JBCS

This review aims to provide the readers of the Journal of the Brazilian Chemical Society with an overview of enzymatic biofuel cells, their development since their first description in 1964, and the most recent outcomes. The latest papers in this field (including implantable technology) and an outlook for future research in this area are also presented.

Two lactones (δ-bromo-γ-lactone and δ-iodo-γ-lactone) obtained from γ,δ-unsaturated acid were transformed by hydrolytic dehalogenation carried out by filamentous fungi into hydroxylactone. This hydroxylactone inhibited growth of some microorganisms.

Calorific values of (RME) and (SME) biodiesel blends have been. T and P dependences of the calorific values in the range (273 to 373) K and (1 to 200) bar have been derived.

Eleven cyclodipeptides were heterogeneously expressed in plate culture of an antibacterial clone functionally screened from metagenomic library of Japanese marine sponge D. calyx. These cyclodipeptides, two of them containing D-proline residue despite non-NRPS products, were firstly reported from metagenomic library.

We have investigated the sex pheromone composition of the eucalyptus brown-looper and developed an efficient asymmetric synthesis for the four stereoisomers of 3,4-epoxy-6,9-heneicosadiene, possible major pheromone component.

Boron-doped diamond electrode was used to evaluate the interaction of the DNA nucleotides guanosine monophosphate and adenosine monophosphate with the organophosphorus pesticides methamidophos, monocrotophos and chlorpyrifos.

Three new neo-clerodanes, antiscorbuticane A, B and C, and seven known compounds were isolated from the methanol extract of Tinnea antiscorbutica. Antiscorbuticane B exhibited no mutagenic activity and did not induce micronucleus formation in the V79 cell line.

A new series of spiroacenaphthene pyrroloisoquinolines were synthesized by one-pot, three component condensation of azomethine ylides, generated from 1,2,3,4-tetrahydroisoquinoline with acenaphthenequinone by a 1,5-prototropic shift route, with chalcone and nitrostyrene derivatives in a regio- and stereoselective manner.

The electrochemical reduction of nitrofurazone and its analogues was studied by cyclic voltammetry, differential pulse voltammetry and chronoamperometry in aqueous medium by using a glassy carbon electrode. The nitro anion radical was generated electrochemically and undergoes a disproportionation chemical reaction. The nitro anion radical obtained using the nitrothiophene thiosemicarbazone (NTS) analogue was significantly more stable than the one from nitrofurazone.

Biological synthesis of metal nanoparticles using fungi has been proved to be eco-friendly, economical and green approach. In the present study, different Fusarium species were screened to select an efficient species for the synthesis of silver nanoparticles.

The species generated by oxidative stress combined with endogenous and exogenous compounds to promote changes in DNA and proteins, triggering various pathologies.

One new pyranoisoflavone and three known pyranoisoflavones, together with rutin and sucrose, were isolated from Polygala molluginifolia and evaluated for their acetylcholinesterase inhibition, antioxidant activity and PAMPA permeability.

Comparative results obtained by different methods for experimental determination of solubility parameter (δ) of low and high molar mass molecules. UV-Vis and µDSC were suitable to measure δ for a wide molar mass range.

The general reaction mechanism of a typical atom transfer radical polymerization (ATRP) and the definition of equilibrium constant. P_nX is the "dormant" polymer, MⁿY/L is the catalytic system, P_n* is the "living" polymer and P_n+m / P_n + P_m are the "dead" polymers.

The influence of the type of extractor and extracting humic substances from peat for agricultural application and environmental impacts.

The structures of four new dibenzocyclooctadiene lignans isolated from the stems of Schisandra neglecta were elucidated by spectroscopic methods. These compounds showed moderate anti-HIV-1 activities and weak cytotoxic activities for some selected cell lines.

The classical Belousov-Zhabotinsky oscillating reaction, in a batch reactor added with phenol, shows a set of non-usual behaviors in function of the initial concentration of phenol. The most remarkable of them is a burst firing, which was explained by a competition between two redox cycles, one with aliphatic species and one with phenolic species.

B5-diesel, a blend of biodiesel and diesel oil, is widely used in Brazil and it is responsible for the emission of trace elements to the atmosphere. In this work, a simple procedure aiming at the analysis of B5-diesel samples by high-resolution continuum source electrothermal atomic absorption spectrometry (HR-CS ET AAS) is described.

This paper describes a method for determining chlorpyrifos and thiamethoxam in potato and soil using the technique of solid-liquid extraction with low temperature partitioning and determination by gas chromatography.

A nickel-loaded activated carbon (Ni/AC) composite particle electrode was prepared by electroless plating with palladium-free pretreatment. The electrocatalytic performance of Ni/AC electrode was superior to that of AC electrode under the same electrolysis conditions in the three-dimensional electrode cell.

This work describes the synthesis of a novel alkyl 1H-pyrazole-5-carboxylate series from versatile precursors 1,1,1-trihalo-4-methoxy-3-alken-2-ones obtained from long chain ketones. These are promising new oleochemical derivatives.