Herein, we report reactivity studies of the mononuclear water-soluble complex [Mn(II)(HPClNOL)(η 1 -NO 3 )(η 2 -NO 3 )] 1, where HPClNOL ) 1-(bis-pyridin-2-ylmethyl-amino)-3-chloropropan-2-ol, toward peroxides (H 2 O 2 and tertbutylhydroperoxide). Both the catalase (in aqueous solution) and peroxidase (in CH 3 CN) activities of 1 were evaluated using a range of techniques including electronic absorption spectroscopy, volumetry (kinetic studies), pH monitoring during H 2 O 2 disproportionation, electron paramagnetic resonance (EPR), electrospray ionization mass spectrometry in the positive ion mode [ESI(+)-MS], and gas chromatography (GC). Electrochemical studies showed that 1 can be oxidized to Mn(III) and Mn(IV). The catalase-like activity of 1 was evaluated with and without pH control. The results show that the pH decreases when the reaction is performed in unbuffered media. Furthermore, the activity of 1 is greater in buffered than in unbuffered media, demonstrating that pH influences the activity of 1 toward H 2 O 2 . . The peroxidase activity of 1 was also evaluated by monitoring cyclohexane oxidation, using H 2 O 2 or tert-butylhydroperoxide as the terminal oxidants. Low yields (<7%) were obtained for H 2 O 2 , probably because it competes with 1 for the catalase-like activity. In contrast, using tert-butylhydroperoxide, up to 29% of cyclohexane conversion was obtained. A mechanistic model for the catalase activity of 1 that incorporates the observed lag phase in O 2 production, the pH variation, and the formation of a Mn(III)-(µ-O) 2 -Mn(IV) intermediate is proposed.

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Abstract:A new natural product, a 3,9-(1,2,3-trioxocine)-type steroid, named rauianodoxy (6), was isolated from Rauia nodosa, together with five steroids: sistostenone (1), stigmastenone (2), sitosterol (3), stigmasterol (4) and ergosterol peroxide (5), one coumarin, O-geranylosthenol (7), and three alkaloids, N-methylflindersine (8), zantobungeanine (9) and veprissine (10). Compounds 5-8 were isolated for the first time in the genus Rauia. These compounds were characterized on the basis of their spectral data, mainly one and twodimensional NMR, and mass spectra, also involving comparison with the literature data. Theoretical studies at the DFT level reveal structural parameters for the 1,2,3-trioxole bridge compatible with known structures containing a similar group.

Synthesis, characterization, antibacterial and antitumoral activities of mononuclear zinc complexes containing tridentade amine based ligands with N3 or N2O donor groups, Inorganica Chimica Acta (2014), doi: http://dx.doi.org/10.1016/j.ica. 2014.02.040 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

A novel alkaloid 3-hydroxy-4-(2-hydroxyethyl)-4'-methoxy-7'H-quinolino[2,1-b]quinazolin-7'-one, named atlanticol (1), was isolated from Spiranthera atlantica (Rutaceae), along with five known compounds: lupeol (3), γ-fagarine (4), skimmianine (5), 7-methoxy-1-methyl-2-phenyl-4-quinolone (6) and 8methoxy-1-methyl-2-phenyl-4-quinolone (7). Compound 6 was isolated from the Spiranthera genus for the first time. These compounds were characterized based on their spectral data, mainly through one and two-dimensional NMR and mass spectra, but also involving comparison with literature data.