62 research outputs found

    Chemoenzymatic Synthesis of Luliconazole Mediated by Lipases

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    A straightforward chemoenzymatic synthesis of luli- conazole has been developed. The key step involved the preparation of the enantiomerically pure beta-halohydrin (1S)-2-chloro- 1-(2,4-dichlorophenyl)-1-ethanol through kinetic resolution of the corresponding racemic acetate. This was achieved by a hydrolytic approach, mediated by the lipase from Thermomyces lanuginosus or Novozym 435\uae. The latter enzyme proved to be a robust biocatalyst for the kinetic resolution, and the halohydrin was obtained with high selectivity (ee > 99%, E > 200) after just 15 min, at 45 \ub0C. It could be reused five times with maintenance of high values of both conversion and enantioselectivity. Subsequently, the (S)-beta-halohydrin was sub- jected to a mesylation reaction; the mesylated derivative re- acted with 1-cyanomethylimidazole in the presence of CS2 to give luliconazole in 43 % yield with >99 % ee

    Lipase mediated enzymatic kinetic resolution of phenylethyl halohydrins acetates: A case of study and rationalization

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    Racemic phenylethyl halohydrins acetates containing several groups attached to the aromatic ring were resolved via hydrolysis reaction in the presence of lipase B from Candida antarctica (Novozym\uae 435). In all cases, the kinetic resolution was highly selective (E > 200) leading to the corresponding (S)-\u3b2-halohydrin with ee > 99 %. However, the time required for an ideal 50 % conversion ranged from 15 min for 2,4-dichlorophenyl chlorohydrin acetate to 216 h for 2-chlorophenyl bromohydrin acetate. Six chlorohydrins and five bromohydrins were evaluated, the latter being less reactive. For the \u3b2-brominated substrates, steric hindrance on the aromatic ring played a crucial role, which was not observed for the \u3b2-chlorinated derivatives. To shed light on the different reaction rates, docking studies were carried out with all the substrates using MD simulations. The computational data obtained for the \u3b2-brominated substrates, based on the parameters analysed such as NAC (near attack conformation), distance between Ser-O and carbonyl-C and oxyanion site stabilization were in agreement with the experimental results. On the other hand, the data obtained for \u3b2-chlorinated substrates suggested that physical aspects such as high hydrophobicity or induced change in the conformation of the enzymatic active site are more relevant aspects when compared to steric hindrance effects

    The flavonoid agathisflavone modulates the microglial neuroinflammatory response and enhances remyelination

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    Myelin loss is the hallmark of the demyelinating disease multiple sclerosis (MS) and plays a significant role in multiple neurodegenerative diseases. A common factor in all neuropathologies is the central role of microglia, the intrinsic immune cells of the central nervous system (CNS). Microglia are activated in pathology and can have both pro- and anti-inflammatory functions. Here, we examined the effects of the flavonoid agathisflavone on microglia and remyelination in the cerebellar slice model following lysolecithin induced demyelination. Notably, agathisflavone enhances remyelination and alters microglial activation state, as determined by their morphology and cytokine profile. Furthermore, these effects of agathisflavone on remyelination and microglial activation were inhibited by blockade of estrogen receptor α. Thus, our results identify agathisflavone as a novel compound that may act via ER to regulate microglial activation and enhance remyelination and repair

    Chemoenzymatic synthesis of (S)-Pindolol using lipases

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    A straightforward chemoenzymatic synthesis of (S)-Pindolol has been developed. The key step involved the enzymatic kinetic resolution of rac-2-acetoxy-1-(1H-indol-4-yloxy)-3-chloropropane with lipase from Pseudomonas fluorescens via hydrolytic process to obtain enantiomerically enriched halohydrin (2S)-1-(1H-indol-4-yloxy)-3-chloro-2-propanol (96% ee) and (2R)-2-acetoxy-1-(1H-indol-4-yloxy)-3-chloropropane (97% ee). The latter was subjected to a hydrolysis reaction catalyzed by Candida rugosa leading to (2R)-1-(1H-indol-4-yloxy)-3-chloro-2-propanol (97% ee), followed by a reaction with isopropylamine, producing (S)-Pindolol (97% ee) in quantitative yield

    Differences between unipolar mania and bipolar-I disorder: Evidence from nine epidemiological studies.

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    Although clinical evidence suggests important differences between unipolar mania and bipolar-I disorder (BP-I), epidemiological data are limited. Combining data from nine population-based studies, we compared subjects with mania (M) or mania with mild depression (Md) to those with BP-I with both manic and depressive episodes with respect to demographic and clinical characteristics in order to highlight differences. Participants were compared for gender, age, age at onset of mania, psychiatric comorbidity, temperament, and family history of mental disorders. Generalized linear mixed models with adjustment for sex and age as well as for each study source were applied. Analyses were performed for the pooled adult and adolescent samples, separately. Within the included cohorts, 109 adults and 195 adolescents were diagnosed with M/Md and 323 adults and 182 adolescents with BP-I. In both adult and adolescent samples, there was a male preponderance in M/Md, whereas lifetime generalized anxiety and/panic disorders and suicide attempts were less common in M/Md than in BP-I. Furthermore, adults with mania revealed bulimia/binge eating and drug use disorders less frequently than those with BP-I. The significant differences found in gender and comorbidity between mania and BP-I suggest that unipolar mania, despite its low prevalence, should be established as a separate diagnosis both for clinical and research purposes. In clinical settings, the rarer occurrence of suicide attempts, anxiety, and drug use disorders among individuals with unipolar mania may facilitate successful treatment of the disorder and lead to a more favorable course than that of BP-I disorder
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