Abstract In the paper we characterize the two-dimensional generalized Berwald manifolds in terms of the classical setting of Finsler surfaces (Berwald frame, main scalar etc.). As an application we prove that if a Lands-berg surface is a generalized Berwald manifold then it must be a Berwald manifold. Especially, we reproduce Wagner’s original result in honor of the 75th anniversary of publishing his pioneering work about generalized Berwald manifolds.

In this study, the piperazine formation step of vortioxetine synthesis was investigated under continuous flow conditions. The batch variant of this step could be carried out at laboratory scale at 130–135 °C with a long reaction time (27 h) followed by a laborious optimization process, but the formation of a significant amount of side-products could be detected, thus an efficient purification procedure was necessary. In the attempted scale-up of the batch reaction, a complete conversion could not at all be reached, even after elongated reaction times (36 h). The continuous-flow experiments were carried out in a new, purpose-built flow system. The examinations were extended to a wide range of reaction parameters (ratio of solvents, concentration and molar ratio of reagents, geometry of coiled loop reactor, residence time, temperature) and to the feasibility study of scale-up. In the second part of the experiments, the fine-tuning of scaled-up reaction parameters of continuous flow synthesis was carried out using a systematic design of experiments approach. Finally 190 °C reaction temperature and 30 min of residence time led to the highest efficacy in the production of vortioxetine drug substance with high yield and purity.

Let $m=2l$ be a positive natural number, $l=1, 2, \ldots. $ A Finslerian metric $F$ is called an $m$-th root metric if its $m$-th power $F^m$ is of class $C^{m}$ on the tangent manifold $TM$. Using some homogenity properties, the local expression of an $m$-th root metric is a polynomial of degree $m$ in the variables $y^1$, $\ldots$, $y^n$, where $\dim M=n$. $F$ is locally symmetric if each point has a coordinate neighbourhood such that $F^m$ is a symmetric polynomial of degree $m$ in the variables $y^1$, $\ldots$, $y^n$ of the induced coordinate system on the tangent manifold. Using the fundamental theorem of symmetric polynomials, the reduction of the number of the coefficients depending on the position makes the computational processes more effective and simple. In the paper we present some general observations about locally symmetric $m$-th root metrics. Especially, we are interested in generalized Berwald surfaces with locally symmetric fourth root metrics. The main result (Theorem 1) is their intrinsic characterization in terms of the basic notions of linear algebra. We present a one-parameter family of examples as well. The last section contains some computations in 3D. They are supported by the MAPLE mathematics softwer (LinearAlgebra).

In this study, the activity of acetic acid esters modified with electron withdrawing 2-alkoxy-groups was investigated as acylating agent in kinetic resolution (KR) of racemic amines. A homologous series of the isopropyl esters of four 2-alkoxyacetic acids (2-methoxy-, 2-ethoxy-, 2-propoxy- and 2-butoxyacetic acids) were prepared and investigated for enantiomer selective N-acylation, catalyzed by lipase B from Candida antarctica, under batch and continuous-flow conditions. In the first set of experiments, isopropyl 2-propoxyacetate showed the highest effectivity with all of the four racemic amines [(+/-)-1-phenylethylamine, (+/-)-4-phenylbutan-2-amine, (+/-)-heptan-2-amine and (+/-)-1-methoxypropane-2-amine] in the set enabling excellent conversions (>= 46%) and enantiomeric excess values (ee >= 99%) with each amines in continuous-flow mode KRs under the optimized reaction conditions. In a second set of experiments, KRs of five additional amines - being substituted derivatives of (+/-)-1-phenylethylamine - further demonstrated the usefulness of isopropyl 2-propoxyacetate - being the best acylating agent in the first set of KRs - in KRs leading to (R)-N-propoxyacetamides with high ee values (>= 99.8%). (C) 2018 Elsevier Ltd. All rights reserved.

Hollow silica microspheres with promising physical properties (MAT540TM) as support for enzyme immobilization and biocatalyst were investigated in this study. The amine-functionalized MAT540TM was activated by six bisepoxides inclosing different spacers and used as epoxy-functionalized carrier for immobilization of lipase B from Candida antarctica (CaLB). The novel, covalently fixed CaLB biocatalysts were compared in kinetic resolution (KR) of racemic 1-phenyethanol rac-1 and five racemic amines rac-3a-e using shaken flasks and continuous-flow packed-bed microreactors. Mechanic stability, re-usability and the effect of temperature (0–90 °C) on productivity and enantiomer selectivity of the covalently immobilized CaLB were investigated. The best performing CaLB biocatalyst showed good mechanic stability after 24 h operation time in continuous-flow mode at 60 °C and provided in KRs of racemic 1-phenyethanol rac-1 with vinyl acetate and of five racemic amines with isopropyl 2-ethoxyacetate as acylating agent the non-reacted (S)-alcohol [(S)-1] or (S)-amines [(S)-3a-e] and the forming (R)-ester [(R)-2] or (R)-amide [(R)-4a-e] in good yields with high enantiomeric excess (ee > 99 %, for all).

In this study, lipase-mediated dynamic kinetic resolution (DKR) of various benzylic amines (1a-g) is presented which is realized in a so far unprecedented fully continuous-flow system. The DKR process applying sol gel immobilized lipase B from Candida antarctica as biocatalyst, palladium on 3-aminopropyl-functionalized silica as racemization catalyst, isopropyl 2-ethoxyacetate as acylating agent, ammonium formate as hydrogen and nitrogen sources, and 2-methyl-2-butanol as solvent under regulated pressure provided the desired products in moderate to good yields with excellent enantiomeric excesses.

In their paper [6] the authors posed the problem of the characterization of closed subsets in the Euclidean plane that can be realized as the equidistant set of two connected disjoint closed sets. We are going to solve the problem for a special class of equidistant sets. As a main result we give necessary and sufficient conditions for a function to be a so-called equidistant function. This means that its graph is the equidistant set of a line (the first coordinate axis) and the (convex) epigraph of a positive valued convex function satisfying some regularity conditions. In the first step we present a parametric expression for equidistant functions. The parametric expression allows us to use the basic differential geometric tools. We also give a sufficient and necessary condition for a function to be equidistant. In the conluding remarks section some perspectives and extensions of such a special approach will be presented together with some open problems.

An immobilization engineering approach using bioinformatics and experimental design tools was applied to improve the sol–gel enzyme entrapment methodology.

In the present study the molecular cloning, expression and purification of recombinant PcPAL, with a cleavable N-terminal His-tag is described. The PcPAL gene was cloned into pET-19b vector and transformed to different E.coli host cells. The optimization of expression and purification processes provided recombinant protein with high purity in its native, tetrameric fold with a yield of 7-8 mg protein / 1 L culture. The activity of the recombinant protein was tested towards its natural substrate L-Phe, the KM, and kcat values suggesting excellent catalytic properties of the recombinant enzyme.

Productivity [conversion (c) and specific reaction rate (r(batch) or r(flow))] and enantiomer selectivity [enantiomeric ratio (E) and enantiomeric excess (ee) of the products] of ethyl and isopropyl esters of acetic, 2-methoxyacetic and 2-ethoxyacetic acids as acylating agents were compared in the N-acylation of (+/-)-1-phenylethanamine rac-1 catalyzed by variously immobilized forms of Candida antarctica lipase B (CaLB) using shake flasks and continuous-flow reactors. The effect of the temperature in the 0-80 degrees C range on productivity and enantiomer selectivity in KRs of rac-1 was investigated with the isopropyl esters in continuous-flow mode using CaLB-filled minireactors. Isopropyl 2-ethoxyacetate surpassed the performance of ethyl 2-methoxyacetate in terms of both productivity (1.9-2.9 times higher rate in batch mode) and enantiomeric selectivity (ee((R)-amide)>99.9% compared to 99.8%) providing at 40 degrees C high volumetric productivity (2.22 kg L-1 h(-1)), specific reaction rate and enantiomeric excess (r(flow)=783 mu mol min(-1) g(-1), ee((R)),e((R)-2c)>99.9%). (C) 2015 Elsevier Ltd. All rights reserved.

The effect of temperature on enantiomeric ratio (E) and specific reaction rate (rflow) in the continuous-flow mode acetylation of (±)-1-phenylethanamine (rac-1a), (±)-4-phenylbutan-2-amine (rac-1b) and (±)-1,2,3,4-tetrahydro-1-naphthalenamine (rac-1c) by variously immobilized Candida antarctica lipase B biocatalysts was studied in the 0–70°C range. In the continuous-flow kinetic resolutions with differently immobilized CaLB biocatalysts, the character of temperature effect depended significantly both on the substrate and on the mode of immobilization. Alteration of E in the kinetic resolutions of three differently flexible amines rac-1a–c as a function of temperature was rationalized by the various flexibility of the lipase in its different forms. Our results indicated that the optimal method of immobilization depended both on the nature of the substrate and the reaction conditions.

A series of eighteen novel surface modified silica gels were systematically studied as carriers of lipase A and B from Candida antarctica (CaLA and CaLB) by using hydrophobic adsorption methodology. Many of the mechanically stable novel hydrophobic silica gels were found as efficient lipase carriers resulting in new biocatalysts with different degrees of activity and enantioselectivity. Selective adsorption preferring CaLB from the mixture of the two lipases onto the novel supports indicated that proper hydrophobic adsorbents can offer us a simple, efficient and low-cost technology to separate useful lipases from their mixture or even from a crude extract. The usefulness of the methodology was demonstrated by production of a selective lipase from Pseudozyma aphidis (PaL) as immobilized biocatalyst directly from the fermentation supernatant in a single step.

Caveolae‐mediated endocytosis is a highly regulated endocytic pathway that exists in parallel to other forms of clathrin‐dependent and ‐independent endocytosis. Internalized caveolae accumulate in intermediate organelles called caveosomes. Here we addressed the further fate of internalized caveolae by inducing caveolae‐mediated uptake of albumin by HepG2 cells. We followed the route of internalized caveolin‐1 by immunogold labelling of ultrathin frozen sections and by Western blot analyses of purified membrane fractions. Long‐term (1 and 3 hrs) albumin treatment resulted in the appearance of albumin‐containing caveolae in special multi‐caveolar complexes (consisting of multiple caveolae clustered together) connected to the plasma membrane and caveosome‐like structures in the cytoplasm. In addition, numerous CD63 (LIMP‐1) positive late endosomes/multi‐vesicular bodies were found positive for caveolin‐1, suggesting that upon albumin incubation, caveolin‐1 is endocytosed and enters the degradative pathway. Surprisingly, the number of caveolae at the plasma membrane increased after addition of albumin. This increase was blocked by cycloheximide treatment, indicating that albumin internalization also stimulates de novo protein synthesis, which is necessary for new caveolae formation. Together, our results show that during long‐term albumin uptake, caveolin‐1 travels to late endosomes and is replaced by newly synthesized caveolin‐1 at the plasma membrane.

We have recently demonstrated that salsolinol (SAL), a dopamine (DA)-derived compound, is present in the posterior pituitary gland and is able to stimulate the release of prolactin (PRL) in ruminants. The aim of the present study was to clarify the effect that the interaction of SAL with thyrotropin-releasing hormone (TRH) or DA has on the secretion of PRL in ruminants. A single intravenous (i.v.) injection of SAL (5mg/kg body weight (b.w.)), TRH (1μg/kg b.w.), and SAL plus TRH significantly stimulated the release of PRL in goats (P<0.05). The cumulative response curve (area under the curve: AUC) during 120min was 1.53 and 1.47 times greater after the injection of SAL plus TRH than either SAL or TRH alone, respectively (P<0.05). A single i.v. injection of sulpiride (a DA receptor antagonist, 0.1mg/kg b.w.), sulpiride plus SAL (5mg/kg b.w.), and sulpiride plus TRH (1μg/kg b.w.) significantly stimulated the release of PRL in goats (P<0.05). The AUC of PRL during 120min was 2.12 and 1.78 times greater after the injection of sulpiride plus TRH than either sulpiride alone or sulpiride plus SAL, respectively (P<0.05). In cultured bovine anterior pituitary (AP) cells, SAL (10−6M), TRH (10−8M), and SAL plus TRH significantly increased the release of PRL (P<0.05), but the additive effect of SAL and TRH detected in vivo was not observed in vitro. In contrast, DA (10−6M) inhibited the TRH-, as well as SAL-induced PRL release in vitro. All together, these results clearly show that SAL can stimulate the release of PRL in ruminants. Furthermore, they also demonstrate that the additive effect of SAL and TRH on the release of PRL detected in vivo may not be mediated at the level of the AP, but that DA can overcome their releasing activity both in vivo and in vitro, confirming the dominant role of DA in the inhibitory regulation of PRL secretion in ruminants.