxicity of 5-FU-SUL-PLGA NPs were found to both cancer cell lines when compared to normal cell lines, demonstrating that the presence of SUL could significantly enhance the cytotoxicity of the 5-FU-SUL-PLGA NPs when compared with 5-FU-PLGA NPs. Thus, the development of 5-FU-SUL-PLGA NPs to cancer cells is a promising strategy for the 5-FU antitumor formulation in the future

Improvement of genistein content in solid genistein/-cyclodextrin complexes β

Genistein:β-cyclodextrin complexes with high drug loading (19.22%) were prepared by freeze-drying and characterized by differential scanning calorimetry and hydrogen nuclear magnetic resonance spectroscopy. The spatial configuration of the complex was proposed by means of 2D-NOESY experiment combined with molecular modeling. According to the results obtained, the interaction of genistein with β -cyclodextrin in a 1:1 complex is supposed to occur mainly through the insertion of the guest A-ring in cyclodextrin cavity, without rule out the possibility of inclusion through the B-ring, as previously reported in the literature