RESUMO
A one-pot cross double-Mannich reaction of acetaldehyde was developed, and densely functionalized 1,3-diamines were obtained as a single stereoisomer by use of axially chiral amino sulfonamide (S)-1 as catalyst. Using this catalyst, the one-pot Mannich reaction-aminoxylation was also realized.
RESUMO
Aromatic ketones were reduced using suspension culture of Chlorella sp. MK201 under fluorescent light illumination producing the corresponding chiral alcohols in high yields with excellent enantiomeric excess (ee). For example, 2',3',4',5',6'-pentafluoroacetophenone at 0.25 mg/ml was converted to the corresponding (S)-alcohol in 80 % yield with >99 % ee by 1 mg dry wt of Chlorella/ml in 12 h illumination (2,000 lux).
Assuntos
Chlorella/metabolismo , Cetonas/química , Cetonas/metabolismo , Álcoois/química , Álcoois/metabolismo , Fluorescência , Oxirredução , Processos Fotoquímicos , EstereoisomerismoRESUMO
Sodium tert-butoxide mediates the coupling of aryl halides with benzene derivatives without the aid of transition metal catalysts but with a catalytic 1,10-phenanthroline derivative.
RESUMO
Suspension cultured cells of Caragana chamlagu (Leguminosae) converted zerumbone (1) into zerumbone epoxide (2) as the intermediate, (2R,3R,7R)-2,3-epoxy-9-humulen-8-one (3) and (2R,3S,7R)-2,3-epoxy-9-humulen-8-one (4) as new sesquiterpenes in 11%, 36% and 21% yields, respectively.
Assuntos
Caragana/metabolismo , Sesquiterpenos/metabolismo , Biotransformação , Caragana/citologia , Espectrometria de Massas , Estrutura Molecular , Sesquiterpenos/químicaRESUMO
The biotransformation of racemic 1-phenylethanol (30 mg) with plant cultured cells of basil (Ocimum basilicum cv. Purpurascens, 5 g wet wt) by shaking 120 rpm at 25 degrees C for 7 days in the dark gave (R)-(+)-1-phenylethanol and acetophenone in 34 and 24% yields, respectively. The biotransformation can be applied to other 1-arylethanols and basil cells oxidized the (S)-alcohols to the corresponding ketones remaining the (R)-alcohols in excellent ee.
Assuntos
Acetofenonas/metabolismo , Ocimum basilicum/metabolismo , Álcool Feniletílico/metabolismo , Biotransformação , Células Cultivadas , Cromatografia Gasosa , Oxirredução , EstereoisomerismoRESUMO
The aim of this study was to investigate the features of the loading vectors of the temporomandibular joint (TMJ) generated during bilateral static bites at the molars and at the premolars, and to determine the major factors affecting the difference between the two loading vectors. We computed the subjects' estimated and theoretical minimum TMJ loadings under the two different bite conditions by applying the subjects' bite-force and electromyographic (EMG) data to a two-dimensional (2D) standard model of the jaw based on a rigid-body spring model of the TMJ. For a molar bite, (1) the estimated loading vector was not equal to its theoretical minimum; (2) the TMJ-loading/bite-force ratio, describing the proportion of TMJ loading, was relatively small, 0.477 on average; and (3) the estimated loading vector pointed in the direction of the central part of the articular disk's intermediate zone. For a premolar bite, on the other hand, (1) the estimated loading vector was nearly equal to its theoretical minimum; (2) the TMJ-loading/bite-force ratio was relatively large, 0.904 on average; and (3) the estimated loading vector pointed at the superior portion of the articular disk's intermediate zone. The differences between the TMJ-loading vectors for molar and premolar bites originated primarily from changes in the bite-point location.
Assuntos
Força de Mordida , Interpretação Estatística de Dados , Músculos da Mastigação/fisiologia , Articulação Temporomandibular/fisiologia , Dente Pré-Molar , Fenômenos Biomecânicos , Eletromiografia , Humanos , Modelos Biológicos , Dente MolarRESUMO
Changes in correlation dimensions of the electroencephalogram (EEG) were examined in three different tasks. These three tasks differed from each other with respect to the number of procedures. In the present experiment, left-hand movement and mental arithmetic were controlled, respectively, during an auditory linguistic task. Subjects were 13 healthy right-handed males. EEG signals from eight electrode sites were analyzed and the correlation dimensions were obtained. In addition, the relative power was obtained for the alpha band. An increase in the number of procedures yielded high dimensionality on the occipital EEG. In contrast, left-hand movement had no significant effect on EEG dimensions over the motor area. The relative power of the alpha band was seen to decrease in all channels as the number of procedures increased. The fact that changes in EEG dimensions did not necessarily exhibit a simple correspondence to changes in alpha wave activity was also discussed.