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Whole seeds of Bauhinia variegata L. (Fabaceae) were utilized as a biological reducer to transform benzaldehyde into benzyl alcohol. The effects of some variables such as temperature, the load of substrate and co-solvent, were established to optimize the reductive process. Utilizing the optimal reaction conditions, a laboratory-scale reaction (final concentration of the substrate: 21.2 mM) was performed to obtain benzyl alcohol (conversion: 95%; isolated yield: 49%; productivity: 1.11 g L−1 or 0.046 g L−1h−1 of benzyl alcohol). In addition, using these optimal conditions, fourteen substituted benzaldehydes were reduced, with a conversion achieved to their corresponding benzyl alcohols ranging from 62% to >99% (isolated yields from 7% to 70%). Moreover, useful building blocks by the synthesis of the drugs and important commercial products were also obtained. The scope, limitations and advantages of this new biocatalytic synthetic method are also discussed., Fil: Demmel, Gabriel I. Universidad Católica de Córdoba. Facultad de Ciencias Químicas; Argentina, Fil: Bordón, Daniela L. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina, Fil: Vázquez, Ana M. Universidad Católica de Córdoba. Facultad de Ciencias Químicas; Argentina, Fil: Decarlini, María F. Universidad Católica de Córdoba. Facultad de Ciencias Químicas; Argentina, Fil: Díaz Panero, Mariángeles. Universidad Católica de Córdoba. Facultad de Ciencias Químicas; Argentina, Fil: Rossi, Laura I. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina, Fil: Rossi, Laura I. Instituto de Investigaciones en Físico-Química de Córdoba (INFIQC-CONICET); Argentina, Fil: Aimar, Mario L. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina

The acetophenone stereoselective reduction reactions carried out by different chemical or biochemical methodologies reported in the literature were analyzed. This study showed the importance of evaluation in each reaction step, both holistically and quantitatively, even if the amounts used are at the mmol level. It is clear that the use of catalysts does not guarantee that the chemical process is environmentally friendly, as well as that the benefits of bio-driven processes can be diminished due to the complications of product purification. This work shows that the development of tools to determine the sustainability of a process is extremely important., Fil: Bordón, Daniela L. Universidad Nacional De Córdoba. Facultad De Ciencias Exactas Físicas Y Naturales; Argentina, Fil: Decarlini, María F. Universidad Católica De Córdoba. Facultad De Ciencias Químicas; Argentina, Fil: Vázquez, Ana M. Universidad Católica De Córdoba. Facultad De Ciencias Químicas; Argentina, Fil: Demmel, Gabriela I. Universidad Católica De Córdoba. Facultad De Ciencias Químicas; Argentina, Fil: Rossi, Laura I. Universidad Nacional De Córdoba. Facultad De Ciencias Químicas. Departamento De Química Orgánica. SuNaLab; Argentina, Fil: Rossi, Laura I. CONICET-INFIQC; Argentina, Fil: Aimar, Mario L. Universidad Nacional De Córdoba. Facultad De Ciencias Exactas Físicas Y Naturales; Argentina

The fruits of Ligustrum lucidum were used as an efficient biological reducer of carbonyl compounds, and trials were carried out to optimise the reductive process using acetophenone as the model substrate. In order to try to eliminate the dependence on the seasonal production of the fruits, a study was carried out to find ways to conserve them. The results reported here show that it is possible to store the dehydrated fruits of glossy privet at room temperature over a prolonged period of time, during which time they can be used as a common chemical reagent. On the other hand, studies performed on different parts of the fruits established that the seeds are responsible for the bioreduction process, with the best reduction conditions found being isolated seeds from the fruits of glossy privet at 25 °C, in a 100 mM phosphate buffer pH 6.0, using 0.67% w/v of DMSO as co-solvent with an acetophenone charge of 2.67 g/L (22 mM). Moreover, seed reuse studies showed that it is possible to recycle them, providing almost the same activity and enantioselectivity from the first to the fifth cycle, without any loss of biocatalytic properties. Finally, using whole seeds of glossy privet in optimal reaction conditions, important alcohols useful as key intermediates in the synthesis of industrial products were obtained on a laboratory scale through the reduction of specially selected ketones and aldehydes.

Fil: Demmel, Gabriela Ines. Universidad Catolica de Cordoba. Facultad de Ciencias Quimicas; Argentina

Twenty strains of fungi isolated from food samples were screened for the asymmetric reduction of acetophenone. A dimorphic fungus denominated initially as GZ1 and isolated from a carrot sour rot showed very high reduction activities, and based on phenotypic and genetic characteristics was identified as Galactomyces candidus. The only product of the reduction was confirmed to be (R)-1-phenylethanol. The bioreduction conditions mediated by Gal. candidus GZ1 were investigated, and the optimal conditions in terms of acetophenone concentration, temperature, pH media, co-solvent, the charge of inoculum and shaking speed were established. Under the optimal conditions of 1.875 g/L of acetophenone dissolved in DMSO (1.25% v/v), 112.5 g/L of microorganism cells in 100 mM sterile phosphate buffer solution at pH 7.0, 25 °C and 150 rpm, the conversion and enantiomeric excess values after 48 h reaction were 99% and > 99.9%, respectively. A preparative scale reaction of (R)-1-phenylethanol was made and the isolated yield was 82% with > 99.9 e.e.%. Additionally, a study using several substituted acetophenones was carried out, and the advantages and scope of GZ1 in the production of chiral 1-phenylethanols were established. In this sense, good results were obtained with 3′-hydroxyacetophenone and a preparative scale reaction was performed which give (R)-1-(3′-hydroxyphenyl)ethanol (key intermediate of Rivastigmine) with 53% of isolated yield and > 99.9 e.e.%. Fil: Decarlini, Maria Florencia. Universidad Católica de Córdoba. Facultad de Ciencias Químicas; Argentina Fil: Aimar, Mario Leandro. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Química; Argentina Fil: Vázquez, Ana M.. Universidad Católica de Córdoba. Facultad de Ciencias Químicas; Argentina Fil: Vero, Silvana. Universidad de la República; Uruguay Fil: Rossi, Laura Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina Fil: Yang, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Area de Ciencias Agrarias, Ingeniería, Ciencias Biológicas y de la Salud de la Universidad Católica de Córdoba; Argentina

Introduction: The appearance and color of the teeth are common concerns for patients and are associated with an increased need for treatments that can improve dental aesthetics. For this reason, in the past 20 years, dental science has been searching for new techniques and materials able to reduce dental discoloration. Method: Gummy candies containing two different concentrations (7% and 14% w/v) of hydrogen peroxide microencapsulated by ionic gelation were prepared. In vitro tooth whitening treatment was carried out for 30 days to test the bleaching action of these formulations. The surface color of the treated teeth was measured using a colorimetric technique. Results: Significant differences were found on comparing the whitening treatments for the two formulations with a control group, with two daily treatments using the formulation with 7% hydrogen peroxide being more effective for whitening than a daily single treatment using the formulation with 14 %. Conclusions: The two formulations developed had an in vitro higher bleaching effect in comparison with the control group, and in addition, better results were achieved if the daily dose was provided by more applications at a lower concentration of hydrogen peroxide.

A mechanistic interpretation of the kinetic profiles obtained for the stereoselective reduction of acetophenone promoted by Galactomyces candidus GZ1 under aerobic and anaerobic conditions was made. Based on experimental and bibliographical data, a mechanism which may involve the participation of two alcohol dehydrogenases with opposite stereoselectivities and alcohol oxidase is discussed. Due to the stereoselectivity of the reduction of acetophenone being changed when anaerobic conditions were used, this microorganism also permitted (S)-1-phenylethanol to be obtained in the absence of oxygen. Moreover, the kinetic profiles of the reactions of a racemic mixture of (R,S)-1-phenylethanol and pure (S)-1-phenylethanol with Gal. candidus were analyzed, which corroborated that there existed a reaction step where (S)-1-phenylethanol was oxidized to acetophenone. The results presented here show that not only is it possible to resolve racemic mixtures of phenylethanols when Gal. candidus is used as a biocatalyst, but that this is also efficient in causing the complete stereoinversion of pure (S)-1-phenylethanol to (R)-1-phenylethanol. Fil: Decarlini, Maria Florencia. Universidad Católica de Córdoba; Argentina Fil: Bordon, Daniela Laura. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Vázquez, Ana M.. Universidad Católica de Córdoba; Argentina Fil: Demmel, Gabriela Ines. Universidad Católica de Córdoba; Argentina Fil: Rossi, Laura Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina Fil: Aimar, Mario Leandro. Universidad Nacional de Córdoba; Argentina

This paper describes the search for novel vegetal biocatalysts for the stereoselective reduction of prochiral phenylketones. In this study, twenty native weeds were tested and Eryngium horridum Malme (Apiaceae) was proven to be an effective biocatalyst for the stereoselective reduction of acetophenone to (S)-1-phenylethanol (96% conversion, >99.9 e.e.%). Using this biocatalyst, fourteen chiral (S)-phenylethanols with excellent enantiomeric excesses (>98%) and variable conversions (30–100%) were obtained. Fil: Bordon, Daniela Laura. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina Fil: Villalba, Leonardo D.. Provincia de Córdoba. Ministerio de Ciencia y Técnica. Centro de Excelencia en Productos y Procesos de Córdoba; Argentina Fil: Aimar, Mario Leandro. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina Fil: Cantero, Juan Jose. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Vázquez, Ana María. Universidad Catolica de Córdoba. Facultad de Ciencias Químicas; Argentina Fil: Formica, Stella Maris. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina Fil: Krapacher, Claudio Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina Fil: Rossi, Laura Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina

The screening of four invasive plant species for use as biocatalysts in the stereoselective reduction of ketones is reported. Our studies revealed that fruits of Ligustrum lucidum can be used for the bioreduction of acetophenone to (S)-1-phenylethanol (94% conversion, > 99 enantiomeric excess [ee]%). Using this methodology, 13 substituted (S)-phenylethanols were synthesized with good ee values (> 99.9 to 78%) using a technique which is more environmentally friendly than classical reduction of prochiral ketones. The results reveal the fruits of L. lucidum to be promising biocatalysts for the production of key intermediates. Fil: Aimar, Mario Leandro. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina Fil: Bordon, Daniela Laura. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina Fil: Formica, Stella Maris. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina Fil: Cantero, Juan Jose. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; Argentina Fil: Vazquez, Ana M.. Universidad Católica de Córdoba. Facultad de Ciencias Químicas. Cátedra de Tecnología Química. Cordoba; Argentina Fil: Velasco, Manuel Isaac. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina Fil: Rossi, Laura Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina

Context. Coriandrum sativum L. (Apiaceae) (coriander) is an herb grown throughout the world as a culinary, medicinal or essential crop. In traditional medicine, it is used for the relief of anxiety and insomnia. Systemic hydro-alcoholic and aqueous extract from aerial parts and seeds had anxiolytic and sedative action in rodents, but little is known about its central effect in chicks. Objective To study the effects of intracerebroventricular administration of essential oil from coriander seeds and its major component linalool on locomotor activity and emotionality of neonatal chicks. Materials and methods. The chemical composition of coriander essential oil was determined by a gas-chromatographic analysis (> 80% linalool). Behavioural effects of central administration of coriander oil and linalool (both at doses of 0.86, 8.6 and 86 μg/chick) versus saline and a sedative diazepam dose (17.5 μg/chick, standard drug) in an open field test for 10 min were observed. Results. Doses of 8.6 and 86 μg from coriander oil and linalool significantly decreased (p < 0.05) squares crossed number, attempted escapes, defecation number and distress calls, and significantly increased (p < 0.05) the sleeping posture on an open field compared with saline and were similar to the diazepam group. Discussion and conclusion. The results indicate that intracerebroventricular injection of essential oil from Coriandrum sativum seeds induced a sedative effect at 8.6 and 86 μg doses. This effect may be due to monoterpene linalool, which also induced a similar sedative effect, and, therefore, could be considered as a potential therapeutic agent similar to diazepam. Fil: Gastón, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina Fil: Cid, Mariana Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina Fil: Vázquez, Ana María. Universidad Catolica de Córdoba. Facultad de Ciencias Químicas; Argentina Fil: Decarlini, Maria Florencia. Universidad Catolica de Córdoba. Facultad de Ciencias Químicas; Argentina Fil: Demmel, Gabriela Ines. Universidad Catolica de Córdoba. Facultad de Ciencias Químicas; Argentina Fil: Rossi, Laura Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina Fil: Aimar, Mario Leandro. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina Fil: Salvatierra, Nancy Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina

The reaction of dialkyl malonate esters with P 2S5/S8 in boiling xylene in the presence of 2-mercaptobenzothiazole/ZnO as catalyst produces 5-alkylthio-3 H-1,2-dithiole-3-thiones as major identifiable product. Moderate yields were obtained with malonate esters of primary alcohols. The reaction fails with malonate esters of secondary alcohols. Regarding the substituent in position two, di- alkyl malonates with groups such as CH3, Ph, CH2Ph, OCH3 and Cl afford the corresponding 4-substituted derivatives whereas with Br and NO2 do not give the expected products. Some mechanistic evi- dences are described.

Dialkyl malonate esters reacted with P 2 S 5 S 8 in boiling xylene and with 2-mercaptobenzothiazole ZnO as catalyst to yield 5-alkylthio-3H-1,2-dithiole-3-thiones as major products.

The reaction of dithiolmalonic esters with P 2 S 5 /S 8 in boiling xylene and with 2-mercaptobenzothiazole/ZnO as catalyst produces 5-R (R=alkyl or aryl) thio-3 H -1,2-dithiole-3-thiones as the major identifiable product. The use of Lawesson's reagent as sulfurizing agent gives even better yields. For instance with R=phenyl the yield rises from 44 to 82%.

The reactions of 3-butenyl 2,4-dinitrophenyl ether (1), allyl 2,4-dinitrophenyl ether (5), and n-butyl 2,4-dinitrophenyl ether (6) with KOH in two DMSO-water mixtures (50% v/v and 70% v/v) were studied. In all cases, no evidence was found for a single electron transfer mechanism; 2,4-dinitrophenol was the only product formed. The reaction follows the classical S N Ar mechanism. The order of reactivity is 5>1>6 in both solvents, although the reactivities differ only by factors of 1.4 and 2 in 50 and 70% DMSO, respectively

Dialkyl malonate esters reacted with P 2 S 5 S 8 in boiling xylene and with 2-mercaptobenzothiazole ZnO as catalyst to yield 5-alkylthio-3H-1,2-dithiole-3-thiones as major products.

The reaction of dithiolmalonic esters with P 2 S 5 /S 8 in boiling xylene and with 2-mercaptobenzothiazole/ZnO as catalyst produces 5-R (R=alkyl or aryl) thio-3 H -1,2-dithiole-3-thiones as the major identifiable product. The use of Lawesson's reagent as sulfurizing agent gives even better yields. For instance with R=phenyl the yield rises from 44 to 82%.

The title compound, C12H12S4, crystallizes in P\overline{1} with two independent mol­ecules in the asymmetric unit labelled (A) and (B). In both molecules the phenyl and 3H-1,2-dithiole-3-thione rings are almost perpendicular to each other, the main difference being the position of the ethyl group which lies in the same plane as the heterocyclic ring in (A) but points outwards in (B). The crystal packing is governed by short S⋯S interactions.

As part of our project devoted to the search of new antifungal agents, we report here the in vitro–in vivo antifungal evaluations and a structure–activity relationship (SAR) study of 17 thione derivatives.Some compounds of this series exhibited remarkable antifungal activity against a broad spectrum of pathogenic opportunistic fungi. SAR studies provide a useful information for the determination of the minimum structural requirements for producing the biological response.