Abstract This report describes the photoacoustic and electron paramagnetic resonance investigations of Brazilian and Cuban zeolites. Photoacoustic optical absorption measurements indicate the presence of iron (Fe 3 +) ions with their respective transition bands for both zeolites. Two species of manganese (Mn 2 + and Mn 3 +) were identified in the Cuban sample and the electronic transitions assigned. Iron and manganese ions were confirmed through nonradiative relaxation ( τ) and characteristic diffusion ( τ β) times evaluation, whose values were found to be τ BRA = 5.40 ms, τ CUB = 4.60 ms, τ β BRA = 387 μs and τ β CUB = 305 μs. Crystal field (Dq- BRA/Dq- CUB = 1048 cm − 1/945 cm − 1) plus Racah (B- BRA/B- CUB = 457 cm − 1/813 cm − 1 and C- BRA/C- CUB = 3655 cm − 1/2496 cm − 1) parameters were assessed as well. Paramagnetic resonance corroborated Fe 3 + ions present in the Brazilian zeolite occupying sites showing axial and/or rhombic symmetry distortions. For the Cuban sample, results reveal the characteristic hyperfine sextet lines of Mn 2 + overlapping the Fe 3 + line. Values of Landé factor and isotropic hyperfine splitting constant were found to be 2.0 and 9.7 mT, respectively. This tells us that the Mn 2 + lies in octahedral symmetry probably replacing calcium ions and point towards an ionic bonding character of the Mn 2 + and its surroundings.

Various vegetables as biological catalysts were evaluated in enantioselective reduction of carbonyl compounds. The stereoselectivity of the process was in agreement with Prelog's rule for twelve of the vegetables, whereas okra and green peppers formed anti-Prelog products. Zingiber officinale exhibited the best results with 30% conversion and 89% ee. The parameters of the reaction such as time, solvent and other substrates investigated, as well as the specie, showed good chemo- and enantioselectivity.

Pathogenic Leptospira spp. are the etiological agents of leptospirosis, an important disease of both humans and animals. In urban settings, L. interrogans serovars are the predominant cause of disease in humans. The purpose of this study was to characterize a novel Leptospira isolate recovered from an abandoned swimming pool. Molecular characterization through sequencing of the rpoB gene revealed 100% identity with L. interrogans and variable-number tandem-repeat (VNTR) analysis resulted in a banding pattern identical to L. interrogans serogroup Icterohaemorrhagiae, serovar Copenhageni or Icterohaemorrhagiae. The virulence of the strain was determined in a hamster model of lethal leptospirosis. The lethal dose 50% (LD50) was calculated to be two leptospires in female hamsters and a histopathological examination of infected animals found typical lesions associated with severe leptospirosis, including renal epithelium degeneration, hepatic karyomegaly, liver-plate disarray and lymphocyte infiltration. This highly virulent strain is now available for use in further studies, especially evaluation of vaccine candidates.

Phytochemical investigation of a propolis sample from Alto Santo - Ceará, Brazil, allowed identification of triterpenes (lupeol, lupenone, germanicone, canaric acid) and flavonoids (quercetin, kaempferol and acacetin), which were identified by spectroscopic data (IR, MS, and NMR, including 2D techniques). This is the first report of canaric acid in propolis. Propolis extract and flavonoids showed antioxidant activity using a DPPH radical scavenging assay.