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This work reports the enzymatic synthesis of butyl stearate and ethyl stearate, two esters with important industrial properties, ranging from cosmetic applications to emollient characteristics (butyl stearate) to food industries, imparting flavor and aroma to beverages and foods (ethyl stearate). Here, reactions were carried out using Novozym 435 as biocatalyst, considering different stirring levels and substrates molar ratios, to determine optimal conditions to produce both esters. The kinetics under optimized conditions, varying the substrates molar ratio was performed and the influence of the fractional addition of the alcohol in the reaction was also verified. It was observed for butyl and ethyl stearate that satisfactory results (92%) occurred when batch kinetics was carried out for 24 h at 60 °C, 1% (by weight of substrates) of the enzyme, agitation of 250 rpm and molar ratio of 1:2 and 1:5, respectively. Enzyme reuse up to five and three cycles led to satisfactory results for butyl stearate and ethyl stearate, respectively. This work represents, therefore, a novelty in the production of these esters by enzymatic route, leading to a high conversion of products, using a low amount of biocatalyst, proving the relevance of the production of these esters by enzymatic means, which makes the process ecologically correct and still add value to the final product.

Teucrium chamaedrys, one of the most common and investigated species of the genus Teucrium, has been used for centuries in traditional medicine for many purposes. Its phytochemical components comprise, among others, phenylethanoid glycosides (PGs) and neo-clerodane diterpenoids. Several reports have demonstrated a wide range of beneficial biological and pharmacological activities of the phenylethanoid components, while the diterpenes were shown to be strongly hepatotoxic. In this work, in vitro cultures were established from leaf explants of T. chamaedrys. Both solid (callus) and liquid (cell suspension) cultures maintained the capacity to produce PGs, with teucrioside (TS) representing the most abundant one. Cell suspensions had a lower TS content than that found in leaf extracts, but higher than that of calli. An NMR-based metabolomics approach was used to compare the product profile of intact plants vs. cell suspension cultures, and results showed that neo-clerodane diterpenes, present in the intact plant, were not detected in cell cultures. Several elicitors were supplied to cell cultures with the aim of increasing TS production, and elicitation was tested at different growth phases and by exposing cells for different periods. Methyl jasmonate and fungal mycelia from Trichoderma viridae and Fusarium moniliforme were able to significantly increase TS production if supplied at the early-exponential growth phase for 24 h. Based on the proposed link between proline and the phenylpropanoid pathways, proline accumulation in cell cultures was followed throughout a 14-day culture period, showing that it strictly reflected that of TS production. Moreover, exogenously supplied proline, and its analogue hydroxyproline, turned out to be very effective in increasing teucrioside production. © 2012 Elsevier Ltd. All rights reserved.

Twelve strains of endophytic fungi, isolated from various plants (i.e. Eugenia hallii, Schinus molle, Crataegus monogyna, Juniperus communis and Sambucus nigra) sampled in Amazonian forest and in Italy, were screened for their reduction activity with a cocktail of ketones 1–4. The four most active strains [i.e. Phomopsis (FE86 and FE290), Pestalotia and Epicoccum] were chosen for the reduction of 5-hexen-2-one 1, acetophenone 2, cis-bicyclo[3.2.0]hept-2-en-6-one 3, 2-methylcyclohexanone 4, 6-methyl-5-hepten-2-one 5, 2-furyl methyl ketone 6, 1-indanone 7, and 2,4,4-trimethyl-2-cyclohexen-1-one 8 and in all cases the S-alcohols were obtained with variable yields and enantiomeric excesses depending on the strains.

A new entry to (1→6)- and (1→5)-aza- C -disaccharides featuring the pyrrolidine ring as the imino sugar component is described via Wittig condensation of polyhydroxylated 2-formylpyrrolidines with galactopyranose 6-phosphorane and ribofuranose 5-phosphorane, respectively.

The preparative-scale regio- and stereo-specific oxidation of hydroxy groups and reduction of keto functions at C(3) of several C21 bile acids, catalyzed by a new 3α-hydroxysteroid dehydrogenase (3α-HSDH), is reported. The crude enzyme, isolated from the cells of Pseudomonas paucimobilis, revealed the presence of a further enzymatic fraction containing a secondary alcohol dehydrogenase (SADH), that has been used to recycle the cofactor.

Preparation of various heteroaryl propanols 2a‐g and of the corresponding propanones 3a‐g as starting materials for microbial redox is described. The kinetic resolution of the racemic propanols 2a‐g is obtained via oxidation with Pseudomonas paucimobilisand Bacillus stearothermophilus[(R)-alcohols, ee 74‐100%]. Similar results are achieved with 3-(2-hydroxypropyl)trifluoromethylbenzene 7 (44%, ee 100% of the (R)-alcohol 6). The reduction of the propanones 3a‐d and 3g with baker’s yeast and other fungi gives the ( S)-alcohols (ee 100%). The pure (S)-alcohols are also obtained by reduction of 1-[3-(trifluoromethyl)phenyl]-2-propanone 7. 1-[(4,4-Dimethyl)2-( 2 )oxazolinyl]-2-propanone 3e and 1[2-( 2 )-thiazolinyl)-2-propanone 3f are not reduced. The heterocyclic rings of (S)-5-(2-hydroxypropyl)-3-methylisoxazole 2d and of (S)-2-(2-hydroxypropyl)-4-methylthiazole 2g are deblocked to the homochiral enamino ketone 8 (78%) and to the protected -hydroxy aldehyde 9 (73%), respectively. The (R)-3-(2-hydroxypropyl)trifluoromethylbenzene 6 is transfomed into the homochiral precursor of (S)-fenfluramine 10 (overall yield 65%). © 1998 Elsevier Science Ltd. All rights reserved.

The first example of oxidation with bacteria in heptane is reported. The kinetic resolution of endo-bicyclic octen- and heptenols is obtained. The methodology is simpler and the volume of the reactions is smaller than in water.